pthreads/sigwait: handle SIGHUP in another thread

Signed-off-by: Stefan Naewe <stefan.naewe@atlas-elektronik.com>
snaewe · Aug 31, 2010 · f5cbfa5 · f5cbfa5
1 parent 84612e1
commit f5cbfa5
Showing 1 changed file with 50 additions and 5 deletions.
diff --git a/pthreads/sigwait.c b/pthreads/sigwait.c
@@ -13,7 +13,6 @@
 pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
 pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
 int interrupted = 0;
-sigset_t signal_set;
 
 /*
  * Wait for the SIGINT signal. When it has occurred 5 times, set
@@ -25,7 +24,10 @@ void *signal_waiter (void *arg)
     int sig_number;
     int signal_count = 0;
     int status;
-
+    sigset_t signal_set;
+
+    sigfillset(&signal_set);
+    sigdelset(&signal_set, SIGHUP);
     while (1) {
         sigwait (&signal_set, &sig_number);
         if (sig_number == SIGINT) {
@@ -44,14 +46,52 @@ void *signal_waiter (void *arg)
                 break;
             }
         }
+        else {
+        	printf("Ignoring signal %d\n", sig_number);
+        }
+    }    
+    return NULL;
+}
+
+void *signal_waiter2 (void *arg)
+{
+    int sig_number;
+    int signal_count = 0;
+    int status;
+    sigset_t signal_set;
+
+    sigfillset(&signal_set);
+    sigdelset(&signal_set, SIGINT);
+    while (1) {
+        sigwait (&signal_set, &sig_number);
+        if (sig_number == SIGHUP) {
+            printf ("Got SIGHUP (%d of 5)\n", signal_count+1);
+            if (++signal_count >= 3) {
+                status = pthread_mutex_lock (&mutex);
+                if (status != 0)
+                    err_abort (status, "Lock mutex");
+                interrupted = 1;
+                status = pthread_cond_signal (&cond);
+                if (status != 0)
+                    err_abort (status, "Signal condition");
+                status = pthread_mutex_unlock (&mutex);
+                if (status != 0)
+                    err_abort (status, "Unlock mutex");
+                break;
+            }
+        }
+        else {
+        	printf("Ignoring signal %d\n", sig_number);
+        }
     }    
     return NULL;
 }
 
 int main (int argc, char *argv[])
 {
-    pthread_t signal_thread_id;
+    pthread_t signal_thread_id, signal_thread_id2;
     int status;
+    sigset_t signal_set;
 
     /*
      * Start by masking the "interesting" signal, SIGINT in the
@@ -64,8 +104,7 @@ int main (int argc, char *argv[])
      * while the sigwaiter is not blocked in sigwait might be
      * delivered to another thread.
      */
-    sigemptyset (&signal_set);
-    sigaddset (&signal_set, SIGINT);
+    sigfillset (&signal_set);
     status = pthread_sigmask (SIG_BLOCK, &signal_set, NULL);
     if (status != 0)
         err_abort (status, "Set signal mask");
@@ -78,6 +117,11 @@ int main (int argc, char *argv[])
     if (status != 0)
         err_abort (status, "Create sigwaiter");
 
+    status = pthread_create (&signal_thread_id2, NULL,
+        signal_waiter2, NULL);
+    if (status != 0)
+        err_abort (status, "Create sigwaiter");
+
     /*
      * Wait for the sigwait thread to receive SIGINT and signal
      * the condition variable.
@@ -96,3 +140,4 @@ int main (int argc, char *argv[])
     printf ("Main terminating with SIGINT\n");
     return 0;
 }
+