The _starpu_data_wait_until_available function blocks until the handle is

available in the requested access mode if sequential consistency is enabled.

src/core/dependencies/implicit_data_deps.c

@@ -323,3 +323,32 @@ void _starpu_unlock_post_sync_tasks(starpu_data_handle handle)
 		}
 	}
 }
+
+int _starpu_data_wait_until_available(starpu_data_handle handle, starpu_access_mode mode)
+{
+	/* If sequential consistency is enabled, wait until data is available */
+	PTHREAD_MUTEX_LOCK(&handle->sequential_consistency_mutex);
+	int sequential_consistency = handle->sequential_consistency;
+	if (sequential_consistency)
+	{
+		struct starpu_task *sync_task;
+		sync_task = starpu_task_create();
+		sync_task->detach = 0;
+		sync_task->destroy = 1;
+
+		/* It is not really a RW access, but we want to make sure that
+		 * all previous accesses are done */
+		_starpu_detect_implicit_data_deps_with_handle(sync_task, sync_task, handle, mode);
+		PTHREAD_MUTEX_UNLOCK(&handle->sequential_consistency_mutex);
+
+		/* TODO detect if this is superflous */
+		int ret = starpu_task_submit(sync_task);
+		STARPU_ASSERT(!ret);
+		starpu_task_wait(sync_task);
+	}
+	else {
+		PTHREAD_MUTEX_UNLOCK(&handle->sequential_consistency_mutex);
+	}
+
+	return 0;
+}

src/core/dependencies/implicit_data_deps.h

@@ -28,5 +28,8 @@ void _starpu_release_data_enforce_sequential_consistency(struct starpu_task *tas
 void _starpu_add_post_sync_tasks(struct starpu_task *post_sync_task, starpu_data_handle handle);
 void _starpu_unlock_post_sync_tasks(starpu_data_handle handle);
 
+/* This function blocks until the handle is available in the requested mode */
+int _starpu_data_wait_until_available(starpu_data_handle handle, starpu_access_mode mode);
+
 #endif // __IMPLICIT_DATA_DEPS_H__
 

src/datawizard/interfaces/data_interface.c

@@ -173,28 +173,7 @@ void starpu_data_unregister(starpu_data_handle handle)
 	unsigned node;
 
 	/* If sequential consistency is enabled, wait until data is available */
-	PTHREAD_MUTEX_LOCK(&handle->sequential_consistency_mutex);
-	int sequential_consistency = handle->sequential_consistency;
-	if (sequential_consistency)
-	{
-		struct starpu_task *sync_task;
-		sync_task = starpu_task_create();
-		sync_task->detach = 0;
-		sync_task->destroy = 1;
-
-		/* It is not really a RW access, but we want to make sure that
-		 * all previous accesses are done */
-		_starpu_detect_implicit_data_deps_with_handle(sync_task, sync_task, handle, STARPU_RW);
-		PTHREAD_MUTEX_UNLOCK(&handle->sequential_consistency_mutex);
-
-		/* TODO detect if this is superflous */
-		int ret = starpu_task_submit(sync_task);
-		STARPU_ASSERT(!ret);
-		starpu_task_wait(sync_task);
-	}
-	else {
-		PTHREAD_MUTEX_UNLOCK(&handle->sequential_consistency_mutex);
-	}
+	_starpu_data_wait_until_available(handle, STARPU_RW);
 
 	/* Fetch data in the home of the data to ensure we have a valid copy
 	 * where we registered it */