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-rw-r--r--lib/util/signal.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/lib/util/signal.c b/lib/util/signal.c
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--- /dev/null
+++ b/lib/util/signal.c
@@ -0,0 +1,146 @@
+/*
+ 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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "replace.h"
+#include "system/wait.h"
+#include "debug.h"
+#include "lib/util/signal.h" /* Avoid /usr/include/signal.h */
+
+/**
+ * @file
+ * @brief Signal handling
+ */
+
+/****************************************************************************
+ 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))(int)
+{
+ return CatchSignal(SIGCLD, sig_cld);
+}
+
+/**
+ Catch SIGCLD but leave the child around so it's status can be reaped.
+**/
+
+void (*CatchChildLeaveStatus(void))(int)
+{
+ return CatchSignal(SIGCLD, sig_cld_leave_status);
+}