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mirror of https://github.com/postgrespro/pg_probackup.git synced 2024-12-11 11:41:33 +02:00
pg_probackup/status.c
Michael Paquier 5c37daca69 Sanitize error checks
All the ERROR_* fields are removed in favor of a more simple layer
made of ERROR, FATAL, PANIC. The two last ones are not actually used
yet, thought there should be some code paths that would need more
polishing on this matter.

The error message emitted before leaving should be fine to let the
user know what is happening.
2016-01-19 12:41:30 +09:00

119 lines
2.3 KiB
C

/*-------------------------------------------------------------------------
*
* status.c
*
* Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
*
* Monitor status of a PostgreSQL server.
*
*-------------------------------------------------------------------------
*/
#include "postgres_fe.h"
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include "pg_arman.h"
/* PID can be negative for standalone backend */
typedef long pgpid_t;
static pgpid_t get_pgpid(void);
static bool postmaster_is_alive(pid_t pid);
/*
* get_pgpid
*
* Get PID of postmaster, by scanning postmaster.pid.
*/
static pgpid_t
get_pgpid(void)
{
FILE *pidf;
long pid;
char pid_file[MAXPGPATH];
snprintf(pid_file, lengthof(pid_file), "%s/postmaster.pid", pgdata);
pidf = fopen(pid_file, "r");
if (pidf == NULL)
{
/* No pid file, not an error on startup */
if (errno == ENOENT)
return 0;
else
{
elog(ERROR, "could not open PID file \"%s\": %s",
pid_file, strerror(errno));
}
}
if (fscanf(pidf, "%ld", &pid) != 1)
{
/* Is the file empty? */
if (ftell(pidf) == 0 && feof(pidf))
elog(ERROR, "the PID file \"%s\" is empty",
pid_file);
else
elog(ERROR, "invalid data in PID file \"%s\"\n",
pid_file);
}
fclose(pidf);
return (pgpid_t) pid;
}
/*
* postmaster_is_alive
*
* Check whether postmaster is alive or not.
*/
static bool
postmaster_is_alive(pid_t pid)
{
/*
* Test to see if the process is still there. Note that we do not
* consider an EPERM failure to mean that the process is still there;
* EPERM must mean that the given PID belongs to some other userid, and
* considering the permissions on $PGDATA, that means it's not the
* postmaster we are after.
*
* Don't believe that our own PID or parent shell's PID is the postmaster,
* either. (Windows hasn't got getppid(), though.)
*/
if (pid == getpid())
return false;
#ifndef WIN32
if (pid == getppid())
return false;
#endif
if (kill(pid, 0) == 0)
return true;
return false;
}
/*
* is_pg_running
*
*
*/
bool
is_pg_running(void)
{
pgpid_t pid;
pid = get_pgpid();
/* 0 means no pid file */
if (pid == 0)
return false;
/* Case of a standalone backend */
if (pid < 0)
pid = -pid;
/* Check if postmaster is alive */
return postmaster_is_alive((pid_t) pid);
}