1# 2010 April 13
2#
3# The author disclaims copyright to this source code.  In place of
4# a legal notice, here is a blessing:
5#
6#    May you do good and not evil.
7#    May you find forgiveness for yourself and forgive others.
8#    May you share freely, never taking more than you give.
9#
10#***********************************************************************
11# This file implements regression tests for SQLite library.  The
12# focus of this file is testing the operation of the library in
13# "PRAGMA journal_mode=WAL" mode.
14#
15
16set testdir [file dirname $argv0]
17source $testdir/tester.tcl
18source $testdir/lock_common.tcl
19source $testdir/wal_common.tcl
20source $testdir/malloc_common.tcl
21ifcapable !wal {finish_test ; return }
22
23set a_string_counter 1
24proc a_string {n} {
25  global a_string_counter
26  incr a_string_counter
27  string range [string repeat "${a_string_counter}." $n] 1 $n
28}
29db func a_string a_string
30
31#-------------------------------------------------------------------------
32# When a rollback or savepoint rollback occurs, the client may remove
33# elements from one of the hash tables in the wal-index. This block
34# of test cases tests that nothing appears to go wrong when this is
35# done.
36#
37do_test wal3-1.0 {
38  execsql {
39    PRAGMA cache_size = 2000;
40    PRAGMA page_size = 1024;
41    PRAGMA auto_vacuum = off;
42    PRAGMA synchronous = normal;
43    PRAGMA journal_mode = WAL;
44    PRAGMA wal_autocheckpoint = 0;
45    BEGIN;
46      CREATE TABLE t1(x);
47      INSERT INTO t1 VALUES( a_string(800) );                  /*    1 */
48      INSERT INTO t1 SELECT a_string(800) FROM t1;             /*    2 */
49      INSERT INTO t1 SELECT a_string(800) FROM t1;             /*    4 */
50      INSERT INTO t1 SELECT a_string(800) FROM t1;             /*    8 */
51      INSERT INTO t1 SELECT a_string(800) FROM t1;             /*   16 */
52      INSERT INTO t1 SELECT a_string(800) FROM t1;             /*   32 */
53      INSERT INTO t1 SELECT a_string(800) FROM t1;             /*   64 */
54      INSERT INTO t1 SELECT a_string(800) FROM t1;             /*  128*/
55      INSERT INTO t1 SELECT a_string(800) FROM t1;             /*  256 */
56      INSERT INTO t1 SELECT a_string(800) FROM t1;             /*  512 */
57      INSERT INTO t1 SELECT a_string(800) FROM t1;             /* 1024 */
58      INSERT INTO t1 SELECT a_string(800) FROM t1;             /* 2048 */
59      INSERT INTO t1 SELECT a_string(800) FROM t1 LIMIT 1970;  /* 4018 */
60    COMMIT;
61    PRAGMA cache_size = 10;
62  }
63  set x [wal_frame_count test.db-wal 1024]
64  if {[permutation]=="memsubsys1"} {
65    if {$x==4251 || $x==4290} {set x 4056}
66  }
67  set x
68} 4056
69
70for {set i 1} {$i < 50} {incr i} {
71
72  do_test wal3-1.$i.1 {
73    set str [a_string 800]
74    execsql { UPDATE t1 SET x = $str WHERE rowid = $i }
75    lappend L [wal_frame_count test.db-wal 1024]
76    execsql {
77      BEGIN;
78        INSERT INTO t1 SELECT a_string(800) FROM t1 LIMIT 100;
79      ROLLBACK;
80      PRAGMA integrity_check;
81    }
82  } {ok}
83
84  # Check that everything looks OK from the point of view of an
85  # external connection.
86  #
87  sqlite3 db2 test.db
88  do_test wal3-1.$i.2 {
89    execsql { SELECT count(*) FROM t1 } db2
90  } 4018
91  do_test wal3-1.$i.3 {
92    execsql { SELECT x FROM t1 WHERE rowid = $i }
93  } $str
94  do_test wal3-1.$i.4 {
95    execsql { PRAGMA integrity_check } db2
96  } {ok}
97  db2 close
98
99  # Check that the file-system in its current state can be recovered.
100  #
101  forcecopy test.db test2.db
102  forcecopy test.db-wal test2.db-wal
103  forcedelete test2.db-journal
104  sqlite3 db2 test2.db
105  do_test wal3-1.$i.5 {
106    execsql { SELECT count(*) FROM t1 } db2
107  } 4018
108  do_test wal3-1.$i.6 {
109    execsql { SELECT x FROM t1 WHERE rowid = $i }
110  } $str
111  do_test wal3-1.$i.7 {
112    execsql { PRAGMA integrity_check } db2
113  } {ok}
114  db2 close
115}
116
117proc byte_is_zero {file offset} {
118  if {[file size test.db] <= $offset} { return 1 }
119  expr { [hexio_read $file $offset 1] == "00" }
120}
121
122do_multiclient_test i {
123
124  set testname(1) multiproc
125  set testname(2) singleproc
126  set tn $testname($i)
127
128  do_test wal3-2.$tn.1 {
129    sql1 {
130      PRAGMA page_size = 1024;
131      PRAGMA journal_mode = WAL;
132    }
133    sql1 {
134      CREATE TABLE t1(a, b);
135      INSERT INTO t1 VALUES(1, 'one');
136      BEGIN;
137        SELECT * FROM t1;
138    }
139  } {1 one}
140  do_test wal3-2.$tn.2 {
141    sql2 {
142      CREATE TABLE t2(a, b);
143      INSERT INTO t2 VALUES(2, 'two');
144      BEGIN;
145        SELECT * FROM t2;
146    }
147  } {2 two}
148  do_test wal3-2.$tn.3 {
149    sql3 {
150      CREATE TABLE t3(a, b);
151      INSERT INTO t3 VALUES(3, 'three');
152      BEGIN;
153        SELECT * FROM t3;
154    }
155  } {3 three}
156
157  # Try to checkpoint the database using [db]. It should be possible to
158  # checkpoint everything except the table added by [db3] (checkpointing
159  # these frames would clobber the snapshot currently being used by [db2]).
160  #
161  # After [db2] has committed, a checkpoint can copy the entire log to the
162  # database file. Checkpointing after [db3] has committed is therefore a
163  # no-op, as the entire log has already been backfilled.
164  #
165  do_test wal3-2.$tn.4 {
166    sql1 {
167      COMMIT;
168      PRAGMA wal_checkpoint;
169    }
170    byte_is_zero test.db [expr $AUTOVACUUM ? 4*1024 : 3*1024]
171  } {1}
172  do_test wal3-2.$tn.5 {
173    sql2 {
174      COMMIT;
175      PRAGMA wal_checkpoint;
176    }
177    list [byte_is_zero test.db [expr $AUTOVACUUM ? 4*1024 : 3*1024]]   \
178         [byte_is_zero test.db [expr $AUTOVACUUM ? 5*1024 : 4*1024]]
179  } {0 1}
180  do_test wal3-2.$tn.6 {
181    sql3 {
182      COMMIT;
183      PRAGMA wal_checkpoint;
184    }
185    list [byte_is_zero test.db [expr $AUTOVACUUM ? 4*1024 : 3*1024]]   \
186         [byte_is_zero test.db [expr $AUTOVACUUM ? 5*1024 : 4*1024]]
187  } {0 1}
188}
189catch {db close}
190
191#-------------------------------------------------------------------------
192# Test that that for the simple test:
193#
194#   CREATE TABLE x(y);
195#   INSERT INTO x VALUES('z');
196#   PRAGMA wal_checkpoint;
197#
198# in WAL mode the xSync method is invoked as expected for each of
199# synchronous=off, synchronous=normal and synchronous=full.
200#
201foreach {tn syncmode synccount} {
202  1 off
203    {}
204  2 normal
205    {test.db-wal normal test.db normal}
206  3 full
207    {test.db-wal normal test.db-wal normal test.db-wal normal test.db normal}
208} {
209
210  proc sync_counter {args} {
211    foreach {method filename id flags} $args break
212    lappend ::syncs [file tail $filename] $flags
213  }
214  do_test wal3-3.$tn {
215    forcedelete test.db test.db-wal test.db-journal
216
217    testvfs T
218    T filter {}
219    T script sync_counter
220    sqlite3 db test.db -vfs T
221
222    execsql "PRAGMA synchronous = $syncmode"
223    execsql "PRAGMA checkpoint_fullfsync = 0"
224    execsql { PRAGMA journal_mode = WAL }
225    execsql { CREATE TABLE filler(a,b,c); }
226
227    set ::syncs [list]
228    T filter xSync
229    execsql {
230      CREATE TABLE x(y);
231      INSERT INTO x VALUES('z');
232      PRAGMA wal_checkpoint;
233    }
234    T filter {}
235    set ::syncs
236  } $synccount
237
238  db close
239  T delete
240}
241
242
243#-------------------------------------------------------------------------
244# Only one client may run recovery at a time. Test this mechanism.
245#
246# When client-2 tries to open a read transaction while client-1 is
247# running recovery, it fails to obtain a lock on an aReadMark[] slot
248# (because they are all locked by recovery). It then tries to obtain
249# a shared lock on the RECOVER lock to see if there really is a
250# recovery running or not.
251#
252# This block of tests checks the effect of an SQLITE_BUSY or SQLITE_IOERR
253# being returned when client-2 attempts a shared lock on the RECOVER byte.
254#
255# An SQLITE_BUSY should be converted to an SQLITE_BUSY_RECOVERY. An
256# SQLITE_IOERR should be returned to the caller.
257#
258do_test wal3-5.1 {
259  faultsim_delete_and_reopen
260  execsql {
261    PRAGMA journal_mode = WAL;
262    CREATE TABLE t1(a, b);
263    INSERT INTO t1 VALUES(1, 2);
264    INSERT INTO t1 VALUES(3, 4);
265  }
266  faultsim_save_and_close
267} {}
268
269testvfs T -default 1
270T script method_callback
271
272proc method_callback {method args} {
273  if {$method == "xShmBarrier"} {
274    incr ::barrier_count
275    if {$::barrier_count == 2} {
276      # This code is executed within the xShmBarrier() callback invoked
277      # by the client running recovery as part of writing the recovered
278      # wal-index header. If a second client attempts to access the
279      # database now, it reads a corrupt (partially written) wal-index
280      # header. But it cannot even get that far, as the first client
281      # is still holding all the locks (recovery takes an exclusive lock
282      # on *all* db locks, preventing access by any other client).
283      #
284      # If global variable ::wal3_do_lockfailure is non-zero, then set
285      # things up so that an IO error occurs within an xShmLock() callback
286      # made by the second client (aka [db2]).
287      #
288      sqlite3 db2 test.db
289      if { $::wal3_do_lockfailure } { T filter xShmLock }
290      set ::testrc [ catch { db2 eval "SELECT * FROM t1" } ::testmsg ]
291      T filter {}
292      db2 close
293    }
294  }
295
296  if {$method == "xShmLock"} {
297    foreach {file handle spec} $args break
298    if { $spec == "2 1 lock shared" } {
299      return SQLITE_IOERR
300    }
301  }
302
303  return SQLITE_OK
304}
305
306# Test a normal SQLITE_BUSY return.
307#
308T filter xShmBarrier
309set testrc ""
310set testmsg ""
311set barrier_count 0
312set wal3_do_lockfailure 0
313do_test wal3-5.2 {
314  faultsim_restore_and_reopen
315  execsql { SELECT * FROM t1 }
316} {1 2 3 4}
317do_test wal3-5.3 {
318  list $::testrc $::testmsg
319} {1 {database is locked}}
320db close
321
322# Test an SQLITE_IOERR return.
323#
324T filter xShmBarrier
325set barrier_count 0
326set wal3_do_lockfailure 1
327set testrc ""
328set testmsg ""
329do_test wal3-5.4 {
330  faultsim_restore_and_reopen
331  execsql { SELECT * FROM t1 }
332} {1 2 3 4}
333do_test wal3-5.5 {
334  list $::testrc $::testmsg
335} {1 {disk I/O error}}
336
337db close
338T delete
339
340#-------------------------------------------------------------------------
341# When opening a read-transaction on a database, if the entire log has
342# already been copied to the database file, the reader grabs a special
343# kind of read lock (on aReadMark[0]). This set of test cases tests the
344# outcome of the following:
345#
346#   + The reader discovering that between the time when it determined
347#     that the log had been completely backfilled and the lock is obtained
348#     that a writer has written to the log. In this case the reader should
349#     acquire a different read-lock (not aReadMark[0]) and read the new
350#     snapshot.
351#
352#   + The attempt to obtain the lock on aReadMark[0] fails with SQLITE_BUSY.
353#     This can happen if a checkpoint is ongoing. In this case also simply
354#     obtain a different read-lock.
355#
356catch {db close}
357testvfs T -default 1
358do_test wal3-6.1.1 {
359  forcedelete test.db test.db-journal test.db wal
360  sqlite3 db test.db
361  execsql { PRAGMA auto_vacuum = off }
362  execsql { PRAGMA journal_mode = WAL }
363  execsql {
364    CREATE TABLE t1(a, b);
365    INSERT INTO t1 VALUES('o', 't');
366    INSERT INTO t1 VALUES('t', 'f');
367  }
368} {}
369do_test wal3-6.1.2 {
370  sqlite3 db2 test.db
371  sqlite3 db3 test.db
372  execsql { BEGIN ; SELECT * FROM t1 } db3
373} {o t t f}
374do_test wal3-6.1.3 {
375  execsql { PRAGMA wal_checkpoint } db2
376} {0 4 4}
377
378# At this point the log file has been fully checkpointed. However,
379# connection [db3] holds a lock that prevents the log from being wrapped.
380# Test case 3.6.1.4 has [db] attempt a read-lock on aReadMark[0]. But
381# as it is obtaining the lock, [db2] appends to the log file.
382#
383T filter xShmLock
384T script lock_callback
385proc lock_callback {method file handle spec} {
386  if {$spec == "3 1 lock shared"} {
387    # This is the callback for [db] to obtain the read lock on aReadMark[0].
388    # Disable future callbacks using [T filter {}] and write to the log
389    # file using [db2]. [db3] is preventing [db2] from wrapping the log
390    # here, so this is an append.
391    T filter {}
392    db2 eval { INSERT INTO t1 VALUES('f', 's') }
393  }
394  return SQLITE_OK
395}
396do_test wal3-6.1.4 {
397  execsql {
398    BEGIN;
399    SELECT * FROM t1;
400  }
401} {o t t f f s}
402
403# [db] should be left holding a read-lock on some slot other than
404# aReadMark[0]. Test this by demonstrating that the read-lock is preventing
405# the log from being wrapped.
406#
407do_test wal3-6.1.5 {
408  db3 eval COMMIT
409  db2 eval { PRAGMA wal_checkpoint }
410  set sz1 [file size test.db-wal]
411  db2 eval { INSERT INTO t1 VALUES('s', 'e') }
412  set sz2 [file size test.db-wal]
413  expr {$sz2>$sz1}
414} {1}
415
416# Test that if [db2] had not interfered when [db] was trying to grab
417# aReadMark[0], it would have been possible to wrap the log in 3.6.1.5.
418#
419do_test wal3-6.1.6 {
420  execsql { COMMIT }
421  execsql { PRAGMA wal_checkpoint } db2
422  execsql {
423    BEGIN;
424    SELECT * FROM t1;
425  }
426} {o t t f f s s e}
427do_test wal3-6.1.7 {
428  db2 eval { PRAGMA wal_checkpoint }
429  set sz1 [file size test.db-wal]
430  db2 eval { INSERT INTO t1 VALUES('n', 't') }
431  set sz2 [file size test.db-wal]
432  expr {$sz2==$sz1}
433} {1}
434
435db3 close
436db2 close
437db close
438
439do_test wal3-6.2.1 {
440  forcedelete test.db test.db-journal test.db wal
441  sqlite3 db test.db
442  sqlite3 db2 test.db
443  execsql { PRAGMA auto_vacuum = off }
444  execsql { PRAGMA journal_mode = WAL }
445  execsql {
446    CREATE TABLE t1(a, b);
447    INSERT INTO t1 VALUES('h', 'h');
448    INSERT INTO t1 VALUES('l', 'b');
449  }
450} {}
451
452T filter xShmLock
453T script lock_callback
454proc lock_callback {method file handle spec} {
455  if {$spec == "3 1 unlock exclusive"} {
456    T filter {}
457    set ::R [db2 eval {
458      BEGIN;
459      SELECT * FROM t1;
460    }]
461  }
462}
463do_test wal3-6.2.2 {
464  execsql { PRAGMA wal_checkpoint }
465} {0 4 4}
466do_test wal3-6.2.3 {
467  set ::R
468} {h h l b}
469do_test wal3-6.2.4 {
470  set sz1 [file size test.db-wal]
471  execsql { INSERT INTO t1 VALUES('b', 'c'); }
472  set sz2 [file size test.db-wal]
473  expr {$sz2 > $sz1}
474} {1}
475do_test wal3-6.2.5 {
476  db2 eval { COMMIT }
477  execsql { PRAGMA wal_checkpoint }
478  set sz1 [file size test.db-wal]
479  execsql { INSERT INTO t1 VALUES('n', 'o'); }
480  set sz2 [file size test.db-wal]
481  expr {$sz2 == $sz1}
482} {1}
483
484db2 close
485db close
486T delete
487
488#-------------------------------------------------------------------------
489# When opening a read-transaction on a database, if the entire log has
490# not yet been copied to the database file, the reader grabs a read
491# lock on aReadMark[x], where x>0. The following test cases experiment
492# with the outcome of the following:
493#
494#   + The reader discovering that between the time when it read the
495#     wal-index header and the lock was obtained that a writer has
496#     written to the log. In this case the reader should re-read the
497#     wal-index header and lock a snapshot corresponding to the new
498#     header.
499#
500#   + The value in the aReadMark[x] slot has been modified since it was
501#     read.
502#
503catch {db close}
504testvfs T -default 1
505do_test wal3-7.1.1 {
506  forcedelete test.db test.db-journal test.db wal
507  sqlite3 db test.db
508  execsql {
509    PRAGMA journal_mode = WAL;
510    CREATE TABLE blue(red PRIMARY KEY, green);
511  }
512} {wal}
513
514T script method_callback
515T filter xOpen
516proc method_callback {method args} {
517  if {$method == "xOpen"} { return "reader" }
518}
519do_test wal3-7.1.2 {
520  sqlite3 db2 test.db
521  execsql { SELECT * FROM blue } db2
522} {}
523
524T filter xShmLock
525set ::locks [list]
526proc method_callback {method file handle spec} {
527  if {$handle != "reader" } { return }
528  if {$method == "xShmLock"} {
529    catch { execsql { INSERT INTO blue VALUES(1, 2) } }
530    catch { execsql { INSERT INTO blue VALUES(3, 4) } }
531  }
532  lappend ::locks $spec
533}
534do_test wal3-7.1.3 {
535  execsql { SELECT * FROM blue } db2
536} {1 2 3 4}
537do_test wal3-7.1.4 {
538  set ::locks
539} {{4 1 lock shared} {4 1 unlock shared} {5 1 lock shared} {5 1 unlock shared}}
540
541set ::locks [list]
542proc method_callback {method file handle spec} {
543  if {$handle != "reader" } { return }
544  if {$method == "xShmLock"} {
545    catch { execsql { INSERT INTO blue VALUES(5, 6) } }
546  }
547  lappend ::locks $spec
548}
549do_test wal3-7.2.1 {
550  execsql { SELECT * FROM blue } db2
551} {1 2 3 4 5 6}
552do_test wal3-7.2.2 {
553  set ::locks
554} {{5 1 lock shared} {5 1 unlock shared} {4 1 lock shared} {4 1 unlock shared}}
555
556db close
557db2 close
558T delete
559
560
561#-------------------------------------------------------------------------
562# When a connection opens a read-lock on the database, it searches for
563# an aReadMark[] slot that is already set to the mxFrame value for the
564# new transaction. If it cannot find one, it attempts to obtain an
565# exclusive lock on an aReadMark[] slot for the purposes of modifying
566# the value, then drops back to a shared-lock for the duration of the
567# transaction.
568#
569# This test case verifies that if an exclusive lock cannot be obtained
570# on any aReadMark[] slot (because there are already several readers),
571# the client takes a shared-lock on a slot without modifying the value
572# and continues.
573#
574set nConn 50
575if { [string match *BSD $tcl_platform(os)] } { set nConn 25 }
576do_test wal3-9.0 {
577  forcedelete test.db test.db-journal test.db wal
578  sqlite3 db test.db
579  execsql {
580    PRAGMA page_size = 1024;
581    PRAGMA journal_mode = WAL;
582    CREATE TABLE whoami(x);
583    INSERT INTO whoami VALUES('nobody');
584  }
585} {wal}
586for {set i 0} {$i < $nConn} {incr i} {
587  set c db$i
588  do_test wal3-9.1.$i {
589    sqlite3 $c test.db
590    execsql { UPDATE whoami SET x = $c }
591    execsql {
592      BEGIN;
593      SELECT * FROM whoami
594    } $c
595  } $c
596}
597for {set i 0} {$i < $nConn} {incr i} {
598  set c db$i
599  do_test wal3-9.2.$i {
600    execsql { SELECT * FROM whoami } $c
601  } $c
602}
603
604set sz [expr 1024 * (2+$AUTOVACUUM)]
605do_test wal3-9.3 {
606  for {set i 0} {$i < ($nConn-1)} {incr i} { db$i close }
607  execsql { PRAGMA wal_checkpoint }
608  byte_is_zero test.db [expr $sz-1024]
609} {1}
610do_test wal3-9.4 {
611  db[expr $nConn-1] close
612  execsql { PRAGMA wal_checkpoint }
613  set sz2 [file size test.db]
614  byte_is_zero test.db [expr $sz-1024]
615} {0}
616
617do_multiclient_test tn {
618  do_test wal3-10.$tn.1 {
619    sql1 {
620      PRAGMA page_size = 1024;
621      CREATE TABLE t1(x);
622      PRAGMA journal_mode = WAL;
623      PRAGMA wal_autocheckpoint = 100000;
624      BEGIN;
625        INSERT INTO t1 VALUES(randomblob(800));
626        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 2
627        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 4
628        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 8
629        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 16
630        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 32
631        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 64
632        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 128
633        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 256
634        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 512
635        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 1024
636        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 2048
637        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 4096
638        INSERT INTO t1 SELECT randomblob(800) FROM t1;   -- 8192
639      COMMIT;
640      CREATE INDEX i1 ON t1(x);
641    }
642
643    expr {[file size test.db-wal] > [expr 1032*9000]}
644  } 1
645
646  do_test wal3-10.$tn.2 {
647    sql2 {PRAGMA integrity_check}
648  } {ok}
649}
650
651finish_test
652