From e8d144f3991b69d775664e66c88814a74f6fec46 Mon Sep 17 00:00:00 2001
From: Nekotekina <nekotekina@gmail.com>
Date: Sat, 18 Aug 2018 21:14:52 +0300
Subject: [PATCH] Improve vm::reader_lock

Add upgrade() method
---
 rpcs3/Emu/Memory/vm.cpp | 22 +++++++++++++++++-----
 rpcs3/Emu/Memory/vm.h   |  7 ++++---
 2 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/rpcs3/Emu/Memory/vm.cpp b/rpcs3/Emu/Memory/vm.cpp
index 8fa7b92eb4..7b02d8c637 100644
--- a/rpcs3/Emu/Memory/vm.cpp
+++ b/rpcs3/Emu/Memory/vm.cpp
@@ -155,7 +155,6 @@ namespace vm
 	}
 
 	reader_lock::reader_lock()
-		: locked(true)
 	{
 		auto cpu = get_current_cpu_thread();
 
@@ -175,12 +174,27 @@ namespace vm
 
 	reader_lock::~reader_lock()
 	{
-		if (locked)
+		if (m_upgraded)
+		{
+			g_mutex.unlock();
+		}
+		else
 		{
 			g_mutex.unlock_shared();
 		}
 	}
 
+	void reader_lock::upgrade()
+	{
+		if (m_upgraded)
+		{
+			return;
+		}
+
+		g_mutex.lock_upgrade();
+		m_upgraded = true;
+	}
+
 	writer_lock::writer_lock(int full)
 		: locked(true)
 	{
@@ -844,15 +858,13 @@ namespace vm
 				{
 					if (location == vm::user64k || location == vm::user1m)
 					{
-						g_mutex.lock_upgrade();
+						lock.upgrade();
 
 						if (!loc)
 						{
 							// Deferred allocation
 							loc = _find_map(0x10000000, 0x10000000, location == vm::user64k ? 0x201 : 0x401);
 						}
-
-						g_mutex.lock_degrade();
 					}
 				}
 
diff --git a/rpcs3/Emu/Memory/vm.h b/rpcs3/Emu/Memory/vm.h
index 9aefb06a8f..b421904520 100644
--- a/rpcs3/Emu/Memory/vm.h
+++ b/rpcs3/Emu/Memory/vm.h
@@ -64,15 +64,16 @@ namespace vm
 	void temporary_unlock(cpu_thread& cpu) noexcept;
 	void temporary_unlock() noexcept;
 
-	struct reader_lock final
+	class reader_lock final
 	{
-		const bool locked;
+		bool m_upgraded = false;
 
+	public:
 		reader_lock(const reader_lock&) = delete;
 		reader_lock();
 		~reader_lock();
 
-		explicit operator bool() const { return locked; }
+		void upgrade();
 	};
 
 	struct writer_lock final