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Defines
#define	POSTMASTER_FD_WATCH 0
#define	POSTMASTER_FD_OWN 1
#define	MAX_BACKENDS 0x7fffff
Functions
void	PostmasterMain (int argc, char *argv[]) __attribute__((noreturn))
void	ClosePostmasterPorts (bool am_syslogger)
int	MaxLivePostmasterChildren (void)
int	GetNumShmemAttachedBgworkers (void)
Variables
bool	EnableSSL
int	ReservedBackends
int	PostPortNumber
int	Unix_socket_permissions
char *	Unix_socket_group
char *	Unix_socket_directories
char *	ListenAddresses
bool	ClientAuthInProgress
int	PreAuthDelay
int	AuthenticationTimeout
bool	Log_connections
bool	log_hostname
bool	enable_bonjour
char *	bonjour_name
bool	restart_after_crash
int	postmaster_alive_fds [2]
const char *	progname

Define Documentation

#define MAX_BACKENDS 0x7fffff

Definition at line 71 of file postmaster.h.

Referenced by check_autovacuum_max_workers(), check_maxconnections(), InitializeMaxBackends(), and RegisterBackgroundWorker().

#define POSTMASTER_FD_OWN 1

Definition at line 44 of file postmaster.h.

Referenced by ClosePostmasterPorts().

#define POSTMASTER_FD_WATCH 0

Definition at line 42 of file postmaster.h.

Referenced by InitPostmasterDeathWatchHandle(), PostmasterIsAlive(), and WaitLatchOrSocket().

Function Documentation

void ClosePostmasterPorts ( bool am_syslogger )

Definition at line 2199 of file postmaster.c.

References close, ereport, errcode_for_file_access(), errmsg_internal(), FATAL, ListenSocket, PGINVALID_SOCKET, POSTMASTER_FD_OWN, StreamClose(), and syslogPipe.

Referenced by BackendStartup(), pgarch_start(), pgstat_start(), start_bgworker(), StartAutoVacLauncher(), StartAutoVacWorker(), StartChildProcess(), and SysLogger_Start().

{
    int         i;

#ifndef WIN32

    /*
     * Close the write end of postmaster death watch pipe. It's important to
     * do this as early as possible, so that if postmaster dies, others won't
     * think that it's still running because we're holding the pipe open.
     */
    if (close(postmaster_alive_fds[POSTMASTER_FD_OWN]))
        ereport(FATAL,
                (errcode_for_file_access(),
                 errmsg_internal("could not close postmaster death monitoring pipe in child process: %m")));
    postmaster_alive_fds[POSTMASTER_FD_OWN] = -1;
#endif

    /* Close the listen sockets */
    for (i = 0; i < MAXLISTEN; i++)
    {
        if (ListenSocket[i] != PGINVALID_SOCKET)
        {
            StreamClose(ListenSocket[i]);
            ListenSocket[i] = PGINVALID_SOCKET;
        }
    }

    /* If using syslogger, close the read side of the pipe */
    if (!am_syslogger)
    {
#ifndef WIN32
        if (syslogPipe[0] >= 0)
            close(syslogPipe[0]);
        syslogPipe[0] = -1;
#else
        if (syslogPipe[0])
            CloseHandle(syslogPipe[0]);
        syslogPipe[0] = 0;
#endif
    }

#ifdef USE_BONJOUR
    /* If using Bonjour, close the connection to the mDNS daemon */
    if (bonjour_sdref)
        close(DNSServiceRefSockFD(bonjour_sdref));
#endif
}

int GetNumShmemAttachedBgworkers ( void )

Definition at line 5540 of file postmaster.c.

References BGWORKER_SHMEM_ACCESS, and GetNumRegisteredBackgroundWorkers().

Referenced by check_autovacuum_max_workers(), check_maxconnections(), and InitializeMaxBackends().

{
    return GetNumRegisteredBackgroundWorkers(BGWORKER_SHMEM_ACCESS);
}

int MaxLivePostmasterChildren ( void )

Definition at line 5130 of file postmaster.c.

References autovacuum_max_workers, GetNumRegisteredBackgroundWorkers(), and MaxConnections.

Referenced by canAcceptConnections(), PMSignalShmemInit(), PMSignalShmemSize(), and processCancelRequest().

{
    return 2 * (MaxConnections + autovacuum_max_workers + 1 +
                GetNumRegisteredBackgroundWorkers(0));
}

void PostmasterMain	(	int	argc,
		char *	argv[]
	)

Definition at line 557 of file postmaster.c.

References AddToDataDirLockFile(), ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE, ALLOCSET_DEFAULT_MINSIZE, AllocSetContextCreate(), Assert, autovac_init(), BlockSig, bonjour_name, ChangeToDataDir(), checkDataDir(), CheckDateTokenTables(), CreateDataDirLockFile(), CreateOptsFile(), DEBUG3, dummy_handler(), elog, enable_bonjour, EnableSSL, environ, ereport, errcode(), errmsg(), errmsg_internal(), ERROR, ExitPostmaster(), external_pid_file, ExtraOptions, FATAL, free, get_stats_option_name(), GetConfigOption(), GetCurrentTimestamp(), getInstallationPaths(), getopt(), gettimeofday(), i, InitializeGUCOptions(), InitializeMaxBackends(), InitPostmasterDeathWatchHandle(), IsBinaryUpgrade, IsPostmasterEnvironment, lfirst, list_free(), list_free_deep(), ListenAddresses, ListenSocket, load_hba(), load_ident(), LOCK_FILE_LINE_LISTEN_ADDR, LOCK_FILE_LINE_SOCKET_DIR, LOG, max_wal_senders, MaxConnections, MemoryContextInit(), MemoryContextSwitchTo(), my_exec_path, MyProcPid, MyStartTime, name, NIL, NULL, on_proc_exit(), optarg, opterr, optind, output_config_variable, ParseLongOption(), pfree(), PG_SETMASK, PGC_POSTMASTER, PGC_S_ARGV, PGINVALID_SOCKET, PgStartTime, pgstat_init(), pmdie(), pmState, PostmasterContext, PostmasterPid, PostPortNumber, pqinitmask(), pqsignal(), process_shared_preload_libraries(), progname, pstrdup(), random_start_time, reaper(), Reinit, RemovePgTempFiles(), ReservedBackends, reset_shared(), S_IRGRP, S_IROTH, S_IRWXG, S_IRWXO, secure_initialize(), SelectConfigFiles(), SendStop, ServerLoop(), set_debug_options(), set_max_safe_fds(), set_plan_disabling_options(), set_stack_base(), SetConfigOption(), SIG_IGN, SIGALRM, SIGCHLD, SIGHUP, SIGHUP_handler(), SIGPIPE, SIGQUIT, SIGTTIN, SIGTTOU, SIGUSR1, sigusr1_handler(), SIGUSR2, snprintf(), SplitDirectoriesString(), SplitIdentifierString(), StartOneBackgroundWorker(), StartupDataBase, StartupPID, STATUS_OK, StreamServerPort(), strerror(), SysLogger_Start(), SysLoggerPID, TopMemoryContext, Unix_socket_directories, unlink_external_pid_file(), userDoption, value, wal_level, WAL_LEVEL_MINIMAL, WARNING, whereToSendOutput, write_stderr, and XLogArchiveMode.

Referenced by main().

{
    int         opt;
    int         status;
    char       *userDoption = NULL;
    bool        listen_addr_saved = false;
    int         i;

    MyProcPid = PostmasterPid = getpid();

    MyStartTime = time(NULL);

    IsPostmasterEnvironment = true;

    /*
     * for security, no dir or file created can be group or other accessible
     */
    umask(S_IRWXG | S_IRWXO);

    /*
     * Fire up essential subsystems: memory management
     */
    MemoryContextInit();

    /*
     * By default, palloc() requests in the postmaster will be allocated in
     * the PostmasterContext, which is space that can be recycled by backends.
     * Allocated data that needs to be available to backends should be
     * allocated in TopMemoryContext.
     */
    PostmasterContext = AllocSetContextCreate(TopMemoryContext,
                                              "Postmaster",
                                              ALLOCSET_DEFAULT_MINSIZE,
                                              ALLOCSET_DEFAULT_INITSIZE,
                                              ALLOCSET_DEFAULT_MAXSIZE);
    MemoryContextSwitchTo(PostmasterContext);

    /* Initialize paths to installation files */
    getInstallationPaths(argv[0]);

    /*
     * Options setup
     */
    InitializeGUCOptions();

    opterr = 1;

    /*
     * Parse command-line options.  CAUTION: keep this in sync with
     * tcop/postgres.c (the option sets should not conflict) and with the
     * common help() function in main/main.c.
     */
    while ((opt = getopt(argc, argv, "A:B:bc:C:D:d:EeFf:h:ijk:lN:nOo:Pp:r:S:sTt:W:-:")) != -1)
    {
        switch (opt)
        {
            case 'A':
                SetConfigOption("debug_assertions", optarg, PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'B':
                SetConfigOption("shared_buffers", optarg, PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'b':
                /* Undocumented flag used for binary upgrades */
                IsBinaryUpgrade = true;
                break;

            case 'C':
                output_config_variable = strdup(optarg);
                break;

            case 'D':
                userDoption = strdup(optarg);
                break;

            case 'd':
                set_debug_options(atoi(optarg), PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'E':
                SetConfigOption("log_statement", "all", PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'e':
                SetConfigOption("datestyle", "euro", PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'F':
                SetConfigOption("fsync", "false", PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'f':
                if (!set_plan_disabling_options(optarg, PGC_POSTMASTER, PGC_S_ARGV))
                {
                    write_stderr("%s: invalid argument for option -f: \"%s\"\n",
                                 progname, optarg);
                    ExitPostmaster(1);
                }
                break;

            case 'h':
                SetConfigOption("listen_addresses", optarg, PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'i':
                SetConfigOption("listen_addresses", "*", PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'j':
                /* only used by interactive backend */
                break;

            case 'k':
                SetConfigOption("unix_socket_directories", optarg, PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'l':
                SetConfigOption("ssl", "true", PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'N':
                SetConfigOption("max_connections", optarg, PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'n':
                /* Don't reinit shared mem after abnormal exit */
                Reinit = false;
                break;

            case 'O':
                SetConfigOption("allow_system_table_mods", "true", PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'o':
                /* Other options to pass to the backend on the command line */
                snprintf(ExtraOptions + strlen(ExtraOptions),
                         sizeof(ExtraOptions) - strlen(ExtraOptions),
                         " %s", optarg);
                break;

            case 'P':
                SetConfigOption("ignore_system_indexes", "true", PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'p':
                SetConfigOption("port", optarg, PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'r':
                /* only used by single-user backend */
                break;

            case 'S':
                SetConfigOption("work_mem", optarg, PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 's':
                SetConfigOption("log_statement_stats", "true", PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'T':

                /*
                 * In the event that some backend dumps core, send SIGSTOP,
                 * rather than SIGQUIT, to all its peers.  This lets the wily
                 * post_hacker collect core dumps from everyone.
                 */
                SendStop = true;
                break;

            case 't':
                {
                    const char *tmp = get_stats_option_name(optarg);

                    if (tmp)
                    {
                        SetConfigOption(tmp, "true", PGC_POSTMASTER, PGC_S_ARGV);
                    }
                    else
                    {
                        write_stderr("%s: invalid argument for option -t: \"%s\"\n",
                                     progname, optarg);
                        ExitPostmaster(1);
                    }
                    break;
                }

            case 'W':
                SetConfigOption("post_auth_delay", optarg, PGC_POSTMASTER, PGC_S_ARGV);
                break;

            case 'c':
            case '-':
                {
                    char       *name,
                               *value;

                    ParseLongOption(optarg, &name, &value);
                    if (!value)
                    {
                        if (opt == '-')
                            ereport(ERROR,
                                    (errcode(ERRCODE_SYNTAX_ERROR),
                                     errmsg("--%s requires a value",
                                            optarg)));
                        else
                            ereport(ERROR,
                                    (errcode(ERRCODE_SYNTAX_ERROR),
                                     errmsg("-c %s requires a value",
                                            optarg)));
                    }

                    SetConfigOption(name, value, PGC_POSTMASTER, PGC_S_ARGV);
                    free(name);
                    if (value)
                        free(value);
                    break;
                }

            default:
                write_stderr("Try \"%s --help\" for more information.\n",
                             progname);
                ExitPostmaster(1);
        }
    }

    /*
     * Postmaster accepts no non-option switch arguments.
     */
    if (optind < argc)
    {
        write_stderr("%s: invalid argument: \"%s\"\n",
                     progname, argv[optind]);
        write_stderr("Try \"%s --help\" for more information.\n",
                     progname);
        ExitPostmaster(1);
    }

    /*
     * Locate the proper configuration files and data directory, and read
     * postgresql.conf for the first time.
     */
    if (!SelectConfigFiles(userDoption, progname))
        ExitPostmaster(2);

    if (output_config_variable != NULL)
    {
        /*
         * permission is handled because the user is reading inside the data
         * dir
         */
        puts(GetConfigOption(output_config_variable, false, false));
        ExitPostmaster(0);
    }

    /* Verify that DataDir looks reasonable */
    checkDataDir();

    /* And switch working directory into it */
    ChangeToDataDir();

    /*
     * Check for invalid combinations of GUC settings.
     */
    if (ReservedBackends >= MaxConnections)
    {
        write_stderr("%s: superuser_reserved_connections must be less than max_connections\n", progname);
        ExitPostmaster(1);
    }
    if (max_wal_senders >= MaxConnections)
    {
        write_stderr("%s: max_wal_senders must be less than max_connections\n", progname);
        ExitPostmaster(1);
    }
    if (XLogArchiveMode && wal_level == WAL_LEVEL_MINIMAL)
        ereport(ERROR,
                (errmsg("WAL archival (archive_mode=on) requires wal_level \"archive\" or \"hot_standby\"")));
    if (max_wal_senders > 0 && wal_level == WAL_LEVEL_MINIMAL)
        ereport(ERROR,
                (errmsg("WAL streaming (max_wal_senders > 0) requires wal_level \"archive\" or \"hot_standby\"")));

    /*
     * Other one-time internal sanity checks can go here, if they are fast.
     * (Put any slow processing further down, after postmaster.pid creation.)
     */
    if (!CheckDateTokenTables())
    {
        write_stderr("%s: invalid datetoken tables, please fix\n", progname);
        ExitPostmaster(1);
    }

    /*
     * Now that we are done processing the postmaster arguments, reset
     * getopt(3) library so that it will work correctly in subprocesses.
     */
    optind = 1;
#ifdef HAVE_INT_OPTRESET
    optreset = 1;               /* some systems need this too */
#endif

    /* For debugging: display postmaster environment */
    {
        extern char **environ;
        char      **p;

        ereport(DEBUG3,
            (errmsg_internal("%s: PostmasterMain: initial environment dump:",
                             progname)));
        ereport(DEBUG3,
             (errmsg_internal("-----------------------------------------")));
        for (p = environ; *p; ++p)
            ereport(DEBUG3,
                    (errmsg_internal("\t%s", *p)));
        ereport(DEBUG3,
             (errmsg_internal("-----------------------------------------")));
    }

    /*
     * Create lockfile for data directory.
     *
     * We want to do this before we try to grab the input sockets, because the
     * data directory interlock is more reliable than the socket-file
     * interlock (thanks to whoever decided to put socket files in /tmp :-().
     * For the same reason, it's best to grab the TCP socket(s) before the
     * Unix socket(s).
     */
    CreateDataDirLockFile(true);

    /*
     * Initialize SSL library, if specified.
     */
#ifdef USE_SSL
    if (EnableSSL)
        secure_initialize();
#endif

    /*
     * process any libraries that should be preloaded at postmaster start
     */
    process_shared_preload_libraries();

    /*
     * Now that loadable modules have had their chance to register background
     * workers, calculate MaxBackends.
     */
    InitializeMaxBackends();

    /*
     * Establish input sockets.
     */
    for (i = 0; i < MAXLISTEN; i++)
        ListenSocket[i] = PGINVALID_SOCKET;

    if (ListenAddresses)
    {
        char       *rawstring;
        List       *elemlist;
        ListCell   *l;
        int         success = 0;

        /* Need a modifiable copy of ListenAddresses */
        rawstring = pstrdup(ListenAddresses);

        /* Parse string into list of hostnames */
        if (!SplitIdentifierString(rawstring, ',', &elemlist))
        {
            /* syntax error in list */
            ereport(FATAL,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("invalid list syntax for \"listen_addresses\"")));
        }

        foreach(l, elemlist)
        {
            char       *curhost = (char *) lfirst(l);

            if (strcmp(curhost, "*") == 0)
                status = StreamServerPort(AF_UNSPEC, NULL,
                                          (unsigned short) PostPortNumber,
                                          NULL,
                                          ListenSocket, MAXLISTEN);
            else
                status = StreamServerPort(AF_UNSPEC, curhost,
                                          (unsigned short) PostPortNumber,
                                          NULL,
                                          ListenSocket, MAXLISTEN);

            if (status == STATUS_OK)
            {
                success++;
                /* record the first successful host addr in lockfile */
                if (!listen_addr_saved)
                {
                    AddToDataDirLockFile(LOCK_FILE_LINE_LISTEN_ADDR, curhost);
                    listen_addr_saved = true;
                }
            }
            else
                ereport(WARNING,
                        (errmsg("could not create listen socket for \"%s\"",
                                curhost)));
        }

        if (!success && elemlist != NIL)
            ereport(FATAL,
                    (errmsg("could not create any TCP/IP sockets")));

        list_free(elemlist);
        pfree(rawstring);
    }

#ifdef USE_BONJOUR
    /* Register for Bonjour only if we opened TCP socket(s) */
    if (enable_bonjour && ListenSocket[0] != PGINVALID_SOCKET)
    {
        DNSServiceErrorType err;

        /*
         * We pass 0 for interface_index, which will result in registering on
         * all "applicable" interfaces.  It's not entirely clear from the
         * DNS-SD docs whether this would be appropriate if we have bound to
         * just a subset of the available network interfaces.
         */
        err = DNSServiceRegister(&bonjour_sdref,
                                 0,
                                 0,
                                 bonjour_name,
                                 "_postgresql._tcp.",
                                 NULL,
                                 NULL,
                                 htons(PostPortNumber),
                                 0,
                                 NULL,
                                 NULL,
                                 NULL);
        if (err != kDNSServiceErr_NoError)
            elog(LOG, "DNSServiceRegister() failed: error code %ld",
                 (long) err);

        /*
         * We don't bother to read the mDNS daemon's reply, and we expect that
         * it will automatically terminate our registration when the socket is
         * closed at postmaster termination.  So there's nothing more to be
         * done here.  However, the bonjour_sdref is kept around so that
         * forked children can close their copies of the socket.
         */
    }
#endif

#ifdef HAVE_UNIX_SOCKETS
    if (Unix_socket_directories)
    {
        char       *rawstring;
        List       *elemlist;
        ListCell   *l;
        int         success = 0;

        /* Need a modifiable copy of Unix_socket_directories */
        rawstring = pstrdup(Unix_socket_directories);

        /* Parse string into list of directories */
        if (!SplitDirectoriesString(rawstring, ',', &elemlist))
        {
            /* syntax error in list */
            ereport(FATAL,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("invalid list syntax for \"unix_socket_directories\"")));
        }

        foreach(l, elemlist)
        {
            char       *socketdir = (char *) lfirst(l);

            status = StreamServerPort(AF_UNIX, NULL,
                                      (unsigned short) PostPortNumber,
                                      socketdir,
                                      ListenSocket, MAXLISTEN);

            if (status == STATUS_OK)
            {
                success++;
                /* record the first successful Unix socket in lockfile */
                if (success == 1)
                    AddToDataDirLockFile(LOCK_FILE_LINE_SOCKET_DIR, socketdir);
            }
            else
                ereport(WARNING,
                        (errmsg("could not create Unix-domain socket in directory \"%s\"",
                                socketdir)));
        }

        if (!success && elemlist != NIL)
            ereport(FATAL,
                    (errmsg("could not create any Unix-domain sockets")));

        list_free_deep(elemlist);
        pfree(rawstring);
    }
#endif

    /*
     * check that we have some socket to listen on
     */
    if (ListenSocket[0] == PGINVALID_SOCKET)
        ereport(FATAL,
                (errmsg("no socket created for listening")));

    /*
     * If no valid TCP ports, write an empty line for listen address,
     * indicating the Unix socket must be used.  Note that this line is not
     * added to the lock file until there is a socket backing it.
     */
    if (!listen_addr_saved)
        AddToDataDirLockFile(LOCK_FILE_LINE_LISTEN_ADDR, "");

    /*
     * Set up shared memory and semaphores.
     */
    reset_shared(PostPortNumber);

    /*
     * Estimate number of openable files.  This must happen after setting up
     * semaphores, because on some platforms semaphores count as open files.
     */
    set_max_safe_fds();

    /*
     * Set reference point for stack-depth checking.
     */
    set_stack_base();

    /*
     * Initialize pipe (or process handle on Windows) that allows children to
     * wake up from sleep on postmaster death.
     */
    InitPostmasterDeathWatchHandle();

#ifdef WIN32

    /*
     * Initialize I/O completion port used to deliver list of dead children.
     */
    win32ChildQueue = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 1);
    if (win32ChildQueue == NULL)
        ereport(FATAL,
           (errmsg("could not create I/O completion port for child queue")));
#endif

    /*
     * Record postmaster options.  We delay this till now to avoid recording
     * bogus options (eg, NBuffers too high for available memory).
     */
    if (!CreateOptsFile(argc, argv, my_exec_path))
        ExitPostmaster(1);

#ifdef EXEC_BACKEND
    /* Write out nondefault GUC settings for child processes to use */
    write_nondefault_variables(PGC_POSTMASTER);
#endif

    /*
     * Write the external PID file if requested
     */
    if (external_pid_file)
    {
        FILE       *fpidfile = fopen(external_pid_file, "w");

        if (fpidfile)
        {
            fprintf(fpidfile, "%d\n", MyProcPid);
            fclose(fpidfile);

            /* Make PID file world readable */
            if (chmod(external_pid_file, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH) != 0)
                write_stderr("%s: could not change permissions of external PID file \"%s\": %s\n",
                             progname, external_pid_file, strerror(errno));
        }
        else
            write_stderr("%s: could not write external PID file \"%s\": %s\n",
                         progname, external_pid_file, strerror(errno));

        on_proc_exit(unlink_external_pid_file, 0);
    }

    /*
     * Set up signal handlers for the postmaster process.
     *
     * CAUTION: when changing this list, check for side-effects on the signal
     * handling setup of child processes.  See tcop/postgres.c,
     * bootstrap/bootstrap.c, postmaster/bgwriter.c, postmaster/walwriter.c,
     * postmaster/autovacuum.c, postmaster/pgarch.c, postmaster/pgstat.c,
     * postmaster/syslogger.c, postmaster/bgworker.c and
     * postmaster/checkpointer.c.
     */
    pqinitmask();
    PG_SETMASK(&BlockSig);

    pqsignal(SIGHUP, SIGHUP_handler);   /* reread config file and have
                                         * children do same */
    pqsignal(SIGINT, pmdie);    /* send SIGTERM and shut down */
    pqsignal(SIGQUIT, pmdie);   /* send SIGQUIT and die */
    pqsignal(SIGTERM, pmdie);   /* wait for children and shut down */
    pqsignal(SIGALRM, SIG_IGN); /* ignored */
    pqsignal(SIGPIPE, SIG_IGN); /* ignored */
    pqsignal(SIGUSR1, sigusr1_handler); /* message from child process */
    pqsignal(SIGUSR2, dummy_handler);   /* unused, reserve for children */
    pqsignal(SIGCHLD, reaper);  /* handle child termination */
    pqsignal(SIGTTIN, SIG_IGN); /* ignored */
    pqsignal(SIGTTOU, SIG_IGN); /* ignored */
    /* ignore SIGXFSZ, so that ulimit violations work like disk full */
#ifdef SIGXFSZ
    pqsignal(SIGXFSZ, SIG_IGN); /* ignored */
#endif

    /*
     * If enabled, start up syslogger collection subprocess
     */
    SysLoggerPID = SysLogger_Start();

    /*
     * Reset whereToSendOutput from DestDebug (its starting state) to
     * DestNone. This stops ereport from sending log messages to stderr unless
     * Log_destination permits.  We don't do this until the postmaster is
     * fully launched, since startup failures may as well be reported to
     * stderr.
     */
    whereToSendOutput = DestNone;

    /*
     * Initialize stats collection subsystem (this does NOT start the
     * collector process!)
     */
    pgstat_init();

    /*
     * Initialize the autovacuum subsystem (again, no process start yet)
     */
    autovac_init();

    /*
     * Load configuration files for client authentication.
     */
    if (!load_hba())
    {
        /*
         * It makes no sense to continue if we fail to load the HBA file,
         * since there is no way to connect to the database in this case.
         */
        ereport(FATAL,
                (errmsg("could not load pg_hba.conf")));
    }
    if (!load_ident())
    {
        /*
         * We can start up without the IDENT file, although it means that you
         * cannot log in using any of the authentication methods that need a
         * user name mapping. load_ident() already logged the details of
         * error to the log.
         */
    }


    /*
     * Remove old temporary files.  At this point there can be no other
     * Postgres processes running in this directory, so this should be safe.
     */
    RemovePgTempFiles();

    /*
     * Remember postmaster startup time
     */
    PgStartTime = GetCurrentTimestamp();
    /* PostmasterRandom wants its own copy */
    gettimeofday(&random_start_time, NULL);

    /*
     * We're ready to rock and roll...
     */
    StartupPID = StartupDataBase();
    Assert(StartupPID != 0);
    pmState = PM_STARTUP;

    /* Some workers may be scheduled to start now */
    StartOneBackgroundWorker();

    status = ServerLoop();

    /*
     * ServerLoop probably shouldn't ever return, but if it does, close down.
     */
    ExitPostmaster(status != STATUS_OK);

    abort();                    /* not reached */
}