Revised non-rtos mbed semaphore implementation to return flag

geky · Aug 15, 2016 · 3470d88 · 3470d88
1 parent bc0a40d
commit 3470d88
Show file tree

Hide file tree

Showing 2 changed files with 14 additions and 9 deletions.
diff --git a/equeue_mbed.cpp b/equeue_mbed.cpp
@@ -100,23 +100,30 @@ void equeue_sema_destroy(equeue_sema_t *s) {
 }
 
 void equeue_sema_signal(equeue_sema_t *s) {
-    *s = true;
+    *s = 1;
+}
+
+static void equeue_sema_timeout(equeue_sema_t *s) {
+    *s = -1;
 }
 
 bool equeue_sema_wait(equeue_sema_t *s, int ms) {
+    int signal = 0;
     Timeout timeout;
-    timeout.attach_us(s, equeue_sema_signal, ms*1000);
+    timeout.attach_us(s, equeue_sema_timeout, ms*1000);
 
     core_util_critical_section_enter();
-    while (!*(volatile equeue_sema_t *)s) {
+    while (!*s) {
         __WFI();
         core_util_critical_section_exit();
         core_util_critical_section_enter();
     }
+
+    signal = *s;
     *s = false;
     core_util_critical_section_exit();
 
-    return true;
+    return (signal > 0);
 }
 
 #endif

diff --git a/equeue_sema.h b/equeue_sema.h
@@ -28,12 +28,10 @@ extern "C" {
 #if defined(__unix__)
 #include <semaphore.h>
 typedef sem_t equeue_sema_t;
-#elif defined(__MBED__)
-#ifdef MBED_CONF_RTOS_PRESENT
+#elif defined(__MBED__) && defined(MBED_CONF_RTOS_PRESENT)
 typedef unsigned equeue_sema_t[8];
-#else
-typedef bool equeue_sema_t;
-#endif
+#elif defined(__MBED__)
+typedef volatile int equeue_sema_t;
 #endif