Change JIT C interface. Create ExecutionEngine on heap to allow one-pass copy of return data.

libevmjit/Runtime.cpp

@@ -26,6 +26,7 @@ bytes_ref Runtime::getReturnData() const
 	if (data < m_memory.data() || data >= m_memory.data() + m_memory.size() || size == 0)
 	{
 		assert(size == 0); // data can be an invalid pointer only if size is 0
+		m_data.callData = nullptr;
 		return {};
 	}
 

libevmjit/RuntimeData.h

@@ -47,7 +47,7 @@ struct RuntimeData
 	i256 		difficulty;
 	i256 		gasLimit;
 	uint64_t 	number = 0;
-	uint64_t 	timestamp = 0;
+	int64_t 	timestamp = 0;
 	byte const* code = nullptr;
 	uint64_t 	codeSize = 0;
 };

libevmjit/interface.cpp

@@ -1,34 +1,36 @@
-#include "interface.h"
-#include <cstring>
 #include "ExecutionEngine.h"
 
 extern "C"
 {
 
-evmjit_result evmjit_run(void* _data, void* _env)
-{
-	using namespace dev::eth::jit;
+using namespace dev::eth::jit;
 
-	auto data = static_cast<RuntimeData*>(_data);
+void* evmjit_create() noexcept
+{
+	return new(std::nothrow) ExecutionEngine;
+}
 
-	ExecutionEngine engine;
+void evmjit_destroy(ExecutionEngine* _engine) noexcept
+{
+	delete _engine;
+}
 
-	auto codePtr = data->code;
-	auto codeSize = data->codeSize;
-	bytes bytecode;
-	bytecode.insert(bytecode.end(), codePtr, codePtr + codeSize);
+int evmjit_run(ExecutionEngine* _engine, RuntimeData* _data, Env* _env) noexcept
+{
+	try
+	{
+		auto codePtr = _data->code;
+		auto codeSize = _data->codeSize;
+		bytes bytecode;
+		bytecode.insert(bytecode.end(), codePtr, codePtr + codeSize);
 
-	auto returnCode = engine.run(bytecode, data, static_cast<Env*>(_env));
-	evmjit_result result = {static_cast<int32_t>(returnCode), 0, nullptr};
-	if (returnCode == ReturnCode::Return && std::get<0>(engine.returnData))
+		auto returnCode = _engine->run(bytecode, _data, _env);
+		return static_cast<int>(returnCode);
+	}
+	catch(...)
 	{
-		// TODO: Optimized returning data. Allocating memory on client side by callback function might be a good idea
-		result.returnDataSize = std::get<1>(engine.returnData);
-		result.returnData = std::malloc(result.returnDataSize);
-		std::memcpy(result.returnData, std::get<0>(engine.returnData), result.returnDataSize);
+		return static_cast<int>(ReturnCode::UnexpectedException);
 	}
-
-	return result;
 }
 
 }

libevmjit/interface.h

@@ -1,19 +1,12 @@
-#include <stddef.h>
-#include <stdint.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-typedef struct evmjit_result
-{
-	int32_t  returnCode;
-	uint64_t returnDataSize;
-	void*    returnData;
+void* evmjit_create();
+int   evmjit_run(void* _jit, void* _data, void* _env);
+void  evmjit_destroy(void* _jit);
 
-} evmjit_result;
-
-evmjit_result evmjit_run(void* _data, void* _env);
 
 #ifdef __cplusplus
 }