1 /*-------------------------------------------------------------------------
2 *
3 * postgres.c
4 * POSTGRES C Backend Interface
5 *
6 * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 *
10 * IDENTIFICATION
11 * src/backend/tcop/postgres.c
12 *
13 * NOTES
14 * this is the "main" module of the postgres backend and
15 * hence the main module of the "traffic cop".
16 *
17 *-------------------------------------------------------------------------
18 */
19
20 #include "postgres.h"
21
22 #include <fcntl.h>
23 #include <limits.h>
24 #include <signal.h>
25 #include <unistd.h>
26 #include <sys/socket.h>
27 #ifdef HAVE_SYS_SELECT_H
28 #include <sys/select.h>
29 #endif
30 #ifdef HAVE_SYS_RESOURCE_H
31 #include <sys/time.h>
32 #include <sys/resource.h>
33 #endif
34
35 #ifndef HAVE_GETRUSAGE
36 #include "rusagestub.h"
37 #endif
38
39 #include "access/parallel.h"
40 #include "access/printtup.h"
41 #include "access/xact.h"
42 #include "catalog/pg_type.h"
43 #include "commands/async.h"
44 #include "commands/prepare.h"
45 #include "libpq/libpq.h"
46 #include "libpq/pqformat.h"
47 #include "libpq/pqsignal.h"
48 #include "miscadmin.h"
49 #include "nodes/print.h"
50 #include "optimizer/planner.h"
51 #include "pgstat.h"
52 #include "pg_trace.h"
53 #include "parser/analyze.h"
54 #include "parser/parser.h"
55 #include "pg_getopt.h"
56 #include "postmaster/autovacuum.h"
57 #include "postmaster/postmaster.h"
58 #include "replication/logicallauncher.h"
59 #include "replication/logicalworker.h"
60 #include "replication/slot.h"
61 #include "replication/walsender.h"
62 #include "rewrite/rewriteHandler.h"
63 #include "storage/bufmgr.h"
64 #include "storage/ipc.h"
65 #include "storage/proc.h"
66 #include "storage/procsignal.h"
67 #include "storage/sinval.h"
68 #include "tcop/fastpath.h"
69 #include "tcop/pquery.h"
70 #include "tcop/tcopprot.h"
71 #include "tcop/utility.h"
72 #include "utils/lsyscache.h"
73 #include "utils/memutils.h"
74 #include "utils/ps_status.h"
75 #include "utils/snapmgr.h"
76 #include "utils/timeout.h"
77 #include "utils/timestamp.h"
78 #include "mb/pg_wchar.h"
79
80
81 /* ----------------
82 * global variables
83 * ----------------
84 */
85 const char *debug_query_string; /* client-supplied query string */
86
87 /* Note: whereToSendOutput is initialized for the bootstrap/standalone case */
88 CommandDest whereToSendOutput = DestDebug;
89
90 /* flag for logging end of session */
91 bool Log_disconnections = false;
92
93 int log_statement = LOGSTMT_NONE;
94
95 /* GUC variable for maximum stack depth (measured in kilobytes) */
96 int max_stack_depth = 100;
97
98 /* wait N seconds to allow attach from a debugger */
99 int PostAuthDelay = 0;
100
101
102
103 /* ----------------
104 * private variables
105 * ----------------
106 */
107
108 /* max_stack_depth converted to bytes for speed of checking */
109 static long max_stack_depth_bytes = 100 * 1024L;
110
111 /*
112 * Stack base pointer -- initialized by PostmasterMain and inherited by
113 * subprocesses. This is not static because old versions of PL/Java modify
114 * it directly. Newer versions use set_stack_base(), but we want to stay
115 * binary-compatible for the time being.
116 */
117 char *stack_base_ptr = NULL;
118
119 /*
120 * On IA64 we also have to remember the register stack base.
121 */
122 #if defined(__ia64__) || defined(__ia64)
123 char *register_stack_base_ptr = NULL;
124 #endif
125
126 /*
127 * Flag to keep track of whether we have started a transaction.
128 * For extended query protocol this has to be remembered across messages.
129 */
130 static bool xact_started = false;
131
132 /*
133 * Flag to indicate that we are doing the outer loop's read-from-client,
134 * as opposed to any random read from client that might happen within
135 * commands like COPY FROM STDIN.
136 */
137 static bool DoingCommandRead = false;
138
139 /*
140 * Flags to implement skip-till-Sync-after-error behavior for messages of
141 * the extended query protocol.
142 */
143 static bool doing_extended_query_message = false;
144 static bool ignore_till_sync = false;
145
146 /*
147 * If an unnamed prepared statement exists, it's stored here.
148 * We keep it separate from the hashtable kept by commands/prepare.c
149 * in order to reduce overhead for short-lived queries.
150 */
151 static CachedPlanSource *unnamed_stmt_psrc = NULL;
152
153 /* assorted command-line switches */
154 static const char *userDoption = NULL; /* -D switch */
155 static bool EchoQuery = false; /* -E switch */
156 static bool UseSemiNewlineNewline = false; /* -j switch */
157
158 /* whether or not, and why, we were canceled by conflict with recovery */
159 static bool RecoveryConflictPending = false;
160 static bool RecoveryConflictRetryable = true;
161 static ProcSignalReason RecoveryConflictReason;
162
163 /* ----------------------------------------------------------------
164 * decls for routines only used in this file
165 * ----------------------------------------------------------------
166 */
167 static int InteractiveBackend(StringInfo inBuf);
168 static int interactive_getc(void);
169 static int SocketBackend(StringInfo inBuf);
170 static int ReadCommand(StringInfo inBuf);
171 static void forbidden_in_wal_sender(char firstchar);
172 static List *pg_rewrite_query(Query *query);
173 static bool check_log_statement(List *stmt_list);
174 static int errdetail_execute(List *raw_parsetree_list);
175 static int errdetail_params(ParamListInfo params);
176 static int errdetail_abort(void);
177 static int errdetail_recovery_conflict(void);
178 static void start_xact_command(void);
179 static void finish_xact_command(void);
180 static bool IsTransactionExitStmt(Node *parsetree);
181 static bool IsTransactionExitStmtList(List *pstmts);
182 static bool IsTransactionStmtList(List *pstmts);
183 static void drop_unnamed_stmt(void);
184 static void log_disconnections(int code, Datum arg);
185
186
187 /* ----------------------------------------------------------------
188 * routines to obtain user input
189 * ----------------------------------------------------------------
190 */
191
192 /* ----------------
193 * InteractiveBackend() is called for user interactive connections
194 *
195 * the string entered by the user is placed in its parameter inBuf,
196 * and we act like a Q message was received.
197 *
198 * EOF is returned if end-of-file input is seen; time to shut down.
199 * ----------------
200 */
201
202 static int
InteractiveBackend(StringInfo inBuf)203 InteractiveBackend(StringInfo inBuf)
204 {
205 int c; /* character read from getc() */
206
207 /*
208 * display a prompt and obtain input from the user
209 */
210 printf("backend> ");
211 fflush(stdout);
212
213 resetStringInfo(inBuf);
214
215 /*
216 * Read characters until EOF or the appropriate delimiter is seen.
217 */
218 while ((c = interactive_getc()) != EOF)
219 {
220 if (c == '\n')
221 {
222 if (UseSemiNewlineNewline)
223 {
224 /*
225 * In -j mode, semicolon followed by two newlines ends the
226 * command; otherwise treat newline as regular character.
227 */
228 if (inBuf->len > 1 &&
229 inBuf->data[inBuf->len - 1] == '\n' &&
230 inBuf->data[inBuf->len - 2] == ';')
231 {
232 /* might as well drop the second newline */
233 break;
234 }
235 }
236 else
237 {
238 /*
239 * In plain mode, newline ends the command unless preceded by
240 * backslash.
241 */
242 if (inBuf->len > 0 &&
243 inBuf->data[inBuf->len - 1] == '\\')
244 {
245 /* discard backslash from inBuf */
246 inBuf->data[--inBuf->len] = '\0';
247 /* discard newline too */
248 continue;
249 }
250 else
251 {
252 /* keep the newline character, but end the command */
253 appendStringInfoChar(inBuf, '\n');
254 break;
255 }
256 }
257 }
258
259 /* Not newline, or newline treated as regular character */
260 appendStringInfoChar(inBuf, (char) c);
261 }
262
263 /* No input before EOF signal means time to quit. */
264 if (c == EOF && inBuf->len == 0)
265 return EOF;
266
267 /*
268 * otherwise we have a user query so process it.
269 */
270
271 /* Add '\0' to make it look the same as message case. */
272 appendStringInfoChar(inBuf, (char) '\0');
273
274 /*
275 * if the query echo flag was given, print the query..
276 */
277 if (EchoQuery)
278 printf("statement: %s\n", inBuf->data);
279 fflush(stdout);
280
281 return 'Q';
282 }
283
284 /*
285 * interactive_getc -- collect one character from stdin
286 *
287 * Even though we are not reading from a "client" process, we still want to
288 * respond to signals, particularly SIGTERM/SIGQUIT.
289 */
290 static int
interactive_getc(void)291 interactive_getc(void)
292 {
293 int c;
294
295 /*
296 * This will not process catchup interrupts or notifications while
297 * reading. But those can't really be relevant for a standalone backend
298 * anyway. To properly handle SIGTERM there's a hack in die() that
299 * directly processes interrupts at this stage...
300 */
301 CHECK_FOR_INTERRUPTS();
302
303 c = getc(stdin);
304
305 ProcessClientReadInterrupt(false);
306
307 return c;
308 }
309
310 /* ----------------
311 * SocketBackend() Is called for frontend-backend connections
312 *
313 * Returns the message type code, and loads message body data into inBuf.
314 *
315 * EOF is returned if the connection is lost.
316 * ----------------
317 */
318 static int
SocketBackend(StringInfo inBuf)319 SocketBackend(StringInfo inBuf)
320 {
321 int qtype;
322
323 /*
324 * Get message type code from the frontend.
325 */
326 HOLD_CANCEL_INTERRUPTS();
327 pq_startmsgread();
328 qtype = pq_getbyte();
329
330 if (qtype == EOF) /* frontend disconnected */
331 {
332 if (IsTransactionState())
333 ereport(COMMERROR,
334 (errcode(ERRCODE_CONNECTION_FAILURE),
335 errmsg("unexpected EOF on client connection with an open transaction")));
336 else
337 {
338 /*
339 * Can't send DEBUG log messages to client at this point. Since
340 * we're disconnecting right away, we don't need to restore
341 * whereToSendOutput.
342 */
343 whereToSendOutput = DestNone;
344 ereport(DEBUG1,
345 (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST),
346 errmsg("unexpected EOF on client connection")));
347 }
348 return qtype;
349 }
350
351 /*
352 * Validate message type code before trying to read body; if we have lost
353 * sync, better to say "command unknown" than to run out of memory because
354 * we used garbage as a length word.
355 *
356 * This also gives us a place to set the doing_extended_query_message flag
357 * as soon as possible.
358 */
359 switch (qtype)
360 {
361 case 'Q': /* simple query */
362 doing_extended_query_message = false;
363 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
364 {
365 /* old style without length word; convert */
366 if (pq_getstring(inBuf))
367 {
368 if (IsTransactionState())
369 ereport(COMMERROR,
370 (errcode(ERRCODE_CONNECTION_FAILURE),
371 errmsg("unexpected EOF on client connection with an open transaction")));
372 else
373 {
374 /*
375 * Can't send DEBUG log messages to client at this
376 * point. Since we're disconnecting right away, we
377 * don't need to restore whereToSendOutput.
378 */
379 whereToSendOutput = DestNone;
380 ereport(DEBUG1,
381 (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST),
382 errmsg("unexpected EOF on client connection")));
383 }
384 return EOF;
385 }
386 }
387 break;
388
389 case 'F': /* fastpath function call */
390 doing_extended_query_message = false;
391 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
392 {
393 if (GetOldFunctionMessage(inBuf))
394 {
395 if (IsTransactionState())
396 ereport(COMMERROR,
397 (errcode(ERRCODE_CONNECTION_FAILURE),
398 errmsg("unexpected EOF on client connection with an open transaction")));
399 else
400 {
401 /*
402 * Can't send DEBUG log messages to client at this
403 * point. Since we're disconnecting right away, we
404 * don't need to restore whereToSendOutput.
405 */
406 whereToSendOutput = DestNone;
407 ereport(DEBUG1,
408 (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST),
409 errmsg("unexpected EOF on client connection")));
410 }
411 return EOF;
412 }
413 }
414 break;
415
416 case 'X': /* terminate */
417 doing_extended_query_message = false;
418 ignore_till_sync = false;
419 break;
420
421 case 'B': /* bind */
422 case 'C': /* close */
423 case 'D': /* describe */
424 case 'E': /* execute */
425 case 'H': /* flush */
426 case 'P': /* parse */
427 doing_extended_query_message = true;
428 /* these are only legal in protocol 3 */
429 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
430 ereport(FATAL,
431 (errcode(ERRCODE_PROTOCOL_VIOLATION),
432 errmsg("invalid frontend message type %d", qtype)));
433 break;
434
435 case 'S': /* sync */
436 /* stop any active skip-till-Sync */
437 ignore_till_sync = false;
438 /* mark not-extended, so that a new error doesn't begin skip */
439 doing_extended_query_message = false;
440 /* only legal in protocol 3 */
441 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
442 ereport(FATAL,
443 (errcode(ERRCODE_PROTOCOL_VIOLATION),
444 errmsg("invalid frontend message type %d", qtype)));
445 break;
446
447 case 'd': /* copy data */
448 case 'c': /* copy done */
449 case 'f': /* copy fail */
450 doing_extended_query_message = false;
451 /* these are only legal in protocol 3 */
452 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
453 ereport(FATAL,
454 (errcode(ERRCODE_PROTOCOL_VIOLATION),
455 errmsg("invalid frontend message type %d", qtype)));
456 break;
457
458 default:
459
460 /*
461 * Otherwise we got garbage from the frontend. We treat this as
462 * fatal because we have probably lost message boundary sync, and
463 * there's no good way to recover.
464 */
465 ereport(FATAL,
466 (errcode(ERRCODE_PROTOCOL_VIOLATION),
467 errmsg("invalid frontend message type %d", qtype)));
468 break;
469 }
470
471 /*
472 * In protocol version 3, all frontend messages have a length word next
473 * after the type code; we can read the message contents independently of
474 * the type.
475 */
476 if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
477 {
478 if (pq_getmessage(inBuf, 0))
479 return EOF; /* suitable message already logged */
480 }
481 else
482 pq_endmsgread();
483 RESUME_CANCEL_INTERRUPTS();
484
485 return qtype;
486 }
487
488 /* ----------------
489 * ReadCommand reads a command from either the frontend or
490 * standard input, places it in inBuf, and returns the
491 * message type code (first byte of the message).
492 * EOF is returned if end of file.
493 * ----------------
494 */
495 static int
ReadCommand(StringInfo inBuf)496 ReadCommand(StringInfo inBuf)
497 {
498 int result;
499
500 if (whereToSendOutput == DestRemote)
501 result = SocketBackend(inBuf);
502 else
503 result = InteractiveBackend(inBuf);
504 return result;
505 }
506
507 /*
508 * ProcessClientReadInterrupt() - Process interrupts specific to client reads
509 *
510 * This is called just before and after low-level reads.
511 * 'blocked' is true if no data was available to read and we plan to retry,
512 * false if about to read or done reading.
513 *
514 * Must preserve errno!
515 */
516 void
ProcessClientReadInterrupt(bool blocked)517 ProcessClientReadInterrupt(bool blocked)
518 {
519 int save_errno = errno;
520
521 if (DoingCommandRead)
522 {
523 /* Check for general interrupts that arrived before/while reading */
524 CHECK_FOR_INTERRUPTS();
525
526 /* Process sinval catchup interrupts, if any */
527 if (catchupInterruptPending)
528 ProcessCatchupInterrupt();
529
530 /* Process notify interrupts, if any */
531 if (notifyInterruptPending)
532 ProcessNotifyInterrupt();
533 }
534 else if (ProcDiePending)
535 {
536 /*
537 * We're dying. If there is no data available to read, then it's safe
538 * (and sane) to handle that now. If we haven't tried to read yet,
539 * make sure the process latch is set, so that if there is no data
540 * then we'll come back here and die. If we're done reading, also
541 * make sure the process latch is set, as we might've undesirably
542 * cleared it while reading.
543 */
544 if (blocked)
545 CHECK_FOR_INTERRUPTS();
546 else
547 SetLatch(MyLatch);
548 }
549
550 errno = save_errno;
551 }
552
553 /*
554 * ProcessClientWriteInterrupt() - Process interrupts specific to client writes
555 *
556 * This is called just before and after low-level writes.
557 * 'blocked' is true if no data could be written and we plan to retry,
558 * false if about to write or done writing.
559 *
560 * Must preserve errno!
561 */
562 void
ProcessClientWriteInterrupt(bool blocked)563 ProcessClientWriteInterrupt(bool blocked)
564 {
565 int save_errno = errno;
566
567 if (ProcDiePending)
568 {
569 /*
570 * We're dying. If it's not possible to write, then we should handle
571 * that immediately, else a stuck client could indefinitely delay our
572 * response to the signal. If we haven't tried to write yet, make
573 * sure the process latch is set, so that if the write would block
574 * then we'll come back here and die. If we're done writing, also
575 * make sure the process latch is set, as we might've undesirably
576 * cleared it while writing.
577 */
578 if (blocked)
579 {
580 /*
581 * Don't mess with whereToSendOutput if ProcessInterrupts wouldn't
582 * service ProcDiePending.
583 */
584 if (InterruptHoldoffCount == 0 && CritSectionCount == 0)
585 {
586 /*
587 * We don't want to send the client the error message, as a)
588 * that would possibly block again, and b) it would likely
589 * lead to loss of protocol sync because we may have already
590 * sent a partial protocol message.
591 */
592 if (whereToSendOutput == DestRemote)
593 whereToSendOutput = DestNone;
594
595 CHECK_FOR_INTERRUPTS();
596 }
597 }
598 else
599 SetLatch(MyLatch);
600 }
601
602 errno = save_errno;
603 }
604
605 /*
606 * Do raw parsing (only).
607 *
608 * A list of parsetrees (RawStmt nodes) is returned, since there might be
609 * multiple commands in the given string.
610 *
611 * NOTE: for interactive queries, it is important to keep this routine
612 * separate from the analysis & rewrite stages. Analysis and rewriting
613 * cannot be done in an aborted transaction, since they require access to
614 * database tables. So, we rely on the raw parser to determine whether
615 * we've seen a COMMIT or ABORT command; when we are in abort state, other
616 * commands are not processed any further than the raw parse stage.
617 */
618 List *
pg_parse_query(const char * query_string)619 pg_parse_query(const char *query_string)
620 {
621 List *raw_parsetree_list;
622
623 TRACE_POSTGRESQL_QUERY_PARSE_START(query_string);
624
625 if (log_parser_stats)
626 ResetUsage();
627
628 raw_parsetree_list = raw_parser(query_string);
629
630 if (log_parser_stats)
631 ShowUsage("PARSER STATISTICS");
632
633 #ifdef COPY_PARSE_PLAN_TREES
634 /* Optional debugging check: pass raw parsetrees through copyObject() */
635 {
636 List *new_list = copyObject(raw_parsetree_list);
637
638 /* This checks both copyObject() and the equal() routines... */
639 if (!equal(new_list, raw_parsetree_list))
640 elog(WARNING, "copyObject() failed to produce an equal raw parse tree");
641 else
642 raw_parsetree_list = new_list;
643 }
644 #endif
645
646 TRACE_POSTGRESQL_QUERY_PARSE_DONE(query_string);
647
648 return raw_parsetree_list;
649 }
650
651 /*
652 * Given a raw parsetree (gram.y output), and optionally information about
653 * types of parameter symbols ($n), perform parse analysis and rule rewriting.
654 *
655 * A list of Query nodes is returned, since either the analyzer or the
656 * rewriter might expand one query to several.
657 *
658 * NOTE: for reasons mentioned above, this must be separate from raw parsing.
659 */
660 List *
pg_analyze_and_rewrite(RawStmt * parsetree,const char * query_string,Oid * paramTypes,int numParams,QueryEnvironment * queryEnv)661 pg_analyze_and_rewrite(RawStmt *parsetree, const char *query_string,
662 Oid *paramTypes, int numParams,
663 QueryEnvironment *queryEnv)
664 {
665 Query *query;
666 List *querytree_list;
667
668 TRACE_POSTGRESQL_QUERY_REWRITE_START(query_string);
669
670 /*
671 * (1) Perform parse analysis.
672 */
673 if (log_parser_stats)
674 ResetUsage();
675
676 query = parse_analyze(parsetree, query_string, paramTypes, numParams,
677 queryEnv);
678
679 if (log_parser_stats)
680 ShowUsage("PARSE ANALYSIS STATISTICS");
681
682 /*
683 * (2) Rewrite the queries, as necessary
684 */
685 querytree_list = pg_rewrite_query(query);
686
687 TRACE_POSTGRESQL_QUERY_REWRITE_DONE(query_string);
688
689 return querytree_list;
690 }
691
692 /*
693 * Do parse analysis and rewriting. This is the same as pg_analyze_and_rewrite
694 * except that external-parameter resolution is determined by parser callback
695 * hooks instead of a fixed list of parameter datatypes.
696 */
697 List *
pg_analyze_and_rewrite_params(RawStmt * parsetree,const char * query_string,ParserSetupHook parserSetup,void * parserSetupArg,QueryEnvironment * queryEnv)698 pg_analyze_and_rewrite_params(RawStmt *parsetree,
699 const char *query_string,
700 ParserSetupHook parserSetup,
701 void *parserSetupArg,
702 QueryEnvironment *queryEnv)
703 {
704 ParseState *pstate;
705 Query *query;
706 List *querytree_list;
707
708 Assert(query_string != NULL); /* required as of 8.4 */
709
710 TRACE_POSTGRESQL_QUERY_REWRITE_START(query_string);
711
712 /*
713 * (1) Perform parse analysis.
714 */
715 if (log_parser_stats)
716 ResetUsage();
717
718 pstate = make_parsestate(NULL);
719 pstate->p_sourcetext = query_string;
720 pstate->p_queryEnv = queryEnv;
721 (*parserSetup) (pstate, parserSetupArg);
722
723 query = transformTopLevelStmt(pstate, parsetree);
724
725 if (post_parse_analyze_hook)
726 (*post_parse_analyze_hook) (pstate, query);
727
728 free_parsestate(pstate);
729
730 if (log_parser_stats)
731 ShowUsage("PARSE ANALYSIS STATISTICS");
732
733 /*
734 * (2) Rewrite the queries, as necessary
735 */
736 querytree_list = pg_rewrite_query(query);
737
738 TRACE_POSTGRESQL_QUERY_REWRITE_DONE(query_string);
739
740 return querytree_list;
741 }
742
743 /*
744 * Perform rewriting of a query produced by parse analysis.
745 *
746 * Note: query must just have come from the parser, because we do not do
747 * AcquireRewriteLocks() on it.
748 */
749 static List *
pg_rewrite_query(Query * query)750 pg_rewrite_query(Query *query)
751 {
752 List *querytree_list;
753
754 if (Debug_print_parse)
755 elog_node_display(LOG, "parse tree", query,
756 Debug_pretty_print);
757
758 if (log_parser_stats)
759 ResetUsage();
760
761 if (query->commandType == CMD_UTILITY)
762 {
763 /* don't rewrite utilities, just dump 'em into result list */
764 querytree_list = list_make1(query);
765 }
766 else
767 {
768 /* rewrite regular queries */
769 querytree_list = QueryRewrite(query);
770 }
771
772 if (log_parser_stats)
773 ShowUsage("REWRITER STATISTICS");
774
775 #ifdef COPY_PARSE_PLAN_TREES
776 /* Optional debugging check: pass querytree output through copyObject() */
777 {
778 List *new_list;
779
780 new_list = copyObject(querytree_list);
781 /* This checks both copyObject() and the equal() routines... */
782 if (!equal(new_list, querytree_list))
783 elog(WARNING, "copyObject() failed to produce equal parse tree");
784 else
785 querytree_list = new_list;
786 }
787 #endif
788
789 if (Debug_print_rewritten)
790 elog_node_display(LOG, "rewritten parse tree", querytree_list,
791 Debug_pretty_print);
792
793 return querytree_list;
794 }
795
796
797 /*
798 * Generate a plan for a single already-rewritten query.
799 * This is a thin wrapper around planner() and takes the same parameters.
800 */
801 PlannedStmt *
pg_plan_query(Query * querytree,int cursorOptions,ParamListInfo boundParams)802 pg_plan_query(Query *querytree, int cursorOptions, ParamListInfo boundParams)
803 {
804 PlannedStmt *plan;
805
806 /* Utility commands have no plans. */
807 if (querytree->commandType == CMD_UTILITY)
808 return NULL;
809
810 /* Planner must have a snapshot in case it calls user-defined functions. */
811 Assert(ActiveSnapshotSet());
812
813 TRACE_POSTGRESQL_QUERY_PLAN_START();
814
815 if (log_planner_stats)
816 ResetUsage();
817
818 /* call the optimizer */
819 plan = planner(querytree, cursorOptions, boundParams);
820
821 if (log_planner_stats)
822 ShowUsage("PLANNER STATISTICS");
823
824 #ifdef COPY_PARSE_PLAN_TREES
825 /* Optional debugging check: pass plan output through copyObject() */
826 {
827 PlannedStmt *new_plan = copyObject(plan);
828
829 /*
830 * equal() currently does not have routines to compare Plan nodes, so
831 * don't try to test equality here. Perhaps fix someday?
832 */
833 #ifdef NOT_USED
834 /* This checks both copyObject() and the equal() routines... */
835 if (!equal(new_plan, plan))
836 elog(WARNING, "copyObject() failed to produce an equal plan tree");
837 else
838 #endif
839 plan = new_plan;
840 }
841 #endif
842
843 /*
844 * Print plan if debugging.
845 */
846 if (Debug_print_plan)
847 elog_node_display(LOG, "plan", plan, Debug_pretty_print);
848
849 TRACE_POSTGRESQL_QUERY_PLAN_DONE();
850
851 return plan;
852 }
853
854 /*
855 * Generate plans for a list of already-rewritten queries.
856 *
857 * For normal optimizable statements, invoke the planner. For utility
858 * statements, just make a wrapper PlannedStmt node.
859 *
860 * The result is a list of PlannedStmt nodes.
861 */
862 List *
pg_plan_queries(List * querytrees,int cursorOptions,ParamListInfo boundParams)863 pg_plan_queries(List *querytrees, int cursorOptions, ParamListInfo boundParams)
864 {
865 List *stmt_list = NIL;
866 ListCell *query_list;
867
868 foreach(query_list, querytrees)
869 {
870 Query *query = lfirst_node(Query, query_list);
871 PlannedStmt *stmt;
872
873 if (query->commandType == CMD_UTILITY)
874 {
875 /* Utility commands require no planning. */
876 stmt = makeNode(PlannedStmt);
877 stmt->commandType = CMD_UTILITY;
878 stmt->canSetTag = query->canSetTag;
879 stmt->utilityStmt = query->utilityStmt;
880 stmt->stmt_location = query->stmt_location;
881 stmt->stmt_len = query->stmt_len;
882 }
883 else
884 {
885 stmt = pg_plan_query(query, cursorOptions, boundParams);
886 }
887
888 stmt_list = lappend(stmt_list, stmt);
889 }
890
891 return stmt_list;
892 }
893
894
895 /*
896 * exec_simple_query
897 *
898 * Execute a "simple Query" protocol message.
899 */
900 static void
exec_simple_query(const char * query_string)901 exec_simple_query(const char *query_string)
902 {
903 CommandDest dest = whereToSendOutput;
904 MemoryContext oldcontext;
905 List *parsetree_list;
906 ListCell *parsetree_item;
907 bool save_log_statement_stats = log_statement_stats;
908 bool was_logged = false;
909 bool isTopLevel;
910 char msec_str[32];
911
912
913 /*
914 * Report query to various monitoring facilities.
915 */
916 debug_query_string = query_string;
917
918 pgstat_report_activity(STATE_RUNNING, query_string);
919
920 TRACE_POSTGRESQL_QUERY_START(query_string);
921
922 /*
923 * We use save_log_statement_stats so ShowUsage doesn't report incorrect
924 * results because ResetUsage wasn't called.
925 */
926 if (save_log_statement_stats)
927 ResetUsage();
928
929 /*
930 * Start up a transaction command. All queries generated by the
931 * query_string will be in this same command block, *unless* we find a
932 * BEGIN/COMMIT/ABORT statement; we have to force a new xact command after
933 * one of those, else bad things will happen in xact.c. (Note that this
934 * will normally change current memory context.)
935 */
936 start_xact_command();
937
938 /*
939 * Zap any pre-existing unnamed statement. (While not strictly necessary,
940 * it seems best to define simple-Query mode as if it used the unnamed
941 * statement and portal; this ensures we recover any storage used by prior
942 * unnamed operations.)
943 */
944 drop_unnamed_stmt();
945
946 /*
947 * Switch to appropriate context for constructing parsetrees.
948 */
949 oldcontext = MemoryContextSwitchTo(MessageContext);
950
951 /*
952 * Do basic parsing of the query or queries (this should be safe even if
953 * we are in aborted transaction state!)
954 */
955 parsetree_list = pg_parse_query(query_string);
956
957 /* Log immediately if dictated by log_statement */
958 if (check_log_statement(parsetree_list))
959 {
960 ereport(LOG,
961 (errmsg("statement: %s", query_string),
962 errhidestmt(true),
963 errdetail_execute(parsetree_list)));
964 was_logged = true;
965 }
966
967 /*
968 * Switch back to transaction context to enter the loop.
969 */
970 MemoryContextSwitchTo(oldcontext);
971
972 /*
973 * We'll tell PortalRun it's a top-level command iff there's exactly one
974 * raw parsetree. If more than one, it's effectively a transaction block
975 * and we want PreventTransactionChain to reject unsafe commands. (Note:
976 * we're assuming that query rewrite cannot add commands that are
977 * significant to PreventTransactionChain.)
978 */
979 isTopLevel = (list_length(parsetree_list) == 1);
980
981 /*
982 * Run through the raw parsetree(s) and process each one.
983 */
984 foreach(parsetree_item, parsetree_list)
985 {
986 RawStmt *parsetree = lfirst_node(RawStmt, parsetree_item);
987 bool snapshot_set = false;
988 const char *commandTag;
989 char completionTag[COMPLETION_TAG_BUFSIZE];
990 List *querytree_list,
991 *plantree_list;
992 Portal portal;
993 DestReceiver *receiver;
994 int16 format;
995
996 /*
997 * Get the command name for use in status display (it also becomes the
998 * default completion tag, down inside PortalRun). Set ps_status and
999 * do any special start-of-SQL-command processing needed by the
1000 * destination.
1001 */
1002 commandTag = CreateCommandTag(parsetree->stmt);
1003
1004 set_ps_display(commandTag, false);
1005
1006 BeginCommand(commandTag, dest);
1007
1008 /*
1009 * If we are in an aborted transaction, reject all commands except
1010 * COMMIT/ABORT. It is important that this test occur before we try
1011 * to do parse analysis, rewrite, or planning, since all those phases
1012 * try to do database accesses, which may fail in abort state. (It
1013 * might be safe to allow some additional utility commands in this
1014 * state, but not many...)
1015 */
1016 if (IsAbortedTransactionBlockState() &&
1017 !IsTransactionExitStmt(parsetree->stmt))
1018 ereport(ERROR,
1019 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
1020 errmsg("current transaction is aborted, "
1021 "commands ignored until end of transaction block"),
1022 errdetail_abort()));
1023
1024 /* Make sure we are in a transaction command */
1025 start_xact_command();
1026
1027 /* If we got a cancel signal in parsing or prior command, quit */
1028 CHECK_FOR_INTERRUPTS();
1029
1030 /*
1031 * Set up a snapshot if parse analysis/planning will need one.
1032 */
1033 if (analyze_requires_snapshot(parsetree))
1034 {
1035 PushActiveSnapshot(GetTransactionSnapshot());
1036 snapshot_set = true;
1037 }
1038
1039 /*
1040 * OK to analyze, rewrite, and plan this query.
1041 *
1042 * Switch to appropriate context for constructing querytrees (again,
1043 * these must outlive the execution context).
1044 */
1045 oldcontext = MemoryContextSwitchTo(MessageContext);
1046
1047 querytree_list = pg_analyze_and_rewrite(parsetree, query_string,
1048 NULL, 0, NULL);
1049
1050 plantree_list = pg_plan_queries(querytree_list,
1051 CURSOR_OPT_PARALLEL_OK, NULL);
1052
1053 /* Done with the snapshot used for parsing/planning */
1054 if (snapshot_set)
1055 PopActiveSnapshot();
1056
1057 /* If we got a cancel signal in analysis or planning, quit */
1058 CHECK_FOR_INTERRUPTS();
1059
1060 /*
1061 * Create unnamed portal to run the query or queries in. If there
1062 * already is one, silently drop it.
1063 */
1064 portal = CreatePortal("", true, true);
1065 /* Don't display the portal in pg_cursors */
1066 portal->visible = false;
1067
1068 /*
1069 * We don't have to copy anything into the portal, because everything
1070 * we are passing here is in MessageContext, which will outlive the
1071 * portal anyway.
1072 */
1073 PortalDefineQuery(portal,
1074 NULL,
1075 query_string,
1076 commandTag,
1077 plantree_list,
1078 NULL);
1079
1080 /*
1081 * Start the portal. No parameters here.
1082 */
1083 PortalStart(portal, NULL, 0, InvalidSnapshot);
1084
1085 /*
1086 * Select the appropriate output format: text unless we are doing a
1087 * FETCH from a binary cursor. (Pretty grotty to have to do this here
1088 * --- but it avoids grottiness in other places. Ah, the joys of
1089 * backward compatibility...)
1090 */
1091 format = 0; /* TEXT is default */
1092 if (IsA(parsetree->stmt, FetchStmt))
1093 {
1094 FetchStmt *stmt = (FetchStmt *) parsetree->stmt;
1095
1096 if (!stmt->ismove)
1097 {
1098 Portal fportal = GetPortalByName(stmt->portalname);
1099
1100 if (PortalIsValid(fportal) &&
1101 (fportal->cursorOptions & CURSOR_OPT_BINARY))
1102 format = 1; /* BINARY */
1103 }
1104 }
1105 PortalSetResultFormat(portal, 1, &format);
1106
1107 /*
1108 * Now we can create the destination receiver object.
1109 */
1110 receiver = CreateDestReceiver(dest);
1111 if (dest == DestRemote)
1112 SetRemoteDestReceiverParams(receiver, portal);
1113
1114 /*
1115 * Switch back to transaction context for execution.
1116 */
1117 MemoryContextSwitchTo(oldcontext);
1118
1119 /*
1120 * Run the portal to completion, and then drop it (and the receiver).
1121 */
1122 (void) PortalRun(portal,
1123 FETCH_ALL,
1124 isTopLevel,
1125 true,
1126 receiver,
1127 receiver,
1128 completionTag);
1129
1130 (*receiver->rDestroy) (receiver);
1131
1132 PortalDrop(portal, false);
1133
1134 if (IsA(parsetree->stmt, TransactionStmt))
1135 {
1136 /*
1137 * If this was a transaction control statement, commit it. We will
1138 * start a new xact command for the next command (if any).
1139 */
1140 finish_xact_command();
1141 }
1142 else if (lnext(parsetree_item) == NULL)
1143 {
1144 /*
1145 * If this is the last parsetree of the query string, close down
1146 * transaction statement before reporting command-complete. This
1147 * is so that any end-of-transaction errors are reported before
1148 * the command-complete message is issued, to avoid confusing
1149 * clients who will expect either a command-complete message or an
1150 * error, not one and then the other. But for compatibility with
1151 * historical Postgres behavior, we do not force a transaction
1152 * boundary between queries appearing in a single query string.
1153 */
1154 finish_xact_command();
1155 }
1156 else
1157 {
1158 /*
1159 * We need a CommandCounterIncrement after every query, except
1160 * those that start or end a transaction block.
1161 */
1162 CommandCounterIncrement();
1163 }
1164
1165 /*
1166 * Tell client that we're done with this query. Note we emit exactly
1167 * one EndCommand report for each raw parsetree, thus one for each SQL
1168 * command the client sent, regardless of rewriting. (But a command
1169 * aborted by error will not send an EndCommand report at all.)
1170 */
1171 EndCommand(completionTag, dest);
1172 } /* end loop over parsetrees */
1173
1174 /*
1175 * Close down transaction statement, if one is open.
1176 */
1177 finish_xact_command();
1178
1179 /*
1180 * If there were no parsetrees, return EmptyQueryResponse message.
1181 */
1182 if (!parsetree_list)
1183 NullCommand(dest);
1184
1185 /*
1186 * Emit duration logging if appropriate.
1187 */
1188 switch (check_log_duration(msec_str, was_logged))
1189 {
1190 case 1:
1191 ereport(LOG,
1192 (errmsg("duration: %s ms", msec_str),
1193 errhidestmt(true)));
1194 break;
1195 case 2:
1196 ereport(LOG,
1197 (errmsg("duration: %s ms statement: %s",
1198 msec_str, query_string),
1199 errhidestmt(true),
1200 errdetail_execute(parsetree_list)));
1201 break;
1202 }
1203
1204 if (save_log_statement_stats)
1205 ShowUsage("QUERY STATISTICS");
1206
1207 TRACE_POSTGRESQL_QUERY_DONE(query_string);
1208
1209 debug_query_string = NULL;
1210 }
1211
1212 /*
1213 * exec_parse_message
1214 *
1215 * Execute a "Parse" protocol message.
1216 */
1217 static void
exec_parse_message(const char * query_string,const char * stmt_name,Oid * paramTypes,int numParams)1218 exec_parse_message(const char *query_string, /* string to execute */
1219 const char *stmt_name, /* name for prepared stmt */
1220 Oid *paramTypes, /* parameter types */
1221 int numParams) /* number of parameters */
1222 {
1223 MemoryContext unnamed_stmt_context = NULL;
1224 MemoryContext oldcontext;
1225 List *parsetree_list;
1226 RawStmt *raw_parse_tree;
1227 const char *commandTag;
1228 List *querytree_list;
1229 CachedPlanSource *psrc;
1230 bool is_named;
1231 bool save_log_statement_stats = log_statement_stats;
1232 char msec_str[32];
1233
1234 /*
1235 * Report query to various monitoring facilities.
1236 */
1237 debug_query_string = query_string;
1238
1239 pgstat_report_activity(STATE_RUNNING, query_string);
1240
1241 set_ps_display("PARSE", false);
1242
1243 if (save_log_statement_stats)
1244 ResetUsage();
1245
1246 ereport(DEBUG2,
1247 (errmsg("parse %s: %s",
1248 *stmt_name ? stmt_name : "<unnamed>",
1249 query_string)));
1250
1251 /*
1252 * Start up a transaction command so we can run parse analysis etc. (Note
1253 * that this will normally change current memory context.) Nothing happens
1254 * if we are already in one.
1255 */
1256 start_xact_command();
1257
1258 /*
1259 * Switch to appropriate context for constructing parsetrees.
1260 *
1261 * We have two strategies depending on whether the prepared statement is
1262 * named or not. For a named prepared statement, we do parsing in
1263 * MessageContext and copy the finished trees into the prepared
1264 * statement's plancache entry; then the reset of MessageContext releases
1265 * temporary space used by parsing and rewriting. For an unnamed prepared
1266 * statement, we assume the statement isn't going to hang around long, so
1267 * getting rid of temp space quickly is probably not worth the costs of
1268 * copying parse trees. So in this case, we create the plancache entry's
1269 * query_context here, and do all the parsing work therein.
1270 */
1271 is_named = (stmt_name[0] != '\0');
1272 if (is_named)
1273 {
1274 /* Named prepared statement --- parse in MessageContext */
1275 oldcontext = MemoryContextSwitchTo(MessageContext);
1276 }
1277 else
1278 {
1279 /* Unnamed prepared statement --- release any prior unnamed stmt */
1280 drop_unnamed_stmt();
1281 /* Create context for parsing */
1282 unnamed_stmt_context =
1283 AllocSetContextCreate(MessageContext,
1284 "unnamed prepared statement",
1285 ALLOCSET_DEFAULT_SIZES);
1286 oldcontext = MemoryContextSwitchTo(unnamed_stmt_context);
1287 }
1288
1289 /*
1290 * Do basic parsing of the query or queries (this should be safe even if
1291 * we are in aborted transaction state!)
1292 */
1293 parsetree_list = pg_parse_query(query_string);
1294
1295 /*
1296 * We only allow a single user statement in a prepared statement. This is
1297 * mainly to keep the protocol simple --- otherwise we'd need to worry
1298 * about multiple result tupdescs and things like that.
1299 */
1300 if (list_length(parsetree_list) > 1)
1301 ereport(ERROR,
1302 (errcode(ERRCODE_SYNTAX_ERROR),
1303 errmsg("cannot insert multiple commands into a prepared statement")));
1304
1305 if (parsetree_list != NIL)
1306 {
1307 Query *query;
1308 bool snapshot_set = false;
1309 int i;
1310
1311 raw_parse_tree = linitial_node(RawStmt, parsetree_list);
1312
1313 /*
1314 * Get the command name for possible use in status display.
1315 */
1316 commandTag = CreateCommandTag(raw_parse_tree->stmt);
1317
1318 /*
1319 * If we are in an aborted transaction, reject all commands except
1320 * COMMIT/ROLLBACK. It is important that this test occur before we
1321 * try to do parse analysis, rewrite, or planning, since all those
1322 * phases try to do database accesses, which may fail in abort state.
1323 * (It might be safe to allow some additional utility commands in this
1324 * state, but not many...)
1325 */
1326 if (IsAbortedTransactionBlockState() &&
1327 !IsTransactionExitStmt(raw_parse_tree->stmt))
1328 ereport(ERROR,
1329 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
1330 errmsg("current transaction is aborted, "
1331 "commands ignored until end of transaction block"),
1332 errdetail_abort()));
1333
1334 /*
1335 * Create the CachedPlanSource before we do parse analysis, since it
1336 * needs to see the unmodified raw parse tree.
1337 */
1338 psrc = CreateCachedPlan(raw_parse_tree, query_string, commandTag);
1339
1340 /*
1341 * Set up a snapshot if parse analysis will need one.
1342 */
1343 if (analyze_requires_snapshot(raw_parse_tree))
1344 {
1345 PushActiveSnapshot(GetTransactionSnapshot());
1346 snapshot_set = true;
1347 }
1348
1349 /*
1350 * Analyze and rewrite the query. Note that the originally specified
1351 * parameter set is not required to be complete, so we have to use
1352 * parse_analyze_varparams().
1353 */
1354 if (log_parser_stats)
1355 ResetUsage();
1356
1357 query = parse_analyze_varparams(raw_parse_tree,
1358 query_string,
1359 ¶mTypes,
1360 &numParams);
1361
1362 /*
1363 * Check all parameter types got determined.
1364 */
1365 for (i = 0; i < numParams; i++)
1366 {
1367 Oid ptype = paramTypes[i];
1368
1369 if (ptype == InvalidOid || ptype == UNKNOWNOID)
1370 ereport(ERROR,
1371 (errcode(ERRCODE_INDETERMINATE_DATATYPE),
1372 errmsg("could not determine data type of parameter $%d",
1373 i + 1)));
1374 }
1375
1376 if (log_parser_stats)
1377 ShowUsage("PARSE ANALYSIS STATISTICS");
1378
1379 querytree_list = pg_rewrite_query(query);
1380
1381 /* Done with the snapshot used for parsing */
1382 if (snapshot_set)
1383 PopActiveSnapshot();
1384 }
1385 else
1386 {
1387 /* Empty input string. This is legal. */
1388 raw_parse_tree = NULL;
1389 commandTag = NULL;
1390 psrc = CreateCachedPlan(raw_parse_tree, query_string, commandTag);
1391 querytree_list = NIL;
1392 }
1393
1394 /*
1395 * CachedPlanSource must be a direct child of MessageContext before we
1396 * reparent unnamed_stmt_context under it, else we have a disconnected
1397 * circular subgraph. Klugy, but less so than flipping contexts even more
1398 * above.
1399 */
1400 if (unnamed_stmt_context)
1401 MemoryContextSetParent(psrc->context, MessageContext);
1402
1403 /* Finish filling in the CachedPlanSource */
1404 CompleteCachedPlan(psrc,
1405 querytree_list,
1406 unnamed_stmt_context,
1407 paramTypes,
1408 numParams,
1409 NULL,
1410 NULL,
1411 CURSOR_OPT_PARALLEL_OK, /* allow parallel mode */
1412 true); /* fixed result */
1413
1414 /* If we got a cancel signal during analysis, quit */
1415 CHECK_FOR_INTERRUPTS();
1416
1417 if (is_named)
1418 {
1419 /*
1420 * Store the query as a prepared statement.
1421 */
1422 StorePreparedStatement(stmt_name, psrc, false);
1423 }
1424 else
1425 {
1426 /*
1427 * We just save the CachedPlanSource into unnamed_stmt_psrc.
1428 */
1429 SaveCachedPlan(psrc);
1430 unnamed_stmt_psrc = psrc;
1431 }
1432
1433 MemoryContextSwitchTo(oldcontext);
1434
1435 /*
1436 * We do NOT close the open transaction command here; that only happens
1437 * when the client sends Sync. Instead, do CommandCounterIncrement just
1438 * in case something happened during parse/plan.
1439 */
1440 CommandCounterIncrement();
1441
1442 /*
1443 * Send ParseComplete.
1444 */
1445 if (whereToSendOutput == DestRemote)
1446 pq_putemptymessage('1');
1447
1448 /*
1449 * Emit duration logging if appropriate.
1450 */
1451 switch (check_log_duration(msec_str, false))
1452 {
1453 case 1:
1454 ereport(LOG,
1455 (errmsg("duration: %s ms", msec_str),
1456 errhidestmt(true)));
1457 break;
1458 case 2:
1459 ereport(LOG,
1460 (errmsg("duration: %s ms parse %s: %s",
1461 msec_str,
1462 *stmt_name ? stmt_name : "<unnamed>",
1463 query_string),
1464 errhidestmt(true)));
1465 break;
1466 }
1467
1468 if (save_log_statement_stats)
1469 ShowUsage("PARSE MESSAGE STATISTICS");
1470
1471 debug_query_string = NULL;
1472 }
1473
1474 /*
1475 * exec_bind_message
1476 *
1477 * Process a "Bind" message to create a portal from a prepared statement
1478 */
1479 static void
exec_bind_message(StringInfo input_message)1480 exec_bind_message(StringInfo input_message)
1481 {
1482 const char *portal_name;
1483 const char *stmt_name;
1484 int numPFormats;
1485 int16 *pformats = NULL;
1486 int numParams;
1487 int numRFormats;
1488 int16 *rformats = NULL;
1489 CachedPlanSource *psrc;
1490 CachedPlan *cplan;
1491 Portal portal;
1492 char *query_string;
1493 char *saved_stmt_name;
1494 ParamListInfo params;
1495 MemoryContext oldContext;
1496 bool save_log_statement_stats = log_statement_stats;
1497 bool snapshot_set = false;
1498 char msec_str[32];
1499
1500 /* Get the fixed part of the message */
1501 portal_name = pq_getmsgstring(input_message);
1502 stmt_name = pq_getmsgstring(input_message);
1503
1504 ereport(DEBUG2,
1505 (errmsg("bind %s to %s",
1506 *portal_name ? portal_name : "<unnamed>",
1507 *stmt_name ? stmt_name : "<unnamed>")));
1508
1509 /* Find prepared statement */
1510 if (stmt_name[0] != '\0')
1511 {
1512 PreparedStatement *pstmt;
1513
1514 pstmt = FetchPreparedStatement(stmt_name, true);
1515 psrc = pstmt->plansource;
1516 }
1517 else
1518 {
1519 /* special-case the unnamed statement */
1520 psrc = unnamed_stmt_psrc;
1521 if (!psrc)
1522 ereport(ERROR,
1523 (errcode(ERRCODE_UNDEFINED_PSTATEMENT),
1524 errmsg("unnamed prepared statement does not exist")));
1525 }
1526
1527 /*
1528 * Report query to various monitoring facilities.
1529 */
1530 debug_query_string = psrc->query_string;
1531
1532 pgstat_report_activity(STATE_RUNNING, psrc->query_string);
1533
1534 set_ps_display("BIND", false);
1535
1536 if (save_log_statement_stats)
1537 ResetUsage();
1538
1539 /*
1540 * Start up a transaction command so we can call functions etc. (Note that
1541 * this will normally change current memory context.) Nothing happens if
1542 * we are already in one.
1543 */
1544 start_xact_command();
1545
1546 /* Switch back to message context */
1547 MemoryContextSwitchTo(MessageContext);
1548
1549 /* Get the parameter format codes */
1550 numPFormats = pq_getmsgint(input_message, 2);
1551 if (numPFormats > 0)
1552 {
1553 int i;
1554
1555 pformats = (int16 *) palloc(numPFormats * sizeof(int16));
1556 for (i = 0; i < numPFormats; i++)
1557 pformats[i] = pq_getmsgint(input_message, 2);
1558 }
1559
1560 /* Get the parameter value count */
1561 numParams = pq_getmsgint(input_message, 2);
1562
1563 if (numPFormats > 1 && numPFormats != numParams)
1564 ereport(ERROR,
1565 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1566 errmsg("bind message has %d parameter formats but %d parameters",
1567 numPFormats, numParams)));
1568
1569 if (numParams != psrc->num_params)
1570 ereport(ERROR,
1571 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1572 errmsg("bind message supplies %d parameters, but prepared statement \"%s\" requires %d",
1573 numParams, stmt_name, psrc->num_params)));
1574
1575 /*
1576 * If we are in aborted transaction state, the only portals we can
1577 * actually run are those containing COMMIT or ROLLBACK commands. We
1578 * disallow binding anything else to avoid problems with infrastructure
1579 * that expects to run inside a valid transaction. We also disallow
1580 * binding any parameters, since we can't risk calling user-defined I/O
1581 * functions.
1582 */
1583 if (IsAbortedTransactionBlockState() &&
1584 (!(psrc->raw_parse_tree &&
1585 IsTransactionExitStmt(psrc->raw_parse_tree->stmt)) ||
1586 numParams != 0))
1587 ereport(ERROR,
1588 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
1589 errmsg("current transaction is aborted, "
1590 "commands ignored until end of transaction block"),
1591 errdetail_abort()));
1592
1593 /*
1594 * Create the portal. Allow silent replacement of an existing portal only
1595 * if the unnamed portal is specified.
1596 */
1597 if (portal_name[0] == '\0')
1598 portal = CreatePortal(portal_name, true, true);
1599 else
1600 portal = CreatePortal(portal_name, false, false);
1601
1602 /*
1603 * Prepare to copy stuff into the portal's memory context. We do all this
1604 * copying first, because it could possibly fail (out-of-memory) and we
1605 * don't want a failure to occur between GetCachedPlan and
1606 * PortalDefineQuery; that would result in leaking our plancache refcount.
1607 */
1608 oldContext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
1609
1610 /* Copy the plan's query string into the portal */
1611 query_string = pstrdup(psrc->query_string);
1612
1613 /* Likewise make a copy of the statement name, unless it's unnamed */
1614 if (stmt_name[0])
1615 saved_stmt_name = pstrdup(stmt_name);
1616 else
1617 saved_stmt_name = NULL;
1618
1619 /*
1620 * Set a snapshot if we have parameters to fetch (since the input
1621 * functions might need it) or the query isn't a utility command (and
1622 * hence could require redoing parse analysis and planning). We keep the
1623 * snapshot active till we're done, so that plancache.c doesn't have to
1624 * take new ones.
1625 */
1626 if (numParams > 0 ||
1627 (psrc->raw_parse_tree &&
1628 analyze_requires_snapshot(psrc->raw_parse_tree)))
1629 {
1630 PushActiveSnapshot(GetTransactionSnapshot());
1631 snapshot_set = true;
1632 }
1633
1634 /*
1635 * Fetch parameters, if any, and store in the portal's memory context.
1636 */
1637 if (numParams > 0)
1638 {
1639 int paramno;
1640
1641 params = (ParamListInfo) palloc(offsetof(ParamListInfoData, params) +
1642 numParams * sizeof(ParamExternData));
1643 /* we have static list of params, so no hooks needed */
1644 params->paramFetch = NULL;
1645 params->paramFetchArg = NULL;
1646 params->parserSetup = NULL;
1647 params->parserSetupArg = NULL;
1648 params->numParams = numParams;
1649 params->paramMask = NULL;
1650
1651 for (paramno = 0; paramno < numParams; paramno++)
1652 {
1653 Oid ptype = psrc->param_types[paramno];
1654 int32 plength;
1655 Datum pval;
1656 bool isNull;
1657 StringInfoData pbuf;
1658 char csave;
1659 int16 pformat;
1660
1661 plength = pq_getmsgint(input_message, 4);
1662 isNull = (plength == -1);
1663
1664 if (!isNull)
1665 {
1666 const char *pvalue = pq_getmsgbytes(input_message, plength);
1667
1668 /*
1669 * Rather than copying data around, we just set up a phony
1670 * StringInfo pointing to the correct portion of the message
1671 * buffer. We assume we can scribble on the message buffer so
1672 * as to maintain the convention that StringInfos have a
1673 * trailing null. This is grotty but is a big win when
1674 * dealing with very large parameter strings.
1675 */
1676 pbuf.data = (char *) pvalue;
1677 pbuf.maxlen = plength + 1;
1678 pbuf.len = plength;
1679 pbuf.cursor = 0;
1680
1681 csave = pbuf.data[plength];
1682 pbuf.data[plength] = '\0';
1683 }
1684 else
1685 {
1686 pbuf.data = NULL; /* keep compiler quiet */
1687 csave = 0;
1688 }
1689
1690 if (numPFormats > 1)
1691 pformat = pformats[paramno];
1692 else if (numPFormats > 0)
1693 pformat = pformats[0];
1694 else
1695 pformat = 0; /* default = text */
1696
1697 if (pformat == 0) /* text mode */
1698 {
1699 Oid typinput;
1700 Oid typioparam;
1701 char *pstring;
1702
1703 getTypeInputInfo(ptype, &typinput, &typioparam);
1704
1705 /*
1706 * We have to do encoding conversion before calling the
1707 * typinput routine.
1708 */
1709 if (isNull)
1710 pstring = NULL;
1711 else
1712 pstring = pg_client_to_server(pbuf.data, plength);
1713
1714 pval = OidInputFunctionCall(typinput, pstring, typioparam, -1);
1715
1716 /* Free result of encoding conversion, if any */
1717 if (pstring && pstring != pbuf.data)
1718 pfree(pstring);
1719 }
1720 else if (pformat == 1) /* binary mode */
1721 {
1722 Oid typreceive;
1723 Oid typioparam;
1724 StringInfo bufptr;
1725
1726 /*
1727 * Call the parameter type's binary input converter
1728 */
1729 getTypeBinaryInputInfo(ptype, &typreceive, &typioparam);
1730
1731 if (isNull)
1732 bufptr = NULL;
1733 else
1734 bufptr = &pbuf;
1735
1736 pval = OidReceiveFunctionCall(typreceive, bufptr, typioparam, -1);
1737
1738 /* Trouble if it didn't eat the whole buffer */
1739 if (!isNull && pbuf.cursor != pbuf.len)
1740 ereport(ERROR,
1741 (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
1742 errmsg("incorrect binary data format in bind parameter %d",
1743 paramno + 1)));
1744 }
1745 else
1746 {
1747 ereport(ERROR,
1748 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1749 errmsg("unsupported format code: %d",
1750 pformat)));
1751 pval = 0; /* keep compiler quiet */
1752 }
1753
1754 /* Restore message buffer contents */
1755 if (!isNull)
1756 pbuf.data[plength] = csave;
1757
1758 params->params[paramno].value = pval;
1759 params->params[paramno].isnull = isNull;
1760
1761 /*
1762 * We mark the params as CONST. This ensures that any custom plan
1763 * makes full use of the parameter values.
1764 */
1765 params->params[paramno].pflags = PARAM_FLAG_CONST;
1766 params->params[paramno].ptype = ptype;
1767 }
1768 }
1769 else
1770 params = NULL;
1771
1772 /* Done storing stuff in portal's context */
1773 MemoryContextSwitchTo(oldContext);
1774
1775 /* Get the result format codes */
1776 numRFormats = pq_getmsgint(input_message, 2);
1777 if (numRFormats > 0)
1778 {
1779 int i;
1780
1781 rformats = (int16 *) palloc(numRFormats * sizeof(int16));
1782 for (i = 0; i < numRFormats; i++)
1783 rformats[i] = pq_getmsgint(input_message, 2);
1784 }
1785
1786 pq_getmsgend(input_message);
1787
1788 /*
1789 * Obtain a plan from the CachedPlanSource. Any cruft from (re)planning
1790 * will be generated in MessageContext. The plan refcount will be
1791 * assigned to the Portal, so it will be released at portal destruction.
1792 */
1793 cplan = GetCachedPlan(psrc, params, false, NULL);
1794
1795 /*
1796 * Now we can define the portal.
1797 *
1798 * DO NOT put any code that could possibly throw an error between the
1799 * above GetCachedPlan call and here.
1800 */
1801 PortalDefineQuery(portal,
1802 saved_stmt_name,
1803 query_string,
1804 psrc->commandTag,
1805 cplan->stmt_list,
1806 cplan);
1807
1808 /* Done with the snapshot used for parameter I/O and parsing/planning */
1809 if (snapshot_set)
1810 PopActiveSnapshot();
1811
1812 /*
1813 * And we're ready to start portal execution.
1814 */
1815 PortalStart(portal, params, 0, InvalidSnapshot);
1816
1817 /*
1818 * Apply the result format requests to the portal.
1819 */
1820 PortalSetResultFormat(portal, numRFormats, rformats);
1821
1822 /*
1823 * Send BindComplete.
1824 */
1825 if (whereToSendOutput == DestRemote)
1826 pq_putemptymessage('2');
1827
1828 /*
1829 * Emit duration logging if appropriate.
1830 */
1831 switch (check_log_duration(msec_str, false))
1832 {
1833 case 1:
1834 ereport(LOG,
1835 (errmsg("duration: %s ms", msec_str),
1836 errhidestmt(true)));
1837 break;
1838 case 2:
1839 ereport(LOG,
1840 (errmsg("duration: %s ms bind %s%s%s: %s",
1841 msec_str,
1842 *stmt_name ? stmt_name : "<unnamed>",
1843 *portal_name ? "/" : "",
1844 *portal_name ? portal_name : "",
1845 psrc->query_string),
1846 errhidestmt(true),
1847 errdetail_params(params)));
1848 break;
1849 }
1850
1851 if (save_log_statement_stats)
1852 ShowUsage("BIND MESSAGE STATISTICS");
1853
1854 debug_query_string = NULL;
1855 }
1856
1857 /*
1858 * exec_execute_message
1859 *
1860 * Process an "Execute" message for a portal
1861 */
1862 static void
exec_execute_message(const char * portal_name,long max_rows)1863 exec_execute_message(const char *portal_name, long max_rows)
1864 {
1865 CommandDest dest;
1866 DestReceiver *receiver;
1867 Portal portal;
1868 bool completed;
1869 char completionTag[COMPLETION_TAG_BUFSIZE];
1870 const char *sourceText;
1871 const char *prepStmtName;
1872 ParamListInfo portalParams;
1873 bool save_log_statement_stats = log_statement_stats;
1874 bool is_xact_command;
1875 bool execute_is_fetch;
1876 bool was_logged = false;
1877 char msec_str[32];
1878
1879 /* Adjust destination to tell printtup.c what to do */
1880 dest = whereToSendOutput;
1881 if (dest == DestRemote)
1882 dest = DestRemoteExecute;
1883
1884 portal = GetPortalByName(portal_name);
1885 if (!PortalIsValid(portal))
1886 ereport(ERROR,
1887 (errcode(ERRCODE_UNDEFINED_CURSOR),
1888 errmsg("portal \"%s\" does not exist", portal_name)));
1889
1890 /*
1891 * If the original query was a null string, just return
1892 * EmptyQueryResponse.
1893 */
1894 if (portal->commandTag == NULL)
1895 {
1896 Assert(portal->stmts == NIL);
1897 NullCommand(dest);
1898 return;
1899 }
1900
1901 /* Does the portal contain a transaction command? */
1902 is_xact_command = IsTransactionStmtList(portal->stmts);
1903
1904 /*
1905 * We must copy the sourceText and prepStmtName into MessageContext in
1906 * case the portal is destroyed during finish_xact_command. Can avoid the
1907 * copy if it's not an xact command, though.
1908 */
1909 if (is_xact_command)
1910 {
1911 sourceText = pstrdup(portal->sourceText);
1912 if (portal->prepStmtName)
1913 prepStmtName = pstrdup(portal->prepStmtName);
1914 else
1915 prepStmtName = "<unnamed>";
1916
1917 /*
1918 * An xact command shouldn't have any parameters, which is a good
1919 * thing because they wouldn't be around after finish_xact_command.
1920 */
1921 portalParams = NULL;
1922 }
1923 else
1924 {
1925 sourceText = portal->sourceText;
1926 if (portal->prepStmtName)
1927 prepStmtName = portal->prepStmtName;
1928 else
1929 prepStmtName = "<unnamed>";
1930 portalParams = portal->portalParams;
1931 }
1932
1933 /*
1934 * Report query to various monitoring facilities.
1935 */
1936 debug_query_string = sourceText;
1937
1938 pgstat_report_activity(STATE_RUNNING, sourceText);
1939
1940 set_ps_display(portal->commandTag, false);
1941
1942 if (save_log_statement_stats)
1943 ResetUsage();
1944
1945 BeginCommand(portal->commandTag, dest);
1946
1947 /*
1948 * Create dest receiver in MessageContext (we don't want it in transaction
1949 * context, because that may get deleted if portal contains VACUUM).
1950 */
1951 receiver = CreateDestReceiver(dest);
1952 if (dest == DestRemoteExecute)
1953 SetRemoteDestReceiverParams(receiver, portal);
1954
1955 /*
1956 * Ensure we are in a transaction command (this should normally be the
1957 * case already due to prior BIND).
1958 */
1959 start_xact_command();
1960
1961 /*
1962 * If we re-issue an Execute protocol request against an existing portal,
1963 * then we are only fetching more rows rather than completely re-executing
1964 * the query from the start. atStart is never reset for a v3 portal, so we
1965 * are safe to use this check.
1966 */
1967 execute_is_fetch = !portal->atStart;
1968
1969 /* Log immediately if dictated by log_statement */
1970 if (check_log_statement(portal->stmts))
1971 {
1972 ereport(LOG,
1973 (errmsg("%s %s%s%s: %s",
1974 execute_is_fetch ?
1975 _("execute fetch from") :
1976 _("execute"),
1977 prepStmtName,
1978 *portal_name ? "/" : "",
1979 *portal_name ? portal_name : "",
1980 sourceText),
1981 errhidestmt(true),
1982 errdetail_params(portalParams)));
1983 was_logged = true;
1984 }
1985
1986 /*
1987 * If we are in aborted transaction state, the only portals we can
1988 * actually run are those containing COMMIT or ROLLBACK commands.
1989 */
1990 if (IsAbortedTransactionBlockState() &&
1991 !IsTransactionExitStmtList(portal->stmts))
1992 ereport(ERROR,
1993 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
1994 errmsg("current transaction is aborted, "
1995 "commands ignored until end of transaction block"),
1996 errdetail_abort()));
1997
1998 /* Check for cancel signal before we start execution */
1999 CHECK_FOR_INTERRUPTS();
2000
2001 /*
2002 * Okay to run the portal.
2003 */
2004 if (max_rows <= 0)
2005 max_rows = FETCH_ALL;
2006
2007 completed = PortalRun(portal,
2008 max_rows,
2009 true, /* always top level */
2010 !execute_is_fetch && max_rows == FETCH_ALL,
2011 receiver,
2012 receiver,
2013 completionTag);
2014
2015 (*receiver->rDestroy) (receiver);
2016
2017 if (completed)
2018 {
2019 if (is_xact_command)
2020 {
2021 /*
2022 * If this was a transaction control statement, commit it. We
2023 * will start a new xact command for the next command (if any).
2024 */
2025 finish_xact_command();
2026 }
2027 else
2028 {
2029 /*
2030 * We need a CommandCounterIncrement after every query, except
2031 * those that start or end a transaction block.
2032 */
2033 CommandCounterIncrement();
2034 }
2035
2036 /* Send appropriate CommandComplete to client */
2037 EndCommand(completionTag, dest);
2038 }
2039 else
2040 {
2041 /* Portal run not complete, so send PortalSuspended */
2042 if (whereToSendOutput == DestRemote)
2043 pq_putemptymessage('s');
2044 }
2045
2046 /*
2047 * Emit duration logging if appropriate.
2048 */
2049 switch (check_log_duration(msec_str, was_logged))
2050 {
2051 case 1:
2052 ereport(LOG,
2053 (errmsg("duration: %s ms", msec_str),
2054 errhidestmt(true)));
2055 break;
2056 case 2:
2057 ereport(LOG,
2058 (errmsg("duration: %s ms %s %s%s%s: %s",
2059 msec_str,
2060 execute_is_fetch ?
2061 _("execute fetch from") :
2062 _("execute"),
2063 prepStmtName,
2064 *portal_name ? "/" : "",
2065 *portal_name ? portal_name : "",
2066 sourceText),
2067 errhidestmt(true),
2068 errdetail_params(portalParams)));
2069 break;
2070 }
2071
2072 if (save_log_statement_stats)
2073 ShowUsage("EXECUTE MESSAGE STATISTICS");
2074
2075 debug_query_string = NULL;
2076 }
2077
2078 /*
2079 * check_log_statement
2080 * Determine whether command should be logged because of log_statement
2081 *
2082 * stmt_list can be either raw grammar output or a list of planned
2083 * statements
2084 */
2085 static bool
check_log_statement(List * stmt_list)2086 check_log_statement(List *stmt_list)
2087 {
2088 ListCell *stmt_item;
2089
2090 if (log_statement == LOGSTMT_NONE)
2091 return false;
2092 if (log_statement == LOGSTMT_ALL)
2093 return true;
2094
2095 /* Else we have to inspect the statement(s) to see whether to log */
2096 foreach(stmt_item, stmt_list)
2097 {
2098 Node *stmt = (Node *) lfirst(stmt_item);
2099
2100 if (GetCommandLogLevel(stmt) <= log_statement)
2101 return true;
2102 }
2103
2104 return false;
2105 }
2106
2107 /*
2108 * check_log_duration
2109 * Determine whether current command's duration should be logged
2110 *
2111 * Returns:
2112 * 0 if no logging is needed
2113 * 1 if just the duration should be logged
2114 * 2 if duration and query details should be logged
2115 *
2116 * If logging is needed, the duration in msec is formatted into msec_str[],
2117 * which must be a 32-byte buffer.
2118 *
2119 * was_logged should be TRUE if caller already logged query details (this
2120 * essentially prevents 2 from being returned).
2121 */
2122 int
check_log_duration(char * msec_str,bool was_logged)2123 check_log_duration(char *msec_str, bool was_logged)
2124 {
2125 if (log_duration || log_min_duration_statement >= 0)
2126 {
2127 long secs;
2128 int usecs;
2129 int msecs;
2130 bool exceeded;
2131
2132 TimestampDifference(GetCurrentStatementStartTimestamp(),
2133 GetCurrentTimestamp(),
2134 &secs, &usecs);
2135 msecs = usecs / 1000;
2136
2137 /*
2138 * This odd-looking test for log_min_duration_statement being exceeded
2139 * is designed to avoid integer overflow with very long durations:
2140 * don't compute secs * 1000 until we've verified it will fit in int.
2141 */
2142 exceeded = (log_min_duration_statement == 0 ||
2143 (log_min_duration_statement > 0 &&
2144 (secs > log_min_duration_statement / 1000 ||
2145 secs * 1000 + msecs >= log_min_duration_statement)));
2146
2147 if (exceeded || log_duration)
2148 {
2149 snprintf(msec_str, 32, "%ld.%03d",
2150 secs * 1000 + msecs, usecs % 1000);
2151 if (exceeded && !was_logged)
2152 return 2;
2153 else
2154 return 1;
2155 }
2156 }
2157
2158 return 0;
2159 }
2160
2161 /*
2162 * errdetail_execute
2163 *
2164 * Add an errdetail() line showing the query referenced by an EXECUTE, if any.
2165 * The argument is the raw parsetree list.
2166 */
2167 static int
errdetail_execute(List * raw_parsetree_list)2168 errdetail_execute(List *raw_parsetree_list)
2169 {
2170 ListCell *parsetree_item;
2171
2172 foreach(parsetree_item, raw_parsetree_list)
2173 {
2174 RawStmt *parsetree = lfirst_node(RawStmt, parsetree_item);
2175
2176 if (IsA(parsetree->stmt, ExecuteStmt))
2177 {
2178 ExecuteStmt *stmt = (ExecuteStmt *) parsetree->stmt;
2179 PreparedStatement *pstmt;
2180
2181 pstmt = FetchPreparedStatement(stmt->name, false);
2182 if (pstmt)
2183 {
2184 errdetail("prepare: %s", pstmt->plansource->query_string);
2185 return 0;
2186 }
2187 }
2188 }
2189
2190 return 0;
2191 }
2192
2193 /*
2194 * errdetail_params
2195 *
2196 * Add an errdetail() line showing bind-parameter data, if available.
2197 */
2198 static int
errdetail_params(ParamListInfo params)2199 errdetail_params(ParamListInfo params)
2200 {
2201 /* We mustn't call user-defined I/O functions when in an aborted xact */
2202 if (params && params->numParams > 0 && !IsAbortedTransactionBlockState())
2203 {
2204 StringInfoData param_str;
2205 MemoryContext oldcontext;
2206 int paramno;
2207
2208 /* Make sure any trash is generated in MessageContext */
2209 oldcontext = MemoryContextSwitchTo(MessageContext);
2210
2211 initStringInfo(¶m_str);
2212
2213 for (paramno = 0; paramno < params->numParams; paramno++)
2214 {
2215 ParamExternData *prm = ¶ms->params[paramno];
2216 Oid typoutput;
2217 bool typisvarlena;
2218 char *pstring;
2219 char *p;
2220
2221 appendStringInfo(¶m_str, "%s$%d = ",
2222 paramno > 0 ? ", " : "",
2223 paramno + 1);
2224
2225 if (prm->isnull || !OidIsValid(prm->ptype))
2226 {
2227 appendStringInfoString(¶m_str, "NULL");
2228 continue;
2229 }
2230
2231 getTypeOutputInfo(prm->ptype, &typoutput, &typisvarlena);
2232
2233 pstring = OidOutputFunctionCall(typoutput, prm->value);
2234
2235 appendStringInfoCharMacro(¶m_str, '\'');
2236 for (p = pstring; *p; p++)
2237 {
2238 if (*p == '\'') /* double single quotes */
2239 appendStringInfoCharMacro(¶m_str, *p);
2240 appendStringInfoCharMacro(¶m_str, *p);
2241 }
2242 appendStringInfoCharMacro(¶m_str, '\'');
2243
2244 pfree(pstring);
2245 }
2246
2247 errdetail("parameters: %s", param_str.data);
2248
2249 pfree(param_str.data);
2250
2251 MemoryContextSwitchTo(oldcontext);
2252 }
2253
2254 return 0;
2255 }
2256
2257 /*
2258 * errdetail_abort
2259 *
2260 * Add an errdetail() line showing abort reason, if any.
2261 */
2262 static int
errdetail_abort(void)2263 errdetail_abort(void)
2264 {
2265 if (MyProc->recoveryConflictPending)
2266 errdetail("abort reason: recovery conflict");
2267
2268 return 0;
2269 }
2270
2271 /*
2272 * errdetail_recovery_conflict
2273 *
2274 * Add an errdetail() line showing conflict source.
2275 */
2276 static int
errdetail_recovery_conflict(void)2277 errdetail_recovery_conflict(void)
2278 {
2279 switch (RecoveryConflictReason)
2280 {
2281 case PROCSIG_RECOVERY_CONFLICT_BUFFERPIN:
2282 errdetail("User was holding shared buffer pin for too long.");
2283 break;
2284 case PROCSIG_RECOVERY_CONFLICT_LOCK:
2285 errdetail("User was holding a relation lock for too long.");
2286 break;
2287 case PROCSIG_RECOVERY_CONFLICT_TABLESPACE:
2288 errdetail("User was or might have been using tablespace that must be dropped.");
2289 break;
2290 case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT:
2291 errdetail("User query might have needed to see row versions that must be removed.");
2292 break;
2293 case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK:
2294 errdetail("User transaction caused buffer deadlock with recovery.");
2295 break;
2296 case PROCSIG_RECOVERY_CONFLICT_DATABASE:
2297 errdetail("User was connected to a database that must be dropped.");
2298 break;
2299 default:
2300 break;
2301 /* no errdetail */
2302 }
2303
2304 return 0;
2305 }
2306
2307 /*
2308 * exec_describe_statement_message
2309 *
2310 * Process a "Describe" message for a prepared statement
2311 */
2312 static void
exec_describe_statement_message(const char * stmt_name)2313 exec_describe_statement_message(const char *stmt_name)
2314 {
2315 CachedPlanSource *psrc;
2316 StringInfoData buf;
2317 int i;
2318
2319 /*
2320 * Start up a transaction command. (Note that this will normally change
2321 * current memory context.) Nothing happens if we are already in one.
2322 */
2323 start_xact_command();
2324
2325 /* Switch back to message context */
2326 MemoryContextSwitchTo(MessageContext);
2327
2328 /* Find prepared statement */
2329 if (stmt_name[0] != '\0')
2330 {
2331 PreparedStatement *pstmt;
2332
2333 pstmt = FetchPreparedStatement(stmt_name, true);
2334 psrc = pstmt->plansource;
2335 }
2336 else
2337 {
2338 /* special-case the unnamed statement */
2339 psrc = unnamed_stmt_psrc;
2340 if (!psrc)
2341 ereport(ERROR,
2342 (errcode(ERRCODE_UNDEFINED_PSTATEMENT),
2343 errmsg("unnamed prepared statement does not exist")));
2344 }
2345
2346 /* Prepared statements shouldn't have changeable result descs */
2347 Assert(psrc->fixed_result);
2348
2349 /*
2350 * If we are in aborted transaction state, we can't run
2351 * SendRowDescriptionMessage(), because that needs catalog accesses.
2352 * Hence, refuse to Describe statements that return data. (We shouldn't
2353 * just refuse all Describes, since that might break the ability of some
2354 * clients to issue COMMIT or ROLLBACK commands, if they use code that
2355 * blindly Describes whatever it does.) We can Describe parameters
2356 * without doing anything dangerous, so we don't restrict that.
2357 */
2358 if (IsAbortedTransactionBlockState() &&
2359 psrc->resultDesc)
2360 ereport(ERROR,
2361 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
2362 errmsg("current transaction is aborted, "
2363 "commands ignored until end of transaction block"),
2364 errdetail_abort()));
2365
2366 if (whereToSendOutput != DestRemote)
2367 return; /* can't actually do anything... */
2368
2369 /*
2370 * First describe the parameters...
2371 */
2372 pq_beginmessage(&buf, 't'); /* parameter description message type */
2373 pq_sendint(&buf, psrc->num_params, 2);
2374
2375 for (i = 0; i < psrc->num_params; i++)
2376 {
2377 Oid ptype = psrc->param_types[i];
2378
2379 pq_sendint(&buf, (int) ptype, 4);
2380 }
2381 pq_endmessage(&buf);
2382
2383 /*
2384 * Next send RowDescription or NoData to describe the result...
2385 */
2386 if (psrc->resultDesc)
2387 {
2388 List *tlist;
2389
2390 /* Get the plan's primary targetlist */
2391 tlist = CachedPlanGetTargetList(psrc, NULL);
2392
2393 SendRowDescriptionMessage(psrc->resultDesc, tlist, NULL);
2394 }
2395 else
2396 pq_putemptymessage('n'); /* NoData */
2397
2398 }
2399
2400 /*
2401 * exec_describe_portal_message
2402 *
2403 * Process a "Describe" message for a portal
2404 */
2405 static void
exec_describe_portal_message(const char * portal_name)2406 exec_describe_portal_message(const char *portal_name)
2407 {
2408 Portal portal;
2409
2410 /*
2411 * Start up a transaction command. (Note that this will normally change
2412 * current memory context.) Nothing happens if we are already in one.
2413 */
2414 start_xact_command();
2415
2416 /* Switch back to message context */
2417 MemoryContextSwitchTo(MessageContext);
2418
2419 portal = GetPortalByName(portal_name);
2420 if (!PortalIsValid(portal))
2421 ereport(ERROR,
2422 (errcode(ERRCODE_UNDEFINED_CURSOR),
2423 errmsg("portal \"%s\" does not exist", portal_name)));
2424
2425 /*
2426 * If we are in aborted transaction state, we can't run
2427 * SendRowDescriptionMessage(), because that needs catalog accesses.
2428 * Hence, refuse to Describe portals that return data. (We shouldn't just
2429 * refuse all Describes, since that might break the ability of some
2430 * clients to issue COMMIT or ROLLBACK commands, if they use code that
2431 * blindly Describes whatever it does.)
2432 */
2433 if (IsAbortedTransactionBlockState() &&
2434 portal->tupDesc)
2435 ereport(ERROR,
2436 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
2437 errmsg("current transaction is aborted, "
2438 "commands ignored until end of transaction block"),
2439 errdetail_abort()));
2440
2441 if (whereToSendOutput != DestRemote)
2442 return; /* can't actually do anything... */
2443
2444 if (portal->tupDesc)
2445 SendRowDescriptionMessage(portal->tupDesc,
2446 FetchPortalTargetList(portal),
2447 portal->formats);
2448 else
2449 pq_putemptymessage('n'); /* NoData */
2450 }
2451
2452
2453 /*
2454 * Convenience routines for starting/committing a single command.
2455 */
2456 static void
start_xact_command(void)2457 start_xact_command(void)
2458 {
2459 if (!xact_started)
2460 {
2461 StartTransactionCommand();
2462
2463 /* Set statement timeout running, if any */
2464 /* NB: this mustn't be enabled until we are within an xact */
2465 if (StatementTimeout > 0)
2466 enable_timeout_after(STATEMENT_TIMEOUT, StatementTimeout);
2467 else
2468 disable_timeout(STATEMENT_TIMEOUT, false);
2469
2470 xact_started = true;
2471 }
2472 }
2473
2474 static void
finish_xact_command(void)2475 finish_xact_command(void)
2476 {
2477 if (xact_started)
2478 {
2479 /* Cancel any active statement timeout before committing */
2480 disable_timeout(STATEMENT_TIMEOUT, false);
2481
2482 CommitTransactionCommand();
2483
2484 #ifdef MEMORY_CONTEXT_CHECKING
2485 /* Check all memory contexts that weren't freed during commit */
2486 /* (those that were, were checked before being deleted) */
2487 MemoryContextCheck(TopMemoryContext);
2488 #endif
2489
2490 #ifdef SHOW_MEMORY_STATS
2491 /* Print mem stats after each commit for leak tracking */
2492 MemoryContextStats(TopMemoryContext);
2493 #endif
2494
2495 xact_started = false;
2496 }
2497 }
2498
2499
2500 /*
2501 * Convenience routines for checking whether a statement is one of the
2502 * ones that we allow in transaction-aborted state.
2503 */
2504
2505 /* Test a bare parsetree */
2506 static bool
IsTransactionExitStmt(Node * parsetree)2507 IsTransactionExitStmt(Node *parsetree)
2508 {
2509 if (parsetree && IsA(parsetree, TransactionStmt))
2510 {
2511 TransactionStmt *stmt = (TransactionStmt *) parsetree;
2512
2513 if (stmt->kind == TRANS_STMT_COMMIT ||
2514 stmt->kind == TRANS_STMT_PREPARE ||
2515 stmt->kind == TRANS_STMT_ROLLBACK ||
2516 stmt->kind == TRANS_STMT_ROLLBACK_TO)
2517 return true;
2518 }
2519 return false;
2520 }
2521
2522 /* Test a list that contains PlannedStmt nodes */
2523 static bool
IsTransactionExitStmtList(List * pstmts)2524 IsTransactionExitStmtList(List *pstmts)
2525 {
2526 if (list_length(pstmts) == 1)
2527 {
2528 PlannedStmt *pstmt = linitial_node(PlannedStmt, pstmts);
2529
2530 if (pstmt->commandType == CMD_UTILITY &&
2531 IsTransactionExitStmt(pstmt->utilityStmt))
2532 return true;
2533 }
2534 return false;
2535 }
2536
2537 /* Test a list that contains PlannedStmt nodes */
2538 static bool
IsTransactionStmtList(List * pstmts)2539 IsTransactionStmtList(List *pstmts)
2540 {
2541 if (list_length(pstmts) == 1)
2542 {
2543 PlannedStmt *pstmt = linitial_node(PlannedStmt, pstmts);
2544
2545 if (pstmt->commandType == CMD_UTILITY &&
2546 IsA(pstmt->utilityStmt, TransactionStmt))
2547 return true;
2548 }
2549 return false;
2550 }
2551
2552 /* Release any existing unnamed prepared statement */
2553 static void
drop_unnamed_stmt(void)2554 drop_unnamed_stmt(void)
2555 {
2556 /* paranoia to avoid a dangling pointer in case of error */
2557 if (unnamed_stmt_psrc)
2558 {
2559 CachedPlanSource *psrc = unnamed_stmt_psrc;
2560
2561 unnamed_stmt_psrc = NULL;
2562 DropCachedPlan(psrc);
2563 }
2564 }
2565
2566
2567 /* --------------------------------
2568 * signal handler routines used in PostgresMain()
2569 * --------------------------------
2570 */
2571
2572 /*
2573 * quickdie() occurs when signalled SIGQUIT by the postmaster.
2574 *
2575 * Some backend has bought the farm,
2576 * so we need to stop what we're doing and exit.
2577 */
2578 void
quickdie(SIGNAL_ARGS)2579 quickdie(SIGNAL_ARGS)
2580 {
2581 sigaddset(&BlockSig, SIGQUIT); /* prevent nested calls */
2582 PG_SETMASK(&BlockSig);
2583
2584 /*
2585 * Prevent interrupts while exiting; though we just blocked signals that
2586 * would queue new interrupts, one may have been pending. We don't want a
2587 * quickdie() downgraded to a mere query cancel.
2588 */
2589 HOLD_INTERRUPTS();
2590
2591 /*
2592 * If we're aborting out of client auth, don't risk trying to send
2593 * anything to the client; we will likely violate the protocol, not to
2594 * mention that we may have interrupted the guts of OpenSSL or some
2595 * authentication library.
2596 */
2597 if (ClientAuthInProgress && whereToSendOutput == DestRemote)
2598 whereToSendOutput = DestNone;
2599
2600 /*
2601 * Notify the client before exiting, to give a clue on what happened.
2602 *
2603 * It's dubious to call ereport() from a signal handler. It is certainly
2604 * not async-signal safe. But it seems better to try, than to disconnect
2605 * abruptly and leave the client wondering what happened. It's remotely
2606 * possible that we crash or hang while trying to send the message, but
2607 * receiving a SIGQUIT is a sign that something has already gone badly
2608 * wrong, so there's not much to lose. Assuming the postmaster is still
2609 * running, it will SIGKILL us soon if we get stuck for some reason.
2610 *
2611 * Ideally this should be ereport(FATAL), but then we'd not get control
2612 * back...
2613 */
2614 ereport(WARNING,
2615 (errcode(ERRCODE_CRASH_SHUTDOWN),
2616 errmsg("terminating connection because of crash of another server process"),
2617 errdetail("The postmaster has commanded this server process to roll back"
2618 " the current transaction and exit, because another"
2619 " server process exited abnormally and possibly corrupted"
2620 " shared memory."),
2621 errhint("In a moment you should be able to reconnect to the"
2622 " database and repeat your command.")));
2623
2624 /*
2625 * We DO NOT want to run proc_exit() or atexit() callbacks -- we're here
2626 * because shared memory may be corrupted, so we don't want to try to
2627 * clean up our transaction. Just nail the windows shut and get out of
2628 * town. The callbacks wouldn't be safe to run from a signal handler,
2629 * anyway.
2630 *
2631 * Note we do _exit(2) not _exit(0). This is to force the postmaster into
2632 * a system reset cycle if someone sends a manual SIGQUIT to a random
2633 * backend. This is necessary precisely because we don't clean up our
2634 * shared memory state. (The "dead man switch" mechanism in pmsignal.c
2635 * should ensure the postmaster sees this as a crash, too, but no harm in
2636 * being doubly sure.)
2637 */
2638 _exit(2);
2639 }
2640
2641 /*
2642 * Shutdown signal from postmaster: abort transaction and exit
2643 * at soonest convenient time
2644 */
2645 void
die(SIGNAL_ARGS)2646 die(SIGNAL_ARGS)
2647 {
2648 int save_errno = errno;
2649
2650 /* Don't joggle the elbow of proc_exit */
2651 if (!proc_exit_inprogress)
2652 {
2653 InterruptPending = true;
2654 ProcDiePending = true;
2655 }
2656
2657 /* If we're still here, waken anything waiting on the process latch */
2658 SetLatch(MyLatch);
2659
2660 /*
2661 * If we're in single user mode, we want to quit immediately - we can't
2662 * rely on latches as they wouldn't work when stdin/stdout is a file.
2663 * Rather ugly, but it's unlikely to be worthwhile to invest much more
2664 * effort just for the benefit of single user mode.
2665 */
2666 if (DoingCommandRead && whereToSendOutput != DestRemote)
2667 ProcessInterrupts();
2668
2669 errno = save_errno;
2670 }
2671
2672 /*
2673 * Query-cancel signal from postmaster: abort current transaction
2674 * at soonest convenient time
2675 */
2676 void
StatementCancelHandler(SIGNAL_ARGS)2677 StatementCancelHandler(SIGNAL_ARGS)
2678 {
2679 int save_errno = errno;
2680
2681 /*
2682 * Don't joggle the elbow of proc_exit
2683 */
2684 if (!proc_exit_inprogress)
2685 {
2686 InterruptPending = true;
2687 QueryCancelPending = true;
2688 }
2689
2690 /* If we're still here, waken anything waiting on the process latch */
2691 SetLatch(MyLatch);
2692
2693 errno = save_errno;
2694 }
2695
2696 /* signal handler for floating point exception */
2697 void
FloatExceptionHandler(SIGNAL_ARGS)2698 FloatExceptionHandler(SIGNAL_ARGS)
2699 {
2700 /* We're not returning, so no need to save errno */
2701 ereport(ERROR,
2702 (errcode(ERRCODE_FLOATING_POINT_EXCEPTION),
2703 errmsg("floating-point exception"),
2704 errdetail("An invalid floating-point operation was signaled. "
2705 "This probably means an out-of-range result or an "
2706 "invalid operation, such as division by zero.")));
2707 }
2708
2709 /*
2710 * SIGHUP: set flag to re-read config file at next convenient time.
2711 *
2712 * Sets the ConfigReloadPending flag, which should be checked at convenient
2713 * places inside main loops. (Better than doing the reading in the signal
2714 * handler, ey?)
2715 */
2716 void
PostgresSigHupHandler(SIGNAL_ARGS)2717 PostgresSigHupHandler(SIGNAL_ARGS)
2718 {
2719 int save_errno = errno;
2720
2721 ConfigReloadPending = true;
2722 SetLatch(MyLatch);
2723
2724 errno = save_errno;
2725 }
2726
2727 /*
2728 * RecoveryConflictInterrupt: out-of-line portion of recovery conflict
2729 * handling following receipt of SIGUSR1. Designed to be similar to die()
2730 * and StatementCancelHandler(). Called only by a normal user backend
2731 * that begins a transaction during recovery.
2732 */
2733 void
RecoveryConflictInterrupt(ProcSignalReason reason)2734 RecoveryConflictInterrupt(ProcSignalReason reason)
2735 {
2736 int save_errno = errno;
2737
2738 /*
2739 * Don't joggle the elbow of proc_exit
2740 */
2741 if (!proc_exit_inprogress)
2742 {
2743 RecoveryConflictReason = reason;
2744 switch (reason)
2745 {
2746 case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK:
2747
2748 /*
2749 * If we aren't waiting for a lock we can never deadlock.
2750 */
2751 if (!IsWaitingForLock())
2752 return;
2753
2754 /* Intentional drop through to check wait for pin */
2755
2756 case PROCSIG_RECOVERY_CONFLICT_BUFFERPIN:
2757
2758 /*
2759 * If PROCSIG_RECOVERY_CONFLICT_BUFFERPIN is requested but we
2760 * aren't blocking the Startup process there is nothing more
2761 * to do.
2762 *
2763 * When PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK is
2764 * requested, if we're waiting for locks and the startup
2765 * process is not waiting for buffer pin (i.e., also waiting
2766 * for locks), we set the flag so that ProcSleep() will check
2767 * for deadlocks.
2768 */
2769 if (!HoldingBufferPinThatDelaysRecovery())
2770 {
2771 if (reason == PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK &&
2772 GetStartupBufferPinWaitBufId() < 0)
2773 CheckDeadLockAlert();
2774 return;
2775 }
2776
2777 MyProc->recoveryConflictPending = true;
2778
2779 /* Intentional drop through to error handling */
2780
2781 case PROCSIG_RECOVERY_CONFLICT_LOCK:
2782 case PROCSIG_RECOVERY_CONFLICT_TABLESPACE:
2783 case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT:
2784
2785 /*
2786 * If we aren't in a transaction any longer then ignore.
2787 */
2788 if (!IsTransactionOrTransactionBlock())
2789 return;
2790
2791 /*
2792 * If we can abort just the current subtransaction then we are
2793 * OK to throw an ERROR to resolve the conflict. Otherwise
2794 * drop through to the FATAL case.
2795 *
2796 * XXX other times that we can throw just an ERROR *may* be
2797 * PROCSIG_RECOVERY_CONFLICT_LOCK if no locks are held in
2798 * parent transactions
2799 *
2800 * PROCSIG_RECOVERY_CONFLICT_SNAPSHOT if no snapshots are held
2801 * by parent transactions and the transaction is not
2802 * transaction-snapshot mode
2803 *
2804 * PROCSIG_RECOVERY_CONFLICT_TABLESPACE if no temp files or
2805 * cursors open in parent transactions
2806 */
2807 if (!IsSubTransaction())
2808 {
2809 /*
2810 * If we already aborted then we no longer need to cancel.
2811 * We do this here since we do not wish to ignore aborted
2812 * subtransactions, which must cause FATAL, currently.
2813 */
2814 if (IsAbortedTransactionBlockState())
2815 return;
2816
2817 RecoveryConflictPending = true;
2818 QueryCancelPending = true;
2819 InterruptPending = true;
2820 break;
2821 }
2822
2823 /* Intentional drop through to session cancel */
2824
2825 case PROCSIG_RECOVERY_CONFLICT_DATABASE:
2826 RecoveryConflictPending = true;
2827 ProcDiePending = true;
2828 InterruptPending = true;
2829 break;
2830
2831 default:
2832 elog(FATAL, "unrecognized conflict mode: %d",
2833 (int) reason);
2834 }
2835
2836 Assert(RecoveryConflictPending && (QueryCancelPending || ProcDiePending));
2837
2838 /*
2839 * All conflicts apart from database cause dynamic errors where the
2840 * command or transaction can be retried at a later point with some
2841 * potential for success. No need to reset this, since non-retryable
2842 * conflict errors are currently FATAL.
2843 */
2844 if (reason == PROCSIG_RECOVERY_CONFLICT_DATABASE)
2845 RecoveryConflictRetryable = false;
2846 }
2847
2848 /*
2849 * Set the process latch. This function essentially emulates signal
2850 * handlers like die() and StatementCancelHandler() and it seems prudent
2851 * to behave similarly as they do.
2852 */
2853 SetLatch(MyLatch);
2854
2855 errno = save_errno;
2856 }
2857
2858 /*
2859 * ProcessInterrupts: out-of-line portion of CHECK_FOR_INTERRUPTS() macro
2860 *
2861 * If an interrupt condition is pending, and it's safe to service it,
2862 * then clear the flag and accept the interrupt. Called only when
2863 * InterruptPending is true.
2864 *
2865 * Note: if INTERRUPTS_CAN_BE_PROCESSED() is true, then ProcessInterrupts
2866 * is guaranteed to clear the InterruptPending flag before returning.
2867 * (This is not the same as guaranteeing that it's still clear when we
2868 * return; another interrupt could have arrived. But we promise that
2869 * any pre-existing one will have been serviced.)
2870 */
2871 void
ProcessInterrupts(void)2872 ProcessInterrupts(void)
2873 {
2874 /* OK to accept any interrupts now? */
2875 if (InterruptHoldoffCount != 0 || CritSectionCount != 0)
2876 return;
2877 InterruptPending = false;
2878
2879 if (ProcDiePending)
2880 {
2881 ProcDiePending = false;
2882 QueryCancelPending = false; /* ProcDie trumps QueryCancel */
2883 LockErrorCleanup();
2884 /* As in quickdie, don't risk sending to client during auth */
2885 if (ClientAuthInProgress && whereToSendOutput == DestRemote)
2886 whereToSendOutput = DestNone;
2887 if (ClientAuthInProgress)
2888 ereport(FATAL,
2889 (errcode(ERRCODE_QUERY_CANCELED),
2890 errmsg("canceling authentication due to timeout")));
2891 else if (IsAutoVacuumWorkerProcess())
2892 ereport(FATAL,
2893 (errcode(ERRCODE_ADMIN_SHUTDOWN),
2894 errmsg("terminating autovacuum process due to administrator command")));
2895 else if (IsLogicalWorker())
2896 ereport(FATAL,
2897 (errcode(ERRCODE_ADMIN_SHUTDOWN),
2898 errmsg("terminating logical replication worker due to administrator command")));
2899 else if (IsLogicalLauncher())
2900 {
2901 ereport(DEBUG1,
2902 (errmsg("logical replication launcher shutting down")));
2903
2904 /*
2905 * The logical replication launcher can be stopped at any time.
2906 * Use exit status 1 so the background worker is restarted.
2907 */
2908 proc_exit(1);
2909 }
2910 else if (RecoveryConflictPending && RecoveryConflictRetryable)
2911 {
2912 pgstat_report_recovery_conflict(RecoveryConflictReason);
2913 ereport(FATAL,
2914 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
2915 errmsg("terminating connection due to conflict with recovery"),
2916 errdetail_recovery_conflict()));
2917 }
2918 else if (RecoveryConflictPending)
2919 {
2920 /* Currently there is only one non-retryable recovery conflict */
2921 Assert(RecoveryConflictReason == PROCSIG_RECOVERY_CONFLICT_DATABASE);
2922 pgstat_report_recovery_conflict(RecoveryConflictReason);
2923 ereport(FATAL,
2924 (errcode(ERRCODE_DATABASE_DROPPED),
2925 errmsg("terminating connection due to conflict with recovery"),
2926 errdetail_recovery_conflict()));
2927 }
2928 else
2929 ereport(FATAL,
2930 (errcode(ERRCODE_ADMIN_SHUTDOWN),
2931 errmsg("terminating connection due to administrator command")));
2932 }
2933 if (ClientConnectionLost)
2934 {
2935 QueryCancelPending = false; /* lost connection trumps QueryCancel */
2936 LockErrorCleanup();
2937 /* don't send to client, we already know the connection to be dead. */
2938 whereToSendOutput = DestNone;
2939 ereport(FATAL,
2940 (errcode(ERRCODE_CONNECTION_FAILURE),
2941 errmsg("connection to client lost")));
2942 }
2943
2944 /*
2945 * If a recovery conflict happens while we are waiting for input from the
2946 * client, the client is presumably just sitting idle in a transaction,
2947 * preventing recovery from making progress. Terminate the connection to
2948 * dislodge it.
2949 */
2950 if (RecoveryConflictPending && DoingCommandRead)
2951 {
2952 QueryCancelPending = false; /* this trumps QueryCancel */
2953 RecoveryConflictPending = false;
2954 LockErrorCleanup();
2955 pgstat_report_recovery_conflict(RecoveryConflictReason);
2956 ereport(FATAL,
2957 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
2958 errmsg("terminating connection due to conflict with recovery"),
2959 errdetail_recovery_conflict(),
2960 errhint("In a moment you should be able to reconnect to the"
2961 " database and repeat your command.")));
2962 }
2963
2964 /*
2965 * Don't allow query cancel interrupts while reading input from the
2966 * client, because we might lose sync in the FE/BE protocol. (Die
2967 * interrupts are OK, because we won't read any further messages from
2968 * the client in that case.)
2969 */
2970 if (QueryCancelPending && QueryCancelHoldoffCount != 0)
2971 {
2972 /*
2973 * Re-arm InterruptPending so that we process the cancel request as
2974 * soon as we're done reading the message. (XXX this is seriously
2975 * ugly: it complicates INTERRUPTS_CAN_BE_PROCESSED(), and it means we
2976 * can't use that macro directly as the initial test in this function,
2977 * meaning that this code also creates opportunities for other bugs to
2978 * appear.)
2979 */
2980 InterruptPending = true;
2981 }
2982 else if (QueryCancelPending)
2983 {
2984 bool lock_timeout_occurred;
2985 bool stmt_timeout_occurred;
2986
2987 QueryCancelPending = false;
2988
2989 /*
2990 * If LOCK_TIMEOUT and STATEMENT_TIMEOUT indicators are both set, we
2991 * need to clear both, so always fetch both.
2992 */
2993 lock_timeout_occurred = get_timeout_indicator(LOCK_TIMEOUT, true);
2994 stmt_timeout_occurred = get_timeout_indicator(STATEMENT_TIMEOUT, true);
2995
2996 /*
2997 * If both were set, we want to report whichever timeout completed
2998 * earlier; this ensures consistent behavior if the machine is slow
2999 * enough that the second timeout triggers before we get here. A tie
3000 * is arbitrarily broken in favor of reporting a lock timeout.
3001 */
3002 if (lock_timeout_occurred && stmt_timeout_occurred &&
3003 get_timeout_finish_time(STATEMENT_TIMEOUT) < get_timeout_finish_time(LOCK_TIMEOUT))
3004 lock_timeout_occurred = false; /* report stmt timeout */
3005
3006 if (lock_timeout_occurred)
3007 {
3008 LockErrorCleanup();
3009 ereport(ERROR,
3010 (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
3011 errmsg("canceling statement due to lock timeout")));
3012 }
3013 if (stmt_timeout_occurred)
3014 {
3015 LockErrorCleanup();
3016 ereport(ERROR,
3017 (errcode(ERRCODE_QUERY_CANCELED),
3018 errmsg("canceling statement due to statement timeout")));
3019 }
3020 if (IsAutoVacuumWorkerProcess())
3021 {
3022 LockErrorCleanup();
3023 ereport(ERROR,
3024 (errcode(ERRCODE_QUERY_CANCELED),
3025 errmsg("canceling autovacuum task")));
3026 }
3027 if (RecoveryConflictPending)
3028 {
3029 RecoveryConflictPending = false;
3030 LockErrorCleanup();
3031 pgstat_report_recovery_conflict(RecoveryConflictReason);
3032 ereport(ERROR,
3033 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
3034 errmsg("canceling statement due to conflict with recovery"),
3035 errdetail_recovery_conflict()));
3036 }
3037
3038 /*
3039 * If we are reading a command from the client, just ignore the cancel
3040 * request --- sending an extra error message won't accomplish
3041 * anything. Otherwise, go ahead and throw the error.
3042 */
3043 if (!DoingCommandRead)
3044 {
3045 LockErrorCleanup();
3046 ereport(ERROR,
3047 (errcode(ERRCODE_QUERY_CANCELED),
3048 errmsg("canceling statement due to user request")));
3049 }
3050 }
3051
3052 if (IdleInTransactionSessionTimeoutPending)
3053 {
3054 /* Has the timeout setting changed since last we looked? */
3055 if (IdleInTransactionSessionTimeout > 0)
3056 ereport(FATAL,
3057 (errcode(ERRCODE_IDLE_IN_TRANSACTION_SESSION_TIMEOUT),
3058 errmsg("terminating connection due to idle-in-transaction timeout")));
3059 else
3060 IdleInTransactionSessionTimeoutPending = false;
3061
3062 }
3063
3064 if (ParallelMessagePending)
3065 HandleParallelMessages();
3066 }
3067
3068
3069 /*
3070 * IA64-specific code to fetch the AR.BSP register for stack depth checks.
3071 *
3072 * We currently support gcc, icc, and HP-UX's native compiler here.
3073 *
3074 * Note: while icc accepts gcc asm blocks on x86[_64], this is not true on
3075 * ia64 (at least not in icc versions before 12.x). So we have to carry a
3076 * separate implementation for it.
3077 */
3078 #if defined(__ia64__) || defined(__ia64)
3079
3080 #if defined(__hpux) && !defined(__GNUC__) && !defined(__INTEL_COMPILER)
3081 /* Assume it's HP-UX native compiler */
3082 #include <ia64/sys/inline.h>
3083 #define ia64_get_bsp() ((char *) (_Asm_mov_from_ar(_AREG_BSP, _NO_FENCE)))
3084 #elif defined(__INTEL_COMPILER)
3085 /* icc */
3086 #include <asm/ia64regs.h>
3087 #define ia64_get_bsp() ((char *) __getReg(_IA64_REG_AR_BSP))
3088 #else
3089 /* gcc */
3090 static __inline__ char *
ia64_get_bsp(void)3091 ia64_get_bsp(void)
3092 {
3093 char *ret;
3094
3095 /* the ;; is a "stop", seems to be required before fetching BSP */
3096 __asm__ __volatile__(
3097 ";;\n"
3098 " mov %0=ar.bsp \n"
3099 : "=r"(ret));
3100
3101 return ret;
3102 }
3103 #endif
3104 #endif /* IA64 */
3105
3106
3107 /*
3108 * set_stack_base: set up reference point for stack depth checking
3109 *
3110 * Returns the old reference point, if any.
3111 */
3112 pg_stack_base_t
set_stack_base(void)3113 set_stack_base(void)
3114 {
3115 char stack_base;
3116 pg_stack_base_t old;
3117
3118 #if defined(__ia64__) || defined(__ia64)
3119 old.stack_base_ptr = stack_base_ptr;
3120 old.register_stack_base_ptr = register_stack_base_ptr;
3121 #else
3122 old = stack_base_ptr;
3123 #endif
3124
3125 /* Set up reference point for stack depth checking */
3126 stack_base_ptr = &stack_base;
3127 #if defined(__ia64__) || defined(__ia64)
3128 register_stack_base_ptr = ia64_get_bsp();
3129 #endif
3130
3131 return old;
3132 }
3133
3134 /*
3135 * restore_stack_base: restore reference point for stack depth checking
3136 *
3137 * This can be used after set_stack_base() to restore the old value. This
3138 * is currently only used in PL/Java. When PL/Java calls a backend function
3139 * from different thread, the thread's stack is at a different location than
3140 * the main thread's stack, so it sets the base pointer before the call, and
3141 * restores it afterwards.
3142 */
3143 void
restore_stack_base(pg_stack_base_t base)3144 restore_stack_base(pg_stack_base_t base)
3145 {
3146 #if defined(__ia64__) || defined(__ia64)
3147 stack_base_ptr = base.stack_base_ptr;
3148 register_stack_base_ptr = base.register_stack_base_ptr;
3149 #else
3150 stack_base_ptr = base;
3151 #endif
3152 }
3153
3154 /*
3155 * check_stack_depth/stack_is_too_deep: check for excessively deep recursion
3156 *
3157 * This should be called someplace in any recursive routine that might possibly
3158 * recurse deep enough to overflow the stack. Most Unixen treat stack
3159 * overflow as an unrecoverable SIGSEGV, so we want to error out ourselves
3160 * before hitting the hardware limit.
3161 *
3162 * check_stack_depth() just throws an error summarily. stack_is_too_deep()
3163 * can be used by code that wants to handle the error condition itself.
3164 */
3165 void
check_stack_depth(void)3166 check_stack_depth(void)
3167 {
3168 if (stack_is_too_deep())
3169 {
3170 ereport(ERROR,
3171 (errcode(ERRCODE_STATEMENT_TOO_COMPLEX),
3172 errmsg("stack depth limit exceeded"),
3173 errhint("Increase the configuration parameter \"max_stack_depth\" (currently %dkB), "
3174 "after ensuring the platform's stack depth limit is adequate.",
3175 max_stack_depth)));
3176 }
3177 }
3178
3179 bool
stack_is_too_deep(void)3180 stack_is_too_deep(void)
3181 {
3182 char stack_top_loc;
3183 long stack_depth;
3184
3185 /*
3186 * Compute distance from reference point to my local variables
3187 */
3188 stack_depth = (long) (stack_base_ptr - &stack_top_loc);
3189
3190 /*
3191 * Take abs value, since stacks grow up on some machines, down on others
3192 */
3193 if (stack_depth < 0)
3194 stack_depth = -stack_depth;
3195
3196 /*
3197 * Trouble?
3198 *
3199 * The test on stack_base_ptr prevents us from erroring out if called
3200 * during process setup or in a non-backend process. Logically it should
3201 * be done first, but putting it here avoids wasting cycles during normal
3202 * cases.
3203 */
3204 if (stack_depth > max_stack_depth_bytes &&
3205 stack_base_ptr != NULL)
3206 return true;
3207
3208 /*
3209 * On IA64 there is a separate "register" stack that requires its own
3210 * independent check. For this, we have to measure the change in the
3211 * "BSP" pointer from PostgresMain to here. Logic is just as above,
3212 * except that we know IA64's register stack grows up.
3213 *
3214 * Note we assume that the same max_stack_depth applies to both stacks.
3215 */
3216 #if defined(__ia64__) || defined(__ia64)
3217 stack_depth = (long) (ia64_get_bsp() - register_stack_base_ptr);
3218
3219 if (stack_depth > max_stack_depth_bytes &&
3220 register_stack_base_ptr != NULL)
3221 return true;
3222 #endif /* IA64 */
3223
3224 return false;
3225 }
3226
3227 /* GUC check hook for max_stack_depth */
3228 bool
check_max_stack_depth(int * newval,void ** extra,GucSource source)3229 check_max_stack_depth(int *newval, void **extra, GucSource source)
3230 {
3231 long newval_bytes = *newval * 1024L;
3232 long stack_rlimit = get_stack_depth_rlimit();
3233
3234 if (stack_rlimit > 0 && newval_bytes > stack_rlimit - STACK_DEPTH_SLOP)
3235 {
3236 GUC_check_errdetail("\"max_stack_depth\" must not exceed %ldkB.",
3237 (stack_rlimit - STACK_DEPTH_SLOP) / 1024L);
3238 GUC_check_errhint("Increase the platform's stack depth limit via \"ulimit -s\" or local equivalent.");
3239 return false;
3240 }
3241 return true;
3242 }
3243
3244 /* GUC assign hook for max_stack_depth */
3245 void
assign_max_stack_depth(int newval,void * extra)3246 assign_max_stack_depth(int newval, void *extra)
3247 {
3248 long newval_bytes = newval * 1024L;
3249
3250 max_stack_depth_bytes = newval_bytes;
3251 }
3252
3253
3254 /*
3255 * set_debug_options --- apply "-d N" command line option
3256 *
3257 * -d is not quite the same as setting log_min_messages because it enables
3258 * other output options.
3259 */
3260 void
set_debug_options(int debug_flag,GucContext context,GucSource source)3261 set_debug_options(int debug_flag, GucContext context, GucSource source)
3262 {
3263 if (debug_flag > 0)
3264 {
3265 char debugstr[64];
3266
3267 sprintf(debugstr, "debug%d", debug_flag);
3268 SetConfigOption("log_min_messages", debugstr, context, source);
3269 }
3270 else
3271 SetConfigOption("log_min_messages", "notice", context, source);
3272
3273 if (debug_flag >= 1 && context == PGC_POSTMASTER)
3274 {
3275 SetConfigOption("log_connections", "true", context, source);
3276 SetConfigOption("log_disconnections", "true", context, source);
3277 }
3278 if (debug_flag >= 2)
3279 SetConfigOption("log_statement", "all", context, source);
3280 if (debug_flag >= 3)
3281 SetConfigOption("debug_print_parse", "true", context, source);
3282 if (debug_flag >= 4)
3283 SetConfigOption("debug_print_plan", "true", context, source);
3284 if (debug_flag >= 5)
3285 SetConfigOption("debug_print_rewritten", "true", context, source);
3286 }
3287
3288
3289 bool
set_plan_disabling_options(const char * arg,GucContext context,GucSource source)3290 set_plan_disabling_options(const char *arg, GucContext context, GucSource source)
3291 {
3292 const char *tmp = NULL;
3293
3294 switch (arg[0])
3295 {
3296 case 's': /* seqscan */
3297 tmp = "enable_seqscan";
3298 break;
3299 case 'i': /* indexscan */
3300 tmp = "enable_indexscan";
3301 break;
3302 case 'o': /* indexonlyscan */
3303 tmp = "enable_indexonlyscan";
3304 break;
3305 case 'b': /* bitmapscan */
3306 tmp = "enable_bitmapscan";
3307 break;
3308 case 't': /* tidscan */
3309 tmp = "enable_tidscan";
3310 break;
3311 case 'n': /* nestloop */
3312 tmp = "enable_nestloop";
3313 break;
3314 case 'm': /* mergejoin */
3315 tmp = "enable_mergejoin";
3316 break;
3317 case 'h': /* hashjoin */
3318 tmp = "enable_hashjoin";
3319 break;
3320 }
3321 if (tmp)
3322 {
3323 SetConfigOption(tmp, "false", context, source);
3324 return true;
3325 }
3326 else
3327 return false;
3328 }
3329
3330
3331 const char *
get_stats_option_name(const char * arg)3332 get_stats_option_name(const char *arg)
3333 {
3334 switch (arg[0])
3335 {
3336 case 'p':
3337 if (optarg[1] == 'a') /* "parser" */
3338 return "log_parser_stats";
3339 else if (optarg[1] == 'l') /* "planner" */
3340 return "log_planner_stats";
3341 break;
3342
3343 case 'e': /* "executor" */
3344 return "log_executor_stats";
3345 break;
3346 }
3347
3348 return NULL;
3349 }
3350
3351
3352 /* ----------------------------------------------------------------
3353 * process_postgres_switches
3354 * Parse command line arguments for PostgresMain
3355 *
3356 * This is called twice, once for the "secure" options coming from the
3357 * postmaster or command line, and once for the "insecure" options coming
3358 * from the client's startup packet. The latter have the same syntax but
3359 * may be restricted in what they can do.
3360 *
3361 * argv[0] is ignored in either case (it's assumed to be the program name).
3362 *
3363 * ctx is PGC_POSTMASTER for secure options, PGC_BACKEND for insecure options
3364 * coming from the client, or PGC_SU_BACKEND for insecure options coming from
3365 * a superuser client.
3366 *
3367 * If a database name is present in the command line arguments, it's
3368 * returned into *dbname (this is allowed only if *dbname is initially NULL).
3369 * ----------------------------------------------------------------
3370 */
3371 void
process_postgres_switches(int argc,char * argv[],GucContext ctx,const char ** dbname)3372 process_postgres_switches(int argc, char *argv[], GucContext ctx,
3373 const char **dbname)
3374 {
3375 bool secure = (ctx == PGC_POSTMASTER);
3376 int errs = 0;
3377 GucSource gucsource;
3378 int flag;
3379
3380 if (secure)
3381 {
3382 gucsource = PGC_S_ARGV; /* switches came from command line */
3383
3384 /* Ignore the initial --single argument, if present */
3385 if (argc > 1 && strcmp(argv[1], "--single") == 0)
3386 {
3387 argv++;
3388 argc--;
3389 }
3390 }
3391 else
3392 {
3393 gucsource = PGC_S_CLIENT; /* switches came from client */
3394 }
3395
3396 #ifdef HAVE_INT_OPTERR
3397
3398 /*
3399 * Turn this off because it's either printed to stderr and not the log
3400 * where we'd want it, or argv[0] is now "--single", which would make for
3401 * a weird error message. We print our own error message below.
3402 */
3403 opterr = 0;
3404 #endif
3405
3406 /*
3407 * Parse command-line options. CAUTION: keep this in sync with
3408 * postmaster/postmaster.c (the option sets should not conflict) and with
3409 * the common help() function in main/main.c.
3410 */
3411 while ((flag = getopt(argc, argv, "B:bc:C:D:d:EeFf:h:ijk:lN:nOo:Pp:r:S:sTt:v:W:-:")) != -1)
3412 {
3413 switch (flag)
3414 {
3415 case 'B':
3416 SetConfigOption("shared_buffers", optarg, ctx, gucsource);
3417 break;
3418
3419 case 'b':
3420 /* Undocumented flag used for binary upgrades */
3421 if (secure)
3422 IsBinaryUpgrade = true;
3423 break;
3424
3425 case 'C':
3426 /* ignored for consistency with the postmaster */
3427 break;
3428
3429 case 'D':
3430 if (secure)
3431 userDoption = strdup(optarg);
3432 break;
3433
3434 case 'd':
3435 set_debug_options(atoi(optarg), ctx, gucsource);
3436 break;
3437
3438 case 'E':
3439 if (secure)
3440 EchoQuery = true;
3441 break;
3442
3443 case 'e':
3444 SetConfigOption("datestyle", "euro", ctx, gucsource);
3445 break;
3446
3447 case 'F':
3448 SetConfigOption("fsync", "false", ctx, gucsource);
3449 break;
3450
3451 case 'f':
3452 if (!set_plan_disabling_options(optarg, ctx, gucsource))
3453 errs++;
3454 break;
3455
3456 case 'h':
3457 SetConfigOption("listen_addresses", optarg, ctx, gucsource);
3458 break;
3459
3460 case 'i':
3461 SetConfigOption("listen_addresses", "*", ctx, gucsource);
3462 break;
3463
3464 case 'j':
3465 if (secure)
3466 UseSemiNewlineNewline = true;
3467 break;
3468
3469 case 'k':
3470 SetConfigOption("unix_socket_directories", optarg, ctx, gucsource);
3471 break;
3472
3473 case 'l':
3474 SetConfigOption("ssl", "true", ctx, gucsource);
3475 break;
3476
3477 case 'N':
3478 SetConfigOption("max_connections", optarg, ctx, gucsource);
3479 break;
3480
3481 case 'n':
3482 /* ignored for consistency with postmaster */
3483 break;
3484
3485 case 'O':
3486 SetConfigOption("allow_system_table_mods", "true", ctx, gucsource);
3487 break;
3488
3489 case 'o':
3490 errs++;
3491 break;
3492
3493 case 'P':
3494 SetConfigOption("ignore_system_indexes", "true", ctx, gucsource);
3495 break;
3496
3497 case 'p':
3498 SetConfigOption("port", optarg, ctx, gucsource);
3499 break;
3500
3501 case 'r':
3502 /* send output (stdout and stderr) to the given file */
3503 if (secure)
3504 strlcpy(OutputFileName, optarg, MAXPGPATH);
3505 break;
3506
3507 case 'S':
3508 SetConfigOption("work_mem", optarg, ctx, gucsource);
3509 break;
3510
3511 case 's':
3512 SetConfigOption("log_statement_stats", "true", ctx, gucsource);
3513 break;
3514
3515 case 'T':
3516 /* ignored for consistency with the postmaster */
3517 break;
3518
3519 case 't':
3520 {
3521 const char *tmp = get_stats_option_name(optarg);
3522
3523 if (tmp)
3524 SetConfigOption(tmp, "true", ctx, gucsource);
3525 else
3526 errs++;
3527 break;
3528 }
3529
3530 case 'v':
3531
3532 /*
3533 * -v is no longer used in normal operation, since
3534 * FrontendProtocol is already set before we get here. We keep
3535 * the switch only for possible use in standalone operation,
3536 * in case we ever support using normal FE/BE protocol with a
3537 * standalone backend.
3538 */
3539 if (secure)
3540 FrontendProtocol = (ProtocolVersion) atoi(optarg);
3541 break;
3542
3543 case 'W':
3544 SetConfigOption("post_auth_delay", optarg, ctx, gucsource);
3545 break;
3546
3547 case 'c':
3548 case '-':
3549 {
3550 char *name,
3551 *value;
3552
3553 ParseLongOption(optarg, &name, &value);
3554 if (!value)
3555 {
3556 if (flag == '-')
3557 ereport(ERROR,
3558 (errcode(ERRCODE_SYNTAX_ERROR),
3559 errmsg("--%s requires a value",
3560 optarg)));
3561 else
3562 ereport(ERROR,
3563 (errcode(ERRCODE_SYNTAX_ERROR),
3564 errmsg("-c %s requires a value",
3565 optarg)));
3566 }
3567 SetConfigOption(name, value, ctx, gucsource);
3568 free(name);
3569 if (value)
3570 free(value);
3571 break;
3572 }
3573
3574 default:
3575 errs++;
3576 break;
3577 }
3578
3579 if (errs)
3580 break;
3581 }
3582
3583 /*
3584 * Optional database name should be there only if *dbname is NULL.
3585 */
3586 if (!errs && dbname && *dbname == NULL && argc - optind >= 1)
3587 *dbname = strdup(argv[optind++]);
3588
3589 if (errs || argc != optind)
3590 {
3591 if (errs)
3592 optind--; /* complain about the previous argument */
3593
3594 /* spell the error message a bit differently depending on context */
3595 if (IsUnderPostmaster)
3596 ereport(FATAL,
3597 (errcode(ERRCODE_SYNTAX_ERROR),
3598 errmsg("invalid command-line argument for server process: %s", argv[optind]),
3599 errhint("Try \"%s --help\" for more information.", progname)));
3600 else
3601 ereport(FATAL,
3602 (errcode(ERRCODE_SYNTAX_ERROR),
3603 errmsg("%s: invalid command-line argument: %s",
3604 progname, argv[optind]),
3605 errhint("Try \"%s --help\" for more information.", progname)));
3606 }
3607
3608 /*
3609 * Reset getopt(3) library so that it will work correctly in subprocesses
3610 * or when this function is called a second time with another array.
3611 */
3612 optind = 1;
3613 #ifdef HAVE_INT_OPTRESET
3614 optreset = 1; /* some systems need this too */
3615 #endif
3616 }
3617
3618
3619 /* ----------------------------------------------------------------
3620 * PostgresMain
3621 * postgres main loop -- all backends, interactive or otherwise start here
3622 *
3623 * argc/argv are the command line arguments to be used. (When being forked
3624 * by the postmaster, these are not the original argv array of the process.)
3625 * dbname is the name of the database to connect to, or NULL if the database
3626 * name should be extracted from the command line arguments or defaulted.
3627 * username is the PostgreSQL user name to be used for the session.
3628 * ----------------------------------------------------------------
3629 */
3630 void
PostgresMain(int argc,char * argv[],const char * dbname,const char * username)3631 PostgresMain(int argc, char *argv[],
3632 const char *dbname,
3633 const char *username)
3634 {
3635 int firstchar;
3636 StringInfoData input_message;
3637 sigjmp_buf local_sigjmp_buf;
3638 volatile bool send_ready_for_query = true;
3639 bool disable_idle_in_transaction_timeout = false;
3640
3641 /* Initialize startup process environment if necessary. */
3642 if (!IsUnderPostmaster)
3643 InitStandaloneProcess(argv[0]);
3644
3645 SetProcessingMode(InitProcessing);
3646
3647 /*
3648 * Set default values for command-line options.
3649 */
3650 if (!IsUnderPostmaster)
3651 InitializeGUCOptions();
3652
3653 /*
3654 * Parse command-line options.
3655 */
3656 process_postgres_switches(argc, argv, PGC_POSTMASTER, &dbname);
3657
3658 /* Must have gotten a database name, or have a default (the username) */
3659 if (dbname == NULL)
3660 {
3661 dbname = username;
3662 if (dbname == NULL)
3663 ereport(FATAL,
3664 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
3665 errmsg("%s: no database nor user name specified",
3666 progname)));
3667 }
3668
3669 /* Acquire configuration parameters, unless inherited from postmaster */
3670 if (!IsUnderPostmaster)
3671 {
3672 if (!SelectConfigFiles(userDoption, progname))
3673 proc_exit(1);
3674 }
3675
3676 /*
3677 * Set up signal handlers and masks.
3678 *
3679 * Note that postmaster blocked all signals before forking child process,
3680 * so there is no race condition whereby we might receive a signal before
3681 * we have set up the handler.
3682 *
3683 * Also note: it's best not to use any signals that are SIG_IGNored in the
3684 * postmaster. If such a signal arrives before we are able to change the
3685 * handler to non-SIG_IGN, it'll get dropped. Instead, make a dummy
3686 * handler in the postmaster to reserve the signal. (Of course, this isn't
3687 * an issue for signals that are locally generated, such as SIGALRM and
3688 * SIGPIPE.)
3689 */
3690 if (am_walsender)
3691 WalSndSignals();
3692 else
3693 {
3694 pqsignal(SIGHUP, PostgresSigHupHandler); /* set flag to read config
3695 * file */
3696 pqsignal(SIGINT, StatementCancelHandler); /* cancel current query */
3697 pqsignal(SIGTERM, die); /* cancel current query and exit */
3698
3699 /*
3700 * In a standalone backend, SIGQUIT can be generated from the keyboard
3701 * easily, while SIGTERM cannot, so we make both signals do die()
3702 * rather than quickdie().
3703 */
3704 if (IsUnderPostmaster)
3705 pqsignal(SIGQUIT, quickdie); /* hard crash time */
3706 else
3707 pqsignal(SIGQUIT, die); /* cancel current query and exit */
3708 InitializeTimeouts(); /* establishes SIGALRM handler */
3709
3710 /*
3711 * Ignore failure to write to frontend. Note: if frontend closes
3712 * connection, we will notice it and exit cleanly when control next
3713 * returns to outer loop. This seems safer than forcing exit in the
3714 * midst of output during who-knows-what operation...
3715 */
3716 pqsignal(SIGPIPE, SIG_IGN);
3717 pqsignal(SIGUSR1, procsignal_sigusr1_handler);
3718 pqsignal(SIGUSR2, SIG_IGN);
3719 pqsignal(SIGFPE, FloatExceptionHandler);
3720
3721 /*
3722 * Reset some signals that are accepted by postmaster but not by
3723 * backend
3724 */
3725 pqsignal(SIGCHLD, SIG_DFL); /* system() requires this on some
3726 * platforms */
3727 }
3728
3729 pqinitmask();
3730
3731 if (IsUnderPostmaster)
3732 {
3733 /* We allow SIGQUIT (quickdie) at all times */
3734 sigdelset(&BlockSig, SIGQUIT);
3735 }
3736
3737 PG_SETMASK(&BlockSig); /* block everything except SIGQUIT */
3738
3739 if (!IsUnderPostmaster)
3740 {
3741 /*
3742 * Validate we have been given a reasonable-looking DataDir (if under
3743 * postmaster, assume postmaster did this already).
3744 */
3745 Assert(DataDir);
3746 ValidatePgVersion(DataDir);
3747
3748 /* Change into DataDir (if under postmaster, was done already) */
3749 ChangeToDataDir();
3750
3751 /*
3752 * Create lockfile for data directory.
3753 */
3754 CreateDataDirLockFile(false);
3755
3756 /* Initialize MaxBackends (if under postmaster, was done already) */
3757 InitializeMaxBackends();
3758 }
3759
3760 /* Early initialization */
3761 BaseInit();
3762
3763 /*
3764 * Create a per-backend PGPROC struct in shared memory, except in the
3765 * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do
3766 * this before we can use LWLocks (and in the EXEC_BACKEND case we already
3767 * had to do some stuff with LWLocks).
3768 */
3769 #ifdef EXEC_BACKEND
3770 if (!IsUnderPostmaster)
3771 InitProcess();
3772 #else
3773 InitProcess();
3774 #endif
3775
3776 /* We need to allow SIGINT, etc during the initial transaction */
3777 PG_SETMASK(&UnBlockSig);
3778
3779 /*
3780 * General initialization.
3781 *
3782 * NOTE: if you are tempted to add code in this vicinity, consider putting
3783 * it inside InitPostgres() instead. In particular, anything that
3784 * involves database access should be there, not here.
3785 */
3786 InitPostgres(dbname, InvalidOid, username, InvalidOid, NULL);
3787
3788 /*
3789 * If the PostmasterContext is still around, recycle the space; we don't
3790 * need it anymore after InitPostgres completes. Note this does not trash
3791 * *MyProcPort, because ConnCreate() allocated that space with malloc()
3792 * ... else we'd need to copy the Port data first. Also, subsidiary data
3793 * such as the username isn't lost either; see ProcessStartupPacket().
3794 */
3795 if (PostmasterContext)
3796 {
3797 MemoryContextDelete(PostmasterContext);
3798 PostmasterContext = NULL;
3799 }
3800
3801 SetProcessingMode(NormalProcessing);
3802
3803 /*
3804 * Now all GUC states are fully set up. Report them to client if
3805 * appropriate.
3806 */
3807 BeginReportingGUCOptions();
3808
3809 /*
3810 * Also set up handler to log session end; we have to wait till now to be
3811 * sure Log_disconnections has its final value.
3812 */
3813 if (IsUnderPostmaster && Log_disconnections)
3814 on_proc_exit(log_disconnections, 0);
3815
3816 /* Perform initialization specific to a WAL sender process. */
3817 if (am_walsender)
3818 InitWalSender();
3819
3820 /*
3821 * process any libraries that should be preloaded at backend start (this
3822 * likewise can't be done until GUC settings are complete)
3823 */
3824 process_session_preload_libraries();
3825
3826 /*
3827 * Send this backend's cancellation info to the frontend.
3828 */
3829 if (whereToSendOutput == DestRemote)
3830 {
3831 StringInfoData buf;
3832
3833 pq_beginmessage(&buf, 'K');
3834 pq_sendint(&buf, (int32) MyProcPid, sizeof(int32));
3835 pq_sendint(&buf, (int32) MyCancelKey, sizeof(int32));
3836 pq_endmessage(&buf);
3837 /* Need not flush since ReadyForQuery will do it. */
3838 }
3839
3840 /* Welcome banner for standalone case */
3841 if (whereToSendOutput == DestDebug)
3842 printf("\nPostgreSQL stand-alone backend %s\n", PG_VERSION);
3843
3844 /*
3845 * Create the memory context we will use in the main loop.
3846 *
3847 * MessageContext is reset once per iteration of the main loop, ie, upon
3848 * completion of processing of each command message from the client.
3849 */
3850 MessageContext = AllocSetContextCreate(TopMemoryContext,
3851 "MessageContext",
3852 ALLOCSET_DEFAULT_SIZES);
3853
3854 /*
3855 * Remember stand-alone backend startup time
3856 */
3857 if (!IsUnderPostmaster)
3858 PgStartTime = GetCurrentTimestamp();
3859
3860 /*
3861 * POSTGRES main processing loop begins here
3862 *
3863 * If an exception is encountered, processing resumes here so we abort the
3864 * current transaction and start a new one.
3865 *
3866 * You might wonder why this isn't coded as an infinite loop around a
3867 * PG_TRY construct. The reason is that this is the bottom of the
3868 * exception stack, and so with PG_TRY there would be no exception handler
3869 * in force at all during the CATCH part. By leaving the outermost setjmp
3870 * always active, we have at least some chance of recovering from an error
3871 * during error recovery. (If we get into an infinite loop thereby, it
3872 * will soon be stopped by overflow of elog.c's internal state stack.)
3873 *
3874 * Note that we use sigsetjmp(..., 1), so that this function's signal mask
3875 * (to wit, UnBlockSig) will be restored when longjmp'ing to here. This
3876 * is essential in case we longjmp'd out of a signal handler on a platform
3877 * where that leaves the signal blocked. It's not redundant with the
3878 * unblock in AbortTransaction() because the latter is only called if we
3879 * were inside a transaction.
3880 */
3881
3882 if (sigsetjmp(local_sigjmp_buf, 1) != 0)
3883 {
3884 /*
3885 * NOTE: if you are tempted to add more code in this if-block,
3886 * consider the high probability that it should be in
3887 * AbortTransaction() instead. The only stuff done directly here
3888 * should be stuff that is guaranteed to apply *only* for outer-level
3889 * error recovery, such as adjusting the FE/BE protocol status.
3890 */
3891
3892 /* Since not using PG_TRY, must reset error stack by hand */
3893 error_context_stack = NULL;
3894
3895 /* Prevent interrupts while cleaning up */
3896 HOLD_INTERRUPTS();
3897
3898 /*
3899 * Forget any pending QueryCancel request, since we're returning to
3900 * the idle loop anyway, and cancel any active timeout requests. (In
3901 * future we might want to allow some timeout requests to survive, but
3902 * at minimum it'd be necessary to do reschedule_timeouts(), in case
3903 * we got here because of a query cancel interrupting the SIGALRM
3904 * interrupt handler.) Note in particular that we must clear the
3905 * statement and lock timeout indicators, to prevent any future plain
3906 * query cancels from being misreported as timeouts in case we're
3907 * forgetting a timeout cancel.
3908 */
3909 disable_all_timeouts(false);
3910 QueryCancelPending = false; /* second to avoid race condition */
3911
3912 /* Not reading from the client anymore. */
3913 DoingCommandRead = false;
3914
3915 /* Make sure libpq is in a good state */
3916 pq_comm_reset();
3917
3918 /* Report the error to the client and/or server log */
3919 EmitErrorReport();
3920
3921 /*
3922 * Make sure debug_query_string gets reset before we possibly clobber
3923 * the storage it points at.
3924 */
3925 debug_query_string = NULL;
3926
3927 /*
3928 * Abort the current transaction in order to recover.
3929 */
3930 AbortCurrentTransaction();
3931
3932 if (am_walsender)
3933 WalSndErrorCleanup();
3934
3935 /*
3936 * We can't release replication slots inside AbortTransaction() as we
3937 * need to be able to start and abort transactions while having a slot
3938 * acquired. But we never need to hold them across top level errors,
3939 * so releasing here is fine. There's another cleanup in ProcKill()
3940 * ensuring we'll correctly cleanup on FATAL errors as well.
3941 */
3942 if (MyReplicationSlot != NULL)
3943 ReplicationSlotRelease();
3944
3945 /* We also want to cleanup temporary slots on error. */
3946 ReplicationSlotCleanup();
3947
3948 /*
3949 * Now return to normal top-level context and clear ErrorContext for
3950 * next time.
3951 */
3952 MemoryContextSwitchTo(TopMemoryContext);
3953 FlushErrorState();
3954
3955 /*
3956 * If we were handling an extended-query-protocol message, initiate
3957 * skip till next Sync. This also causes us not to issue
3958 * ReadyForQuery (until we get Sync).
3959 */
3960 if (doing_extended_query_message)
3961 ignore_till_sync = true;
3962
3963 /* We don't have a transaction command open anymore */
3964 xact_started = false;
3965
3966 /*
3967 * If an error occurred while we were reading a message from the
3968 * client, we have potentially lost track of where the previous
3969 * message ends and the next one begins. Even though we have
3970 * otherwise recovered from the error, we cannot safely read any more
3971 * messages from the client, so there isn't much we can do with the
3972 * connection anymore.
3973 */
3974 if (pq_is_reading_msg())
3975 ereport(FATAL,
3976 (errcode(ERRCODE_PROTOCOL_VIOLATION),
3977 errmsg("terminating connection because protocol synchronization was lost")));
3978
3979 /* Now we can allow interrupts again */
3980 RESUME_INTERRUPTS();
3981 }
3982
3983 /* We can now handle ereport(ERROR) */
3984 PG_exception_stack = &local_sigjmp_buf;
3985
3986 if (!ignore_till_sync)
3987 send_ready_for_query = true; /* initially, or after error */
3988
3989 /*
3990 * Non-error queries loop here.
3991 */
3992
3993 for (;;)
3994 {
3995 /*
3996 * At top of loop, reset extended-query-message flag, so that any
3997 * errors encountered in "idle" state don't provoke skip.
3998 */
3999 doing_extended_query_message = false;
4000
4001 /*
4002 * Release storage left over from prior query cycle, and create a new
4003 * query input buffer in the cleared MessageContext.
4004 */
4005 MemoryContextSwitchTo(MessageContext);
4006 MemoryContextResetAndDeleteChildren(MessageContext);
4007
4008 initStringInfo(&input_message);
4009
4010 /*
4011 * Also consider releasing our catalog snapshot if any, so that it's
4012 * not preventing advance of global xmin while we wait for the client.
4013 */
4014 InvalidateCatalogSnapshotConditionally();
4015
4016 /*
4017 * (1) If we've reached idle state, tell the frontend we're ready for
4018 * a new query.
4019 *
4020 * Note: this includes fflush()'ing the last of the prior output.
4021 *
4022 * This is also a good time to send collected statistics to the
4023 * collector, and to update the PS stats display. We avoid doing
4024 * those every time through the message loop because it'd slow down
4025 * processing of batched messages, and because we don't want to report
4026 * uncommitted updates (that confuses autovacuum). The notification
4027 * processor wants a call too, if we are not in a transaction block.
4028 */
4029 if (send_ready_for_query)
4030 {
4031 if (IsAbortedTransactionBlockState())
4032 {
4033 set_ps_display("idle in transaction (aborted)", false);
4034 pgstat_report_activity(STATE_IDLEINTRANSACTION_ABORTED, NULL);
4035
4036 /* Start the idle-in-transaction timer */
4037 if (IdleInTransactionSessionTimeout > 0)
4038 {
4039 disable_idle_in_transaction_timeout = true;
4040 enable_timeout_after(IDLE_IN_TRANSACTION_SESSION_TIMEOUT,
4041 IdleInTransactionSessionTimeout);
4042 }
4043 }
4044 else if (IsTransactionOrTransactionBlock())
4045 {
4046 set_ps_display("idle in transaction", false);
4047 pgstat_report_activity(STATE_IDLEINTRANSACTION, NULL);
4048
4049 /* Start the idle-in-transaction timer */
4050 if (IdleInTransactionSessionTimeout > 0)
4051 {
4052 disable_idle_in_transaction_timeout = true;
4053 enable_timeout_after(IDLE_IN_TRANSACTION_SESSION_TIMEOUT,
4054 IdleInTransactionSessionTimeout);
4055 }
4056 }
4057 else
4058 {
4059 /* Send out notify signals and transmit self-notifies */
4060 ProcessCompletedNotifies();
4061
4062 /*
4063 * Also process incoming notifies, if any. This is mostly to
4064 * ensure stable behavior in tests: if any notifies were
4065 * received during the just-finished transaction, they'll be
4066 * seen by the client before ReadyForQuery is.
4067 */
4068 if (notifyInterruptPending)
4069 ProcessNotifyInterrupt();
4070
4071 pgstat_report_stat(false);
4072
4073 set_ps_display("idle", false);
4074 pgstat_report_activity(STATE_IDLE, NULL);
4075 }
4076
4077 ReadyForQuery(whereToSendOutput);
4078 send_ready_for_query = false;
4079 }
4080
4081 /*
4082 * (2) Allow asynchronous signals to be executed immediately if they
4083 * come in while we are waiting for client input. (This must be
4084 * conditional since we don't want, say, reads on behalf of COPY FROM
4085 * STDIN doing the same thing.)
4086 */
4087 DoingCommandRead = true;
4088
4089 /*
4090 * (3) read a command (loop blocks here)
4091 */
4092 firstchar = ReadCommand(&input_message);
4093
4094 /*
4095 * (4) turn off the idle-in-transaction timeout, if active. We do
4096 * this before step (5) so that any last-moment timeout is certain to
4097 * be detected in step (5).
4098 */
4099 if (disable_idle_in_transaction_timeout)
4100 {
4101 disable_timeout(IDLE_IN_TRANSACTION_SESSION_TIMEOUT, false);
4102 disable_idle_in_transaction_timeout = false;
4103 }
4104
4105 /*
4106 * (5) disable async signal conditions again.
4107 *
4108 * Query cancel is supposed to be a no-op when there is no query in
4109 * progress, so if a query cancel arrived while we were idle, just
4110 * reset QueryCancelPending. ProcessInterrupts() has that effect when
4111 * it's called when DoingCommandRead is set, so check for interrupts
4112 * before resetting DoingCommandRead.
4113 */
4114 CHECK_FOR_INTERRUPTS();
4115 DoingCommandRead = false;
4116
4117 /*
4118 * (6) check for any other interesting events that happened while we
4119 * slept.
4120 */
4121 if (ConfigReloadPending)
4122 {
4123 ConfigReloadPending = false;
4124 ProcessConfigFile(PGC_SIGHUP);
4125 }
4126
4127 /*
4128 * (7) process the command. But ignore it if we're skipping till
4129 * Sync.
4130 */
4131 if (ignore_till_sync && firstchar != EOF)
4132 continue;
4133
4134 switch (firstchar)
4135 {
4136 case 'Q': /* simple query */
4137 {
4138 const char *query_string;
4139
4140 /* Set statement_timestamp() */
4141 SetCurrentStatementStartTimestamp();
4142
4143 query_string = pq_getmsgstring(&input_message);
4144 pq_getmsgend(&input_message);
4145
4146 if (am_walsender)
4147 {
4148 if (!exec_replication_command(query_string))
4149 exec_simple_query(query_string);
4150 }
4151 else
4152 exec_simple_query(query_string);
4153
4154 send_ready_for_query = true;
4155 }
4156 break;
4157
4158 case 'P': /* parse */
4159 {
4160 const char *stmt_name;
4161 const char *query_string;
4162 int numParams;
4163 Oid *paramTypes = NULL;
4164
4165 forbidden_in_wal_sender(firstchar);
4166
4167 /* Set statement_timestamp() */
4168 SetCurrentStatementStartTimestamp();
4169
4170 stmt_name = pq_getmsgstring(&input_message);
4171 query_string = pq_getmsgstring(&input_message);
4172 numParams = pq_getmsgint(&input_message, 2);
4173 if (numParams > 0)
4174 {
4175 int i;
4176
4177 paramTypes = (Oid *) palloc(numParams * sizeof(Oid));
4178 for (i = 0; i < numParams; i++)
4179 paramTypes[i] = pq_getmsgint(&input_message, 4);
4180 }
4181 pq_getmsgend(&input_message);
4182
4183 exec_parse_message(query_string, stmt_name,
4184 paramTypes, numParams);
4185 }
4186 break;
4187
4188 case 'B': /* bind */
4189 forbidden_in_wal_sender(firstchar);
4190
4191 /* Set statement_timestamp() */
4192 SetCurrentStatementStartTimestamp();
4193
4194 /*
4195 * this message is complex enough that it seems best to put
4196 * the field extraction out-of-line
4197 */
4198 exec_bind_message(&input_message);
4199 break;
4200
4201 case 'E': /* execute */
4202 {
4203 const char *portal_name;
4204 int max_rows;
4205
4206 forbidden_in_wal_sender(firstchar);
4207
4208 /* Set statement_timestamp() */
4209 SetCurrentStatementStartTimestamp();
4210
4211 portal_name = pq_getmsgstring(&input_message);
4212 max_rows = pq_getmsgint(&input_message, 4);
4213 pq_getmsgend(&input_message);
4214
4215 exec_execute_message(portal_name, max_rows);
4216 }
4217 break;
4218
4219 case 'F': /* fastpath function call */
4220 forbidden_in_wal_sender(firstchar);
4221
4222 /* Set statement_timestamp() */
4223 SetCurrentStatementStartTimestamp();
4224
4225 /* Report query to various monitoring facilities. */
4226 pgstat_report_activity(STATE_FASTPATH, NULL);
4227 set_ps_display("<FASTPATH>", false);
4228
4229 /* start an xact for this function invocation */
4230 start_xact_command();
4231
4232 /*
4233 * Note: we may at this point be inside an aborted
4234 * transaction. We can't throw error for that until we've
4235 * finished reading the function-call message, so
4236 * HandleFunctionRequest() must check for it after doing so.
4237 * Be careful not to do anything that assumes we're inside a
4238 * valid transaction here.
4239 */
4240
4241 /* switch back to message context */
4242 MemoryContextSwitchTo(MessageContext);
4243
4244 HandleFunctionRequest(&input_message);
4245
4246 /* commit the function-invocation transaction */
4247 finish_xact_command();
4248
4249 send_ready_for_query = true;
4250 break;
4251
4252 case 'C': /* close */
4253 {
4254 int close_type;
4255 const char *close_target;
4256
4257 forbidden_in_wal_sender(firstchar);
4258
4259 close_type = pq_getmsgbyte(&input_message);
4260 close_target = pq_getmsgstring(&input_message);
4261 pq_getmsgend(&input_message);
4262
4263 switch (close_type)
4264 {
4265 case 'S':
4266 if (close_target[0] != '\0')
4267 DropPreparedStatement(close_target, false);
4268 else
4269 {
4270 /* special-case the unnamed statement */
4271 drop_unnamed_stmt();
4272 }
4273 break;
4274 case 'P':
4275 {
4276 Portal portal;
4277
4278 portal = GetPortalByName(close_target);
4279 if (PortalIsValid(portal))
4280 PortalDrop(portal, false);
4281 }
4282 break;
4283 default:
4284 ereport(ERROR,
4285 (errcode(ERRCODE_PROTOCOL_VIOLATION),
4286 errmsg("invalid CLOSE message subtype %d",
4287 close_type)));
4288 break;
4289 }
4290
4291 if (whereToSendOutput == DestRemote)
4292 pq_putemptymessage('3'); /* CloseComplete */
4293 }
4294 break;
4295
4296 case 'D': /* describe */
4297 {
4298 int describe_type;
4299 const char *describe_target;
4300
4301 forbidden_in_wal_sender(firstchar);
4302
4303 /* Set statement_timestamp() (needed for xact) */
4304 SetCurrentStatementStartTimestamp();
4305
4306 describe_type = pq_getmsgbyte(&input_message);
4307 describe_target = pq_getmsgstring(&input_message);
4308 pq_getmsgend(&input_message);
4309
4310 switch (describe_type)
4311 {
4312 case 'S':
4313 exec_describe_statement_message(describe_target);
4314 break;
4315 case 'P':
4316 exec_describe_portal_message(describe_target);
4317 break;
4318 default:
4319 ereport(ERROR,
4320 (errcode(ERRCODE_PROTOCOL_VIOLATION),
4321 errmsg("invalid DESCRIBE message subtype %d",
4322 describe_type)));
4323 break;
4324 }
4325 }
4326 break;
4327
4328 case 'H': /* flush */
4329 pq_getmsgend(&input_message);
4330 if (whereToSendOutput == DestRemote)
4331 pq_flush();
4332 break;
4333
4334 case 'S': /* sync */
4335 pq_getmsgend(&input_message);
4336 finish_xact_command();
4337 send_ready_for_query = true;
4338 break;
4339
4340 /*
4341 * 'X' means that the frontend is closing down the socket. EOF
4342 * means unexpected loss of frontend connection. Either way,
4343 * perform normal shutdown.
4344 */
4345 case 'X':
4346 case EOF:
4347
4348 /*
4349 * Reset whereToSendOutput to prevent ereport from attempting
4350 * to send any more messages to client.
4351 */
4352 if (whereToSendOutput == DestRemote)
4353 whereToSendOutput = DestNone;
4354
4355 /*
4356 * NOTE: if you are tempted to add more code here, DON'T!
4357 * Whatever you had in mind to do should be set up as an
4358 * on_proc_exit or on_shmem_exit callback, instead. Otherwise
4359 * it will fail to be called during other backend-shutdown
4360 * scenarios.
4361 */
4362 proc_exit(0);
4363
4364 case 'd': /* copy data */
4365 case 'c': /* copy done */
4366 case 'f': /* copy fail */
4367
4368 /*
4369 * Accept but ignore these messages, per protocol spec; we
4370 * probably got here because a COPY failed, and the frontend
4371 * is still sending data.
4372 */
4373 break;
4374
4375 default:
4376 ereport(FATAL,
4377 (errcode(ERRCODE_PROTOCOL_VIOLATION),
4378 errmsg("invalid frontend message type %d",
4379 firstchar)));
4380 }
4381 } /* end of input-reading loop */
4382 }
4383
4384 /*
4385 * Throw an error if we're a WAL sender process.
4386 *
4387 * This is used to forbid anything else than simple query protocol messages
4388 * in a WAL sender process. 'firstchar' specifies what kind of a forbidden
4389 * message was received, and is used to construct the error message.
4390 */
4391 static void
forbidden_in_wal_sender(char firstchar)4392 forbidden_in_wal_sender(char firstchar)
4393 {
4394 if (am_walsender)
4395 {
4396 if (firstchar == 'F')
4397 ereport(ERROR,
4398 (errcode(ERRCODE_PROTOCOL_VIOLATION),
4399 errmsg("fastpath function calls not supported in a replication connection")));
4400 else
4401 ereport(ERROR,
4402 (errcode(ERRCODE_PROTOCOL_VIOLATION),
4403 errmsg("extended query protocol not supported in a replication connection")));
4404 }
4405 }
4406
4407
4408 /*
4409 * Obtain platform stack depth limit (in bytes)
4410 *
4411 * Return -1 if unknown
4412 */
4413 long
get_stack_depth_rlimit(void)4414 get_stack_depth_rlimit(void)
4415 {
4416 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_STACK)
4417 static long val = 0;
4418
4419 /* This won't change after process launch, so check just once */
4420 if (val == 0)
4421 {
4422 struct rlimit rlim;
4423
4424 if (getrlimit(RLIMIT_STACK, &rlim) < 0)
4425 val = -1;
4426 else if (rlim.rlim_cur == RLIM_INFINITY)
4427 val = LONG_MAX;
4428 /* rlim_cur is probably of an unsigned type, so check for overflow */
4429 else if (rlim.rlim_cur >= LONG_MAX)
4430 val = LONG_MAX;
4431 else
4432 val = rlim.rlim_cur;
4433 }
4434 return val;
4435 #else /* no getrlimit */
4436 #if defined(WIN32) || defined(__CYGWIN__)
4437 /* On Windows we set the backend stack size in src/backend/Makefile */
4438 return WIN32_STACK_RLIMIT;
4439 #else /* not windows ... give up */
4440 return -1;
4441 #endif
4442 #endif
4443 }
4444
4445
4446 static struct rusage Save_r;
4447 static struct timeval Save_t;
4448
4449 void
ResetUsage(void)4450 ResetUsage(void)
4451 {
4452 getrusage(RUSAGE_SELF, &Save_r);
4453 gettimeofday(&Save_t, NULL);
4454 }
4455
4456 void
ShowUsage(const char * title)4457 ShowUsage(const char *title)
4458 {
4459 StringInfoData str;
4460 struct timeval user,
4461 sys;
4462 struct timeval elapse_t;
4463 struct rusage r;
4464
4465 getrusage(RUSAGE_SELF, &r);
4466 gettimeofday(&elapse_t, NULL);
4467 memcpy((char *) &user, (char *) &r.ru_utime, sizeof(user));
4468 memcpy((char *) &sys, (char *) &r.ru_stime, sizeof(sys));
4469 if (elapse_t.tv_usec < Save_t.tv_usec)
4470 {
4471 elapse_t.tv_sec--;
4472 elapse_t.tv_usec += 1000000;
4473 }
4474 if (r.ru_utime.tv_usec < Save_r.ru_utime.tv_usec)
4475 {
4476 r.ru_utime.tv_sec--;
4477 r.ru_utime.tv_usec += 1000000;
4478 }
4479 if (r.ru_stime.tv_usec < Save_r.ru_stime.tv_usec)
4480 {
4481 r.ru_stime.tv_sec--;
4482 r.ru_stime.tv_usec += 1000000;
4483 }
4484
4485 /*
4486 * the only stats we don't show here are for memory usage -- i can't
4487 * figure out how to interpret the relevant fields in the rusage struct,
4488 * and they change names across o/s platforms, anyway. if you can figure
4489 * out what the entries mean, you can somehow extract resident set size,
4490 * shared text size, and unshared data and stack sizes.
4491 */
4492 initStringInfo(&str);
4493
4494 appendStringInfoString(&str, "! system usage stats:\n");
4495 appendStringInfo(&str,
4496 "!\t%ld.%06ld s user, %ld.%06ld s system, %ld.%06ld s elapsed\n",
4497 (long) (r.ru_utime.tv_sec - Save_r.ru_utime.tv_sec),
4498 (long) (r.ru_utime.tv_usec - Save_r.ru_utime.tv_usec),
4499 (long) (r.ru_stime.tv_sec - Save_r.ru_stime.tv_sec),
4500 (long) (r.ru_stime.tv_usec - Save_r.ru_stime.tv_usec),
4501 (long) (elapse_t.tv_sec - Save_t.tv_sec),
4502 (long) (elapse_t.tv_usec - Save_t.tv_usec));
4503 appendStringInfo(&str,
4504 "!\t[%ld.%06ld s user, %ld.%06ld s system total]\n",
4505 (long) user.tv_sec,
4506 (long) user.tv_usec,
4507 (long) sys.tv_sec,
4508 (long) sys.tv_usec);
4509 #if defined(HAVE_GETRUSAGE)
4510 appendStringInfo(&str,
4511 "!\t%ld/%ld [%ld/%ld] filesystem blocks in/out\n",
4512 r.ru_inblock - Save_r.ru_inblock,
4513 /* they only drink coffee at dec */
4514 r.ru_oublock - Save_r.ru_oublock,
4515 r.ru_inblock, r.ru_oublock);
4516 appendStringInfo(&str,
4517 "!\t%ld/%ld [%ld/%ld] page faults/reclaims, %ld [%ld] swaps\n",
4518 r.ru_majflt - Save_r.ru_majflt,
4519 r.ru_minflt - Save_r.ru_minflt,
4520 r.ru_majflt, r.ru_minflt,
4521 r.ru_nswap - Save_r.ru_nswap,
4522 r.ru_nswap);
4523 appendStringInfo(&str,
4524 "!\t%ld [%ld] signals rcvd, %ld/%ld [%ld/%ld] messages rcvd/sent\n",
4525 r.ru_nsignals - Save_r.ru_nsignals,
4526 r.ru_nsignals,
4527 r.ru_msgrcv - Save_r.ru_msgrcv,
4528 r.ru_msgsnd - Save_r.ru_msgsnd,
4529 r.ru_msgrcv, r.ru_msgsnd);
4530 appendStringInfo(&str,
4531 "!\t%ld/%ld [%ld/%ld] voluntary/involuntary context switches\n",
4532 r.ru_nvcsw - Save_r.ru_nvcsw,
4533 r.ru_nivcsw - Save_r.ru_nivcsw,
4534 r.ru_nvcsw, r.ru_nivcsw);
4535 #endif /* HAVE_GETRUSAGE */
4536
4537 /* remove trailing newline */
4538 if (str.data[str.len - 1] == '\n')
4539 str.data[--str.len] = '\0';
4540
4541 ereport(LOG,
4542 (errmsg_internal("%s", title),
4543 errdetail_internal("%s", str.data)));
4544
4545 pfree(str.data);
4546 }
4547
4548 /*
4549 * on_proc_exit handler to log end of session
4550 */
4551 static void
log_disconnections(int code,Datum arg)4552 log_disconnections(int code, Datum arg)
4553 {
4554 Port *port = MyProcPort;
4555 long secs;
4556 int usecs;
4557 int msecs;
4558 int hours,
4559 minutes,
4560 seconds;
4561
4562 TimestampDifference(port->SessionStartTime,
4563 GetCurrentTimestamp(),
4564 &secs, &usecs);
4565 msecs = usecs / 1000;
4566
4567 hours = secs / SECS_PER_HOUR;
4568 secs %= SECS_PER_HOUR;
4569 minutes = secs / SECS_PER_MINUTE;
4570 seconds = secs % SECS_PER_MINUTE;
4571
4572 ereport(LOG,
4573 (errmsg("disconnection: session time: %d:%02d:%02d.%03d "
4574 "user=%s database=%s host=%s%s%s",
4575 hours, minutes, seconds, msecs,
4576 port->user_name, port->database_name, port->remote_host,
4577 port->remote_port[0] ? " port=" : "", port->remote_port)));
4578 }
4579