From 4a2812a30df9bd3336130d8b5e3b6a4813051541 Mon Sep 17 00:00:00 2001
From: Henrik Rydgard <hrydgard@gmail.com>
Date: Thu, 2 Mar 2017 10:18:56 +0100
Subject: [PATCH] Fix two mutex issues in CachingFileLoader. See #9370

---
 Core/FileLoaders/CachingFileLoader.cpp | 14 +++++++-------
 Core/FileLoaders/CachingFileLoader.h   |  2 +-
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/Core/FileLoaders/CachingFileLoader.cpp b/Core/FileLoaders/CachingFileLoader.cpp
index 1e3400856..e79508f52 100644
--- a/Core/FileLoaders/CachingFileLoader.cpp
+++ b/Core/FileLoaders/CachingFileLoader.cpp
@@ -132,7 +132,7 @@ void CachingFileLoader::ShutdownCache() {
 		sleep_ms(1);
 	}
 
-	std::lock_guard<std::mutex> guard(blocksMutex_);
+	std::lock_guard<std::recursive_mutex> guard(blocksMutex_);
 	for (auto block : blocks_) {
 		delete [] block.second.ptr;
 	}
@@ -148,7 +148,7 @@ size_t CachingFileLoader::ReadFromCache(s64 pos, size_t bytes, void *data) {
 	size_t offset = (size_t)(pos - (cacheStartPos << BLOCK_SHIFT));
 	u8 *p = (u8 *)data;
 
-	std::lock_guard<std::mutex> guard(blocksMutex_);
+	std::lock_guard<std::recursive_mutex> guard(blocksMutex_);
 	for (s64 i = cacheStartPos; i <= cacheEndPos; ++i) {
 		auto block = blocks_.find(i);
 		if (block == blocks_.end()) {
@@ -170,7 +170,7 @@ void CachingFileLoader::SaveIntoCache(s64 pos, size_t bytes, Flags flags, bool r
 	s64 cacheStartPos = pos >> BLOCK_SHIFT;
 	s64 cacheEndPos = (pos + bytes - 1) >> BLOCK_SHIFT;
 
-	std::lock_guard<std::mutex> guard(blocksMutex_);
+	std::lock_guard<std::recursive_mutex> guard(blocksMutex_);
 	size_t blocksToRead = 0;
 	for (s64 i = cacheStartPos; i <= cacheEndPos; ++i) {
 		auto block = blocks_.find(i);
@@ -235,7 +235,7 @@ bool CachingFileLoader::MakeCacheSpaceFor(size_t blocks, bool readingAhead) {
 		return false;
 	}
 
-	std::lock_guard<std::mutex> guard(blocksMutex_);
+	std::lock_guard<std::recursive_mutex> guard(blocksMutex_);
 	while (cacheSize_ > goal) {
 		u64 minGeneration = generation_;
 
@@ -274,7 +274,7 @@ bool CachingFileLoader::MakeCacheSpaceFor(size_t blocks, bool readingAhead) {
 }
 
 void CachingFileLoader::StartReadAhead(s64 pos) {
-	std::lock_guard<std::mutex> guard(blocksMutex_);
+	std::lock_guard<std::recursive_mutex> guard(blocksMutex_);
 	if (aheadThread_) {
 		// Already going.
 		return;
@@ -288,14 +288,14 @@ void CachingFileLoader::StartReadAhead(s64 pos) {
 	std::thread th([this, pos] {
 		setCurrentThreadName("FileLoaderReadAhead");
 
-		std::lock_guard<std::mutex> guard(blocksMutex_);
+		std::unique_lock<std::recursive_mutex> guard(blocksMutex_);
 		s64 cacheStartPos = pos >> BLOCK_SHIFT;
 		s64 cacheEndPos = cacheStartPos + BLOCK_READAHEAD - 1;
 
 		for (s64 i = cacheStartPos; i <= cacheEndPos; ++i) {
 			auto block = blocks_.find(i);
 			if (block == blocks_.end()) {
-				blocksMutex_.unlock();
+				guard.unlock();
 				SaveIntoCache(i << BLOCK_SHIFT, BLOCK_SIZE * BLOCK_READAHEAD, Flags::NONE, true);
 				break;
 			}
diff --git a/Core/FileLoaders/CachingFileLoader.h b/Core/FileLoaders/CachingFileLoader.h
index e77773be5..2cdd6dcbf 100644
--- a/Core/FileLoaders/CachingFileLoader.h
+++ b/Core/FileLoaders/CachingFileLoader.h
@@ -84,7 +84,7 @@ private:
 	};
 
 	std::map<s64, BlockInfo> blocks_;
-	std::mutex blocksMutex_;
+	std::recursive_mutex blocksMutex_;
 	mutable std::mutex backendMutex_;
 	bool aheadThread_;
 	bool prepared_;