Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit83fb1ca

Browse files
committed
On Darwin, detect and report a multithreaded postmaster.
Darwin --enable-nls builds use a substitute setlocale() that may start athread. Buildfarm member orangutan experienced BackendList corruptionon account of different postmaster threads executing signal handlerssimultaneously. Furthermore, a multithreaded postmaster risks undefinedbehavior from sigprocmask() and fork(). Emit LOG messages about theproblem and its workaround. Back-patch to 9.0 (all supported versions).
1 parente8f82b4 commit83fb1ca

File tree

5 files changed

+60
-2
lines changed

5 files changed

+60
-2
lines changed

‎configure‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -11301,7 +11301,7 @@ fi
1130111301
LIBS_including_readline="$LIBS"
1130211302
LIBS=`echo"$LIBS"| sed -e's/-ledit//g' -e's/-lreadline//g'`
1130311303

11304-
forac_funcin cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat readlink setproctitle setsid shm_open sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l
11304+
forac_funcin cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstatpthread_is_threaded_npreadlink setproctitle setsid shm_open sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l
1130511305
do:
1130611306
as_ac_var=`$as_echo"ac_cv_func_$ac_func"|$as_tr_sh`
1130711307
ac_fn_c_check_func"$LINENO""$ac_func""$as_ac_var"

‎configure.in‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1280,7 +1280,7 @@ PGAC_FUNC_GETTIMEOFDAY_1ARG
12801280
LIBS_including_readline="$LIBS"
12811281
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
12821282

1283-
AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat readlink setproctitle setsid shm_open sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l])
1283+
AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstatpthread_is_threaded_npreadlink setproctitle setsid shm_open sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l])
12841284

12851285
AC_REPLACE_FUNCS(fseeko)
12861286
case $host_os in

‎src/backend/postmaster/postmaster.c‎

Lines changed: 43 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -87,6 +87,10 @@
8787
#include<dns_sd.h>
8888
#endif
8989

90+
#ifdefHAVE_PTHREAD_IS_THREADED_NP
91+
#include<pthread.h>
92+
#endif
93+
9094
#include"access/transam.h"
9195
#include"access/xlog.h"
9296
#include"bootstrap/bootstrap.h"
@@ -1203,6 +1207,24 @@ PostmasterMain(int argc, char *argv[])
12031207
*/
12041208
RemovePgTempFiles();
12051209

1210+
#ifdefHAVE_PTHREAD_IS_THREADED_NP
1211+
1212+
/*
1213+
* On Darwin, libintl replaces setlocale() with a version that calls
1214+
* CFLocaleCopyCurrent() when its second argument is "" and every relevant
1215+
* environment variable is unset or empty. CFLocaleCopyCurrent() makes
1216+
* the process multithreaded. The postmaster calls sigprocmask() and
1217+
* calls fork() without an immediate exec(), both of which have undefined
1218+
* behavior in a multithreaded program. A multithreaded postmaster is the
1219+
* normal case on Windows, which offers neither fork() nor sigprocmask().
1220+
*/
1221+
if (pthread_is_threaded_np()!=0)
1222+
ereport(LOG,
1223+
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1224+
errmsg("postmaster became multithreaded during startup"),
1225+
errhint("Set the LC_ALL environment variable to a valid locale.")));
1226+
#endif
1227+
12061228
/*
12071229
* Remember postmaster startup time
12081230
*/
@@ -1660,6 +1682,15 @@ ServerLoop(void)
16601682
last_touch_time=now;
16611683
}
16621684

1685+
#ifdefHAVE_PTHREAD_IS_THREADED_NP
1686+
1687+
/*
1688+
* With assertions enabled, check regularly for appearance of
1689+
* additional threads. All builds check at start and exit.
1690+
*/
1691+
Assert(pthread_is_threaded_np()==0);
1692+
#endif
1693+
16631694
/*
16641695
* If we already sent SIGQUIT to children and they are slow to shut
16651696
* down, it's time to send them SIGKILL. This doesn't happen
@@ -4738,6 +4769,18 @@ SubPostmasterMain(int argc, char *argv[])
47384769
staticvoid
47394770
ExitPostmaster(intstatus)
47404771
{
4772+
#ifdefHAVE_PTHREAD_IS_THREADED_NP
4773+
4774+
/*
4775+
* There is no known cause for a postmaster to become multithreaded after
4776+
* startup. Recheck to account for the possibility of unknown causes.
4777+
*/
4778+
if (pthread_is_threaded_np()!=0)
4779+
ereport(LOG,
4780+
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4781+
errmsg("postmaster became multithreaded")));
4782+
#endif
4783+
47414784
/* should cleanup shared memory and kill all backends */
47424785

47434786
/*

‎src/common/exec.c‎

Lines changed: 12 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -556,8 +556,20 @@ set_pglocale_pgservice(const char *argv0, const char *app)
556556

557557
/* don't set LC_ALL in the backend */
558558
if (strcmp(app,PG_TEXTDOMAIN("postgres"))!=0)
559+
{
559560
setlocale(LC_ALL,"");
560561

562+
/*
563+
* One could make a case for reproducing here PostmasterMain()'s test
564+
* for whether the process is multithreaded. Unlike the postmaster,
565+
* no frontend program calls sigprocmask() or otherwise provides for
566+
* mutual exclusion between signal handlers. While frontends using
567+
* fork(), if multithreaded, are formally exposed to undefined
568+
* behavior, we have not witnessed a concrete bug. Therefore,
569+
* complaining about multithreading here may be mere pedantry.
570+
*/
571+
}
572+
561573
if (find_my_exec(argv0,my_exec_path)<0)
562574
return;
563575

‎src/include/pg_config.h.in‎

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -372,6 +372,9 @@
372372
/* Define if you have POSIX threads libraries and header files. */
373373
#undef HAVE_PTHREAD
374374

375+
/* Define to 1 if you have the `pthread_is_threaded_np' function. */
376+
#undef HAVE_PTHREAD_IS_THREADED_NP
377+
375378
/* Define to 1 if you have the <pwd.h> header file. */
376379
#undef HAVE_PWD_H
377380

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp