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legacy-pqsignal.c
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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) 1996-2024, 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 does not use this.
32  */
34 pqsignal(int signo, pqsigfunc func)
35 {
36 #ifndef WIN32
37  struct sigaction act,
38  oact;
39 
40  act.sa_handler = func;
41  sigemptyset(&act.sa_mask);
42  act.sa_flags = 0;
43  if (signo != SIGALRM)
44  act.sa_flags |= SA_RESTART;
45 #ifdef SA_NOCLDSTOP
46  if (signo == SIGCHLD)
47  act.sa_flags |= SA_NOCLDSTOP;
48 #endif
49  if (sigaction(signo, &act, &oact) < 0)
50  return SIG_ERR;
51  return oact.sa_handler;
52 #else /* WIN32 */
53  return signal(signo, func);
54 #endif
55 }
pqsigfunc pqsignal(int signo, pqsigfunc func)
void(* pqsigfunc)(SIGNAL_ARGS)
Definition: port.h:490
#define SIGCHLD
Definition: win32_port.h:178
#define SIG_ERR
Definition: win32_port.h:164
#define SIGALRM
Definition: win32_port.h:174