void check_mypid()
{
pid_t pid = 0;
if (can_stat(conf.bot->pid_file))
pid = checkpid(conf.bot->nick, NULL);
if (pid && (pid != getpid()))
fatal(STR("getpid() does not match pid in file. Possible cloned process, exiting.."), 0);
}
/**
* @brief
* Get the pid of the database from the postmaster.pid
* file located inside directory pointed by dbstore
*
* @param[in] dbstore - The path to the database data directory
*
* @retval 0 - Function failed
* @retval >0 - Pid of the postmaster master process
*
* @par MT-safe: Yes
*/
static pid_t
get_pid()
{
char pidfile[MAXPATHLEN+1];
FILE *fp;
char buf[TEMP_BUF_SIZE+1];
pid_t pid = 0;
#ifdef WIN32
snprintf(pidfile, MAXPATHLEN, "%s\\datastore\\postmaster.pid", pbs_conf.pbs_home_path);
#else
snprintf(pidfile, MAXPATHLEN, "%s/datastore/postmaster.pid", pbs_conf.pbs_home_path);
#endif
if (access(pidfile, R_OK) != 0)
return 0;
if ((fp = fopen(pidfile, "r")) == NULL)
return 0;
memset(buf, 0, TEMP_BUF_SIZE + 1);
fgets(buf, TEMP_BUF_SIZE, fp);
buf[TEMP_BUF_SIZE] = '\0';
fclose(fp);
if (strlen(buf) == 0)
return 0;
pid = atol(buf);
if (pid == 0)
return 0;
#ifdef WIN32
if (!checkpid(pid))
return 0;
#else
if (kill(pid, 0) != 0)
return 0;
#endif
return pid;
}
/**
* @brief
* The child part of the monitor functionality on Windows.
*
* This function is called as a separate executable (child) process
* from the parent monitor, and is passed the location of the
* data directory. The parent launches this function as a process and waits
* to read the stdout of the child process.
* @par
* This function attempts to lock the lockfile (inside dbstore) and if it
* fails, it prints the reason of failure to lock, to its stdout; the child
* process also exits in this case.
* @par
* If the function succeeds in locking the file, it prints "0" to its stdout
* resulting in the parent to exit with success to its caller. In that case
* this process (child) continues to run in the background, as long as the
* monitored database process is still up, holding onto the lock, so that no
* other process can lock this file (and thus not be able to start the database).
* @par
* If and when eventually the database goes down, this function unlocks the file
* and quits (allowing others to lock the file and start the database).
*
* @retval 0 : Function succeeded for the given operation
* @retval 1 : Failed (eg to lock the file).
*
* @par MT-safe: Yes
*/
int
win_db_monitor_child()
{
HANDLE hFile;
BOOL fSuccess = FALSE;
pid_t dbpid;
int i;
char lockfile[MAXPATHLEN + 1];
char reason[RES_BUF_SIZE];
reason[0] = '\0';
/* clear any residual stop db file before starting monitoring */
clear_stop_db_file();
snprintf(lockfile, MAXPATHLEN, "%s\\datastore\\pbs_dblock", pbs_conf.pbs_home_path);
hFile = acquire_lock(lockfile, reason, sizeof(reason), NULL);
if (hFile == INVALID_HANDLE_VALUE) {
printf("%s", reason);
fflush(stdout);
return 1;
}
/* set success event */
printf("0");
fflush(stdout);
fclose(stdin);
fclose(stderr);
fclose(stdout); /* dont need stdout after this */
/*
* okay, so we locked the file. Now find postgres pid
* then loop forever as long as pid is up
*/
dbpid = 0;
for (i = 0; i < MAX_DBPID_ATTEMPTS; i++) {
if ((dbpid = get_pid()) > 0)
break;
sleep(1);
}
if (dbpid == 0) {
lock_out(hFile, F_UNLCK);
CloseHandle(hFile);
unlink(lockfile);
return 0; /* this will unlock the lock in the datastore */
}
while (1) {
if (!checkpid(dbpid))
break;
if (!((dbpid = get_pid()) > 0))
break;
/* check if stop db file exists */
check_and_stop_db(dbpid);
sleep(1);
}
/* unlock and return */
lock_out(hFile, F_UNLCK);
CloseHandle(hFile);
unlink(lockfile);
/* clear temporary err files created at startup; windows only case */
clear_tmp_files();
return 0;
}
