setTimeout implemenetation

[Daniel Burchardt]

Hi,

I try implement setTimeout in v8. I have problem: how i can execute js code in other thread in this same context? My code:

v8::Handle<v8::Value> setTimeoutImpl(const v8::FunctionCallbackInfo<v8::Value>& info) {
            v8::Local<v8::Value> callback(info[0]);

            if (callback->IsFunction()) {
                v8::Handle<v8::Function> func = v8::Handle<v8::Function>::Cast(callback);

                v8::Handle<v8::Value> args[0];
                v8::Handle<v8::Value> result;
                result = func->Call(info.GetIsolate()->GetCurrentContext()->Global(), 0, args);

                info.GetReturnValue().Set(result);
            }
}

I try create new thread like that:

                pthread_t tid;
                pthread_attr_t tattr;
                pthread_attr_init(&tattr);
                pthread_attr_setdetachstate(&tattr, PTHREAD_CREATE_DETACHED);
                pthread_create(&tid, &tattr, thread_setTimeout, &ji);
                pthread_attr_destroy(&tattr);

but use v8 in thread is terminated with error segmentation fault... Any one can help me? I found example but use old api.

[Ben Noordhuis]

You need to create a v8::Locker instance first before entering the
isolate and context with v8::Isolate::Scope and v8::Context::Scope
respectively. The timer thread will block until the main thread gives
it a chance to acquire the locker.

(If that all sounds like mumbo jumbo, you need to study v8.h a bit
more, particular the sections on v8::Locker and v8::Unlocker.)

Traditionally though, most embedders solve this by building their
application around an event loop instead of using threads.

[Daniel Burchardt]

I know but i have problem with this:

        static void* thread_setTimeout( void * arg ) {
            v8::Locker locker(v8::Isolate::GetCurrent());
            v8::HandleScope handle_scope(v8::Isolate::GetCurrent());

            usleep( 1000000 );

            v8::Unlocker unlocker(v8::Isolate::GetCurrent());
        }

after run process is terminated by seg fault

0x00007ffff56c6b7f in v8::Locker::Initialize(v8::Isolate*) ()

[Ben Noordhuis]

On Fri, Sep 9, 2016 at 11:14 AM, Daniel Burchardt
<danielb...@gmail.com> wrote:
> I know but i have problem with this:
> static void* thread_setTimeout( void * arg ) {
> v8::Locker locker(v8::Isolate::GetCurrent());
> v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
>
> usleep( 1000000 );
>
> v8::Unlocker unlocker(v8::Isolate::GetCurrent());
> }
>
> after run process is terminated by seg fault
>
> 0x00007ffff56c6b7f in v8::Locker::Initialize(v8::Isolate*) ()

You need to pass the isolate explicitly to your thread.
v8::Isolate::GetCurrent() won't work, it stores the current isolate in
thread-local storage.