Initial release

engine/vendor/vst3sdk/vstgui4/vstgui/lib/tasks.h

@@ -0,0 +1,95 @@
+// This file is part of VSTGUI. It is subject to the license terms
+// in the LICENSE file found in the top-level directory of this
+// distribution and at http://github.com/steinbergmedia/vstgui/LICENSE
+
+#pragma once
+
+#include "platform/iplatformtaskexecutor.h"
+
+//------------------------------------------------------------------------
+namespace VSTGUI {
+/** Simple Task Concurrency API.
+ *
+ *	The Task Concurrency API facilitates scheduling tasks for execution on background threads,
+ *	either concurrently or sequentially. This API also enables the scheduling of tasks on the main
+ *	thread from any other thread.
+ *
+ *	This API can be used while the VSTGUI library is initialized. Upon deinitialization, triggered
+ *	by the mandatory exit() call, this API ensures that all scheduled tasks are completed prior to
+ *	returning.
+ *
+ *	Please note that once a task has been dispatched, it cannot be canceled.
+ */
+namespace Tasks {
+
+//------------------------------------------------------------------------
+/** Get the main/UI serial queue.
+ *
+ *	Tasks scheduled on this queue are performed sequentially on the main/ui thread.
+ *
+ *	Can be called from any thread.
+ *
+ *	@return the shared main queue
+ */
+const Queue& mainQueue ();
+
+//------------------------------------------------------------------------
+/** Get the background concurrent queue.
+ *
+ *	Tasks scheduled on this queue are performed concurrently on background threads.
+ *	The number of background threads depends on the system's CPU core count.
+ *
+ *	Can be called from any thread.
+ *
+ *	@return the shared background queue
+ */
+const Queue& backgroundQueue ();
+
+//------------------------------------------------------------------------
+/** Make a new serial queue.
+ *
+ *	Tasks scheduled on this queue are executed sequentially on a background thread.
+ *
+ *	The caller owns the queue, and needs to release the queue via the releaseSerialQueue() function.
+ *
+ *	Can be called from any thread.
+ *
+ *	@param name		the name of the serial queue (optional)
+ *	@return 		a new serial queue
+ */
+Queue makeSerialQueue (const char* name);
+
+//------------------------------------------------------------------------
+/** Release a serial queue
+ *
+ *	This function will block until all tasks of the queue were executed.
+ *
+ *	Can be called from any thread.
+ *
+ *	@param queue	the queue which to release
+ */
+void releaseSerialQueue (const Queue& queue);
+
+//------------------------------------------------------------------------
+/** Schedule a task to be executed asynchronously on a queue.
+ *
+ *	Can be called from any thread, but should not be called from realtime constraint threads as it
+ *	may involves locks and memory allocations
+ *
+ *	@param queue	on which queue to perform the task
+ *	@param task		task to be performed
+ */
+void schedule (const Queue& queue, Task&& task);
+
+//------------------------------------------------------------------------
+/** Wait for all tasks in the queue to complete execution.
+ *
+ *	Can only be called from the main thread.
+ *
+ *	@param queue	on which queue to perform the task
+ */
+void waitAllTasksExecuted (const Queue& queue);
+
+//------------------------------------------------------------------------
+} // Tasks
+} // VSTGUI