From c9fd52340ec5689780023d6f7d10f4b0c4d56377 Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Sun, 10 Jun 2018 13:35:15 +0200
Subject: [PATCH] - add GroupMemoryBarrierCommand

---
 src/swrenderer/drawers/r_thread.cpp | 12 ++++++++++++
 src/swrenderer/drawers/r_thread.h   | 12 ++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/src/swrenderer/drawers/r_thread.cpp b/src/swrenderer/drawers/r_thread.cpp
index 657960b174..9aa148a6d8 100644
--- a/src/swrenderer/drawers/r_thread.cpp
+++ b/src/swrenderer/drawers/r_thread.cpp
@@ -203,6 +203,8 @@ void DrawerThreads::StopThreads()
 	shutdown_flag = false;
 }
 
+/////////////////////////////////////////////////////////////////////////////
+
 DrawerCommandQueue::DrawerCommandQueue(RenderMemory *frameMemory) : FrameMemory(frameMemory)
 {
 }
@@ -211,3 +213,13 @@ void *DrawerCommandQueue::AllocMemory(size_t size)
 {
 	return FrameMemory->AllocMemory<uint8_t>((int)size);
 }
+
+/////////////////////////////////////////////////////////////////////////////
+
+void GroupMemoryBarrierCommand::Execute(DrawerThread *thread)
+{
+	std::unique_lock<std::mutex> lock(mutex);
+	count++;
+	condition.notify_all();
+	condition.wait(lock, [&]() { return count >= thread->num_cores; });
+}
diff --git a/src/swrenderer/drawers/r_thread.h b/src/swrenderer/drawers/r_thread.h
index f75cc84362..76e6510384 100644
--- a/src/swrenderer/drawers/r_thread.h
+++ b/src/swrenderer/drawers/r_thread.h
@@ -97,6 +97,18 @@ public:
 	virtual void Execute(DrawerThread *thread) = 0;
 };
 
+// Wait for all worker threads before executing next command
+class GroupMemoryBarrierCommand : public DrawerCommand
+{
+public:
+	void Execute(DrawerThread *thread);
+
+private:
+	std::mutex mutex;
+	std::condition_variable condition;
+	size_t count = 0;
+};
+
 class DrawerCommandQueue;
 typedef std::shared_ptr<DrawerCommandQueue> DrawerCommandQueuePtr;