Refactor xlog.c to create src/backend/postmaster/startup.c
authorSimon Riggs <simon@2ndQuadrant.com>
Wed, 2 Nov 2011 14:25:01 +0000 (14:25 +0000)
committerSimon Riggs <simon@2ndQuadrant.com>
Wed, 2 Nov 2011 14:25:01 +0000 (14:25 +0000)
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
src/backend/bootstrap/bootstrap.c
src/backend/postmaster/Makefile
src/backend/postmaster/startup.c [new file with mode: 0644]
src/backend/replication/walreceiverfuncs.c
src/include/access/xlog.h
src/include/postmaster/startup.h [new file with mode: 0644]

index 0944aa4162d4032e5c3cade1aa430030eee921ef..7ac17779c88761b67bf0bf507ac8a211889cf3cf 100644 (file)
@@ -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;
    }
index f9b839c3da78c5a37ea1bd07e740ae5b848f5b9e..6bf2421f65fdc4e448da76879b2f55f1c61113ea 100644 (file)
@@ -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"
index e7414d20debf172765e009d711665b9870123016..3056b09f0d1411960604b5384f3bb026b5439085 100644 (file)
@@ -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 (file)
index 0000000..c414684
--- /dev/null
@@ -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;
+}
index 29c2f806e0b9d70ad579787d0734b4553697b453..5bce1c34a1b5f06670b83efce9636fe49d3eff75 100644 (file)
@@ -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)
index e4a13a18ab3d8c279fba6e4e7255534381316bf4..6c7b0216730f4aedc71b4f49898e1cda07b0492c 100644 (file)
@@ -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 (file)
index 0000000..8c57adf
--- /dev/null
@@ -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 */