Add a signals API

include/golioth/golioth_sys.h

@@ -52,6 +52,19 @@ bool golioth_sys_sem_give(golioth_sys_sem_t sem);
 void golioth_sys_sem_destroy(golioth_sys_sem_t sem);
 int golioth_sys_sem_get_fd(golioth_sys_sem_t sem);
 
+/*--------------------------------------------------
+ * Signals
+ *------------------------------------------------*/
+
+// Opaque handle for signal
+typedef void *golioth_sys_signal_t;
+
+golioth_sys_signal_t golioth_sys_signal_create(void);
+bool golioth_sys_signal_poll(golioth_sys_signal_t sig, int32_t ms_to_wait);
+bool golioth_sys_signal_raise(golioth_sys_signal_t sig);
+void golioth_sys_signal_reset(golioth_sys_signal_t sig);
+void golioth_sys_signal_destroy(golioth_sys_signal_t sig);
+
 /*--------------------------------------------------
  * Software Timers
  *------------------------------------------------*/

port/freertos/golioth_sys_freertos.c

@@ -83,6 +83,59 @@ int golioth_sys_sem_get_fd(golioth_sys_sem_t sem)
     return -1;
 }
 
+/*--------------------------------------------------
+ * Signals
+ *------------------------------------------------*/
+
+golioth_sys_signal_t golioth_sys_signal_create(void)
+{
+    return xTaskGetCurrentTaskHandle();
+}
+
+bool golioth_sys_signal_poll(golioth_sys_signal_t sig, int32_t ms_to_wait)
+{
+    if (!sig)
+    {
+        return false;
+    }
+
+    TickType_t ticks_to_wait = (ms_to_wait < 0 ? portMAX_DELAY : pdMS_TO_TICKS(ms_to_wait));
+
+    return (pdPASS == ulTaskNotifyTake(pdTRUE, ticks_to_wait));
+}
+
+bool golioth_sys_signal_raise(golioth_sys_signal_t sig)
+{
+    if (!sig)
+    {
+        return false;
+    }
+
+    BaseType_t xHigherPriorityTaskWoken = pdFALSE;
+
+    vTaskNotifyGiveFromISR((TaskHandle_t) sig, &xHigherPriorityTaskWoken);
+
+    portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
+    return true;
+}
+
+void golioth_sys_signal_reset(golioth_sys_signal_t sig)
+{
+    if (!sig)
+    {
+        return;
+    }
+
+    xTaskNotifyStateClear((TaskHandle_t) sig);
+}
+
+void golioth_sys_signal_destroy(golioth_sys_signal_t sig)
+{
+    /* We didn't allocate any memory for TaskHandle_t */
+    (void) sig;
+    return;
+}
+
 /*--------------------------------------------------
  * Software Timers
  *------------------------------------------------*/

port/linux/golioth_sys_linux.c

@@ -183,6 +183,83 @@ int golioth_sys_sem_get_fd(golioth_sys_sem_t sem)
     return SEM_TO_FD(sem);
 }
 
+/*--------------------------------------------------
+ * Signals
+ *------------------------------------------------*/
+
+struct condition_and_mutex
+{
+    pthread_cond_t cond;
+    pthread_mutex_t lock;
+};
+
+golioth_sys_signal_t golioth_sys_signal_create(void)
+{
+    struct condition_and_mutex *sig = golioth_sys_malloc(sizeof(struct condition_and_mutex));
+    pthread_cond_init(&sig->cond, NULL);
+    pthread_mutex_init(&sig->lock, NULL);
+    return (golioth_sys_signal_t) sig;
+}
+
+bool golioth_sys_signal_poll(golioth_sys_signal_t sig, int32_t ms_to_wait)
+{
+    if (!sig)
+    {
+        return false;
+    }
+
+    int ret = 0;
+    struct condition_and_mutex *signal = sig;
+    struct timespec abstime;
+
+    pthread_mutex_lock(&signal->lock);
+
+    if (ms_to_wait < 0)
+    {
+        ret = (0 == pthread_cond_wait(&signal->cond, &signal->lock));
+        goto signal_poll_finish;
+    }
+
+    clock_gettime(CLOCK_REALTIME, &abstime);
+
+    if (ms_to_wait)
+    {
+        abstime.tv_sec += ms_to_wait / 1000;
+        abstime.tv_nsec += (ms_to_wait % 1000) * 1000000;
+    }
+
+    ret = (0 == pthread_cond_timedwait(&signal->cond, &signal->lock, &abstime));
+
+signal_poll_finish:
+    pthread_mutex_unlock(&signal->lock);
+    return ret;
+}
+
+bool golioth_sys_signal_raise(golioth_sys_signal_t sig)
+{
+    if (!sig)
+    {
+        return false;
+    }
+
+    struct condition_and_mutex *signal = sig;
+    return (0 == pthread_cond_signal(&signal->cond));
+}
+
+void golioth_sys_signal_reset(golioth_sys_signal_t sig)
+{
+    /* There is nothing to reset */
+    return;
+}
+
+void golioth_sys_signal_destroy(golioth_sys_signal_t sig)
+{
+    struct condition_and_mutex *signal = sig;
+    pthread_cond_destroy(&signal->cond);
+    pthread_mutex_destroy(&signal->lock);
+    golioth_sys_free(sig);
+}
+
 /*--------------------------------------------------
  * Software Timers
  *------------------------------------------------*/

port/zephyr/golioth_sys_zephyr.c

@@ -130,6 +130,58 @@ int golioth_sys_sem_get_fd(golioth_sys_sem_t sem)
     return SEM_TO_FD(sem);
 }
 
+/*--------------------------------------------------
+ * Signals
+ *------------------------------------------------*/
+
+golioth_sys_signal_t golioth_sys_signal_create(void)
+{
+    struct k_poll_signal *sig = golioth_sys_malloc(sizeof(struct k_poll_signal));
+    k_poll_signal_init(sig);
+    return sig;
+}
+
+bool golioth_sys_signal_poll(golioth_sys_signal_t sig, int32_t ms_to_wait)
+{
+    if (!sig)
+    {
+        return false;
+    }
+
+    k_timeout_t timeout = (ms_to_wait <= GOLIOTH_SYS_WAIT_FOREVER ? K_FOREVER : K_MSEC(ms_to_wait));
+
+    struct k_poll_event events[1] = {
+        K_POLL_EVENT_INITIALIZER(K_POLL_TYPE_SIGNAL, K_POLL_MODE_NOTIFY_ONLY, sig),
+    };
+
+    k_poll(events, 1, timeout);
+
+    int signaled, result;
+    k_poll_signal_check(sig, &signaled, &result);
+
+    return (signaled != 0 ? true : false);
+}
+
+bool golioth_sys_signal_raise(golioth_sys_signal_t sig)
+{
+    return (0 == k_poll_signal_raise(sig, 0));
+}
+
+void golioth_sys_signal_reset(golioth_sys_signal_t sig)
+{
+    if (!sig)
+    {
+        return;
+    }
+
+    k_poll_signal_reset(sig);
+}
+
+void golioth_sys_signal_destroy(golioth_sys_signal_t sig)
+{
+    golioth_sys_free(sig);
+}
+
 /*--------------------------------------------------
  * Software Timers
  *------------------------------------------------*/