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authorJelmer Vernooij <jelmer@samba.org>2006-02-23 15:52:24 +0000
committerGerald (Jerry) Carter <jerry@samba.org>2007-10-10 13:52:05 -0500
commitdfc517b05395d925a4d7b1ce9633a849f9468e70 (patch)
treea81c020c89022980e6fbb68116648da217fbb0fc /source4/lib/util/signal.c
parent80c8a522861068e7b0974986936f65052dd6f70f (diff)
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r13658: More moving around of files:
- Collect the generic utility functions into a lib/util/ (a la GLib is for the GNOME folks) - Remove even more files from include/ (This used to be commit ba62880f5b05c2a505dc7f54676b231197a7e707)
Diffstat (limited to 'source4/lib/util/signal.c')
-rw-r--r--source4/lib/util/signal.c140
1 files changed, 140 insertions, 0 deletions
diff --git a/source4/lib/util/signal.c b/source4/lib/util/signal.c
new file mode 100644
index 0000000000..6c0bb4007a
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+++ b/source4/lib/util/signal.c
@@ -0,0 +1,140 @@
+/*
+ Unix SMB/CIFS implementation.
+ signal handling functions
+
+ Copyright (C) Andrew Tridgell 1998
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+#include "system/wait.h"
+
+/****************************************************************************
+ Catch child exits and reap the child zombie status.
+****************************************************************************/
+
+static void sig_cld(int signum)
+{
+ while (waitpid((pid_t)-1,(int *)NULL, WNOHANG) > 0)
+ ;
+
+ /*
+ * Turns out it's *really* important not to
+ * restore the signal handler here if we have real POSIX
+ * signal handling. If we do, then we get the signal re-delivered
+ * immediately - hey presto - instant loop ! JRA.
+ */
+
+#if !defined(HAVE_SIGACTION)
+ CatchSignal(SIGCLD, sig_cld);
+#endif
+}
+
+/****************************************************************************
+catch child exits - leave status;
+****************************************************************************/
+
+static void sig_cld_leave_status(int signum)
+{
+ /*
+ * Turns out it's *really* important not to
+ * restore the signal handler here if we have real POSIX
+ * signal handling. If we do, then we get the signal re-delivered
+ * immediately - hey presto - instant loop ! JRA.
+ */
+
+#if !defined(HAVE_SIGACTION)
+ CatchSignal(SIGCLD, sig_cld_leave_status);
+#endif
+}
+
+/*******************************************************************
+ Block sigs.
+********************************************************************/
+
+void BlockSignals(BOOL block,int signum)
+{
+#ifdef HAVE_SIGPROCMASK
+ sigset_t set;
+ sigemptyset(&set);
+ sigaddset(&set,signum);
+ sigprocmask(block?SIG_BLOCK:SIG_UNBLOCK,&set,NULL);
+#elif defined(HAVE_SIGBLOCK)
+ if (block) {
+ sigblock(sigmask(signum));
+ } else {
+ sigsetmask(siggetmask() & ~sigmask(signum));
+ }
+#else
+ /* yikes! This platform can't block signals? */
+ static int done;
+ if (!done) {
+ DEBUG(0,("WARNING: No signal blocking available\n"));
+ done=1;
+ }
+#endif
+}
+
+/*******************************************************************
+ Catch a signal. This should implement the following semantics:
+
+ 1) The handler remains installed after being called.
+ 2) The signal should be blocked during handler execution.
+********************************************************************/
+
+void (*CatchSignal(int signum,void (*handler)(int )))(int)
+{
+#ifdef HAVE_SIGACTION
+ struct sigaction act;
+ struct sigaction oldact;
+
+ ZERO_STRUCT(act);
+
+ act.sa_handler = handler;
+#ifdef SA_RESTART
+ /*
+ * We *want* SIGALRM to interrupt a system call.
+ */
+ if(signum != SIGALRM)
+ act.sa_flags = SA_RESTART;
+#endif
+ sigemptyset(&act.sa_mask);
+ sigaddset(&act.sa_mask,signum);
+ sigaction(signum,&act,&oldact);
+ return oldact.sa_handler;
+#else /* !HAVE_SIGACTION */
+ /* FIXME: need to handle sigvec and systems with broken signal() */
+ return signal(signum, handler);
+#endif
+}
+
+/*******************************************************************
+ Ignore SIGCLD via whatever means is necessary for this OS.
+********************************************************************/
+
+void CatchChild(void)
+{
+ CatchSignal(SIGCLD, sig_cld);
+}
+
+/*******************************************************************
+ Catch SIGCLD but leave the child around so it's status can be reaped.
+********************************************************************/
+
+void CatchChildLeaveStatus(void)
+{
+ CatchSignal(SIGCLD, sig_cld_leave_status);
+}