*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.200 2000/12/18 18:45:04 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.201 2000/12/20 21:51:52 tgl Exp $
*
* NOTES
*
static int Shutdown = NoShutdown;
-static bool FatalError = false;
+static bool FatalError = false; /* T if recovering from backend crash */
/*
* State for assigning random salts and cancel keys.
pqsignal(SIGTERM, pmdie); /* wait for children and ShutdownDataBase */
pqsignal(SIGALRM, SIG_IGN); /* ignored */
pqsignal(SIGPIPE, SIG_IGN); /* ignored */
- pqsignal(SIGUSR1, SIG_IGN); /* ignored */
+ pqsignal(SIGUSR1, pmdie); /* currently ignored, but see note in pmdie */
pqsignal(SIGUSR2, pmdie); /* send SIGUSR2, don't die */
pqsignal(SIGCHLD, reaper); /* handle child termination */
pqsignal(SIGTTIN, SIG_IGN); /* ignored */
switch (postgres_signal_arg)
{
+ case SIGUSR1:
+ /*
+ * Currently the postmaster ignores SIGUSR1 (maybe it should
+ * do something useful instead?) But we must have some handler
+ * installed for SIGUSR1, not just set it to SIG_IGN. Else, a
+ * freshly spawned backend would likewise have it set to SIG_IGN,
+ * which would mean the backend would ignore any attempt to kill
+ * it before it had gotten as far as setting up its own handler.
+ */
+ errno = save_errno;
+ return;
+
case SIGUSR2:
/*
ExitPostmaster(1);
}
StartupPID = 0;
- FatalError = false;
+ FatalError = false; /* done with recovery */
if (Shutdown > NoShutdown)
{
if (ShutdownPID > 0)
/*
* Wait for all children exit, then reset shmem and StartupDataBase.
*/
- if (DLGetHead(BackendList))
- {
- errno = save_errno;
- return;
- }
- if (StartupPID > 0 || ShutdownPID > 0)
+ if (DLGetHead(BackendList) || StartupPID > 0 || ShutdownPID > 0)
{
errno = save_errno;
return;
Dlelem *curr,
*next;
Backend *bp;
- int sig;
if (DebugLvl)
- {
fprintf(stderr, "%s: CleanupProc: pid %d exited with status %d\n",
progname, pid, exitstatus);
- }
/*
* If a backend dies in an ugly way (i.e. exit status not 0) then we
* we assume everything is hunky dory and simply remove the backend
* from the active backend list.
*/
- if (!exitstatus)
+ if (exitstatus == 0)
{
curr = DLGetHead(BackendList);
while (curr)
if (pid == CheckPointPID)
{
CheckPointPID = 0;
- checkpointed = time(NULL);
+ if (!FatalError)
+ checkpointed = time(NULL);
}
else
- ProcRemove(pid);
+ {
+ /* Why is this done here, and not by the backend itself? */
+ if (!FatalError)
+ ProcRemove(pid);
+ }
return;
}
if (!FatalError)
{
+ /* Make log entry unless we did so already */
tnow = time(NULL);
fprintf(stderr, "Server process (pid %d) exited with status %d at %s"
"Terminating any active server processes...\n",
pid, exitstatus, ctime(&tnow));
fflush(stderr);
}
- FatalError = true;
+
curr = DLGetHead(BackendList);
while (curr)
{
next = DLGetSucc(curr);
bp = (Backend *) DLE_VAL(curr);
-
- /*
- * SIGUSR1 is the special signal that says exit without proc_exit
- * and let the user know what's going on. ProcSemaphoreKill()
- * cleans up the backends semaphore. If SendStop is set (-s on
- * command line), then we send a SIGSTOP so that we can core dumps
- * from all backends by hand.
- */
- sig = (SendStop) ? SIGSTOP : SIGUSR1;
if (bp->pid != pid)
{
- if (DebugLvl)
- fprintf(stderr, "%s: CleanupProc: sending %s to process %d\n",
- progname,
- (sig == SIGUSR1)
- ? "SIGUSR1" : "SIGSTOP",
- bp->pid);
- kill(bp->pid, sig);
+ /*
+ * This backend is still alive. Unless we did so already,
+ * tell it to commit hara-kiri.
+ *
+ * SIGUSR1 is the special signal that says exit without proc_exit
+ * and let the user know what's going on. But if SendStop is set
+ * (-s on command line), then we send SIGSTOP instead, so that we
+ * can get core dumps from all backends by hand.
+ */
+ if (!FatalError)
+ {
+ if (DebugLvl)
+ fprintf(stderr, "%s: CleanupProc: sending %s to process %d\n",
+ progname,
+ (SendStop ? "SIGSTOP" : "SIGUSR1"),
+ bp->pid);
+ kill(bp->pid, (SendStop ? SIGSTOP : SIGUSR1));
+ }
}
else
{
-
/*
- * I don't like that we call ProcRemove() here, assuming that
- * shmem may be corrupted! But is there another way to free
- * backend semaphores? Actually, I believe that we need not in
- * per backend semaphore at all (we use them to wait on lock
- * only, couldn't we just sigpause?), so probably we'll remove
- * this call from here someday. -- vadim 04-10-1999
+ * Found entry for freshly-dead backend, so remove it.
+ *
+ * Don't call ProcRemove() here, since shmem may be corrupted!
+ * We are going to reinitialize shmem and semaphores anyway
+ * once all the children are dead, so no need for it.
*/
- if (pid == CheckPointPID)
- {
- CheckPointPID = 0;
- checkpointed = 0;
- }
- else
- ProcRemove(pid);
-
DLRemove(curr);
free(bp);
DLFreeElem(curr);
curr = next;
}
+ if (pid == CheckPointPID)
+ {
+ CheckPointPID = 0;
+ checkpointed = 0;
+ }
+
+ FatalError = true;
}
/*
*
*
* 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
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 */
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)
{
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");
}
/*
projects / postgresql / commitdiff