Commonalize process startup code.

Move common code, that was duplicated in every postmaster child/every
standalone process, into two functions in miscinit.c.  Not only does
that already result in a fair amount of net code reduction but it also
makes it much easier to remove more duplication in the future. The
prime motivation wasn't code deduplication though, but easier addition
of new common code.

Author: anarazel

src/backend/bootstrap/bootstrap.c

@@ -14,7 +14,6 @@
  */
 #include "postgres.h"
 
-#include <time.h>
 #include <unistd.h>
 #include <signal.h>
 
@@ -191,19 +190,11 @@ AuxiliaryProcessMain(int argc, char *argv[])
 	char	   *userDoption = NULL;
 
 	/*
-	 * initialize globals
+	 * Initialize process environment (already done if under postmaster, but
+	 * not if standalone).
 	 */
-	MyProcPid = getpid();
-
-	MyStartTime = time(NULL);
-
-	/* Compute paths, if we didn't inherit them from postmaster */
-	if (my_exec_path[0] == '\0')
-	{
-		if (find_my_exec(progname, my_exec_path) < 0)
-			elog(FATAL, "%s: could not locate my own executable path",
-				 progname);
-	}
+	if (!IsUnderPostmaster)
+		InitStandaloneProcess(argv[0]);
 
 	/*
 	 * process command arguments
@@ -515,15 +506,6 @@ bootstrap_signals(void)
 {
 	if (IsUnderPostmaster)
 	{
-		/*
-		 * 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
 		 */

src/backend/postmaster/autovacuum.c

@@ -64,7 +64,6 @@
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/time.h>
-#include <time.h>
 #include <unistd.h>
 
 #include "access/heapam.h"
@@ -383,12 +382,11 @@ StartAutoVacLauncher(void)
 #ifndef EXEC_BACKEND
 		case 0:
 			/* in postmaster child ... */
+			InitPostmasterChild();
+
 			/* Close the postmaster's sockets */
 			ClosePostmasterPorts(false);
 
-			/* Lose the postmaster's on-exit routines */
-			on_exit_reset();
-
 			AutoVacLauncherMain(0, NULL);
 			break;
 #endif
@@ -408,16 +406,8 @@ AutoVacLauncherMain(int argc, char *argv[])
 {
 	sigjmp_buf	local_sigjmp_buf;
 
-	/* we are a postmaster subprocess now */
-	IsUnderPostmaster = true;
 	am_autovacuum_launcher = true;
 
-	/* reset MyProcPid */
-	MyProcPid = getpid();
-
-	/* record Start Time for logging */
-	MyStartTime = time(NULL);
-
 	/* Identify myself via ps */
 	init_ps_display("autovacuum launcher process", "", "", "");
 
@@ -429,17 +419,6 @@ AutoVacLauncherMain(int argc, char *argv[])
 
 	SetProcessingMode(InitProcessing);
 
-	/*
-	 * If possible, make this process a group leader, so that the postmaster
-	 * can signal any child processes too.  (autovacuum probably never has any
-	 * child processes, but for consistency we make all postmaster child
-	 * processes do this.)
-	 */
-#ifdef HAVE_SETSID
-	if (setsid() < 0)
-		elog(FATAL, "setsid() failed: %m");
-#endif
-
 	/*
 	 * Set up signal handlers.  We operate on databases much like a regular
 	 * backend, so we use the same signal handling.  See equivalent code in
@@ -1455,12 +1434,11 @@ StartAutoVacWorker(void)
 #ifndef EXEC_BACKEND
 		case 0:
 			/* in postmaster child ... */
+			InitPostmasterChild();
+
 			/* Close the postmaster's sockets */
 			ClosePostmasterPorts(false);
 
-			/* Lose the postmaster's on-exit routines */
-			on_exit_reset();
-
 			AutoVacWorkerMain(0, NULL);
 			break;
 #endif
@@ -1481,32 +1459,13 @@ AutoVacWorkerMain(int argc, char *argv[])
 	sigjmp_buf	local_sigjmp_buf;
 	Oid			dbid;
 
-	/* we are a postmaster subprocess now */
-	IsUnderPostmaster = true;
 	am_autovacuum_worker = true;
 
-	/* reset MyProcPid */
-	MyProcPid = getpid();
-
-	/* record Start Time for logging */
-	MyStartTime = time(NULL);
-
 	/* Identify myself via ps */
 	init_ps_display("autovacuum worker process", "", "", "");
 
 	SetProcessingMode(InitProcessing);
 
-	/*
-	 * If possible, make this process a group leader, so that the postmaster
-	 * can signal any child processes too.  (autovacuum probably never has any
-	 * child processes, but for consistency we make all postmaster child
-	 * processes do this.)
-	 */
-#ifdef HAVE_SETSID
-	if (setsid() < 0)
-		elog(FATAL, "setsid() failed: %m");
-#endif
-
 	/*
 	 * Set up signal handlers.  We operate on databases much like a regular
 	 * backend, so we use the same signal handling.  See equivalent code in

src/backend/postmaster/bgworker.c

@@ -13,7 +13,6 @@
 #include "postgres.h"
 
 #include <unistd.h>
-#include <time.h>
 
 #include "miscadmin.h"
 #include "libpq/pqsignal.h"
@@ -556,16 +555,8 @@ StartBackgroundWorker(void)
 	if (worker == NULL)
 		elog(FATAL, "unable to find bgworker entry");
 
-	/* we are a postmaster subprocess now */
-	IsUnderPostmaster = true;
 	IsBackgroundWorker = true;
 
-	/* reset MyProcPid */
-	MyProcPid = getpid();
-
-	/* record Start Time for logging */
-	MyStartTime = time(NULL);
-
 	/* Identify myself via ps */
 	snprintf(buf, MAXPGPATH, "bgworker: %s", worker->bgw_name);
 	init_ps_display(buf, "", "", "");
@@ -590,15 +581,6 @@ StartBackgroundWorker(void)
 	if (PostAuthDelay > 0)
 		pg_usleep(PostAuthDelay * 1000000L);
 
-	/*
-	 * 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
-
 	/*
 	 * Set up signal handlers.
 	 */

src/backend/postmaster/bgwriter.c

@@ -36,7 +36,6 @@
 
 #include <signal.h>
 #include <sys/time.h>
-#include <time.h>
 #include <unistd.h>
 
 #include "access/xlog.h"
@@ -113,17 +112,6 @@ BackgroundWriterMain(void)
 	MemoryContext bgwriter_context;
 	bool		prev_hibernate;
 
-	/*
-	 * If possible, make this process a group leader, so that the postmaster
-	 * can signal any child processes too.  (bgwriter probably never has any
-	 * child processes, but for consistency we make all postmaster child
-	 * processes do this.)
-	 */
-#ifdef HAVE_SETSID
-	if (setsid() < 0)
-		elog(FATAL, "setsid() failed: %m");
-#endif
-
 	/*
 	 * Properly accept or ignore signals the postmaster might send us.
 	 *

src/backend/postmaster/checkpointer.c

@@ -196,17 +196,6 @@ CheckpointerMain(void)
 
 	CheckpointerShmem->checkpointer_pid = MyProcPid;
 
-	/*
-	 * If possible, make this process a group leader, so that the postmaster
-	 * can signal any child processes too.  (checkpointer probably never has
-	 * any child processes, but for consistency we make all postmaster child
-	 * processes do this.)
-	 */
-#ifdef HAVE_SETSID
-	if (setsid() < 0)
-		elog(FATAL, "setsid() failed: %m");
-#endif
-
 	/*
 	 * Properly accept or ignore signals the postmaster might send us
 	 *

src/backend/postmaster/pgarch.c

@@ -157,12 +157,11 @@ pgarch_start(void)
 #ifndef EXEC_BACKEND
 		case 0:
 			/* in postmaster child ... */
+			InitPostmasterChild();
+
 			/* Close the postmaster's sockets */
 			ClosePostmasterPorts(false);
 
-			/* Lose the postmaster's on-exit routines */
-			on_exit_reset();
-
 			/* Drop our connection to postmaster's shared memory, as well */
 			dsm_detach_all();
 			PGSharedMemoryDetach();
@@ -221,21 +220,6 @@ pgarch_forkexec(void)
 NON_EXEC_STATIC void
 PgArchiverMain(int argc, char *argv[])
 {
-	IsUnderPostmaster = true;	/* we are a postmaster subprocess now */
-
-	MyProcPid = getpid();		/* reset MyProcPid */
-
-	MyStartTime = time(NULL);	/* record Start Time for logging */
-
-	/*
-	 * 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
-
 	InitializeLatchSupport();	/* needed for latch waits */
 
 	InitLatch(&mainloop_latch); /* initialize latch used in main loop */

src/backend/postmaster/pgstat.c

@@ -695,12 +695,11 @@ pgstat_start(void)
 #ifndef EXEC_BACKEND
 		case 0:
 			/* in postmaster child ... */
+			InitPostmasterChild();
+
 			/* Close the postmaster's sockets */
 			ClosePostmasterPorts(false);
 
-			/* Lose the postmaster's on-exit routines */
-			on_exit_reset();
-
 			/* Drop our connection to postmaster's shared memory, as well */
 			dsm_detach_all();
 			PGSharedMemoryDetach();
@@ -3152,23 +3151,6 @@ PgstatCollectorMain(int argc, char *argv[])
 	PgStat_Msg	msg;
 	int			wr;
 
-	IsUnderPostmaster = true;	/* we are a postmaster subprocess now */
-
-	MyProcPid = getpid();		/* reset MyProcPid */
-
-	MyStartTime = time(NULL);	/* record Start Time for logging */
-
-	/*
-	 * If possible, make this process a group leader, so that the postmaster
-	 * can signal any child processes too.  (pgstat probably never has any
-	 * child processes, but for consistency we make all postmaster child
-	 * processes do this.)
-	 */
-#ifdef HAVE_SETSID
-	if (setsid() < 0)
-		elog(FATAL, "setsid() failed: %m");
-#endif
-
 	InitializeLatchSupport();	/* needed for latch waits */
 
 	/* Initialize private latch for use by signal handlers */