startup.c File Reference

#include "postgres.h"
#include "access/xlog.h"
#include "libpq/pqsignal.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "postmaster/interrupt.h"
#include "postmaster/startup.h"
#include "storage/ipc.h"
#include "storage/latch.h"
#include "storage/pmsignal.h"
#include "storage/procsignal.h"
#include "storage/standby.h"
#include "utils/guc.h"
#include "utils/timeout.h"

Include dependency graph for startup.c:

Go to the source code of this file.

Macros
#define	POSTMASTER_POLL_RATE_LIMIT   1024

Functions
static void	StartupProcTriggerHandler (SIGNAL_ARGS)
static void	StartupProcSigHupHandler (SIGNAL_ARGS)
static void	StartupProcExit (int code, Datum arg)
static void	StartupProcShutdownHandler (SIGNAL_ARGS)
static void	StartupRereadConfig (void)
void	HandleStartupProcInterrupts (void)
void	StartupProcessMain (void)
void	PreRestoreCommand (void)
void	PostRestoreCommand (void)
bool	IsPromoteSignaled (void)
void	ResetPromoteSignaled (void)

Variables
static volatile sig_atomic_t	got_SIGHUP = false
static volatile sig_atomic_t	shutdown_requested = false
static volatile sig_atomic_t	promote_signaled = false
static volatile sig_atomic_t	in_restore_command = false

Macro Definition Documentation

POSTMASTER_POLL_RATE_LIMIT

#define POSTMASTER_POLL_RATE_LIMIT   1024

Definition at line 45 of file startup.c.

Referenced by HandleStartupProcInterrupts().

Function Documentation

HandleStartupProcInterrupts()

void HandleStartupProcInterrupts

(

void

)

Definition at line 149 of file startup.c.

References got_SIGHUP, IsUnderPostmaster, POSTMASTER_POLL_RATE_LIMIT, PostmasterIsAlive, proc_exit(), ProcessProcSignalBarrier(), ProcSignalBarrierPending, shutdown_requested, and StartupRereadConfig().

Referenced by recoveryApplyDelay(), recoveryPausesHere(), RecoveryRequiresIntParameter(), StartupXLOG(), and WaitForWALToBecomeAvailable().

{
#ifdef POSTMASTER_POLL_RATE_LIMIT
    static uint32 postmaster_poll_count = 0;
#endif

    /*
     * Process any requests or signals received recently.
     */
    if (got_SIGHUP)
    {
        got_SIGHUP = false;
        StartupRereadConfig();
    }

    /*
     * Check if we were requested to exit without finishing recovery.
     */
    if (shutdown_requested)
        proc_exit(1);

    /*
     * Emergency bailout if postmaster has died.  This is to avoid the
     * necessity for manual cleanup of all postmaster children.  Do this less
     * frequently on systems for which we don't have signals to make that
     * cheap.
     */
    if (IsUnderPostmaster &&
#ifdef POSTMASTER_POLL_RATE_LIMIT
        postmaster_poll_count++ % POSTMASTER_POLL_RATE_LIMIT == 0 &&
#endif
        !PostmasterIsAlive())
        exit(1);

    /* Process barrier events */
    if (ProcSignalBarrierPending)
        ProcessProcSignalBarrier();
}

IsPromoteSignaled()

bool IsPromoteSignaled

(

void

)

Definition at line 274 of file startup.c.

References promote_signaled.

Referenced by CheckForStandbyTrigger().

{
    return promote_signaled;
}

PostRestoreCommand()

void PostRestoreCommand

(

void

)

Definition at line 268 of file startup.c.

References in_restore_command.

Referenced by RestoreArchivedFile().

{
    in_restore_command = false;
}

PreRestoreCommand()

void PreRestoreCommand

(

void

)

Definition at line 254 of file startup.c.

References in_restore_command, proc_exit(), and shutdown_requested.

Referenced by RestoreArchivedFile().

{
    /*
     * Set in_restore_command to tell the signal handler that we should exit
     * right away on SIGTERM. We know that we're at a safe point to do that.
     * Check if we had already received the signal, so that we don't miss a
     * shutdown request received just before this.
     */
    in_restore_command = true;
    if (shutdown_requested)
        proc_exit(1);
}

ResetPromoteSignaled()

void ResetPromoteSignaled

(

void

)

Definition at line 280 of file startup.c.

References promote_signaled.

Referenced by CheckForStandbyTrigger().

{
    promote_signaled = false;
}

StartupProcessMain()

void StartupProcessMain

(

void

)

Definition at line 207 of file startup.c.

References InitializeTimeouts(), on_shmem_exit(), PG_SETMASK, pqsignal(), proc_exit(), procsignal_sigusr1_handler(), RegisterTimeout(), SIG_DFL, SIG_IGN, SIGCHLD, SIGHUP, SIGPIPE, SIGUSR1, SIGUSR2, STANDBY_DEADLOCK_TIMEOUT, STANDBY_LOCK_TIMEOUT, STANDBY_TIMEOUT, StandbyDeadLockHandler(), StandbyLockTimeoutHandler(), StandbyTimeoutHandler(), StartupProcExit(), StartupProcShutdownHandler(), StartupProcSigHupHandler(), StartupProcTriggerHandler(), StartupXLOG(), and UnBlockSig.

Referenced by AuxiliaryProcessMain().

{
    /* Arrange to clean up at startup process exit */
    on_shmem_exit(StartupProcExit, 0);

    /*
     * Properly accept or ignore signals the postmaster might send us.
     */
    pqsignal(SIGHUP, StartupProcSigHupHandler); /* reload config file */
    pqsignal(SIGINT, SIG_IGN);  /* ignore query cancel */
    pqsignal(SIGTERM, StartupProcShutdownHandler);  /* request shutdown */
    /* SIGQUIT handler was already set up by InitPostmasterChild */
    InitializeTimeouts();       /* establishes SIGALRM handler */
    pqsignal(SIGPIPE, SIG_IGN);
    pqsignal(SIGUSR1, procsignal_sigusr1_handler);
    pqsignal(SIGUSR2, StartupProcTriggerHandler);

    /*
     * Reset some signals that are accepted by postmaster but not here
     */
    pqsignal(SIGCHLD, SIG_DFL);

    /*
     * Register timeouts needed for standby mode
     */
    RegisterTimeout(STANDBY_DEADLOCK_TIMEOUT, StandbyDeadLockHandler);
    RegisterTimeout(STANDBY_TIMEOUT, StandbyTimeoutHandler);
    RegisterTimeout(STANDBY_LOCK_TIMEOUT, StandbyLockTimeoutHandler);

    /*
     * Unblock signals (they were blocked when the postmaster forked us)
     */
    PG_SETMASK(&UnBlockSig);

    /*
     * Do what we came for.
     */
    StartupXLOG();

    /*
     * Exit normally. Exit code 0 tells postmaster that we completed recovery
     * successfully.
     */
    proc_exit(0);
}

StartupProcExit()

static void StartupProcExit ( int  code, Datum  arg  )

static

Definition at line 194 of file startup.c.

References ShutdownRecoveryTransactionEnvironment(), STANDBY_DISABLED, and standbyState.

Referenced by StartupProcessMain().

{
    /* Shutdown the recovery environment */
    if (standbyState != STANDBY_DISABLED)
        ShutdownRecoveryTransactionEnvironment();
}

StartupProcShutdownHandler()

static void StartupProcShutdownHandler ( SIGNAL_ARGS  )

static

Definition at line 100 of file startup.c.

References in_restore_command, proc_exit(), shutdown_requested, and WakeupRecovery().

Referenced by StartupProcessMain().

{
    int         save_errno = errno;

    if (in_restore_command)
        proc_exit(1);
    else
        shutdown_requested = true;
    WakeupRecovery();

    errno = save_errno;
}

StartupProcSigHupHandler()

static void StartupProcSigHupHandler ( SIGNAL_ARGS  )

static

Definition at line 88 of file startup.c.

References got_SIGHUP, and WakeupRecovery().

Referenced by StartupProcessMain().

{
    int         save_errno = errno;

    got_SIGHUP = true;
    WakeupRecovery();

    errno = save_errno;
}

StartupProcTriggerHandler()

static void StartupProcTriggerHandler ( SIGNAL_ARGS  )

static

Definition at line 76 of file startup.c.

References promote_signaled, and WakeupRecovery().

Referenced by StartupProcessMain().

{
    int         save_errno = errno;

    promote_signaled = true;
    WakeupRecovery();

    errno = save_errno;
}

StartupRereadConfig()

static void StartupRereadConfig ( void  )

static

Definition at line 120 of file startup.c.

References pfree(), PGC_SIGHUP, PrimaryConnInfo, PrimarySlotName, ProcessConfigFile(), pstrdup(), StartupRequestWalReceiverRestart(), and wal_receiver_create_temp_slot.

Referenced by HandleStartupProcInterrupts().

{
    char       *conninfo = pstrdup(PrimaryConnInfo);
    char       *slotname = pstrdup(PrimarySlotName);
    bool        tempSlot = wal_receiver_create_temp_slot;
    bool        conninfoChanged;
    bool        slotnameChanged;
    bool        tempSlotChanged = false;

    ProcessConfigFile(PGC_SIGHUP);

    conninfoChanged = strcmp(conninfo, PrimaryConnInfo) != 0;
    slotnameChanged = strcmp(slotname, PrimarySlotName) != 0;

    /*
     * wal_receiver_create_temp_slot is used only when we have no slot
     * configured.  We do not need to track this change if it has no effect.
     */
    if (!slotnameChanged && strcmp(PrimarySlotName, "") == 0)
        tempSlotChanged = tempSlot != wal_receiver_create_temp_slot;
    pfree(conninfo);
    pfree(slotname);

    if (conninfoChanged || slotnameChanged || tempSlotChanged)
        StartupRequestWalReceiverRestart();
}

Variable Documentation

got_SIGHUP

volatile sig_atomic_t got_SIGHUP = false

static

Definition at line 51 of file startup.c.

Referenced by HandleStartupProcInterrupts(), and StartupProcSigHupHandler().

in_restore_command

volatile sig_atomic_t in_restore_command = false

static

Definition at line 59 of file startup.c.

Referenced by PostRestoreCommand(), PreRestoreCommand(), and StartupProcShutdownHandler().

promote_signaled

volatile sig_atomic_t promote_signaled = false

static

Definition at line 53 of file startup.c.

Referenced by IsPromoteSignaled(), ResetPromoteSignaled(), and StartupProcTriggerHandler().

shutdown_requested

volatile sig_atomic_t shutdown_requested = false

static

Definition at line 52 of file startup.c.

Referenced by HandleStartupProcInterrupts(), PreRestoreCommand(), and StartupProcShutdownHandler().