* signals that the backend can recognize.
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/port/kill.c,v 1.11 2009/01/01 17:24:04 momjian Exp $
+ * $PostgreSQL: pgsql/src/port/kill.c,v 1.12 2009/02/15 13:58:18 mha Exp $
*
*-------------------------------------------------------------------------
*/
BYTE sigData = sig;
BYTE sigRet = 0;
DWORD bytes;
+ int pipe_tries;
/* we allow signal 0 here, but it will be ignored in pg_queue_signal */
if (sig >= PG_SIGNAL_COUNT || sig < 0)
return -1;
}
snprintf(pipename, sizeof(pipename), "\\\\.\\pipe\\pgsignal_%u", pid);
- if (!CallNamedPipe(pipename, &sigData, 1, &sigRet, 1, &bytes, 1000))
- {
- if (GetLastError() == ERROR_FILE_NOT_FOUND)
- errno = ESRCH;
- else if (GetLastError() == ERROR_ACCESS_DENIED)
- errno = EPERM;
- else
- errno = EINVAL;
- return -1;
- }
- if (bytes != 1 || sigRet != sig)
+
+ /*
+ * Writing data to the named pipe can fail for transient reasons.
+ * Therefore, it is useful to retry if it fails. The maximum number of
+ * calls to make was empirically determined from a 90-hour notification
+ * stress test.
+ */
+ for (pipe_tries = 0; pipe_tries < 3; pipe_tries++)
{
- errno = ESRCH;
- return -1;
+ if (CallNamedPipe(pipename, &sigData, 1, &sigRet, 1, &bytes, 1000))
+ {
+ if (bytes != 1 || sigRet != sig)
+ {
+ errno = ESRCH;
+ return -1;
+ }
+ return 0;
+ }
}
- return 0;
+ if (GetLastError() == ERROR_FILE_NOT_FOUND)
+ errno = ESRCH;
+ else if (GetLastError() == ERROR_ACCESS_DENIED)
+ errno = EPERM;
+ else
+ errno = EINVAL;
+ return -1;
}
#endif