add litmus_task_active() API

Most RT tasks need to do some cleanup before they can terminate.
The litmus_task_active() API automates the catching of signals that
indicate that the RT task should terminate.

2 files changed, 15 insertions, 0 deletions

diff --git a/include/litmus.h b/include/litmus.h
index c16aa3b..3595919 100644
--- a/include/litmus.h
+++ b/include/litmus.h
@@ -109,5 +109,6 @@ task_class_t str2class(const char* str);
 void enter_np(void);
 void exit_np(void);
 
+int litmus_task_active();
 
 #endif
diff --git a/src/litmus.c b/src/litmus.c
index 65ad294..9a2ebea 100644
--- a/src/litmus.c
+++ b/src/litmus.c
@@ -218,6 +218,17 @@ void exit_np(void)
         }
 }
 
+static int exit_requested = 0;
+
+static void sig_handler(int sig)
+{
+        exit_requested = 1;
+}
+
+int litmus_task_active(void)
+{
+        return !exit_requested;
+}
 
 #define check(str) if (ret == -1) {perror(str); fprintf(stderr, \
         "Could not initialize LITMUS^RT, aborting...\n"); exit(1);}
@@ -232,6 +243,9 @@ void init_litmus(void)
         check("mlockall");
         ret = register_np_flag(&np_flag);
         check("register_np_flag");      
+        signal(SIGINT, sig_handler);
+        signal(SIGTERM, sig_handler);
+        signal(SIGHUP, sig_handler);
 }