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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.
1 parent 2b769c8 commit dad8e41

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6 files changed

+92
-73
lines changed

6 files changed

+92
-73
lines changed

‎src/backend/bootstrap/bootstrap.c

Lines changed: 4 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/bootstrap/bootstrap.c,v 1.112 2001/07/16 05:06:57 tgl Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/bootstrap/bootstrap.c,v 1.113 2001/08/04 00:14:43 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -310,13 +310,15 @@ BootstrapMain(int argc, char *argv[])
310310
pqsignal(SIGINT, SIG_IGN); /* ignore query-cancel */
311311
pqsignal(SIGTERM, die);
312312
pqsignal(SIGQUIT, quickdie);
313+
pqsignal(SIGALRM, SIG_IGN);
314+
pqsignal(SIGPIPE, SIG_IGN);
313315
pqsignal(SIGUSR1, SIG_IGN);
314316
pqsignal(SIGUSR2, SIG_IGN);
315317

316318
/*
317319
* Reset some signals that are accepted by postmaster but not here
318320
*/
319-
pqsignal(SIGCHLD, SIG_IGN);
321+
pqsignal(SIGCHLD, SIG_DFL);
320322
pqsignal(SIGTTIN, SIG_DFL);
321323
pqsignal(SIGTTOU, SIG_DFL);
322324
pqsignal(SIGCONT, SIG_DFL);

‎src/backend/commands/dbcommands.c

Lines changed: 3 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -9,7 +9,7 @@
99
*
1010
*
1111
* IDENTIFICATION
12-
* $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.76 2001/07/02 20:50:46 tgl Exp $
12+
* $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.77 2001/08/04 00:14:43 tgl Exp $
1313
*
1414
*-------------------------------------------------------------------------
1515
*/
@@ -58,7 +58,6 @@ createdb(const char *dbname, const char *dbpath,
5858
char *target_dir;
5959
char src_loc[MAXPGPATH];
6060
char buf[2 * MAXPGPATH + 100];
61-
int ret;
6261
bool use_super,
6362
use_createdb;
6463
Oid src_dboid;
@@ -195,9 +194,7 @@ createdb(const char *dbname, const char *dbpath,
195194
/* Copy the template database to the new location */
196195
snprintf(buf, sizeof(buf), "cp -r '%s' '%s'", src_loc, target_dir);
197196

198-
ret = system(buf);
199-
/* Some versions of SunOS seem to return ECHILD after a system() call */
200-
if (ret != 0 && errno != ECHILD)
197+
if (system(buf) != 0)
201198
{
202199
if (remove_dbdirs(nominal_loc, alt_loc))
203200
elog(ERROR, "CREATE DATABASE: could not initialize database directory");
@@ -557,7 +554,7 @@ remove_dbdirs(const char *nominal_loc, const char *alt_loc)
557554

558555
snprintf(buf, sizeof(buf), "rm -rf '%s'", target_dir);
559556

560-
if (system(buf) != 0 && errno != ECHILD)
557+
if (system(buf) != 0)
561558
{
562559
elog(NOTICE, "database directory '%s' could not be removed",
563560
target_dir);

‎src/backend/postmaster/pgstat.c

Lines changed: 73 additions & 55 deletions
Original file line numberDiff line numberDiff line change
@@ -16,41 +16,41 @@
1616
*
1717
* Copyright (c) 2001, PostgreSQL Global Development Group
1818
*
19-
* $Id: pgstat.c,v 1.4 2001/07/05 15:19:40 wieck Exp $
19+
* $Header: /cvsroot/pgsql/src/backend/postmaster/pgstat.c,v 1.5 2001/08/04 00:14:43 tgl Exp $
2020
* ----------
2121
*/
2222
#include "postgres.h"
2323

2424
#include <unistd.h>
2525
#include <fcntl.h>
26-
2726
#include <sys/param.h>
2827
#include <sys/time.h>
2928
#include <sys/types.h>
3029
#include <sys/socket.h>
3130
#include <netinet/in.h>
3231
#include <arpa/inet.h>
33-
3432
#include <errno.h>
3533
#include <signal.h>
3634

35+
#include "access/xact.h"
36+
#include "access/heapam.h"
37+
#include "catalog/catname.h"
38+
#include "catalog/pg_shadow.h"
39+
#include "catalog/pg_database.h"
40+
#include "libpq/pqsignal.h"
3741
#include "miscadmin.h"
3842
#include "utils/memutils.h"
3943
#include "storage/backendid.h"
4044
#include "utils/rel.h"
4145
#include "utils/hsearch.h"
46+
#include "utils/ps_status.h"
4247
#include "utils/syscache.h"
43-
#include "access/xact.h"
44-
#include "access/heapam.h"
45-
#include "catalog/catname.h"
46-
#include "catalog/pg_shadow.h"
47-
#include "catalog/pg_database.h"
4848

4949
#include "pgstat.h"
5050

5151

5252
/* ----------
53-
* Global data
53+
* GUC parameters
5454
* ----------
5555
*/
5656
bool pgstat_collect_startcollector = true;
@@ -95,8 +95,8 @@ static char pgStat_fname[MAXPGPATH];
9595
* Local function forward declarations
9696
* ----------
9797
*/
98-
static void pgstat_main(void);
99-
static void pgstat_recvbuffer(void);
98+
static void pgstat_main(int real_argc, char *real_argv[]);
99+
static void pgstat_recvbuffer(int real_argc, char *real_argv[]);
100100

101101
static int pgstat_add_backend(PgStat_MsgHdr *msg);
102102
static void pgstat_sub_backend(int procpid);
@@ -227,11 +227,14 @@ pgstat_init(void)
227227
* pgstat_start() -
228228
*
229229
* Called from postmaster at startup or after an existing collector
230-
* died. Fire up a fresh statistics collector.
230+
* died. Fire up a fresh statistics collector.
231+
*
232+
* The process' original argc and argv are passed, because they are
233+
* needed by init_ps_display() on some platforms.
231234
* ----------
232235
*/
233236
int
234-
pgstat_start(void)
237+
pgstat_start(int real_argc, char *real_argv[])
235238
{
236239
/*
237240
* Do nothing if no collector needed
@@ -267,7 +270,8 @@ pgstat_start(void)
267270
return 0;
268271
}
269272

270-
pgstat_main();
273+
pgstat_main(real_argc, real_argv);
274+
271275
exit(0);
272276
}
273277

@@ -989,15 +993,6 @@ pgstat_fetch_stat_numbackends(void)
989993

990994

991995

992-
993-
994-
995-
996-
997-
998-
999-
1000-
1001996
/* ------------------------------------------------------------
1002997
* Local support functions follow
1003998
* ------------------------------------------------------------
@@ -1053,7 +1048,7 @@ pgstat_send(void *msg, int len)
10531048
* ----------
10541049
*/
10551050
static void
1056-
pgstat_main(void)
1051+
pgstat_main(int real_argc, char *real_argv[])
10571052
{
10581053
PgStat_Msg msg;
10591054
fd_set rfds;
@@ -1076,27 +1071,22 @@ pgstat_main(void)
10761071
/*
10771072
* Ignore all signals usually bound to some action in the postmaster
10781073
*/
1079-
signal(SIGHUP, SIG_IGN);
1080-
signal(SIGINT, SIG_IGN);
1081-
signal(SIGQUIT, SIG_IGN);
1082-
signal(SIGTERM, SIG_IGN);
1083-
signal(SIGALRM, SIG_IGN);
1084-
signal(SIGPIPE, SIG_IGN);
1085-
signal(SIGUSR1, SIG_IGN);
1086-
signal(SIGUSR2, SIG_IGN);
1087-
signal(SIGCHLD, SIG_IGN);
1088-
signal(SIGTTIN, SIG_IGN);
1089-
signal(SIGTTOU, SIG_IGN);
1090-
signal(SIGWINCH, SIG_IGN);
1091-
1092-
/*
1093-
* Write the initial status file right at startup
1094-
*/
1095-
gettimeofday(&next_statwrite, NULL);
1096-
need_statwrite = TRUE;
1097-
1098-
/*
1099-
* Now we start the buffer process to read from the socket, so
1074+
pqsignal(SIGHUP, SIG_IGN);
1075+
pqsignal(SIGINT, SIG_IGN);
1076+
pqsignal(SIGTERM, SIG_IGN);
1077+
pqsignal(SIGQUIT, SIG_IGN);
1078+
pqsignal(SIGALRM, SIG_IGN);
1079+
pqsignal(SIGPIPE, SIG_IGN);
1080+
pqsignal(SIGUSR1, SIG_IGN);
1081+
pqsignal(SIGUSR2, SIG_IGN);
1082+
pqsignal(SIGCHLD, SIG_DFL);
1083+
pqsignal(SIGTTIN, SIG_DFL);
1084+
pqsignal(SIGTTOU, SIG_DFL);
1085+
pqsignal(SIGCONT, SIG_DFL);
1086+
pqsignal(SIGWINCH, SIG_DFL);
1087+
1088+
/*
1089+
* Start a buffering subprocess to read from the socket, so
11001090
* we have a little more time to process incoming messages.
11011091
*/
11021092
if (pipe(pgStatPipe) < 0)
@@ -1107,19 +1097,38 @@ pgstat_main(void)
11071097

11081098
switch(fork())
11091099
{
1110-
case -1: perror("PGSTAT: fork(2)");
1111-
exit(1);
1100+
case -1:
1101+
perror("PGSTAT: fork(2)");
1102+
exit(1);
11121103

1113-
case 0: close(pgStatPipe[0]);
1114-
signal(SIGPIPE, SIG_DFL);
1115-
pgstat_recvbuffer();
1116-
exit(2);
1104+
case 0:
1105+
close(pgStatPipe[0]);
1106+
/* child process should die if can't pipe to parent collector */
1107+
pqsignal(SIGPIPE, SIG_DFL);
1108+
pgstat_recvbuffer(real_argc, real_argv);
1109+
exit(2);
11171110

1118-
default: close(pgStatPipe[1]);
1119-
close(pgStatSock);
1120-
break;
1111+
default:
1112+
close(pgStatPipe[1]);
1113+
close(pgStatSock);
1114+
break;
11211115
}
11221116

1117+
/*
1118+
* Identify myself via ps
1119+
*
1120+
* WARNING: On some platforms the environment will be moved around to
1121+
* make room for the ps display string.
1122+
*/
1123+
init_ps_display(real_argc, real_argv, "stats collector process", "", "");
1124+
set_ps_display("");
1125+
1126+
/*
1127+
* Arrange to write the initial status file right away
1128+
*/
1129+
gettimeofday(&next_statwrite, NULL);
1130+
need_statwrite = TRUE;
1131+
11231132
/*
11241133
* Read in an existing statistics stats file or initialize the
11251134
* stats to zero.
@@ -1358,7 +1367,7 @@ pgstat_main(void)
13581367
* ----------
13591368
*/
13601369
static void
1361-
pgstat_recvbuffer(void)
1370+
pgstat_recvbuffer(int real_argc, char *real_argv[])
13621371
{
13631372
fd_set rfds;
13641373
fd_set wfds;
@@ -1373,6 +1382,15 @@ pgstat_recvbuffer(void)
13731382
int fromlen;
13741383
int overflow = 0;
13751384

1385+
/*
1386+
* Identify myself via ps
1387+
*
1388+
* WARNING: On some platforms the environment will be moved around to
1389+
* make room for the ps display string.
1390+
*/
1391+
init_ps_display(real_argc, real_argv, "stats buffer process", "", "");
1392+
set_ps_display("");
1393+
13761394
/*
13771395
* Allocate the message buffer
13781396
*/

‎src/backend/postmaster/postmaster.c

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -37,7 +37,7 @@
3737
*
3838
*
3939
* IDENTIFICATION
40-
* $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.233 2001/07/31 22:55:45 tgl Exp $
40+
* $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.234 2001/08/04 00:14:43 tgl Exp $
4141
*
4242
* NOTES
4343
*
@@ -696,7 +696,7 @@ PostmasterMain(int argc, char *argv[])
696696
*/
697697
if (pgstat_init() < 0)
698698
ExitPostmaster(1);
699-
if (pgstat_start() < 0)
699+
if (pgstat_start(real_argc, real_argv) < 0)
700700
ExitPostmaster(1);
701701

702702
/*
@@ -1488,7 +1488,7 @@ reaper(SIGNAL_ARGS)
14881488
{
14891489
fprintf(stderr, "%s: Performance collector exited with status %d\n",
14901490
progname, exitstatus);
1491-
pgstat_start();
1491+
pgstat_start(real_argc, real_argv);
14921492
continue;
14931493
}
14941494

‎src/backend/tcop/postgres.c

Lines changed: 7 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.229 2001/07/31 22:55:45 tgl Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.230 2001/08/04 00:14:43 tgl Exp $
1212
*
1313
* NOTES
1414
* this is the "main" module of the postgres backend and
@@ -1102,7 +1102,9 @@ usage(char *progname)
11021102
* ----------------------------------------------------------------
11031103
*/
11041104
int
1105-
PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[], const char *username)
1105+
PostgresMain(int argc, char *argv[],
1106+
int real_argc, char *real_argv[],
1107+
const char *username)
11061108
{
11071109
int flag;
11081110

@@ -1535,15 +1537,15 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[], const cha
15351537
*/
15361538
pqsignal(SIGPIPE, SIG_IGN);
15371539
pqsignal(SIGUSR1, SIG_IGN); /* this signal available for use */
1540+
15381541
pqsignal(SIGUSR2, Async_NotifyHandler); /* flush also sinval cache */
15391542
pqsignal(SIGFPE, FloatExceptionHandler);
1540-
pqsignal(SIGCHLD, SIG_IGN); /* ignored (may get this in system()
1541-
* calls) */
15421543

15431544
/*
15441545
* Reset some signals that are accepted by postmaster but not by
15451546
* backend
15461547
*/
1548+
pqsignal(SIGCHLD, SIG_DFL); /* system() requires this on some platforms */
15471549
pqsignal(SIGTTIN, SIG_DFL);
15481550
pqsignal(SIGTTOU, SIG_DFL);
15491551
pqsignal(SIGCONT, SIG_DFL);
@@ -1711,7 +1713,7 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[], const cha
17111713
if (!IsUnderPostmaster)
17121714
{
17131715
puts("\nPOSTGRES backend interactive interface ");
1714-
puts("$Revision: 1.229 $ $Date: 2001/07/31 22:55:45 $\n");
1716+
puts("$Revision: 1.230 $ $Date: 2001/08/04 00:14:43 $\n");
17151717
}
17161718

17171719
/*

‎src/include/pgstat.h

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -5,7 +5,7 @@
55
*
66
* Copyright (c) 2001, PostgreSQL Global Development Group
77
*
8-
* $Id: pgstat.h,v 1.4 2001/07/05 15:19:40 wieck Exp $
8+
* $Id: pgstat.h,v 1.5 2001/08/04 00:14:43 tgl Exp $
99
* ----------
1010
*/
1111
#ifndef PGSTAT_H
@@ -336,7 +336,7 @@ extern bool pgstat_collect_blocklevel;
336336
* ----------
337337
*/
338338
extern int pgstat_init(void);
339-
extern int pgstat_start(void);
339+
extern int pgstat_start(int real_argc, char *real_argv[]);
340340
extern int pgstat_ispgstat(int pid);
341341
extern void pgstat_beterm(int pid);
342342

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