react-native/ReactCommon/cxxreact/NativeToJsBridge.h

100 lines
2.9 KiB
C++

// Copyright 2004-present Facebook. All Rights Reserved.
#pragma once
#include <atomic>
#include <functional>
#include <map>
#include <vector>
#include <cxxreact/JSExecutor.h>
namespace folly {
struct dynamic;
}
namespace facebook {
namespace react {
struct InstanceCallback;
class JsToNativeBridge;
class MessageQueueThread;
class ModuleRegistry;
class RAMBundleRegistry;
// This class manages calls from native code to JS. It also manages
// executors and their threads. All functions here can be called from
// any thread.
//
// Except for loadApplicationScriptSync(), all void methods will queue
// work to run on the jsQueue passed to the ctor, and return
// immediately.
class NativeToJsBridge {
public:
friend class JsToNativeBridge;
/**
* This must be called on the main JS thread.
*/
NativeToJsBridge(
JSExecutorFactory* jsExecutorFactory,
std::shared_ptr<ModuleRegistry> registry,
std::shared_ptr<MessageQueueThread> jsQueue,
std::shared_ptr<InstanceCallback> callback);
virtual ~NativeToJsBridge();
/**
* Executes a function with the module ID and method ID and any additional
* arguments in JS.
*/
void callFunction(std::string&& module, std::string&& method, folly::dynamic&& args);
/**
* Invokes a callback with the cbID, and optional additional arguments in JS.
*/
void invokeCallback(double callbackId, folly::dynamic&& args);
/**
* Starts the JS application. If bundleRegistry is non-null, then it is
* used to fetch JavaScript modules as individual scripts.
* Otherwise, the script is assumed to include all the modules.
*/
void loadApplication(
std::unique_ptr<RAMBundleRegistry> bundleRegistry,
std::unique_ptr<const JSBigString> startupCode,
std::string sourceURL);
void loadApplicationSync(
std::unique_ptr<RAMBundleRegistry> bundleRegistry,
std::unique_ptr<const JSBigString> startupCode,
std::string sourceURL);
void registerBundle(uint32_t bundleId, const std::string& bundlePath);
void setGlobalVariable(std::string propName, std::unique_ptr<const JSBigString> jsonValue);
void* getJavaScriptContext();
bool isInspectable();
void handleMemoryPressure(int pressureLevel);
/**
* Synchronously tears down the bridge and the main executor.
*/
void destroy();
private:
void runOnExecutorQueue(std::function<void(JSExecutor*)> task);
// This is used to avoid a race condition where a proxyCallback gets queued
// after ~NativeToJsBridge(), on the same thread. In that case, the callback
// will try to run the task on m_callback which will have been destroyed
// within ~NativeToJsBridge(), thus causing a SIGSEGV.
std::shared_ptr<bool> m_destroyed;
std::shared_ptr<JsToNativeBridge> m_delegate;
std::unique_ptr<JSExecutor> m_executor;
std::shared_ptr<MessageQueueThread> m_executorMessageQueueThread;
#ifdef WITH_FBSYSTRACE
std::atomic_uint_least32_t m_systraceCookie = ATOMIC_VAR_INIT();
#endif
};
} }