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0a78320057
This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
75 lines
2.3 KiB
C
75 lines
2.3 KiB
C
/*-------------------------------------------------------------------------
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*
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* pqsignal.c
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* reliable BSD-style signal(2) routine stolen from RWW who stole it
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* from Stevens...
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*
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* Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/port/pqsignal.c
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*
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* A NOTE ABOUT SIGNAL HANDLING ACROSS THE VARIOUS PLATFORMS.
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*
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* pg_config.h defines the macro HAVE_POSIX_SIGNALS for some platforms and
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* not for others. We use that here to decide how to handle signalling.
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*
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* Ultrix and SunOS provide BSD signal(2) semantics by default.
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*
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* SVID2 and POSIX signal(2) semantics differ from BSD signal(2)
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* semantics. We can use the POSIX sigaction(2) on systems that
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* allow us to request restartable signals (SA_RESTART).
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*
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* Some systems don't allow restartable signals at all unless we
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* link to a special BSD library.
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*
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* We devoutly hope that there aren't any Unix-oid systems that provide
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* neither POSIX signals nor BSD signals. The alternative is to do
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* signal-handler reinstallation, which doesn't work well at all.
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*
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* Windows, of course, is resolutely in a class by itself. In the backend,
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* we don't use this file at all; src/backend/port/win32/signal.c provides
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* pqsignal() for the backend environment. Frontend programs can use
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* this version of pqsignal() if they wish, but beware that Windows
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* requires signal-handler reinstallation, because indeed it provides
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* neither POSIX signals nor BSD signals :-(
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* ------------------------------------------------------------------------
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*/
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#include "c.h"
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#include <signal.h>
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#if !defined(WIN32) || defined(FRONTEND)
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/*
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* Set up a signal handler for signal "signo"
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*
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* Returns the previous handler.
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*/
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pqsigfunc
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pqsignal(int signo, pqsigfunc func)
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{
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#if !defined(HAVE_POSIX_SIGNALS)
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return signal(signo, func);
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#else
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struct sigaction act,
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oact;
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act.sa_handler = func;
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sigemptyset(&act.sa_mask);
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act.sa_flags = SA_RESTART;
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#ifdef SA_NOCLDSTOP
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if (signo == SIGCHLD)
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act.sa_flags |= SA_NOCLDSTOP;
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#endif
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if (sigaction(signo, &act, &oact) < 0)
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return SIG_ERR;
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return oact.sa_handler;
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#endif /* !HAVE_POSIX_SIGNALS */
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}
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#endif /* !defined(WIN32) || defined(FRONTEND) */
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