Age         Owner                  TLA  Line data    Source code

                                  1                 : /*-------------------------------------------------------------------------
                                  2                 :  *
                                  3                 :  * legacy-pqsignal.c
                                  4                 :  *    reliable BSD-style signal(2) routine stolen from RWW who stole it
                                  5                 :  *    from Stevens...
                                  6                 :  *
                                  7                 :  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
                                  8                 :  * Portions Copyright (c) 1994, Regents of the University of California
                                  9                 :  *
                                 10                 :  *
                                 11                 :  * IDENTIFICATION
                                 12                 :  *    src/interfaces/libpq/legacy-pqsignal.c
                                 13                 :  *
                                 14                 :  *-------------------------------------------------------------------------
                                 15                 :  */
                                 16                 : #include "postgres_fe.h"
                                 17                 : 
                                 18                 : #include <signal.h>
                                 19                 : 
                                 20                 : 
                                 21                 : /*
                                 22                 :  * This version of pqsignal() exists only because pre-9.3 releases
                                 23                 :  * of libpq exported pqsignal(), and some old client programs still
                                 24                 :  * depend on that.  (Since 9.3, clients are supposed to get it from
                                 25                 :  * libpgport instead.)
                                 26                 :  *
                                 27                 :  * Because it is only intended for backwards compatibility, we freeze it
                                 28                 :  * with the semantics it had in 9.2; in particular, this has different
                                 29                 :  * behavior for SIGALRM than the version in src/port/pqsignal.c.
                                 30                 :  *
                                 31                 :  * libpq itself uses this only for SIGPIPE (and even then, only in
                                 32                 :  * non-ENABLE_THREAD_SAFETY builds), so the incompatibility isn't
                                 33                 :  * troublesome for internal references.
                                 34                 :  */
                                 35                 : pqsigfunc
 1277 tgl                        36 UBC           0 : pqsignal(int signo, pqsigfunc func)
                                 37                 : {
                                 38                 : #ifndef WIN32
                                 39                 :     struct sigaction act,
                                 40                 :                 oact;
                                 41                 : 
                                 42               0 :     act.sa_handler = func;
                                 43               0 :     sigemptyset(&act.sa_mask);
                                 44               0 :     act.sa_flags = 0;
                                 45               0 :     if (signo != SIGALRM)
                                 46               0 :         act.sa_flags |= SA_RESTART;
                                 47                 : #ifdef SA_NOCLDSTOP
                                 48               0 :     if (signo == SIGCHLD)
                                 49               0 :         act.sa_flags |= SA_NOCLDSTOP;
                                 50                 : #endif
                                 51               0 :     if (sigaction(signo, &act, &oact) < 0)
                                 52               0 :         return SIG_ERR;
                                 53               0 :     return oact.sa_handler;
                                 54                 : #else                           /* WIN32 */
                                 55                 :     return signal(signo, func);
                                 56                 : #endif
                                 57                 : }