From 9359223e694f28c1aa30717694a243d8fb057f07 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Bylica?= <chfast@gmail.com>
Date: Wed, 10 Jun 2015 13:04:19 +0200
Subject: [PATCH 1/2] Remove memory leak detector. Is it not thread-safe.

---
 libevmjit/Array.cpp | 43 ++-----------------------------------------
 1 file changed, 2 insertions(+), 41 deletions(-)

diff --git a/libevmjit/Array.cpp b/libevmjit/Array.cpp
index 3266038db..0b511a058 100644
--- a/libevmjit/Array.cpp
+++ b/libevmjit/Array.cpp
@@ -9,8 +9,6 @@
 #include "Runtime.h"
 #include "Utils.h"
 
-#include <set> // DEBUG only
-
 namespace dev
 {
 namespace eth
@@ -269,52 +267,15 @@ void Array::extend(llvm::Value* _arrayPtr, llvm::Value* _size)
 }
 }
 
-namespace
-{
-	struct AllocatedMemoryWatchdog
-	{
-		std::set<void*> allocatedMemory;
-
-		~AllocatedMemoryWatchdog()
-		{
-			if (!allocatedMemory.empty())
-			{
-				DLOG(mem) << allocatedMemory.size() << " MEM LEAKS!\n";
-				for (auto&& leak : allocatedMemory)
-					DLOG(mem) << "\t" << leak << "\n";
-			}
-		}
-	};
-
-	AllocatedMemoryWatchdog watchdog;
-}
-
 extern "C"
 {
-	using namespace dev::eth::jit;
-
 	EXPORT void* ext_realloc(void* _data, size_t _size) noexcept
 	{
-		//std::cerr << "REALLOC: " << _data << " [" << _size << "]" << std::endl;
-		auto newData = std::realloc(_data, _size);
-		if (_data != newData)
-		{
-			DLOG(mem) << "REALLOC: " << newData << " <- " << _data << " [" << _size << "]\n";
-			watchdog.allocatedMemory.erase(_data);
-			watchdog.allocatedMemory.insert(newData);
-		}
-		return newData;
+		return std::realloc(_data, _size);
 	}
 
 	EXPORT void ext_free(void* _data) noexcept
 	{
 		std::free(_data);
-		if (_data)
-		{
-			DLOG(mem) << "FREE   : " << _data << "\n";
-			watchdog.allocatedMemory.erase(_data);
-		}
 	}
-
-} // extern "C"
-
+}

From 787df33341d084c2d69e1e2dabe9a009744f8dcb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Bylica?= <chfast@gmail.com>
Date: Wed, 10 Jun 2015 14:22:44 +0200
Subject: [PATCH 2/2] Protect EVM JIT cache with mutex.

Fixes ethereum/cpp-ethereum#2086.
---
 libevmjit/Cache.cpp | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/libevmjit/Cache.cpp b/libevmjit/Cache.cpp
index 47a6386e9..42ccf44ac 100644
--- a/libevmjit/Cache.cpp
+++ b/libevmjit/Cache.cpp
@@ -1,5 +1,7 @@
 #include "Cache.h"
 
+#include <mutex>
+
 #include "preprocessor/llvm_includes_start.h"
 #include <llvm/IR/Module.h>
 #include <llvm/IR/LLVMContext.h>
@@ -23,6 +25,8 @@ namespace jit
 
 namespace
 {
+	using Guard = std::lock_guard<std::mutex>;
+	std::mutex x_cacheMutex;
 	CacheMode g_mode;
 	llvm::MemoryBuffer* g_lastObject;
 	ExecutionEngineListener* g_listener;
@@ -43,6 +47,9 @@ namespace
 ObjectCache* Cache::getObjectCache(CacheMode _mode, ExecutionEngineListener* _listener)
 {
 	static ObjectCache objectCache;
+
+	Guard g{x_cacheMutex};
+
 	g_mode = _mode;
 	g_listener = _listener;
 	return &objectCache;
@@ -50,6 +57,8 @@ ObjectCache* Cache::getObjectCache(CacheMode _mode, ExecutionEngineListener* _li
 
 void Cache::clear()
 {
+	Guard g{x_cacheMutex};
+
 	using namespace llvm::sys;
 	llvm::SmallString<256> cachePath;
 	path::system_temp_directory(false, cachePath);
@@ -62,6 +71,8 @@ void Cache::clear()
 
 void Cache::preload(llvm::ExecutionEngine& _ee, std::unordered_map<std::string, uint64_t>& _funcCache)
 {
+	Guard g{x_cacheMutex};
+
 	// TODO: Cache dir should be in one place
 	using namespace llvm::sys;
 	llvm::SmallString<256> cachePath;
@@ -92,11 +103,14 @@ void Cache::preload(llvm::ExecutionEngine& _ee, std::unordered_map<std::string,
 
 std::unique_ptr<llvm::Module> Cache::getObject(std::string const& id)
 {
+	Guard g{x_cacheMutex};
+
 	if (g_mode != CacheMode::on && g_mode != CacheMode::read)
 		return nullptr;
 
-	if (g_listener)
-		g_listener->stateChanged(ExecState::CacheLoad);
+	// TODO: Disabled because is not thread-safe.
+	//if (g_listener)
+	//	g_listener->stateChanged(ExecState::CacheLoad);
 
 	DLOG(cache) << id << ": search\n";
 	if (!CHECK(!g_lastObject))
@@ -136,12 +150,15 @@ std::unique_ptr<llvm::Module> Cache::getObject(std::string const& id)
 
 void ObjectCache::notifyObjectCompiled(llvm::Module const* _module, llvm::MemoryBuffer const* _object)
 {
+	Guard g{x_cacheMutex};
+
 	// Only in "on" and "write" mode
 	if (g_mode != CacheMode::on && g_mode != CacheMode::write)
 		return;
 
-	if (g_listener)
-		g_listener->stateChanged(ExecState::CacheWrite);
+	// TODO: Disabled because is not thread-safe.
+	// if (g_listener)
+		// g_listener->stateChanged(ExecState::CacheWrite);
 
 	auto&& id = _module->getModuleIdentifier();
 	llvm::SmallString<256> cachePath;
@@ -161,6 +178,8 @@ void ObjectCache::notifyObjectCompiled(llvm::Module const* _module, llvm::Memory
 
 llvm::MemoryBuffer* ObjectCache::getObject(llvm::Module const* _module)
 {
+	Guard g{x_cacheMutex};
+
 	DLOG(cache) << _module->getModuleIdentifier() << ": use\n";
 	auto o = g_lastObject;
 	g_lastObject = nullptr;