Separate out bgwriter code into a logically separate module, rather

than being random pieces of other files.  Give bgwriter responsibility
for all checkpoint activity (other than a post-recovery checkpoint);
so this child process absorbs the functionality of the former transient
checkpoint and shutdown subprocesses.  While at it, create an actual
include file for postmaster.c, which for some reason never had its own
file before.

1 files changed, 28 insertions, 95 deletions

diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index a3a4e57c855..c90749ca127 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -13,7 +13,7 @@
  *
  *	Copyright (c) 2001-2003, PostgreSQL Global Development Group
  *
- *	$PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.72 2004/05/28 05:12:58 tgl Exp $
+ *	$PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.73 2004/05/29 22:48:19 tgl Exp $
  * ----------
  */
 #include "postgres.h"
@@ -32,23 +32,25 @@
 
 #include "pgstat.h"
 
-#include "access/xact.h"
 #include "access/heapam.h"
+#include "access/xact.h"
 #include "catalog/catname.h"
-#include "catalog/pg_shadow.h"
 #include "catalog/pg_database.h"
-#include "libpq/pqsignal.h"
+#include "catalog/pg_shadow.h"
 #include "libpq/libpq.h"
+#include "libpq/pqsignal.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
-#include "utils/memutils.h"
+#include "postmaster/postmaster.h"
 #include "storage/backendid.h"
 #include "storage/ipc.h"
 #include "storage/pg_shmem.h"
+#include "storage/pmsignal.h"
 #include "tcop/tcopprot.h"
-#include "utils/rel.h"
 #include "utils/hsearch.h"
+#include "utils/memutils.h"
 #include "utils/ps_status.h"
+#include "utils/rel.h"
 #include "utils/syscache.h"
 
 
@@ -75,8 +77,6 @@ bool		pgstat_is_running = false;
 NON_EXEC_STATIC int	pgStatSock = -1;
 static int	pgStatPipe[2];
 static struct sockaddr_storage pgStatAddr;
-static int	pgStatPmPipe[2] = {-1, -1};
-static int  pgStatCollectorPmPipe[2] = {-1, -1};
 
 static int	pgStatPid;
 static time_t last_pgstat_start_time;
@@ -397,17 +397,6 @@ pgstat_init(void)
 		goto startup_failed;
 	}
 
-	/*
-	 * Create the pipe that controls the statistics collector shutdown
-	 */
-	if (pgpipe(pgStatPmPipe) < 0 || pgpipe(pgStatCollectorPmPipe) < 0)
-	{
-		ereport(LOG,
-				(errcode_for_socket_access(),
-		  errmsg("could not create pipe for statistics collector: %m")));
-		goto startup_failed;
-	}
-
 	freeaddrinfo_all(hints.ai_family, addrs);
 
 	return;
@@ -439,9 +428,9 @@ startup_failed:
 static pid_t
 pgstat_forkexec(STATS_PROCESS_TYPE procType)
 {
-	char *av[12];
+	char *av[10];
 	int ac = 0, bufc = 0, i;
-	char pgstatBuf[7][32];
+	char pgstatBuf[2][32];
 
 	av[ac++] = "postgres";
 
@@ -464,11 +453,7 @@ pgstat_forkexec(STATS_PROCESS_TYPE procType)
 	/* postgres_exec_path is not passed by write_backend_variables */
 	av[ac++] = postgres_exec_path;
 
-	/* Sockets + pipes (those not passed by write_backend_variables) */
-	snprintf(pgstatBuf[bufc++],32,"%d",pgStatPmPipe[0]);
-	snprintf(pgstatBuf[bufc++],32,"%d",pgStatPmPipe[1]);
-	snprintf(pgstatBuf[bufc++],32,"%d",pgStatCollectorPmPipe[0]);
-	snprintf(pgstatBuf[bufc++],32,"%d",pgStatCollectorPmPipe[1]);
+	/* Pipe file ids (those not passed by write_backend_variables) */
 	snprintf(pgstatBuf[bufc++],32,"%d",pgStatPipe[0]);
 	snprintf(pgstatBuf[bufc++],32,"%d",pgStatPipe[1]);
 
@@ -493,14 +478,10 @@ pgstat_forkexec(STATS_PROCESS_TYPE procType)
 static void
 pgstat_parseArgs(int argc, char *argv[])
 {
-	Assert(argc == 10);
+	Assert(argc == 6);
 
 	argc = 3;
 	StrNCpy(postgres_exec_path,	argv[argc++], MAXPGPATH);
-	pgStatPmPipe[0]	= atoi(argv[argc++]);
-	pgStatPmPipe[1]	= atoi(argv[argc++]);
-	pgStatCollectorPmPipe[0] = atoi(argv[argc++]);
-	pgStatCollectorPmPipe[1] = atoi(argv[argc++]);
 	pgStatPipe[0]	= atoi(argv[argc++]);
 	pgStatPipe[1]	= atoi(argv[argc++]);
 }
@@ -592,8 +573,8 @@ pgstat_start(void)
 			/* Specific beos actions after backend startup */
 			beos_backend_startup();
 #endif
-			/* Close the postmaster's sockets, except for pgstat link */
-			ClosePostmasterPorts(false);
+			/* Close the postmaster's sockets */
+			ClosePostmasterPorts();
 
 			/* Drop our connection to postmaster's shared memory, as well */
 			PGSharedMemoryDetach();
@@ -633,31 +614,6 @@ pgstat_ispgstat(int pid)
 
 
 /* ----------
- * pgstat_close_sockets() -
- *
- *	Called when postmaster forks a non-pgstat child process, to close off
- *	file descriptors that should not be held open in child processes.
- * ----------
- */
-void
-pgstat_close_sockets(void)
-{
-	if (pgStatPmPipe[0] >= 0)
-		closesocket(pgStatPmPipe[0]);
-	pgStatPmPipe[0] = -1;
-	if (pgStatPmPipe[1] >= 0)
-		closesocket(pgStatPmPipe[1]);
-	pgStatPmPipe[1] = -1;
-	if (pgStatCollectorPmPipe[0] >= 0)
-		closesocket(pgStatCollectorPmPipe[0]);
-	pgStatCollectorPmPipe[0] = -1;
-	if (pgStatCollectorPmPipe[1] >= 0)
-		closesocket(pgStatCollectorPmPipe[1]);
-	pgStatCollectorPmPipe[1] = -1;
-}
-
-
-/* ----------
  * pgstat_beterm() -
  *
  *	Called from postmaster to tell collector a backend terminated.
@@ -1446,15 +1402,6 @@ PgstatBufferMain(int argc, char *argv[])
 #endif
 
 	/*
-	 * Close the writing end of the postmaster pipe, so we'll see it
-	 * closing when the postmaster terminates and can terminate as well.
-	 */
-	closesocket(pgStatPmPipe[1]);
-	pgStatPmPipe[1] = -1;
-	closesocket(pgStatCollectorPmPipe[1]);
-	pgStatCollectorPmPipe[1] = -1;
-
-	/*
 	 * Start a buffering process to read from the socket, so we have a
 	 * little more time to process incoming messages.
 	 *
@@ -1517,7 +1464,6 @@ PgstatCollectorMain(int argc, char *argv[])
 	PgStat_Msg	msg;
 	fd_set		rfds;
 	int			readPipe;
-	int			pmPipe;
 	int			nready;
 	int			len = 0;
 	struct timeval timeout;
@@ -1555,7 +1501,6 @@ PgstatCollectorMain(int argc, char *argv[])
 	/* Close unwanted files */
 	closesocket(pgStatPipe[1]);
 	closesocket(pgStatSock);
-	pmPipe = pgStatCollectorPmPipe[0];
 
 	/*
 	 * Identify myself via ps
@@ -1823,17 +1768,9 @@ PgstatCollectorMain(int argc, char *argv[])
 	 * shutdown, we want to save the final stats to reuse at next startup.
 	 * But if the buffer process failed, it seems best not to (there may
 	 * even now be a new collector firing up, and we don't want it to read
-	 * a partially- rewritten stats file).	We can tell whether the
-	 * postmaster is still alive by checking to see if the postmaster pipe
-	 * is still open.  If it is read-ready (ie, EOF), the postmaster must
-	 * have quit.
-	 */
-	FD_ZERO(&rfds);
-	FD_SET(pmPipe, &rfds);
-	timeout.tv_sec = 0;
-	timeout.tv_usec = 0;
-	nready = select(pmPipe+1,&rfds,NULL,NULL,&timeout);
-	if (nready > 0 && FD_ISSET(pmPipe, &rfds)) 
+	 * a partially-rewritten stats file).
+	 */
+	if (!PostmasterIsAlive(false))
 		pgstat_write_statsfile();
 }
 
@@ -1852,8 +1789,8 @@ pgstat_recvbuffer(void)
 {
 	fd_set		rfds;
 	fd_set		wfds;
+	struct timeval timeout;
 	int			writePipe = pgStatPipe[1];
-	int			pmPipe = pgStatPmPipe[0];
 	int			maxfd;
 	int			nready;
 	int			len;
@@ -1937,8 +1874,7 @@ pgstat_recvbuffer(void)
 
 		/*
 		 * If we have messages to write out, we add the pipe to the write
-		 * descriptor set. Otherwise, we check if the postmaster might
-		 * have terminated.
+		 * descriptor set.
 		 */
 		if (msg_have > 0)
 		{
@@ -1946,17 +1882,16 @@ pgstat_recvbuffer(void)
 			if (writePipe > maxfd)
 				maxfd = writePipe;
 		}
-		else
-		{
-			FD_SET(pmPipe, &rfds);
-			if (pmPipe > maxfd)
-				maxfd = pmPipe;
-		}
 
 		/*
-		 * Wait for some work to do.
+		 * Wait for some work to do; but not for more than 10 seconds
+		 * (this determines how quickly we will shut down after postmaster
+		 * termination).
 		 */
-		nready = select(maxfd + 1, &rfds, &wfds, NULL, NULL);
+		timeout.tv_sec = 10;
+		timeout.tv_usec = 0;
+
+		nready = select(maxfd + 1, &rfds, &wfds, NULL, &timeout);
 		if (nready < 0)
 		{
 			if (errno == EINTR)
@@ -2062,11 +1997,9 @@ pgstat_recvbuffer(void)
 			continue;
 
 		/*
-		 * If the pipe from the postmaster is ready for reading, the
-		 * kernel must have closed it on exit() (the postmaster never
-		 * really writes to it). So we've done our job.
+		 * If the postmaster has terminated, we've done our job.
 		 */
-		if (FD_ISSET(pmPipe, &rfds))
+		if (!PostmasterIsAlive(true))
 			exit(0);
 	}
 }