Refactor xlog.c to create src/backend/postmaster/startup.c

Startup process now has its own dedicated file, just like all other
special/background processes. Reduces role and size of xlog.c
This commit is contained in:
Simon Riggs 2011-11-02 14:25:01 +00:00
parent 86e3364899
commit 9aceb6ab3c
7 changed files with 291 additions and 197 deletions

View File

@ -41,6 +41,7 @@
#include "miscadmin.h" #include "miscadmin.h"
#include "pgstat.h" #include "pgstat.h"
#include "postmaster/bgwriter.h" #include "postmaster/bgwriter.h"
#include "postmaster/startup.h"
#include "replication/walreceiver.h" #include "replication/walreceiver.h"
#include "replication/walsender.h" #include "replication/walsender.h"
#include "storage/bufmgr.h" #include "storage/bufmgr.h"
@ -584,19 +585,6 @@ typedef struct xl_restore_point
char rp_name[MAXFNAMELEN]; char rp_name[MAXFNAMELEN];
} xl_restore_point; } xl_restore_point;
/*
* Flags set by interrupt handlers for later service in the redo loop.
*/
static volatile sig_atomic_t got_SIGHUP = false;
static volatile sig_atomic_t shutdown_requested = false;
static volatile sig_atomic_t promote_triggered = false;
/*
* Flag set when executing a restore command, to tell SIGTERM signal handler
* that it's safe to just proc_exit.
*/
static volatile sig_atomic_t in_restore_command = false;
static void XLogArchiveNotify(const char *xlog); static void XLogArchiveNotify(const char *xlog);
static void XLogArchiveNotifySeg(uint32 log, uint32 seg); static void XLogArchiveNotifySeg(uint32 log, uint32 seg);
@ -3068,21 +3056,16 @@ RestoreArchivedFile(char *path, const char *xlogfname,
xlogRestoreCmd))); xlogRestoreCmd)));
/* /*
* Set in_restore_command to tell the signal handler that we should exit * Check signals before restore command and reset afterwards.
* 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; PreRestoreCommand();
if (shutdown_requested)
proc_exit(1);
/* /*
* Copy xlog from archival storage to XLOGDIR * Copy xlog from archival storage to XLOGDIR
*/ */
rc = system(xlogRestoreCmd); rc = system(xlogRestoreCmd);
in_restore_command = false; PostRestoreCommand();
if (rc == 0) if (rc == 0)
{ {
@ -9946,177 +9929,6 @@ CancelBackup(void)
} }
} }
/* ------------------------------------------------------
* Startup Process main entry point and signal handlers
* ------------------------------------------------------
*/
/*
* startupproc_quickdie() occurs when signalled SIGQUIT by the postmaster.
*
* Some backend has bought the farm,
* so we need to stop what we're doing and exit.
*/
static void
startupproc_quickdie(SIGNAL_ARGS)
{
PG_SETMASK(&BlockSig);
/*
* We DO NOT want to run proc_exit() callbacks -- we're here because
* shared memory may be corrupted, so we don't want to try to clean up our
* transaction. Just nail the windows shut and get out of town. Now that
* there's an atexit callback to prevent third-party code from breaking
* things by calling exit() directly, we have to reset the callbacks
* explicitly to make this work as intended.
*/
on_exit_reset();
/*
* Note we do exit(2) not exit(0). This is to force the postmaster into a
* system reset cycle if some idiot DBA sends a manual SIGQUIT to a random
* backend. This is necessary precisely because we don't clean up our
* shared memory state. (The "dead man switch" mechanism in pmsignal.c
* should ensure the postmaster sees this as a crash, too, but no harm in
* being doubly sure.)
*/
exit(2);
}
/* SIGUSR1: let latch facility handle the signal */
static void
StartupProcSigUsr1Handler(SIGNAL_ARGS)
{
int save_errno = errno;
latch_sigusr1_handler();
errno = save_errno;
}
/* SIGUSR2: set flag to finish recovery */
static void
StartupProcTriggerHandler(SIGNAL_ARGS)
{
int save_errno = errno;
promote_triggered = true;
WakeupRecovery();
errno = save_errno;
}
/* SIGHUP: set flag to re-read config file at next convenient time */
static void
StartupProcSigHupHandler(SIGNAL_ARGS)
{
int save_errno = errno;
got_SIGHUP = true;
WakeupRecovery();
errno = save_errno;
}
/* SIGTERM: set flag to abort redo and exit */
static void
StartupProcShutdownHandler(SIGNAL_ARGS)
{
int save_errno = errno;
if (in_restore_command)
proc_exit(1);
else
shutdown_requested = true;
WakeupRecovery();
errno = save_errno;
}
/* Handle SIGHUP and SIGTERM signals of startup process */
void
HandleStartupProcInterrupts(void)
{
/*
* Check if we were requested to re-read config file.
*/
if (got_SIGHUP)
{
got_SIGHUP = false;
ProcessConfigFile(PGC_SIGHUP);
}
/*
* 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.
*/
if (IsUnderPostmaster && !PostmasterIsAlive())
exit(1);
}
/* Main entry point for startup process */
void
StartupProcessMain(void)
{
/*
* If possible, make this process a group leader, so that the postmaster
* can signal any child processes too.
*/
#ifdef HAVE_SETSID
if (setsid() < 0)
elog(FATAL, "setsid() failed: %m");
#endif
/*
* Properly accept or ignore signals the postmaster might send us.
*
* Note: ideally we'd not enable handle_standby_sig_alarm unless actually
* doing hot standby, but we don't know that yet. Rely on it to not do
* anything if it shouldn't.
*/
pqsignal(SIGHUP, StartupProcSigHupHandler); /* reload config file */
pqsignal(SIGINT, SIG_IGN); /* ignore query cancel */
pqsignal(SIGTERM, StartupProcShutdownHandler); /* request shutdown */
pqsignal(SIGQUIT, startupproc_quickdie); /* hard crash time */
if (EnableHotStandby)
pqsignal(SIGALRM, handle_standby_sig_alarm); /* ignored unless
* InHotStandby */
else
pqsignal(SIGALRM, SIG_IGN);
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, StartupProcSigUsr1Handler);
pqsignal(SIGUSR2, StartupProcTriggerHandler);
/*
* Reset some signals that are accepted by postmaster but not here
*/
pqsignal(SIGCHLD, SIG_DFL);
pqsignal(SIGTTIN, SIG_DFL);
pqsignal(SIGTTOU, SIG_DFL);
pqsignal(SIGCONT, SIG_DFL);
pqsignal(SIGWINCH, SIG_DFL);
/*
* Unblock signals (they were blocked when the postmaster forked us)
*/
PG_SETMASK(&UnBlockSig);
StartupXLOG();
/*
* Exit normally. Exit code 0 tells postmaster that we completed recovery
* successfully.
*/
proc_exit(0);
}
/* /*
* Read the XLOG page containing RecPtr into readBuf (if not read already). * Read the XLOG page containing RecPtr into readBuf (if not read already).
* Returns true if the page is read successfully. * Returns true if the page is read successfully.
@ -10564,12 +10376,12 @@ CheckForStandbyTrigger(void)
if (triggered) if (triggered)
return true; return true;
if (promote_triggered) if (IsPromoteTriggered())
{ {
ereport(LOG, ereport(LOG,
(errmsg("received promote request"))); (errmsg("received promote request")));
ShutdownWalRcv(); ShutdownWalRcv();
promote_triggered = false; ResetPromoteTriggered();
triggered = true; triggered = true;
return true; return true;
} }

View File

@ -29,6 +29,7 @@
#include "miscadmin.h" #include "miscadmin.h"
#include "nodes/makefuncs.h" #include "nodes/makefuncs.h"
#include "postmaster/bgwriter.h" #include "postmaster/bgwriter.h"
#include "postmaster/startup.h"
#include "postmaster/walwriter.h" #include "postmaster/walwriter.h"
#include "replication/walreceiver.h" #include "replication/walreceiver.h"
#include "storage/bufmgr.h" #include "storage/bufmgr.h"

View File

@ -13,6 +13,6 @@ top_builddir = ../../..
include $(top_builddir)/src/Makefile.global include $(top_builddir)/src/Makefile.global
OBJS = autovacuum.o bgwriter.o fork_process.o pgarch.o pgstat.o postmaster.o \ OBJS = autovacuum.o bgwriter.o fork_process.o pgarch.o pgstat.o postmaster.o \
syslogger.o walwriter.o checkpointer.o startup.o syslogger.o walwriter.o checkpointer.o
include $(top_srcdir)/src/backend/common.mk include $(top_srcdir)/src/backend/common.mk

View File

@ -0,0 +1,259 @@
/*-------------------------------------------------------------------------
*
* startup.c
*
* The Startup process initialises the server and performs any recovery
* actions that have been specified. Notice that there is no "main loop"
* since the Startup process ends as soon as initialisation is complete.
*
*
* Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
*
*
* IDENTIFICATION
* src/backend/postmaster/startup.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <signal.h>
#include <unistd.h>
#include "access/xlog.h"
#include "libpq/pqsignal.h"
#include "miscadmin.h"
#include "postmaster/startup.h"
#include "storage/ipc.h"
#include "storage/latch.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/guc.h"
/*
* Flags set by interrupt handlers for later service in the redo loop.
*/
static volatile sig_atomic_t got_SIGHUP = false;
static volatile sig_atomic_t shutdown_requested = false;
static volatile sig_atomic_t promote_triggered = false;
/*
* Flag set when executing a restore command, to tell SIGTERM signal handler
* that it's safe to just proc_exit.
*/
static volatile sig_atomic_t in_restore_command = false;
/* Signal handlers */
static void startupproc_quickdie(SIGNAL_ARGS);
static void StartupProcSigUsr1Handler(SIGNAL_ARGS);
static void StartupProcTriggerHandler(SIGNAL_ARGS);
static void StartupProcSigHupHandler(SIGNAL_ARGS);
/* --------------------------------
* signal handler routines
* --------------------------------
*/
/*
* startupproc_quickdie() occurs when signalled SIGQUIT by the postmaster.
*
* Some backend has bought the farm,
* so we need to stop what we're doing and exit.
*/
static void
startupproc_quickdie(SIGNAL_ARGS)
{
PG_SETMASK(&BlockSig);
/*
* We DO NOT want to run proc_exit() callbacks -- we're here because
* shared memory may be corrupted, so we don't want to try to clean up our
* transaction. Just nail the windows shut and get out of town. Now that
* there's an atexit callback to prevent third-party code from breaking
* things by calling exit() directly, we have to reset the callbacks
* explicitly to make this work as intended.
*/
on_exit_reset();
/*
* Note we do exit(2) not exit(0). This is to force the postmaster into a
* system reset cycle if some idiot DBA sends a manual SIGQUIT to a random
* backend. This is necessary precisely because we don't clean up our
* shared memory state. (The "dead man switch" mechanism in pmsignal.c
* should ensure the postmaster sees this as a crash, too, but no harm in
* being doubly sure.)
*/
exit(2);
}
/* SIGUSR1: let latch facility handle the signal */
static void
StartupProcSigUsr1Handler(SIGNAL_ARGS)
{
int save_errno = errno;
latch_sigusr1_handler();
errno = save_errno;
}
/* SIGUSR2: set flag to finish recovery */
static void
StartupProcTriggerHandler(SIGNAL_ARGS)
{
int save_errno = errno;
promote_triggered = true;
WakeupRecovery();
errno = save_errno;
}
/* SIGHUP: set flag to re-read config file at next convenient time */
static void
StartupProcSigHupHandler(SIGNAL_ARGS)
{
int save_errno = errno;
got_SIGHUP = true;
WakeupRecovery();
errno = save_errno;
}
/* SIGTERM: set flag to abort redo and exit */
static void
StartupProcShutdownHandler(SIGNAL_ARGS)
{
int save_errno = errno;
if (in_restore_command)
proc_exit(1);
else
shutdown_requested = true;
WakeupRecovery();
errno = save_errno;
}
/* Handle SIGHUP and SIGTERM signals of startup process */
void
HandleStartupProcInterrupts(void)
{
/*
* Check if we were requested to re-read config file.
*/
if (got_SIGHUP)
{
got_SIGHUP = false;
ProcessConfigFile(PGC_SIGHUP);
}
/*
* 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.
*/
if (IsUnderPostmaster && !PostmasterIsAlive())
exit(1);
}
/* ----------------------------------
* Startup Process main entry point
* ----------------------------------
*/
void
StartupProcessMain(void)
{
/*
* If possible, make this process a group leader, so that the postmaster
* can signal any child processes too.
*/
#ifdef HAVE_SETSID
if (setsid() < 0)
elog(FATAL, "setsid() failed: %m");
#endif
/*
* Properly accept or ignore signals the postmaster might send us.
*
* Note: ideally we'd not enable handle_standby_sig_alarm unless actually
* doing hot standby, but we don't know that yet. Rely on it to not do
* anything if it shouldn't.
*/
pqsignal(SIGHUP, StartupProcSigHupHandler); /* reload config file */
pqsignal(SIGINT, SIG_IGN); /* ignore query cancel */
pqsignal(SIGTERM, StartupProcShutdownHandler); /* request shutdown */
pqsignal(SIGQUIT, startupproc_quickdie); /* hard crash time */
if (EnableHotStandby)
pqsignal(SIGALRM, handle_standby_sig_alarm); /* ignored unless
* InHotStandby */
else
pqsignal(SIGALRM, SIG_IGN);
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, StartupProcSigUsr1Handler);
pqsignal(SIGUSR2, StartupProcTriggerHandler);
/*
* Reset some signals that are accepted by postmaster but not here
*/
pqsignal(SIGCHLD, SIG_DFL);
pqsignal(SIGTTIN, SIG_DFL);
pqsignal(SIGTTOU, SIG_DFL);
pqsignal(SIGCONT, SIG_DFL);
pqsignal(SIGWINCH, SIG_DFL);
/*
* Unblock signals (they were blocked when the postmaster forked us)
*/
PG_SETMASK(&UnBlockSig);
StartupXLOG();
/*
* Exit normally. Exit code 0 tells postmaster that we completed recovery
* successfully.
*/
proc_exit(0);
}
void
PreRestoreCommand(void)
{
/*
* 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);
}
void
PostRestoreCommand(void)
{
in_restore_command = false;
}
bool
IsPromoteTriggered(void)
{
return promote_triggered;
}
void
ResetPromoteTriggered(void)
{
promote_triggered = false;
}

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@ -24,6 +24,7 @@
#include <signal.h> #include <signal.h>
#include "access/xlog_internal.h" #include "access/xlog_internal.h"
#include "postmaster/startup.h"
#include "replication/walreceiver.h" #include "replication/walreceiver.h"
#include "storage/pmsignal.h" #include "storage/pmsignal.h"
#include "storage/shmem.h" #include "storage/shmem.h"
@ -110,6 +111,7 @@ WalRcvInProgress(void)
/* /*
* Stop walreceiver (if running) and wait for it to die. * Stop walreceiver (if running) and wait for it to die.
* Executed by the Startup process.
*/ */
void void
ShutdownWalRcv(void) ShutdownWalRcv(void)

View File

@ -312,8 +312,6 @@ extern XLogRecPtr GetFlushRecPtr(void);
extern void GetNextXidAndEpoch(TransactionId *xid, uint32 *epoch); extern void GetNextXidAndEpoch(TransactionId *xid, uint32 *epoch);
extern TimeLineID GetRecoveryTargetTLI(void); extern TimeLineID GetRecoveryTargetTLI(void);
extern void HandleStartupProcInterrupts(void);
extern void StartupProcessMain(void);
extern bool CheckPromoteSignal(void); extern bool CheckPromoteSignal(void);
extern void WakeupRecovery(void); extern void WakeupRecovery(void);

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@ -0,0 +1,22 @@
/*-------------------------------------------------------------------------
*
* startup.h
* Exports from postmaster/startup.c.
*
* Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
*
* src/include/postmaster/startup.h
*
*-------------------------------------------------------------------------
*/
#ifndef _STARTUP_H
#define _STARTUP_H
extern void HandleStartupProcInterrupts(void);
extern void StartupProcessMain(void);
extern void PreRestoreCommand(void);
extern void PostRestoreCommand(void);
extern bool IsPromoteTriggered(void);
extern void ResetPromoteTriggered(void);
#endif /* _STARTUP_H */