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/*-------------------------------------------------------------------------
*
* pqsignal.c
* reliable BSD-style signal(2) routine stolen from RWW who stole it
* from Stevens...
*
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/port/pqsignal.c
*
* We now assume that all Unix-oid systems have POSIX sigaction(2)
* with support for restartable signals (SA_RESTART). We used to also
* support BSD-style signal(2), but there really shouldn't be anything
* out there anymore that doesn't have the POSIX API.
*
* Windows, of course, is resolutely in a class by itself. In the backend,
* we don't use this file at all; src/backend/port/win32/signal.c provides
* pqsignal() for the backend environment. Frontend programs can use
* this version of pqsignal() if they wish, but beware that this does
* not provide restartable signals on Windows.
*
* ------------------------------------------------------------------------
*/
#include "c.h"
#include <signal.h>
#ifndef FRONTEND
#error #include "libpq/pqsignal.h"
#endif
/*
* Set up a signal handler, with SA_RESTART, for signal "signo"
*
* Returns the previous handler.
*/
pqsigfunc
pqsignal(int signo, pqsigfunc func)
{
#if !(defined(WIN32) && defined(FRONTEND))
struct sigaction act,
oact;
act.sa_handler = func;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_RESTART;
#ifdef SA_NOCLDSTOP
if (signo == SIGCHLD)
act.sa_flags |= SA_NOCLDSTOP;
#endif
if (sigaction(signo, &act, &oact) < 0)
return SIG_ERR;
return oact.sa_handler;
#else
/* Forward to Windows native signal system. */
return signal(signo, func);
#endif
}
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