2 Unix SMB/CIFS implementation.
3 signal handling functions
5 Copyright (C) Andrew Tridgell 1998
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
22 #include "system/wait.h"
24 #include "lib/util/signal.h" /* Avoid /usr/include/signal.h */
28 * @brief Signal handling
31 /****************************************************************************
32 Catch child exits and reap the child zombie status.
33 ****************************************************************************/
35 static void sig_cld(int signum)
37 while (waitpid((pid_t)-1,(int *)NULL, WNOHANG) > 0)
41 * Turns out it's *really* important not to
42 * restore the signal handler here if we have real POSIX
43 * signal handling. If we do, then we get the signal re-delivered
44 * immediately - hey presto - instant loop ! JRA.
47 #if !defined(HAVE_SIGACTION)
48 CatchSignal(SIGCLD, sig_cld);
52 /****************************************************************************
53 catch child exits - leave status;
54 ****************************************************************************/
56 static void sig_cld_leave_status(int signum)
59 * Turns out it's *really* important not to
60 * restore the signal handler here if we have real POSIX
61 * signal handling. If we do, then we get the signal re-delivered
62 * immediately - hey presto - instant loop ! JRA.
65 #if !defined(HAVE_SIGACTION)
66 CatchSignal(SIGCLD, sig_cld_leave_status);
74 void BlockSignals(bool block, int signum)
76 #ifdef HAVE_SIGPROCMASK
79 sigaddset(&set,signum);
80 sigprocmask(block?SIG_BLOCK:SIG_UNBLOCK,&set,NULL);
81 #elif defined(HAVE_SIGBLOCK)
83 sigblock(sigmask(signum));
85 sigsetmask(siggetmask() & ~sigmask(signum));
88 /* yikes! This platform can't block signals? */
91 DEBUG(0,("WARNING: No signal blocking available\n"));
98 Catch a signal. This should implement the following semantics:
100 1) The handler remains installed after being called.
101 2) The signal should be blocked during handler execution.
104 void (*CatchSignal(int signum,void (*handler)(int )))(int)
106 #ifdef HAVE_SIGACTION
107 struct sigaction act;
108 struct sigaction oldact;
112 act.sa_handler = handler;
115 * We *want* SIGALRM to interrupt a system call.
117 if(signum != SIGALRM)
118 act.sa_flags = SA_RESTART;
120 sigemptyset(&act.sa_mask);
121 sigaddset(&act.sa_mask,signum);
122 sigaction(signum,&act,&oldact);
123 return oldact.sa_handler;
124 #else /* !HAVE_SIGACTION */
125 /* FIXME: need to handle sigvec and systems with broken signal() */
126 return signal(signum, handler);
131 Ignore SIGCLD via whatever means is necessary for this OS.
134 void (*CatchChild(void))(int)
136 return CatchSignal(SIGCLD, sig_cld);
140 Catch SIGCLD but leave the child around so it's status can be reaped.
143 void (*CatchChildLeaveStatus(void))(int)
145 return CatchSignal(SIGCLD, sig_cld_leave_status);