Remove dependency on signal() function

Replaces uses of signal() with sigaction() which should be far
more portable.

common/os_calls.c

@@ -2987,9 +2987,15 @@ g_set_alarm(void (*func)(int), unsigned int secs)
 #if defined(_WIN32)
     return 0;
 #else
+    struct sigaction action;
+
+    action.sa_handler = func;
+    action.sa_flags = SA_RESTART;
+    sigemptyset (&action.sa_mask);
+
     /* Cancel any previous alarm to prevent a race */
     unsigned int rv = alarm(0);
-    signal(SIGALRM, func);
+    sigaction(SIGALRM, &action, NULL);
     (void)alarm(secs);
     return rv;
 #endif
@@ -3002,7 +3008,14 @@ g_signal_child_stop(void (*func)(int))
 {
 #if defined(_WIN32)
 #else
-    signal(SIGCHLD, func);
+    struct sigaction action;
+
+    action.sa_handler = func;
+    // Don't need to know when children are stopped or started
+    action.sa_flags = (SA_RESTART | SA_NOCLDSTOP);
+    sigemptyset (&action.sa_mask);
+
+    sigaction(SIGCHLD, &action, NULL);
 #endif
 }
 
@@ -3013,7 +3026,13 @@ g_signal_segfault(void (*func)(int))
 {
 #if defined(_WIN32)
 #else
-    signal(SIGSEGV, func);
+    struct sigaction action;
+
+    action.sa_handler = func;
+    action.sa_flags = 0;
+    sigemptyset (&action.sa_mask);
+
+    sigaction(SIGSEGV, &action, NULL);
 #endif
 }
 
@@ -3024,7 +3043,13 @@ g_signal_hang_up(void (*func)(int))
 {
 #if defined(_WIN32)
 #else
-    signal(SIGHUP, func);
+    struct sigaction action;
+
+    action.sa_handler = func;
+    action.sa_flags = SA_RESTART;
+    sigemptyset (&action.sa_mask);
+
+    sigaction(SIGHUP, &action, NULL);
 #endif
 }
 
@@ -3035,7 +3060,13 @@ g_signal_user_interrupt(void (*func)(int))
 {
 #if defined(_WIN32)
 #else
-    signal(SIGINT, func);
+    struct sigaction action;
+
+    action.sa_handler = func;
+    action.sa_flags = SA_RESTART;
+    sigemptyset (&action.sa_mask);
+
+    sigaction(SIGINT, &action, NULL);
 #endif
 }
 
@@ -3046,7 +3077,13 @@ g_signal_terminate(void (*func)(int))
 {
 #if defined(_WIN32)
 #else
-    signal(SIGTERM, func);
+    struct sigaction action;
+
+    action.sa_handler = func;
+    action.sa_flags = SA_RESTART;
+    sigemptyset (&action.sa_mask);
+
+    sigaction(SIGTERM, &action, NULL);
 #endif
 }
 
@@ -3057,7 +3094,13 @@ g_signal_pipe(void (*func)(int))
 {
 #if defined(_WIN32)
 #else
-    signal(SIGPIPE, func);
+    struct sigaction action;
+
+    action.sa_handler = func;
+    action.sa_flags = SA_RESTART;
+    sigemptyset (&action.sa_mask);
+
+    sigaction(SIGPIPE, &action, NULL);
 #endif
 }
 
@@ -3068,7 +3111,13 @@ g_signal_usr1(void (*func)(int))
 {
 #if defined(_WIN32)
 #else
-    signal(SIGUSR1, func);
+    struct sigaction action;
+
+    action.sa_handler = func;
+    action.sa_flags = SA_RESTART;
+    sigemptyset (&action.sa_mask);
+
+    sigaction(SIGUSR1, &action, NULL);
 #endif
 }
 

common/os_calls.h

@@ -176,6 +176,14 @@ g_sck_get_peer_ip_address(int sck,
 const char *
 g_sck_get_peer_description(int sck,
                            char *desc, unsigned int bytes);
+/**
+ * Sleep for the specified number of milli-seconds
+ * @param msecs Milli-seconds
+ *
+ * If a signal is processed, it is possible that this call will
+ * sleep for less than the specified number of milli-seconds. This
+ * is platform-specific
+ */
 void     g_sleep(int msecs);
 int      g_pipe(int fd[2]);