reduce code complexity

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 109 insertions, 0 deletions

diff --git a/src/mds-server/signals.c b/src/mds-server/signals.c
new file mode 100644
index 0000000..18a32b6
--- /dev/null
+++ b/src/mds-server/signals.c
@@ -0,0 +1,109 @@
+/**
+ * mds — A micro-display server
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * 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 "signals.h"
+
+#include "globals.h"
+#include "client.h"
+
+#include <libmdsserver/linked-list.h>
+#include <libmdsserver/macros.h>
+#include <libmdsserver/util.h>
+
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <signal.h>
+
+
+/**
+ * Send a singal to all threads except the current thread
+ * 
+ * @param  signo  The signal
+ */
+static void signal_all(int signo)
+{      
+  pthread_t current_thread;
+  ssize_t node;
+  
+  current_thread = pthread_self();
+  
+  if (pthread_equal(current_thread, master_thread) == 0)
+    pthread_kill(master_thread, signo);
+  
+  with_mutex (slave_mutex,
+	      foreach_linked_list_node (client_list, node)
+	        {
+		  client_t* value = (client_t*)(void*)(client_list.values[node]);
+		  if (pthread_equal(current_thread, value->thread) == 0)
+		    pthread_kill(value->thread, signo);
+		}
+	      );
+}
+
+
+/**
+ * Called with the signal SIGUSR1 is caught.
+ * This function should cue a re-exec of the program.
+ * 
+ * @param  signo  The caught signal
+ */
+static void sigusr1_trap(int signo)
+{
+  if (reexecing == 0)
+    {
+      terminating = reexecing = 1;
+      eprint("re-exec signal received.");
+      signal_all(signo);
+    }
+}
+
+
+/**
+ * Called with the signal SIGTERM is caught.
+ * This function should cue a termination of the program.
+ * 
+ * @param  signo  The caught signal
+ */
+static void sigterm_trap(int signo)
+{
+  if (terminating == 0)
+    {
+      terminating = 1;
+      eprint("terminate signal received.");
+      signal_all(signo);
+    }
+}
+
+
+/**
+ * Set up signal traps for all especially handled signals
+ * 
+ * @return  Zero on success, -1 on error
+ */
+int trap_signals(void)
+{
+  /* Make the server update without all slaves dying on SIGUSR1. */
+  if (xsigaction(SIGUSR1, sigusr1_trap) < 0)  return -1;
+  
+  /* Implement clean exit on SIGTERM. */
+  if (xsigaction(SIGTERM, sigterm_trap) < 0)  return -1;
+  
+  return 0;
+}
+