From 79d8c1b9ecfc8a8d3b763a85d0ef7933c4b9def6 Mon Sep 17 00:00:00 2001
From: Hans-Kristian Arntzen <post@themaister.net>
Date: Sun, 29 Oct 2023 11:39:37 +0100
Subject: [PATCH] Add next_frame_context_in_async_thread.

Only reclaim frame contexts when WSI thread actually goes to sleep.
---
 video/ffmpeg_decode.cpp |  2 +-
 vulkan/device.cpp       | 18 ++++++++++++++++++
 vulkan/device.hpp       |  9 +++++++++
 vulkan/wsi.cpp          |  2 ++
 4 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/video/ffmpeg_decode.cpp b/video/ffmpeg_decode.cpp
index 49d269a9..49ed8c91 100644
--- a/video/ffmpeg_decode.cpp
+++ b/video/ffmpeg_decode.cpp
@@ -1576,7 +1576,7 @@ void VideoDecoder::Impl::process_video_frame_in_task_upload(DecodedImage &img, A
 	// we don't leak unbounded memory when the window is minimized on Windows.
 	// In that scenario the main thread will not pump frame contexts regularly.
 	if (opts.realtime)
-		device->next_frame_context();
+		device->next_frame_context_in_async_thread();
 }
 
 void VideoDecoder::Impl::process_video_frame_in_task(unsigned frame, AVFrame *av_frame)
diff --git a/vulkan/device.cpp b/vulkan/device.cpp
index 9679be62..14d1363a 100644
--- a/vulkan/device.cpp
+++ b/vulkan/device.cpp
@@ -2565,6 +2565,24 @@ void Device::promote_read_write_caches_to_read_only()
 	}
 }
 
+bool Device::set_enable_async_thread_frame_context(bool enable)
+{
+	LOCK();
+	lock.async_frame_context = enable;
+}
+
+void Device::next_frame_context_in_async_thread()
+{
+	bool do_next_frame_context;
+	{
+		LOCK();
+		do_next_frame_context = lock.async_frame_context;
+	}
+
+	if (do_next_frame_context)
+		next_frame_context();
+}
+
 void Device::next_frame_context()
 {
 	DRAIN_FRAME_LOCK();
diff --git a/vulkan/device.hpp b/vulkan/device.hpp
index b6eae3df..cbaee4d8 100644
--- a/vulkan/device.hpp
+++ b/vulkan/device.hpp
@@ -249,6 +249,14 @@ class Device
 
 	// Frame-pushing interface.
 	void next_frame_context();
+
+	// Normally, the main thread ensures forward progress of the frame context
+	// so that async tasks don't have to care about it,
+	// but in the case where async threads are continuously pumping Vulkan work
+	// in the background, they need to reclaim memory if WSI goes to sleep for a long period of time.
+	void next_frame_context_in_async_thread();
+	bool set_enable_async_thread_frame_context(bool enable);
+
 	void wait_idle();
 	void end_frame_context();
 
@@ -587,6 +595,7 @@ class Device
 		std::condition_variable cond;
 		Util::RWSpinLock read_only_cache;
 		unsigned counter = 0;
+		bool async_frame_context = false;
 	} lock;
 
 	struct PerFrame
diff --git a/vulkan/wsi.cpp b/vulkan/wsi.cpp
index 6cbd9733..23c965ce 100644
--- a/vulkan/wsi.cpp
+++ b/vulkan/wsi.cpp
@@ -886,7 +886,9 @@ bool WSI::blocking_init_swapchain(unsigned width, unsigned height)
 		else if (err == SwapchainError::NoSurface)
 		{
 			LOGW("WSI cannot make forward progress due to minimization, blocking ...\n");
+			device->set_enable_async_thread_frame_context(true);
 			platform->block_until_wsi_forward_progress(*this);
+			device->set_enable_async_thread_frame_context(false);
 			LOGW("Woke up!\n");
 		}
 	} while (err != SwapchainError::None);