add mutex_unlock_and_sleep()

core/include/mutex.h

@@ -68,6 +68,13 @@ int mutex_lock(struct mutex_t *mutex);
  */
 void mutex_unlock(struct mutex_t *mutex);
 
+/**
+ * @brief Unlocks the mutex and sends the current thread to sleep
+ *
+ * @param mutex Mutex-Object to unlock.
+ */
+void mutex_unlock_and_sleep(struct mutex_t *mutex);
+
 #define MUTEX_YIELD 1
 #define MUTEX_INISR 2
 

core/mutex.c

@@ -117,3 +117,25 @@ void mutex_unlock(struct mutex_t *mutex)
 
     restoreIRQ(irqstate);
 }
+
+void mutex_unlock_and_sleep(struct mutex_t *mutex)
+{
+    DEBUG("%s: unlocking mutex. val: %u pid: %u, and take a nap\n", active_thread->name, mutex->val, thread_pid);
+    int irqstate = disableIRQ();
+
+    if (mutex->val != 0) {
+        if (mutex->queue.next) {
+            queue_node_t *next = queue_remove_head(&(mutex->queue));
+            tcb_t *process = (tcb_t*) next->data;
+            DEBUG("%s: waking up waiter.\n", process->name);
+            sched_set_status(process, STATUS_PENDING);
+        }
+        else {
+            mutex->val = 0;
+        }
+    }
+    DEBUG("%s: going to sleep.\n", active_thread->name);
+    sched_set_status((tcb_t*) active_thread, STATUS_SLEEPING);
+    restoreIRQ(irqstate);
+    thread_yield();
+}