From 9aceb6ab3c202a5bf00d5f00436bb6ad285fc0bf Mon Sep 17 00:00:00 2001
From: Simon Riggs <simon@2ndQuadrant.com>
Date: Wed, 2 Nov 2011 14:25:01 +0000
Subject: [PATCH] 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
---
src/backend/access/transam/xlog.c | 200 +---------------
src/backend/bootstrap/bootstrap.c | 1 +
src/backend/postmaster/Makefile | 2 +-
src/backend/postmaster/startup.c | 259 +++++++++++++++++++++
src/backend/replication/walreceiverfuncs.c | 2 +
src/include/access/xlog.h | 2 -
src/include/postmaster/startup.h | 22 ++
7 files changed, 291 insertions(+), 197 deletions(-)
create mode 100644 src/backend/postmaster/startup.c
create mode 100644 src/include/postmaster/startup.h
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 0944aa4162d..7ac17779c88 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -41,6 +41,7 @@
#include "miscadmin.h"
#include "pgstat.h"
#include "postmaster/bgwriter.h"
+#include "postmaster/startup.h"
#include "replication/walreceiver.h"
#include "replication/walsender.h"
#include "storage/bufmgr.h"
@@ -584,19 +585,6 @@ typedef struct xl_restore_point
char rp_name[MAXFNAMELEN];
} 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 XLogArchiveNotifySeg(uint32 log, uint32 seg);
@@ -3068,21 +3056,16 @@ RestoreArchivedFile(char *path, const char *xlogfname,
xlogRestoreCmd)));
/*
- * 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.
+ * Check signals before restore command and reset afterwards.
*/
- in_restore_command = true;
- if (shutdown_requested)
- proc_exit(1);
+ PreRestoreCommand();
/*
* Copy xlog from archival storage to XLOGDIR
*/
rc = system(xlogRestoreCmd);
- in_restore_command = false;
+ PostRestoreCommand();
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).
* Returns true if the page is read successfully.
@@ -10564,12 +10376,12 @@ CheckForStandbyTrigger(void)
if (triggered)
return true;
- if (promote_triggered)
+ if (IsPromoteTriggered())
{
ereport(LOG,
(errmsg("received promote request")));
ShutdownWalRcv();
- promote_triggered = false;
+ ResetPromoteTriggered();
triggered = true;
return true;
}
diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index f9b839c3da7..6bf2421f65f 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -29,6 +29,7 @@
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "postmaster/bgwriter.h"
+#include "postmaster/startup.h"
#include "postmaster/walwriter.h"
#include "replication/walreceiver.h"
#include "storage/bufmgr.h"
diff --git a/src/backend/postmaster/Makefile b/src/backend/postmaster/Makefile
index e7414d20deb..3056b09f0d1 100644
--- a/src/backend/postmaster/Makefile
+++ b/src/backend/postmaster/Makefile
@@ -13,6 +13,6 @@ top_builddir = ../../..
include $(top_builddir)/src/Makefile.global
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
diff --git a/src/backend/postmaster/startup.c b/src/backend/postmaster/startup.c
new file mode 100644
index 00000000000..c4146845f2a
--- /dev/null
+++ b/src/backend/postmaster/startup.c
@@ -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;
+}
diff --git a/src/backend/replication/walreceiverfuncs.c b/src/backend/replication/walreceiverfuncs.c
index 29c2f806e0b..5bce1c34a1b 100644
--- a/src/backend/replication/walreceiverfuncs.c
+++ b/src/backend/replication/walreceiverfuncs.c
@@ -24,6 +24,7 @@
#include <signal.h>
#include "access/xlog_internal.h"
+#include "postmaster/startup.h"
#include "replication/walreceiver.h"
#include "storage/pmsignal.h"
#include "storage/shmem.h"
@@ -110,6 +111,7 @@ WalRcvInProgress(void)
/*
* Stop walreceiver (if running) and wait for it to die.
+ * Executed by the Startup process.
*/
void
ShutdownWalRcv(void)
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index e4a13a18ab3..6c7b0216730 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -312,8 +312,6 @@ extern XLogRecPtr GetFlushRecPtr(void);
extern void GetNextXidAndEpoch(TransactionId *xid, uint32 *epoch);
extern TimeLineID GetRecoveryTargetTLI(void);
-extern void HandleStartupProcInterrupts(void);
-extern void StartupProcessMain(void);
extern bool CheckPromoteSignal(void);
extern void WakeupRecovery(void);
diff --git a/src/include/postmaster/startup.h b/src/include/postmaster/startup.h
new file mode 100644
index 00000000000..8c57adf0bba
--- /dev/null
+++ b/src/include/postmaster/startup.h
@@ -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 */
--
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