|
|
|
|
@ -17,6 +17,10 @@ |
|
|
|
|
#include <signal.h> |
|
|
|
|
#include <unistd.h> |
|
|
|
|
|
|
|
|
|
#ifdef HAVE_SYS_PRCTL_H |
|
|
|
|
#include <sys/prctl.h> |
|
|
|
|
#endif |
|
|
|
|
|
|
|
|
|
#include "miscadmin.h" |
|
|
|
|
#include "postmaster/postmaster.h" |
|
|
|
|
#include "replication/walsender.h" |
|
|
|
|
@ -71,6 +75,35 @@ struct PMSignalData |
|
|
|
|
|
|
|
|
|
NON_EXEC_STATIC volatile PMSignalData *PMSignalState = NULL; |
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Signal handler to be notified if postmaster dies. |
|
|
|
|
*/ |
|
|
|
|
#ifdef USE_POSTMASTER_DEATH_SIGNAL |
|
|
|
|
volatile sig_atomic_t postmaster_possibly_dead = false; |
|
|
|
|
|
|
|
|
|
static void |
|
|
|
|
postmaster_death_handler(int signo) |
|
|
|
|
{ |
|
|
|
|
postmaster_possibly_dead = true; |
|
|
|
|
} |
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* The available signals depend on the OS. SIGUSR1 and SIGUSR2 are already |
|
|
|
|
* used for other things, so choose another one. |
|
|
|
|
* |
|
|
|
|
* Currently, we assume that we can always find a signal to use. That |
|
|
|
|
* seems like a reasonable assumption for all platforms that are modern |
|
|
|
|
* enough to have a parent-death signaling mechanism. |
|
|
|
|
*/ |
|
|
|
|
#if defined(SIGINFO) |
|
|
|
|
#define POSTMASTER_DEATH_SIGNAL SIGINFO |
|
|
|
|
#elif defined(SIGPWR) |
|
|
|
|
#define POSTMASTER_DEATH_SIGNAL SIGPWR |
|
|
|
|
#else |
|
|
|
|
#error "cannot find a signal to use for postmaster death" |
|
|
|
|
#endif |
|
|
|
|
|
|
|
|
|
#endif /* USE_POSTMASTER_DEATH_SIGNAL */ |
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* PMSignalShmemSize |
|
|
|
|
@ -266,28 +299,94 @@ MarkPostmasterChildInactive(void) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* PostmasterIsAlive - check whether postmaster process is still alive |
|
|
|
|
* PostmasterIsAliveInternal - check whether postmaster process is still alive |
|
|
|
|
* |
|
|
|
|
* This is the slow path of PostmasterIsAlive(), where the caller has already |
|
|
|
|
* checked 'postmaster_possibly_dead'. (On platforms that don't support |
|
|
|
|
* a signal for parent death, PostmasterIsAlive() is just an alias for this.) |
|
|
|
|
*/ |
|
|
|
|
bool |
|
|
|
|
PostmasterIsAlive(void) |
|
|
|
|
PostmasterIsAliveInternal(void) |
|
|
|
|
{ |
|
|
|
|
#ifndef WIN32 |
|
|
|
|
char c; |
|
|
|
|
ssize_t rc; |
|
|
|
|
#ifdef USE_POSTMASTER_DEATH_SIGNAL |
|
|
|
|
/*
|
|
|
|
|
* Reset the flag before checking, so that we don't miss a signal if |
|
|
|
|
* postmaster dies right after the check. If postmaster was indeed dead, |
|
|
|
|
* we'll re-arm it before returning to caller. |
|
|
|
|
*/ |
|
|
|
|
postmaster_possibly_dead = false; |
|
|
|
|
#endif |
|
|
|
|
|
|
|
|
|
rc = read(postmaster_alive_fds[POSTMASTER_FD_WATCH], &c, 1); |
|
|
|
|
if (rc < 0) |
|
|
|
|
#ifndef WIN32 |
|
|
|
|
{ |
|
|
|
|
if (errno == EAGAIN || errno == EWOULDBLOCK) |
|
|
|
|
char c; |
|
|
|
|
ssize_t rc; |
|
|
|
|
|
|
|
|
|
rc = read(postmaster_alive_fds[POSTMASTER_FD_WATCH], &c, 1); |
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* In the usual case, the postmaster is still alive, and there is no |
|
|
|
|
* data in the pipe. |
|
|
|
|
*/ |
|
|
|
|
if (rc < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) |
|
|
|
|
return true; |
|
|
|
|
else |
|
|
|
|
elog(FATAL, "read on postmaster death monitoring pipe failed: %m"); |
|
|
|
|
{ |
|
|
|
|
/*
|
|
|
|
|
* Postmaster is dead, or something went wrong with the read() |
|
|
|
|
* call. |
|
|
|
|
*/ |
|
|
|
|
|
|
|
|
|
#ifdef USE_POSTMASTER_DEATH_SIGNAL |
|
|
|
|
postmaster_possibly_dead = true; |
|
|
|
|
#endif |
|
|
|
|
|
|
|
|
|
if (rc < 0) |
|
|
|
|
elog(FATAL, "read on postmaster death monitoring pipe failed: %m"); |
|
|
|
|
else if (rc > 0) |
|
|
|
|
elog(FATAL, "unexpected data in postmaster death monitoring pipe"); |
|
|
|
|
|
|
|
|
|
return false; |
|
|
|
|
} |
|
|
|
|
} |
|
|
|
|
else if (rc > 0) |
|
|
|
|
elog(FATAL, "unexpected data in postmaster death monitoring pipe"); |
|
|
|
|
|
|
|
|
|
return false; |
|
|
|
|
#else /* WIN32 */ |
|
|
|
|
return (WaitForSingleObject(PostmasterHandle, 0) == WAIT_TIMEOUT); |
|
|
|
|
if (WaitForSingleObject(PostmasterHandle, 0) == WAIT_TIMEOUT) |
|
|
|
|
return true; |
|
|
|
|
else |
|
|
|
|
{ |
|
|
|
|
#ifdef USE_POSTMASTER_DEATH_SIGNAL |
|
|
|
|
postmaster_possibly_dead = true; |
|
|
|
|
#endif |
|
|
|
|
return false; |
|
|
|
|
} |
|
|
|
|
#endif /* WIN32 */ |
|
|
|
|
} |
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* PostmasterDeathSignalInit - request signal on postmaster death if possible |
|
|
|
|
*/ |
|
|
|
|
void |
|
|
|
|
PostmasterDeathSignalInit(void) |
|
|
|
|
{ |
|
|
|
|
#ifdef USE_POSTMASTER_DEATH_SIGNAL |
|
|
|
|
int signum = POSTMASTER_DEATH_SIGNAL; |
|
|
|
|
|
|
|
|
|
/* Register our signal handler. */ |
|
|
|
|
pqsignal(signum, postmaster_death_handler); |
|
|
|
|
|
|
|
|
|
/* Request a signal on parent exit. */ |
|
|
|
|
#if defined(PR_SET_PDEATHSIG) |
|
|
|
|
if (prctl(PR_SET_PDEATHSIG, signum) < 0) |
|
|
|
|
elog(ERROR, "could not request parent death signal: %m"); |
|
|
|
|
#else |
|
|
|
|
#error "USE_POSTMASTER_DEATH_SIGNAL set, but there is no mechanism to request the signal" |
|
|
|
|
#endif |
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Just in case the parent was gone already and we missed it, we'd better |
|
|
|
|
* check the slow way on the first call. |
|
|
|
|
*/ |
|
|
|
|
postmaster_possibly_dead = true; |
|
|
|
|
#endif /* USE_POSTMASTER_DEATH_SIGNAL */ |
|
|
|
|
} |
|
|
|
|
|
Thomas Munro
7 years ago