1 /*-------------------------------------------------------------------------
2  *
3  * pg_backup_utils.c
4  *	Utility routines shared by pg_dump and pg_restore
5  *
6  *
7  * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/bin/pg_dump/pg_backup_utils.c
11  *
12  *-------------------------------------------------------------------------
13  */
14 #include "postgres_fe.h"
15 
16 #include "parallel.h"
17 #include "pg_backup_utils.h"
18 
19 /* Globals exported by this file */
20 const char *progname = NULL;
21 
22 #define MAX_ON_EXIT_NICELY				20
23 
24 static struct
25 {
26 	on_exit_nicely_callback function;
27 	void	   *arg;
28 }	on_exit_nicely_list[MAX_ON_EXIT_NICELY];
29 
30 static int	on_exit_nicely_index;
31 
32 /*
33  * Parse a --section=foo command line argument.
34  *
35  * Set or update the bitmask in *dumpSections according to arg.
36  * dumpSections is initialised as DUMP_UNSECTIONED by pg_dump and
37  * pg_restore so they can know if this has even been called.
38  */
39 void
set_dump_section(const char * arg,int * dumpSections)40 set_dump_section(const char *arg, int *dumpSections)
41 {
42 	/* if this is the first call, clear all the bits */
43 	if (*dumpSections == DUMP_UNSECTIONED)
44 		*dumpSections = 0;
45 
46 	if (strcmp(arg, "pre-data") == 0)
47 		*dumpSections |= DUMP_PRE_DATA;
48 	else if (strcmp(arg, "data") == 0)
49 		*dumpSections |= DUMP_DATA;
50 	else if (strcmp(arg, "post-data") == 0)
51 		*dumpSections |= DUMP_POST_DATA;
52 	else
53 	{
54 		fprintf(stderr, _("%s: unrecognized section name: \"%s\"\n"),
55 				progname, arg);
56 		fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
57 				progname);
58 		exit_nicely(1);
59 	}
60 }
61 
62 
63 /*
64  * Write a printf-style message to stderr.
65  *
66  * The program name is prepended, if "progname" has been set.
67  * Also, if modulename isn't NULL, that's included too.
68  * Note that we'll try to translate the modulename and the fmt string.
69  */
70 void
write_msg(const char * modulename,const char * fmt,...)71 write_msg(const char *modulename, const char *fmt,...)
72 {
73 	va_list		ap;
74 
75 	va_start(ap, fmt);
76 	vwrite_msg(modulename, fmt, ap);
77 	va_end(ap);
78 }
79 
80 /*
81  * As write_msg, but pass a va_list not variable arguments.
82  */
83 void
vwrite_msg(const char * modulename,const char * fmt,va_list ap)84 vwrite_msg(const char *modulename, const char *fmt, va_list ap)
85 {
86 	if (progname)
87 	{
88 		if (modulename)
89 			fprintf(stderr, "%s: [%s] ", progname, _(modulename));
90 		else
91 			fprintf(stderr, "%s: ", progname);
92 	}
93 	vfprintf(stderr, _(fmt), ap);
94 }
95 
96 /*
97  * Fail and die, with a message to stderr.  Parameters as for write_msg.
98  *
99  * Note that on_exit_nicely callbacks will get run.
100  */
101 void
exit_horribly(const char * modulename,const char * fmt,...)102 exit_horribly(const char *modulename, const char *fmt,...)
103 {
104 	va_list		ap;
105 
106 	va_start(ap, fmt);
107 	vwrite_msg(modulename, fmt, ap);
108 	va_end(ap);
109 
110 	exit_nicely(1);
111 }
112 
113 /* Register a callback to be run when exit_nicely is invoked. */
114 void
on_exit_nicely(on_exit_nicely_callback function,void * arg)115 on_exit_nicely(on_exit_nicely_callback function, void *arg)
116 {
117 	if (on_exit_nicely_index >= MAX_ON_EXIT_NICELY)
118 		exit_horribly(NULL, "out of on_exit_nicely slots\n");
119 	on_exit_nicely_list[on_exit_nicely_index].function = function;
120 	on_exit_nicely_list[on_exit_nicely_index].arg = arg;
121 	on_exit_nicely_index++;
122 }
123 
124 /*
125  * Run accumulated on_exit_nicely callbacks in reverse order and then exit
126  * without printing any message.
127  *
128  * If running in a parallel worker thread on Windows, we only exit the thread,
129  * not the whole process.
130  *
131  * Note that in parallel operation on Windows, the callback(s) will be run
132  * by each thread since the list state is necessarily shared by all threads;
133  * each callback must contain logic to ensure it does only what's appropriate
134  * for its thread.  On Unix, callbacks are also run by each process, but only
135  * for callbacks established before we fork off the child processes.  (It'd
136  * be cleaner to reset the list after fork(), and let each child establish
137  * its own callbacks; but then the behavior would be completely inconsistent
138  * between Windows and Unix.  For now, just be sure to establish callbacks
139  * before forking to avoid inconsistency.)
140  */
141 void
exit_nicely(int code)142 exit_nicely(int code)
143 {
144 	int			i;
145 
146 	for (i = on_exit_nicely_index - 1; i >= 0; i--)
147 		(*on_exit_nicely_list[i].function) (code,
148 											on_exit_nicely_list[i].arg);
149 
150 #ifdef WIN32
151 	if (parallel_init_done && GetCurrentThreadId() != mainThreadId)
152 		_endthreadex(code);
153 #endif
154 
155 	exit(code);
156 }
157