From 09ab139407b6ce9b3bfbeaeafbd7b51faae1863b Mon Sep 17 00:00:00 2001
From: Flyinghead <raphael.jean@gmail.com>
Date: Thu, 15 Aug 2024 11:55:07 +0200
Subject: [PATCH] android: deadlock when Emulator::checkStatus is called
 concurrently

If checkStatus(wait = true) is called, any other thread will be blocked
even when calling with wait = false since the mutex is locked. This
happens on Android when JNIdc.rendinitNative(null) is called by the app
main thread.
Use a shared_future instead and unlock the mutex before waiting.
---
 core/emulator.cpp | 13 +++++++++----
 core/emulator.h   |  2 +-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/core/emulator.cpp b/core/emulator.cpp
index e39fc19d4..1ed9a22dc 100644
--- a/core/emulator.cpp
+++ b/core/emulator.cpp
@@ -908,15 +908,20 @@ void Emulator::start()
 bool Emulator::checkStatus(bool wait)
 {
 	try {
-		const std::lock_guard<std::mutex> lock(mutex);
+		std::unique_lock<std::mutex> lock(mutex);
 		if (threadResult.valid())
 		{
-			if (!wait)
-			{
-				auto result = threadResult.wait_for(std::chrono::seconds(0));
+			lock.unlock();
+			auto localResult = threadResult;
+			if (wait) {
+				localResult.wait();
+			}
+			else {
+				auto result = localResult.wait_for(std::chrono::seconds(0));
 				if (result == std::future_status::timeout)
 					return true;
 			}
+			lock.lock();
 			threadResult.get();
 		}
 		return false;
diff --git a/core/emulator.h b/core/emulator.h
index 6802b00e8..eb2a698be 100644
--- a/core/emulator.h
+++ b/core/emulator.h
@@ -179,7 +179,7 @@ private:
 		Terminated,
 	};
 	State state = Uninitialized;
-	std::future<void> threadResult;
+	std::shared_future<void> threadResult;
 	bool resetRequested = false;
 	bool singleStep = false;
 	u64 startTime = 0;