react-native/ReactCommon/cxxreact/NativeToJsBridge.h

188 lines
6.1 KiB
C++

// Copyright 2004-present Facebook. All Rights Reserved.
#pragma once
#include <atomic>
#include <functional>
#include <map>
#include <vector>
#include <cxxreact/Executor.h>
#include <cxxreact/ExecutorToken.h>
#include <cxxreact/JSCExecutor.h>
#include <cxxreact/JSModulesUnbundle.h>
#include <cxxreact/MessageQueueThread.h>
#include <cxxreact/MethodCall.h>
#include <cxxreact/NativeModule.h>
#include <folly/dynamic.h>
#include <jschelpers/Value.h>
namespace folly {
struct dynamic;
}
namespace facebook {
namespace react {
struct InstanceCallback;
class ModuleRegistry;
class ExecutorRegistration {
public:
ExecutorRegistration(
std::unique_ptr<JSExecutor> executor,
std::shared_ptr<MessageQueueThread> executorMessageQueueThread) :
executor_(std::move(executor)),
messageQueueThread_(executorMessageQueueThread) {}
std::unique_ptr<JSExecutor> executor_;
std::shared_ptr<MessageQueueThread> messageQueueThread_;
};
class JsToNativeBridge;
// 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::unique_ptr<MessageQueueThread> nativeQueue,
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(
ExecutorToken executorToken,
std::string&& module,
std::string&& method,
folly::dynamic&& args);
/**
* Invokes a callback with the cbID, and optional additional arguments in JS.
*/
void invokeCallback(ExecutorToken executorToken, double callbackId, folly::dynamic&& args);
/**
* Executes a JS method on the given executor synchronously, returning its
* return value. JSException will be thrown if JS throws an exception;
* another standard exception may be thrown for C++ bridge failures, or if
* the executor is not capable of synchronous calls.
*
* This method is experimental, and may be modified or removed.
*
* loadApplicationScriptSync() must be called and finished executing
* before callFunctionSync().
*/
template <typename T>
Value callFunctionSync(const std::string& module, const std::string& method, T&& args) {
if (*m_destroyed) {
throw std::logic_error(
folly::to<std::string>("Synchronous call to ", module, ".", method,
" after bridge is destroyed"));
}
JSCExecutor *jscExecutor = dynamic_cast<JSCExecutor*>(m_mainExecutor);
if (!jscExecutor) {
throw std::invalid_argument(
folly::to<std::string>("Executor type ", typeid(*m_mainExecutor).name(),
" does not support synchronous calls"));
}
return jscExecutor->callFunctionSync(module, method, std::forward<T>(args));
}
/**
* Starts the JS application. If unbundle 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<JSModulesUnbundle> unbundle,
std::unique_ptr<const JSBigString> startupCode,
std::string sourceURL);
void loadApplicationSync(
std::unique_ptr<JSModulesUnbundle> unbundle,
std::unique_ptr<const JSBigString> startupCode,
std::string sourceURL);
void setGlobalVariable(std::string propName, std::unique_ptr<const JSBigString> jsonValue);
void* getJavaScriptContext();
bool supportsProfiling();
void startProfiler(const std::string& title);
void stopProfiler(const std::string& title, const std::string& filename);
void handleMemoryPressureUiHidden();
void handleMemoryPressureModerate();
void handleMemoryPressureCritical();
/**
* Returns the ExecutorToken corresponding to the main JSExecutor.
*/
ExecutorToken getMainExecutorToken() const;
/**
* Synchronously tears down the bridge and the main executor.
*/
void destroy();
private:
/**
* Registers the given JSExecutor which runs on the given MessageQueueThread
* with the NativeToJsBridge. Part of this registration is transfering
* ownership of this JSExecutor to the NativeToJsBridge for the duration of
* the registration.
*
* Returns a ExecutorToken which can be used to refer to this JSExecutor
* in the NativeToJsBridge.
*/
ExecutorToken registerExecutor(
ExecutorToken token,
std::unique_ptr<JSExecutor> executor,
std::shared_ptr<MessageQueueThread> executorMessageQueueThread);
/**
* Unregisters a JSExecutor that was previously registered with this NativeToJsBridge
* using registerExecutor.
*/
std::unique_ptr<JSExecutor> unregisterExecutor(JSExecutor& executorToken);
void runOnExecutorQueue(ExecutorToken token, 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;
JSExecutor* m_mainExecutor;
ExecutorToken m_mainExecutorToken;
std::shared_ptr<JsToNativeBridge> m_delegate;
std::unordered_map<JSExecutor*, ExecutorToken> m_executorTokenMap;
std::unordered_map<ExecutorToken, ExecutorRegistration> m_executorMap;
std::mutex m_registrationMutex;
#ifdef WITH_FBSYSTRACE
std::atomic_uint_least32_t m_systraceCookie = ATOMIC_VAR_INIT();
#endif
MessageQueueThread* getMessageQueueThread(const ExecutorToken& executorToken);
JSExecutor* getExecutor(const ExecutorToken& executorToken);
ExecutorToken getTokenForExecutor(JSExecutor& executor);
};
} }