src/bin/pg_dump/pg_backup_utils.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pg_backup_utils.c
   4  *      Utility routines shared by pg_dump and pg_restore
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2025, 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 #ifdef WIN32
  17 #include "parallel.h"
  18 #endif
  19 #include "pg_backup_utils.h"
  20
  21 /* Globals exported by this file */
  22 const char *progname = NULL;
  23
  24 #define MAX_ON_EXIT_NICELY                              20
  25
  26 static struct
  27 {
  28         on_exit_nicely_callback function;
  29         void       *arg;
  30 }                       on_exit_nicely_list[MAX_ON_EXIT_NICELY];
  31
  32 static int      on_exit_nicely_index;
  33
  34 /*
  35  * Parse a --section=foo command line argument.
  36  *
  37  * Set or update the bitmask in *dumpSections according to arg.
  38  * dumpSections is initialised as DUMP_UNSECTIONED by pg_dump and
  39  * pg_restore so they can know if this has even been called.
  40  */
  41 void
  42 set_dump_section(const char *arg, int *dumpSections)
  43 {
  44         /* if this is the first call, clear all the bits */
  45         if (*dumpSections == DUMP_UNSECTIONED)
  46                 *dumpSections = 0;
  47
  48         if (strcmp(arg, "pre-data") == 0)
  49                 *dumpSections |= DUMP_PRE_DATA;
  50         else if (strcmp(arg, "data") == 0)
  51                 *dumpSections |= DUMP_DATA;
  52         else if (strcmp(arg, "post-data") == 0)
  53                 *dumpSections |= DUMP_POST_DATA;
  54         else
  55         {
  56                 pg_log_error("unrecognized section name: \"%s\"", arg);
  57                 pg_log_error_hint("Try \"%s --help\" for more information.", progname);
  58                 exit_nicely(1);
  59         }
  60 }
  61
  62
  63 /* Register a callback to be run when exit_nicely is invoked. */
  64 void
  65 on_exit_nicely(on_exit_nicely_callback function, void *arg)
  66 {
  67         if (on_exit_nicely_index >= MAX_ON_EXIT_NICELY)
  68                 pg_fatal("out of on_exit_nicely slots");
  69         on_exit_nicely_list[on_exit_nicely_index].function = function;
  70         on_exit_nicely_list[on_exit_nicely_index].arg = arg;
  71         on_exit_nicely_index++;
  72 }
  73
  74 /*
  75  * Run accumulated on_exit_nicely callbacks in reverse order and then exit
  76  * without printing any message.
  77  *
  78  * If running in a parallel worker thread on Windows, we only exit the thread,
  79  * not the whole process.
  80  *
  81  * Note that in parallel operation on Windows, the callback(s) will be run
  82  * by each thread since the list state is necessarily shared by all threads;
  83  * each callback must contain logic to ensure it does only what's appropriate
  84  * for its thread.  On Unix, callbacks are also run by each process, but only
  85  * for callbacks established before we fork off the child processes.  (It'd
  86  * be cleaner to reset the list after fork(), and let each child establish
  87  * its own callbacks; but then the behavior would be completely inconsistent
  88  * between Windows and Unix.  For now, just be sure to establish callbacks
  89  * before forking to avoid inconsistency.)
  90  */
  91 void
  92 exit_nicely(int code)
  93 {
  94         int                     i;
  95
  96         for (i = on_exit_nicely_index - 1; i >= 0; i--)
  97                 on_exit_nicely_list[i].function(code,
  98                                                                                 on_exit_nicely_list[i].arg);
  99
 100 #ifdef WIN32
 101         if (parallel_init_done && GetCurrentThreadId() != mainThreadId)
 102                 _endthreadex(code);
 103 #endif
 104
 105         exit(code);
 106 }