From dad8e410d0c4329ec68392c442e1f9dafc8ec17c Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 4 Aug 2001 00:14:43 +0000
Subject: [PATCH] Fix handling of SIGCHLD, per recent pghackers discussion: on
some platforms system(2) gets confused unless the signal handler is set to
SIG_DFL, not SIG_IGN. pgstats.c now uses pqsignal() as it should, not
signal(). Also, arrange for the stats collector process to show a reasonable
ID in 'ps', rather than looking like a postmaster.
---
src/backend/bootstrap/bootstrap.c | 6 +-
src/backend/commands/dbcommands.c | 9 +-
src/backend/postmaster/pgstat.c | 128 ++++++++++++++++------------
src/backend/postmaster/postmaster.c | 6 +-
src/backend/tcop/postgres.c | 12 +--
src/include/pgstat.h | 4 +-
6 files changed, 92 insertions(+), 73 deletions(-)
diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 7fc54779680..56009217090 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/bootstrap/bootstrap.c,v 1.112 2001/07/16 05:06:57 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/bootstrap/bootstrap.c,v 1.113 2001/08/04 00:14:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -310,13 +310,15 @@ BootstrapMain(int argc, char *argv[])
pqsignal(SIGINT, SIG_IGN); /* ignore query-cancel */
pqsignal(SIGTERM, die);
pqsignal(SIGQUIT, quickdie);
+ pqsignal(SIGALRM, SIG_IGN);
+ pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, SIG_IGN);
pqsignal(SIGUSR2, SIG_IGN);
/*
* Reset some signals that are accepted by postmaster but not here
*/
- pqsignal(SIGCHLD, SIG_IGN);
+ pqsignal(SIGCHLD, SIG_DFL);
pqsignal(SIGTTIN, SIG_DFL);
pqsignal(SIGTTOU, SIG_DFL);
pqsignal(SIGCONT, SIG_DFL);
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index dca75bd71d9..16b1241a027 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.76 2001/07/02 20:50:46 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.77 2001/08/04 00:14:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -58,7 +58,6 @@ createdb(const char *dbname, const char *dbpath,
char *target_dir;
char src_loc[MAXPGPATH];
char buf[2 * MAXPGPATH + 100];
- int ret;
bool use_super,
use_createdb;
Oid src_dboid;
@@ -195,9 +194,7 @@ createdb(const char *dbname, const char *dbpath,
/* Copy the template database to the new location */
snprintf(buf, sizeof(buf), "cp -r '%s' '%s'", src_loc, target_dir);
- ret = system(buf);
- /* Some versions of SunOS seem to return ECHILD after a system() call */
- if (ret != 0 && errno != ECHILD)
+ if (system(buf) != 0)
{
if (remove_dbdirs(nominal_loc, alt_loc))
elog(ERROR, "CREATE DATABASE: could not initialize database directory");
@@ -557,7 +554,7 @@ remove_dbdirs(const char *nominal_loc, const char *alt_loc)
snprintf(buf, sizeof(buf), "rm -rf '%s'", target_dir);
- if (system(buf) != 0 && errno != ECHILD)
+ if (system(buf) != 0)
{
elog(NOTICE, "database directory '%s' could not be removed",
target_dir);
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 8efda5c90ff..6c571aaebcf 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -16,41 +16,41 @@
*
* Copyright (c) 2001, PostgreSQL Global Development Group
*
- * $Id: pgstat.c,v 1.4 2001/07/05 15:19:40 wieck Exp $
+ * $Header: /cvsroot/pgsql/src/backend/postmaster/pgstat.c,v 1.5 2001/08/04 00:14:43 tgl Exp $
* ----------
*/
#include "postgres.h"
#include <unistd.h>
#include <fcntl.h>
-
#include <sys/param.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
-
#include <errno.h>
#include <signal.h>
+#include "access/xact.h"
+#include "access/heapam.h"
+#include "catalog/catname.h"
+#include "catalog/pg_shadow.h"
+#include "catalog/pg_database.h"
+#include "libpq/pqsignal.h"
#include "miscadmin.h"
#include "utils/memutils.h"
#include "storage/backendid.h"
#include "utils/rel.h"
#include "utils/hsearch.h"
+#include "utils/ps_status.h"
#include "utils/syscache.h"
-#include "access/xact.h"
-#include "access/heapam.h"
-#include "catalog/catname.h"
-#include "catalog/pg_shadow.h"
-#include "catalog/pg_database.h"
#include "pgstat.h"
/* ----------
- * Global data
+ * GUC parameters
* ----------
*/
bool pgstat_collect_startcollector = true;
@@ -95,8 +95,8 @@ static char pgStat_fname[MAXPGPATH];
* Local function forward declarations
* ----------
*/
-static void pgstat_main(void);
-static void pgstat_recvbuffer(void);
+static void pgstat_main(int real_argc, char *real_argv[]);
+static void pgstat_recvbuffer(int real_argc, char *real_argv[]);
static int pgstat_add_backend(PgStat_MsgHdr *msg);
static void pgstat_sub_backend(int procpid);
@@ -227,11 +227,14 @@ pgstat_init(void)
* pgstat_start() -
*
* Called from postmaster at startup or after an existing collector
- * died. Fire up a fresh statistics collector.
+ * died. Fire up a fresh statistics collector.
+ *
+ * The process' original argc and argv are passed, because they are
+ * needed by init_ps_display() on some platforms.
* ----------
*/
int
-pgstat_start(void)
+pgstat_start(int real_argc, char *real_argv[])
{
/*
* Do nothing if no collector needed
@@ -267,7 +270,8 @@ pgstat_start(void)
return 0;
}
- pgstat_main();
+ pgstat_main(real_argc, real_argv);
+
exit(0);
}
@@ -989,15 +993,6 @@ pgstat_fetch_stat_numbackends(void)
-
-
-
-
-
-
-
-
-
/* ------------------------------------------------------------
* Local support functions follow
* ------------------------------------------------------------
@@ -1053,7 +1048,7 @@ pgstat_send(void *msg, int len)
* ----------
*/
static void
-pgstat_main(void)
+pgstat_main(int real_argc, char *real_argv[])
{
PgStat_Msg msg;
fd_set rfds;
@@ -1076,27 +1071,22 @@ pgstat_main(void)
/*
* Ignore all signals usually bound to some action in the postmaster
*/
- signal(SIGHUP, SIG_IGN);
- signal(SIGINT, SIG_IGN);
- signal(SIGQUIT, SIG_IGN);
- signal(SIGTERM, SIG_IGN);
- signal(SIGALRM, SIG_IGN);
- signal(SIGPIPE, SIG_IGN);
- signal(SIGUSR1, SIG_IGN);
- signal(SIGUSR2, SIG_IGN);
- signal(SIGCHLD, SIG_IGN);
- signal(SIGTTIN, SIG_IGN);
- signal(SIGTTOU, SIG_IGN);
- signal(SIGWINCH, SIG_IGN);
-
- /*
- * Write the initial status file right at startup
- */
- gettimeofday(&next_statwrite, NULL);
- need_statwrite = TRUE;
-
- /*
- * Now we start the buffer process to read from the socket, so
+ pqsignal(SIGHUP, SIG_IGN);
+ pqsignal(SIGINT, SIG_IGN);
+ pqsignal(SIGTERM, SIG_IGN);
+ pqsignal(SIGQUIT, SIG_IGN);
+ pqsignal(SIGALRM, SIG_IGN);
+ pqsignal(SIGPIPE, SIG_IGN);
+ pqsignal(SIGUSR1, SIG_IGN);
+ pqsignal(SIGUSR2, SIG_IGN);
+ pqsignal(SIGCHLD, SIG_DFL);
+ pqsignal(SIGTTIN, SIG_DFL);
+ pqsignal(SIGTTOU, SIG_DFL);
+ pqsignal(SIGCONT, SIG_DFL);
+ pqsignal(SIGWINCH, SIG_DFL);
+
+ /*
+ * Start a buffering subprocess to read from the socket, so
* we have a little more time to process incoming messages.
*/
if (pipe(pgStatPipe) < 0)
@@ -1107,19 +1097,38 @@ pgstat_main(void)
switch(fork())
{
- case -1: perror("PGSTAT: fork(2)");
- exit(1);
+ case -1:
+ perror("PGSTAT: fork(2)");
+ exit(1);
- case 0: close(pgStatPipe[0]);
- signal(SIGPIPE, SIG_DFL);
- pgstat_recvbuffer();
- exit(2);
+ case 0:
+ close(pgStatPipe[0]);
+ /* child process should die if can't pipe to parent collector */
+ pqsignal(SIGPIPE, SIG_DFL);
+ pgstat_recvbuffer(real_argc, real_argv);
+ exit(2);
- default: close(pgStatPipe[1]);
- close(pgStatSock);
- break;
+ default:
+ close(pgStatPipe[1]);
+ close(pgStatSock);
+ break;
}
+ /*
+ * Identify myself via ps
+ *
+ * WARNING: On some platforms the environment will be moved around to
+ * make room for the ps display string.
+ */
+ init_ps_display(real_argc, real_argv, "stats collector process", "", "");
+ set_ps_display("");
+
+ /*
+ * Arrange to write the initial status file right away
+ */
+ gettimeofday(&next_statwrite, NULL);
+ need_statwrite = TRUE;
+
/*
* Read in an existing statistics stats file or initialize the
* stats to zero.
@@ -1358,7 +1367,7 @@ pgstat_main(void)
* ----------
*/
static void
-pgstat_recvbuffer(void)
+pgstat_recvbuffer(int real_argc, char *real_argv[])
{
fd_set rfds;
fd_set wfds;
@@ -1373,6 +1382,15 @@ pgstat_recvbuffer(void)
int fromlen;
int overflow = 0;
+ /*
+ * Identify myself via ps
+ *
+ * WARNING: On some platforms the environment will be moved around to
+ * make room for the ps display string.
+ */
+ init_ps_display(real_argc, real_argv, "stats buffer process", "", "");
+ set_ps_display("");
+
/*
* Allocate the message buffer
*/
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index fb51695e98b..511f9bc0ee6 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -37,7 +37,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.233 2001/07/31 22:55:45 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.234 2001/08/04 00:14:43 tgl Exp $
*
* NOTES
*
@@ -696,7 +696,7 @@ PostmasterMain(int argc, char *argv[])
*/
if (pgstat_init() < 0)
ExitPostmaster(1);
- if (pgstat_start() < 0)
+ if (pgstat_start(real_argc, real_argv) < 0)
ExitPostmaster(1);
/*
@@ -1488,7 +1488,7 @@ reaper(SIGNAL_ARGS)
{
fprintf(stderr, "%s: Performance collector exited with status %d\n",
progname, exitstatus);
- pgstat_start();
+ pgstat_start(real_argc, real_argv);
continue;
}
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 4083d0cd020..ac701704c16 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.229 2001/07/31 22:55:45 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.230 2001/08/04 00:14:43 tgl Exp $
*
* NOTES
* this is the "main" module of the postgres backend and
@@ -1102,7 +1102,9 @@ usage(char *progname)
* ----------------------------------------------------------------
*/
int
-PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[], const char *username)
+PostgresMain(int argc, char *argv[],
+ int real_argc, char *real_argv[],
+ const char *username)
{
int flag;
@@ -1535,15 +1537,15 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[], const cha
*/
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, SIG_IGN); /* this signal available for use */
+
pqsignal(SIGUSR2, Async_NotifyHandler); /* flush also sinval cache */
pqsignal(SIGFPE, FloatExceptionHandler);
- pqsignal(SIGCHLD, SIG_IGN); /* ignored (may get this in system()
- * calls) */
/*
* Reset some signals that are accepted by postmaster but not by
* backend
*/
+ pqsignal(SIGCHLD, SIG_DFL); /* system() requires this on some platforms */
pqsignal(SIGTTIN, SIG_DFL);
pqsignal(SIGTTOU, SIG_DFL);
pqsignal(SIGCONT, SIG_DFL);
@@ -1711,7 +1713,7 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[], const cha
if (!IsUnderPostmaster)
{
puts("\nPOSTGRES backend interactive interface ");
- puts("$Revision: 1.229 $ $Date: 2001/07/31 22:55:45 $\n");
+ puts("$Revision: 1.230 $ $Date: 2001/08/04 00:14:43 $\n");
}
/*
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 51bb00dc16b..fc9dc43326a 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -5,7 +5,7 @@
*
* Copyright (c) 2001, PostgreSQL Global Development Group
*
- * $Id: pgstat.h,v 1.4 2001/07/05 15:19:40 wieck Exp $
+ * $Id: pgstat.h,v 1.5 2001/08/04 00:14:43 tgl Exp $
* ----------
*/
#ifndef PGSTAT_H
@@ -336,7 +336,7 @@ extern bool pgstat_collect_blocklevel;
* ----------
*/
extern int pgstat_init(void);
-extern int pgstat_start(void);
+extern int pgstat_start(int real_argc, char *real_argv[]);
extern int pgstat_ispgstat(int pid);
extern void pgstat_beterm(int pid);
--
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