From daf43989fcefe8c8e5436909758fb70f4c5f788d Mon Sep 17 00:00:00 2001
From: Eladash <elad3356p@gmail.com>
Date: Thu, 25 Aug 2022 12:12:29 +0300
Subject: [PATCH] Thread.h: Improve thread abort performance

---
 Utilities/Thread.h          | 10 +++++++++-
 rpcs3/Emu/CPU/CPUThread.cpp | 15 +++++++++++++--
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/Utilities/Thread.h b/Utilities/Thread.h
index c378b872f9..ae4d625f1e 100644
--- a/Utilities/Thread.h
+++ b/Utilities/Thread.h
@@ -635,9 +635,11 @@ public:
 	// Join thread by thread_state::finished
 	named_thread& operator=(thread_state s)
 	{
+		bool notify_sync = false;
+
 		if (s >= thread_state::aborting && thread::m_sync.fetch_op([](u64& v){ return !(v & 3) && (v |= 1); }).second)
 		{
-			thread::m_sync.notify_one(1);
+			notify_sync = true;
 		}
 
 		if constexpr (std::is_assignable_v<Context&, thread_state>)
@@ -645,6 +647,12 @@ public:
 			static_cast<Context&>(*this) = s;
 		}
 
+		if (notify_sync)
+		{
+			// Notify after context abortion has been made so all conditions for wake-up be satisfied by the time of notification
+			thread::m_sync.notify_one(1);
+		}
+
 		if (s == thread_state::finished)
 		{
 			// This participates in emulation stopping, use destruction-alike semantics
diff --git a/rpcs3/Emu/CPU/CPUThread.cpp b/rpcs3/Emu/CPU/CPUThread.cpp
index d48f902f63..211e5b2924 100644
--- a/rpcs3/Emu/CPU/CPUThread.cpp
+++ b/rpcs3/Emu/CPU/CPUThread.cpp
@@ -881,8 +881,19 @@ void cpu_thread::notify()
 
 cpu_thread& cpu_thread::operator=(thread_state)
 {
-	state += cpu_flag::exit;
-	state.notify_one(cpu_flag::exit);
+	if (state & cpu_flag::exit)
+	{
+		// Must be notified elsewhere or self-raised
+		return *this;
+	}
+
+	const auto old = state.fetch_add(cpu_flag::exit);
+
+	if (old & cpu_flag::wait && old.none_of(cpu_flag::again + cpu_flag::exit))
+	{
+		state.notify_one(cpu_flag::exit);
+	}
+
 	return *this;
 }