Patch by Vasilis Kaoutsis (modified by myself): Implemented sigset().

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22947 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/posix/signal.h

@@ -147,6 +147,7 @@ extern "C" {
 #endif
 
 sighandler_t signal(int sig, sighandler_t signalHandler);
+sighandler_t sigset(int sig, sighandler_t signalHandler);
 int     raise(int sig);
 int     kill(pid_t pid, int sig);
 int     send_signal(pid_t tid, unsigned int sig);

src/system/libroot/posix/signal/Jamfile

@@ -7,6 +7,7 @@ MergeObject posix_signal.o :
 	killpg.cpp
 	raise.c
 	send_signal.c
+	set_signal_disposition.cpp
 	set_signal_stack.c
 	sigaction.c
 	sigaltstack.c

src/system/libroot/posix/signal/set_signal_disposition.cpp

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2007, Vasilis Kaoutsis, [email protected]
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <signal.h>
+
+
+sighandler_t
+sigset(int signal, sighandler_t signalHandler)
+{
+	struct sigaction newAction;
+	struct sigaction oldAction;
+
+	newAction.sa_handler = signalHandler;
+	newAction.sa_flags = 0;
+	if (signal == SIGCHLD && signalHandler == SIG_IGN) {
+		// In case of SIGCHLD the specification requires SA_NOCLDWAIT behavior.
+		newAction.sa_flags |= SA_NOCLDWAIT;
+	}
+
+	sigemptyset(&newAction.sa_mask);
+	if (sigaction(signal, signalHandler == SIG_HOLD ? NULL : &newAction,
+			&oldAction) == -1) {
+		return SIG_ERR;
+	}
+	
+	sigset_t newSet;
+	sigset_t oldSet;
+
+	sigemptyset(&newSet);
+	sigaddset(&newSet, signal);
+	
+	if (signalHandler == SIG_HOLD) {
+		if (sigprocmask(SIG_BLOCK, &newSet, &oldSet) == -1)
+			return SIG_ERR;
+	} else {
+		// Disposition is not equal to SIG_HOLD, so sig will be 
+		// removed from the calling process' signal mask.
+		if (sigprocmask(SIG_UNBLOCK, &newSet, &oldSet) == -1)
+			return SIG_ERR;
+	}
+
+	if (sigismember(&oldSet, signal))
+		return SIG_HOLD;
+	else
+		return oldAction.sa_handler;
+}