From f442a8a84ca798f20f924279593106454c54cbb8 Mon Sep 17 00:00:00 2001
From: Nekotekina <nekotekina@gmail.com>
Date: Tue, 27 Nov 2018 20:00:07 +0300
Subject: [PATCH] SPU TG: add thread group stop counter

Fix possible race condition introduced by waiting on `running` value
---
 rpcs3/Emu/Cell/SPUThread.cpp   | 1 +
 rpcs3/Emu/Cell/lv2/sys_spu.cpp | 8 ++++++--
 rpcs3/Emu/Cell/lv2/sys_spu.h   | 2 ++
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/rpcs3/Emu/Cell/SPUThread.cpp b/rpcs3/Emu/Cell/SPUThread.cpp
index afba170867..a2d8ff31bd 100644
--- a/rpcs3/Emu/Cell/SPUThread.cpp
+++ b/rpcs3/Emu/Cell/SPUThread.cpp
@@ -487,6 +487,7 @@ void spu_thread::cpu_stop()
 		if (verify(HERE, group->running--) == 1)
 		{
 			// Notify on last thread stopped
+			group->stop_count++;
 			group->mutex.lock_unlock();
 			group->cond.notify_all();
 		}
diff --git a/rpcs3/Emu/Cell/lv2/sys_spu.cpp b/rpcs3/Emu/Cell/lv2/sys_spu.cpp
index 7c198c363f..581e17f812 100644
--- a/rpcs3/Emu/Cell/lv2/sys_spu.cpp
+++ b/rpcs3/Emu/Cell/lv2/sys_spu.cpp
@@ -623,7 +623,9 @@ error_code sys_spu_thread_group_terminate(u32 id, s32 value)
 	group->join_state |= SPU_TGJSF_TERMINATED;
 
 	// Wait until the threads are actually stopped
-	while (group->running)
+	const u64 last_stop = group->stop_count - !group->running;
+
+	while (group->stop_count == last_stop)
 	{
 		group->cond.wait(lock);
 	}
@@ -661,9 +663,11 @@ error_code sys_spu_thread_group_join(ppu_thread& ppu, u32 id, vm::ptr<u32> cause
 			return CELL_EBUSY;
 		}
 
+		const u64 last_stop = group->stop_count - !group->running;
+
 		lv2_obj::sleep(ppu);
 
-		while (group->running)
+		while (group->stop_count == last_stop)
 		{
 			if (ppu.is_stopped())
 			{
diff --git a/rpcs3/Emu/Cell/lv2/sys_spu.h b/rpcs3/Emu/Cell/lv2/sys_spu.h
index 853bfb327a..72b416fe2c 100644
--- a/rpcs3/Emu/Cell/lv2/sys_spu.h
+++ b/rpcs3/Emu/Cell/lv2/sys_spu.h
@@ -236,6 +236,7 @@ struct lv2_spu_group
 	atomic_t<u32> join_state; // flags used to detect exit cause
 	atomic_t<u32> running; // Number of running threads
 	cond_variable cond; // used to signal waiting PPU thread
+	atomic_t<u64> stop_count;
 
 	std::array<std::shared_ptr<named_thread<spu_thread>>, 256> threads; // SPU Threads
 	std::array<std::pair<sys_spu_image, std::vector<sys_spu_segment>>, 256> imgs; // SPU Images
@@ -257,6 +258,7 @@ struct lv2_spu_group
 		, exit_status(0)
 		, join_state(0)
 		, running(0)
+		, stop_count(0)
 	{
 	}