在V8中使用TerminateExecution [英] Use of TerminateExecution in V8

问题描述

此刻，我正在尝试V8.我希望能够在一个线程中运行一些(可能是长时间运行的)javascript，然后能够随意从另一个线程优雅地"终止执行.

I'm experimenting with V8 at the moment. I want to be able to run some (possibly long-running) javascript in one thread and then be able to terminate the execution "gracefully" at will from another thread.

我已经编写了这个简单的代码片段来测试Lockers的概念以及TerminateExecution的用法:

I've written this simple snippet to test the concept of Lockers and the usage of TerminateExecution:

void breaker( Isolate* isolate, int tid ) {

    getchar();      //wait for keyboard input on stdin

    std::cout << "Breaking V8 execution" << std::endl;

    v8::Locker locker( isolate );       //lock the isolate
    v8::V8::TerminateExecution( tid );  //and terminate it
}

int main( int argc, char **argv ) {

    if( argc != 2 ) {
        std::cout << "No script name given" << std::endl;
        return 1;
    }

    Isolate* isolate = Isolate::New();              //create a new isolate
    Isolate::Scope isolateScope( isolate );         //enter it

    v8::Locker locker( isolate );                   //lock the isolate
    v8::Locker::StartPreemption( 100 );             //and start preemption

    v8::HandleScope handle_scope( isolate );        //open a new handle scope


    /*** inject a console object into the global context ***/
    v8::Handle<v8::ObjectTemplate> globalTemplate = v8::ObjectTemplate::New();

    Handle<Context> context = Context::New( NULL, globalTemplate );
    v8::Context::Scope context_scope( context );

    Console* console = new Console;
    Handle<Object> jsConsole = wrap_console( isolate, console );
    expose_property( jsConsole, String::New( "log" ), InvocationCallback( Console::consoleLog ) );
    context->Global()->Set( String::New( "console" ), jsConsole, v8::ReadOnly );
    /*******************************************************/


    //read a javascript file supplied via console
    std::string contents = read_file( argv[1] );
    v8::Handle<v8::String> js = v8::String::New( contents.c_str() );

    v8::TryCatch try_catch;
    v8::Handle<v8::Script> script = v8::Script::Compile( js );

    if( script.IsEmpty() ) {
        report_exception( try_catch );
    }

    //start the breaker thread
    std::thread th( breaker, isolate, v8::V8::GetCurrentThreadId() );

    log_info( "running script" );
    script->Run();
    log_info( "Script execution finished" );

    th.join();
}

但是，我总是在terminateExecution()调用中遇到段错误.我在这里做什么错了?

However, I always get a segfault on the terminateExecution() call. What am I doing wrong here?

感谢您的帮助

推荐答案

v8::V8::GetCurrentThreadId()和v8::V8::TerminateExecution(int)方法已从V8 API中删除.我建议您不要使用它们.抢占功能对于这个世界来说可能还不长.

The v8::V8::GetCurrentThreadId() and v8::V8::TerminateExecution(int) methods have been removed from the V8 API. I recommend that you don't use them. The preemption feature is probably also not long for this world.

相反，只需调用v8::V8::TerminateExecution(v8::Isolate*).并且不要将隔离锁锁定在中断线程中，因为这样做会阻塞，直到您的运行器线程释放隔离锁为止，直到脚本执行完成后，隔离锁才会执行.

Instead, simply call v8::V8::TerminateExecution(v8::Isolate*). And don't lock the isolate in your breaker thread, as doing so will block until your runner thread releases the isolate, which it won't do until script execution is finished.

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