database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-13 07:41:39 +03:00
Code Activity

Prevent freshly-started backend from ignoring SIGUSR1, per race condition

Browse Source 
observed by Inoue.  Also, don't call ProcRemove() from postmaster if we
have detected a backend crash --- too risky if shared memory is corrupted.
It's not needed anyway, considering we are going to reinitialize shared
memory and semaphores as soon as the last child is dead.
This commit is contained in:
Tom Lane
2000-12-20 21:51:52 +00:00
parent e4d97cb70e
commit 39b547f430
2 changed files with 74 additions and 63 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
src/backend/tcop/postgres.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.197 2000/12/18 18:45:05 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.198 2000/12/20 21:51:52 tgl Exp $
*
* NOTES
* this is the "main" module of the postgres backend and
@ -1462,21 +1462,12 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[], const cha
Assert(DataDir);
/*
* 1. Set BlockSig and UnBlockSig masks. 2. Set up signal handlers. 3.
* Allow only SIGUSR1 signal (we never block it) during
* initialization.
* Set up signal handlers and masks.
*
* Note that postmaster already blocked ALL signals to make us happy.
* Note that postmaster blocked all signals before forking child process,
* so there is no race condition whereby we might receive a signal before
* we have set up the handler.
*/
pqinitmask();
#ifdef HAVE_SIGPROCMASK
sigdelset(&BlockSig, SIGUSR1);
#else
BlockSig &= ~(sigmask(SIGUSR1));
#endif
PG_SETMASK(&BlockSig); /* block everything except SIGUSR1 */
pqsignal(SIGHUP, SigHupHandler); /* set flag to read config file */
pqsignal(SIGINT, QueryCancelHandler); /* cancel current query */
@ -1499,6 +1490,17 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[], const cha
pqsignal(SIGTTOU, SIG_DFL);
pqsignal(SIGCONT, SIG_DFL);
pqinitmask();
/* We allow SIGUSR1 (quickdie) at all times */
#ifdef HAVE_SIGPROCMASK
sigdelset(&BlockSig, SIGUSR1);
#else
BlockSig &= ~(sigmask(SIGUSR1));
#endif
PG_SETMASK(&BlockSig); /* block everything except SIGUSR1 */
if (IsUnderPostmaster)
{
@ -1649,7 +1651,7 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[], const cha
if (!IsUnderPostmaster)
{
puts("\nPOSTGRES backend interactive interface ");
puts("$Revision: 1.197 $ $Date: 2000/12/18 18:45:05 $\n");
puts("$Revision: 1.198 $ $Date: 2000/12/20 21:51:52 $\n");
}
/*