Move everything into a separate futatabi/ subdir, for the upcoming merge with Nageru.

[nageru] / futatabi / queue_spot_holder.h

diff --git a/futatabi/queue_spot_holder.h b/futatabi/queue_spot_holder.h
new file mode 100644 (file)
index 0000000..b9dee06
--- /dev/null
+++ b/futatabi/queue_spot_holder.h
@@ -0,0 +1,46 @@
+#ifndef _QUEUE_SPOT_HOLDER
+#define _QUEUE_SPOT_HOLDER 1
+
+// A RAII class to hold a shared resource, in our case an (unordered!) spot in a queue,
+// for as long as a frame is under computation.
+
+class QueueInterface {
+public:
+       virtual ~QueueInterface() {}
+       virtual void take_queue_spot() = 0;
+       virtual void release_queue_spot() = 0;
+};
+
+class QueueSpotHolder {
+public:
+       QueueSpotHolder() : queue(nullptr) {}
+
+       explicit QueueSpotHolder(QueueInterface *queue) : queue(queue) {
+               queue->take_queue_spot();
+       }
+
+       QueueSpotHolder(QueueSpotHolder &&other) : queue(other.queue) {
+               other.queue = nullptr;
+       }
+
+       QueueSpotHolder &operator=(QueueSpotHolder &&other) {
+               queue = other.queue;
+               other.queue = nullptr;
+               return *this;
+       }
+
+       ~QueueSpotHolder() {
+               if (queue != nullptr) {
+                       queue->release_queue_spot();
+               }
+       }
+
+       // Movable only.
+       QueueSpotHolder(QueueSpotHolder &) = delete;
+       QueueSpotHolder &operator=(QueueSpotHolder &) = delete;
+
+private:
+       QueueInterface *queue;  
+};
+
+#endif // !defined(_QUEUE_SPOT_HOLDER)