I have attached to node with the program executing in the middle of a
while/busy loop.
I think I found what node is doing.
https://github.com/v8/v8/blob/96a039aab14b71069e88c4c04543e6bc9514a0d6/include/v8.h#L7969
void v8::Isolate::RequestInterrupt(InterruptCallback callback, void* data);
This function stops JavaScript execution and might be the answer to my
problem. The callback is called on the isolate's thread.
Cheers,
Konrad
On Wednesday, November 14, 2018 at 10:52:53 AM UTC-5, @soylentgraham wrote:
>
> Going off topic now, but can you attach & break into node.js whilst it's
> in a big blocking function?
> Or can you only break if you've previously attached? (I've only done
> light, very-async stuff in node)
>
> In long-running funcs (well, accidental massive loops) in chrome I find I
> struggle to break, so I kinda thought this was how it was, but maybe I'm
> wrong :)
>
>
> On Wednesday, 14 November 2018 13:55:34 UTC, Konrad Piascik wrote:
>>
>> Yeah I can't make any assumptions or impose any requirements about what
>> the javascript to be executed will look like.
>> It must be possible since Node.js already does this for long running
>> JavaScript.
>>
>> Thanks for the suggestions and quick responses
>>
>> -Konrad
>>
>> On Wednesday, November 14, 2018 at 7:53:57 AM UTC-5, @soylentgraham wrote:
>>>
>>> The only way I could interrupt long runs of javascript, assuming you
>>> can't break it yourself into asynchronous code (via promises/await, this is
>>> the nicest approach IMO me), is adding a yield function to let the event
>>> loop run (I have other multithread-y reasons for this too, but letting
>>> external actions run is one)
>>>
>>> But if you can't add code at all, you are probably stuck (afaik, there's
>>> no real interrupting, because you're basically calling one big
>>> RunJavascript() func on your thread :)
>>>
>>> In case it's useful, this is the C++ side, (and I call yield() in JS to
>>> let other threads do JS calls, and let the debugger interrupt)
>>>
>>>
>>> void TV8Container::Yield(size_t SleepMilliseconds)
>>>
>>> {
>>>
>>> // gr: temporary unlock, but need to exit&enter too
>>>
>>> {
>>>
>>> mIsolate->Exit();
>>>
>>> v8::Unlocker unlocker(mIsolate);
>>>
>>> // isolate unlock for a moment, let another thread jump in and run stuff
>>>
>>> auto ms = std::chrono::milliseconds(SleepMilliseconds);
>>>
>>> std::this_thread::sleep_for( ms );
>>>
>>> }
>>>
>>> // re-enter after unlocker has gone out of scope
>>>
>>> mIsolate->Enter();
>>>
>>> }
>>>
>>>
>>> On Tuesday, 13 November 2018 21:06:59 UTC, Konrad Piascik wrote:
>>>>
>>>> Hi @soylentgraham,
>>>>
>>>> I'm trying to replicate what you're doing as well but am running into
>>>> some other problems. The most notable of which is that my websocket is on
>>>> a different thread than my isolate creation.
>>>> I see from your solution that you're adding the frontend messages to a
>>>> queue and looking through them in your event loop. My problem is that I
>>>> have long running javascript that is not intended to exit/return until the
>>>> program stops. Do you have any suggestions/ideas?
>>>>
>>>> Thanks,
>>>> Konrad
>>>>
>>>>
>>>> On Tuesday, September 18, 2018 at 10:49:43 AM UTC-4, @soylentgraham
>>>> wrote:
>>>>>
>>>>> YetAnotherUpdate
>>>>>
>>>>> After some more digging, I found the issue I have is identified node
>>>>> and chromium too...
>>>>>
>>>>> https://github.com/nodejs/node/commit/b1e26128f317a6f5a5808a0a727e98f80f088b84
>>>>>
>>>>> So, it looks like the default v8 [platform] isn't chrome-dev-tools
>>>>> compatible.
>>>>> Ibon's case worked as it has a specific Android platform
>>>>> implementation. Chromium and Node also have their own platform.
>>>>>
>>>>> So, I made the most basic platform proxy possible to work around it...
>>>>>
>>>>> https://github.com/SoylentGraham/V8InspectorMinimal/blob/master/src/TV8Platform.h
>>>>>
>>>>> And it works!
>>>>> I can now modify code on the fly, execute from the console.
>>>>> I can't seem to debug, and pressing pause-execution a few times gives
>>>>> me a new assert, but the higher level code is a bit of a mess at this
>>>>> point, so I'm probably implementing something wrong...
>>>>>
>>>>> Still, if anyone else ever finds this problem... V8 alone cannot be
>>>>> used with chrome dev tools. (as of 7.1.0.0
>>>>>
>>>>> 4544e18b0c3845a9fca422cf0903df4803343cf1)
>>>>>
>>>>> On Friday, 14 September 2018 11:44:33 UTC+1, @soylentgraham wrote:
>>>>>>
>>>>>> So the core of my issue at the moment, is this assert (UNIMPLEMENTED)
>>>>>>
>>>>>> void
>>>>>> DefaultWorkerThreadsTaskRunner::PostDelayedTask(std::unique_ptr<Task>
>>>>>> task,
>>>>>>
>>>>>> double
>>>>>> delay_in_seconds) {
>>>>>>
>>>>>> base::LockGuard<base::Mutex> guard(&lock_);
>>>>>>
>>>>>> if (terminated_) return;
>>>>>>
>>>>>> if (delay_in_seconds == 0) {
>>>>>>
>>>>>> queue_.Append(std::move(task));
>>>>>>
>>>>>> return;
>>>>>>
>>>>>> }
>>>>>>
>>>>>> // There is no use case for this function with non zero
>>>>>> delay_in_second on a
>>>>>>
>>>>>> // worker thread at the moment, but it is still part of the
>>>>>> interface.
>>>>>>
>>>>>> UNIMPLEMENTED();
>>>>>>
>>>>>> }
>>>>>>
>>>>>> from
>>>>>>
>>>>>> DefaultPlatform::CallDelayedOnWorkerThread(
>>>>>>
>>>>>> being called by
>>>>>>
>>>>>> protocol::Response V8InspectorImpl::EvaluateScope::setTimeout(double
>>>>>> timeout) {
>>>>>>
>>>>>> if (m_isolate->IsExecutionTerminating()) {
>>>>>>
>>>>>> return protocol::Response::Error("Execution was terminated");
>>>>>>
>>>>>> }
>>>>>>
>>>>>> m_cancelToken.reset(new CancelToken());
>>>>>>
>>>>>> v8::debug::GetCurrentPlatform()->CallDelayedOnWorkerThread(
>>>>>>
>>>>>> v8::base::make_unique<TerminateTask>(m_isolate,
>>>>>> m_cancelToken), timeout);
>>>>>>
>>>>>> return protocol::Response::OK();
>>>>>>
>>>>>> }
>>>>>>
>>>>>>
>>>>>>
>>>>>> so, SetTimeout in the inspector, explicitly uses something
>>>>>> we[developers] know isn't implemented...
>>>>>> From reading things before, Node.js was using the default platform, I
>>>>>> think now it has it's own platform. Maybe chromium does too...
>>>>>> Perhaps the demo/unittest debugger/d8/inspector doesn't call
>>>>>> settimeout, so this hasn't been found with default setups...
>>>>>>
>>>>>> Maybe I HAVE to implement my own platform to support chrome dev tools
>>>>>> and handle delayed jobs...
>>>>>>
>>>>>>
>>>>>> On Thursday, 13 September 2018 17:14:58 UTC+1, @soylentgraham wrote:
>>>>>>>
>>>>>>> For any future readers;
>>>>>>> I went back to trying to build a debug v8 set of libs (wouldnt
>>>>>>> compile before, added is_component_build=false which I think fixed that)
>>>>>>> Built with latest master (4544e18b0c3845a9fca422cf0903df4803343cf1)
>>>>>>>
>>>>>>> Which forced me to correct a few uses of deprecated functions,
>>>>>>> including v8::String::NewFromUtf8() with no isolate, so *possibly*
>>>>>>> that was the source of the crash re: scriptorigin. I now get an origin
>>>>>>> in
>>>>>>> CDT (kinda, it still breaks in a VMXX file)
>>>>>>>
>>>>>>> Then asserts as before in "code that should never be reached" (see
>>>>>>> earlier in the thread)
>>>>>>>
>>>>>>> [image: Screen Shot 2018-09-13 at 17.08.09.png]
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Wednesday, 12 September 2018 17:34:30 UTC+1, @soylentgraham wrote:
>>>>>>>>
>>>>>>>> With a lot of back & forth help from Ibon/hyperandroid, we've got a
>>>>>>>> bit further in working out which things are good, and which are bad.
>>>>>>>> Feels like we're close, but things are still unstable, and a bit
>>>>>>>> unresponsive.
>>>>>>>>
>>>>>>>> I can kinda break into the code (which only shows *this *in
>>>>>>>> sources)
>>>>>>>> Still get the assert above from trying to autocomplete too many
>>>>>>>> times. (albeit after a RunMessageLoop callback now)
>>>>>>>> And if I add a script origin, I get a crash trying to stacktrace
>>>>>>>> (immediately when connecting, still trying to figure this out, as my
>>>>>>>> scriptorigin is okay)
>>>>>>>>
>>>>>>>> More stripped back version here (cutting more dependencies out, but
>>>>>>>> all my setup, inspector, frontend, messaging is in v8minimal.cpp)
>>>>>>>> https://github.com/SoylentGraham/V8InspectorMinimal
>>>>>>>>
>>>>>>>> On Monday, 27 August 2018 13:49:37 UTC+1, @soylentgraham wrote:
>>>>>>>>>
>>>>>>>>> Through various sources (ie, googling & github) I've finally got a
>>>>>>>>> bit of a grasp of the flow for connecting chrome dev tools to my v8
>>>>>>>>> app.
>>>>>>>>> (which is using a pretty recent HEAD build I've built myself with all
>>>>>>>>> default settings other than compiling as a static lib[s].
>>>>>>>>> v8-version.h says
>>>>>>>>> 7.0.0.0)
>>>>>>>>>
>>>>>>>>> I connect via an explicit url (can't quite get json/list/ to show
>>>>>>>>> up in chrome yet)
>>>>>>>>> *chrome-devtools://devtools/bundled/inspector.html?experiments=true&v8only=true&ws=127.0.0.1:8008
>>>>>>>>>
>>>>>>>>> <http://127.0.0.1:8008>*
>>>>>>>>> (Not sure how relevant the v8only=true and experiments=true are,
>>>>>>>>> couldn't find any documentation on this)
>>>>>>>>>
>>>>>>>>> This connects to my websocket, and I pass all messages straight to
>>>>>>>>> *Session->dispatchProtocolMessage*
>>>>>>>>>
>>>>>>>>> My channel then gets *sendResponse's* in return, which I send
>>>>>>>>> back to chrome over my websocket.
>>>>>>>>>
>>>>>>>>> Chrome dev tools shows essentially an empty debugger, no sources,
>>>>>>>>> no console output, no errors...
>>>>>>>>>
>>>>>>>>> The responses my isolate/context sends back, suggest maybe I have
>>>>>>>>> some JS symbols/modules missing, which maybe I need to implement?
>>>>>>>>> I'm kinda assuming this, as the debugger. methods succeed, but
>>>>>>>>> things like *Inspector.enable* (which I haven't found anyone
>>>>>>>>> implementing, but some people are implementing Inspector objects,
>>>>>>>>> just with
>>>>>>>>> different methods) fail
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":16,"method":"Inspector.enable"}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Inspector.enable' wasn't
>>>>>>>>> found"},"id":16}*
>>>>>>>>> Is this why chrome isn't proceeding with anything?
>>>>>>>>> Am I supposed to implement these, or perhaps are they missing from
>>>>>>>>> my native blobs when I built my v8 libraries?
>>>>>>>>>
>>>>>>>>> My overloads of the inspector client functions like
>>>>>>>>> *runMessageLoopOnPause* aren't being called, but I assume that's
>>>>>>>>> just because I haven't gotten to any stage where commands are being
>>>>>>>>> evaluated?
>>>>>>>>>
>>>>>>>>> Below is what I get when I connect chrome, but then it just sits
>>>>>>>>> there :)
>>>>>>>>>
>>>>>>>>> Thanks for any pointers in the right direction!
>>>>>>>>>
>>>>>>>>> *Chrome tools message:
>>>>>>>>> {"id":1,"method":"Network.enable","params":{"maxPostDataSize":65536}}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Network.enable' wasn't
>>>>>>>>> found"},"id":1}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":2,"method":"Page.enable"}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Page.enable' wasn't
>>>>>>>>> found"},"id":2}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":3,"method":"Page.getResourceTree"}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":4,"method":"Profiler.enable"}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Page.getResourceTree' wasn't
>>>>>>>>> found"},"id":3}*
>>>>>>>>>
>>>>>>>>> *Channel response: {"id":4,"result":{}}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":5,"method":"Runtime.enable"}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"method":"Runtime.executionContextCreated","params":{"context":{"id":1,"origin":"","name":"PopEngineContextName"}}}*
>>>>>>>>>
>>>>>>>>> *Channel response: {"id":5,"result":{}}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":6,"method":"Debugger.enable"}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"method":"Debugger.scriptParsed","params":{"scriptId":"9","url":"","startLine":0,"startColumn":0,"endLine":1,"endColumn":0,"executionContextId":1,"hash":"2a70962568dbbde00fb323decd63c2ca137b304c","isLiveEdit":false,"sourceMapURL":"","hasSourceURL":false,"isModule":false,"length":17}}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"id":6,"result":{"debuggerId":"(6B1A58050CBFAE70E5B41C5556E5520D)"}}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message:
>>>>>>>>> {"id":7,"method":"Debugger.setPauseOnExceptions","params":{"state":"uncaught"}}*
>>>>>>>>>
>>>>>>>>> *Channel response: {"id":7,"result":{}}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message:
>>>>>>>>> {"id":8,"method":"Debugger.setAsyncCallStackDepth","params":{"maxDepth":32}}*
>>>>>>>>>
>>>>>>>>> *Channel response: {"id":8,"result":{}}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":9,"method":"DOM.enable"}*
>>>>>>>>>
>>>>>>>>> *Channel response: {"error":{"code":-32601,"message":"'DOM.enable'
>>>>>>>>> wasn't found"},"id":9}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":10,"method":"CSS.enable"}*
>>>>>>>>>
>>>>>>>>> *Channel response: {"error":{"code":-32601,"message":"'CSS.enable'
>>>>>>>>> wasn't found"},"id":10}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":11,"method":"Overlay.enable"}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Overlay.enable' wasn't
>>>>>>>>> found"},"id":11}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message:
>>>>>>>>> {"id":12,"method":"Overlay.setShowViewportSizeOnResize","params":{"show":true}}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Overlay.setShowViewportSizeOnResize'
>>>>>>>>>
>>>>>>>>> wasn't found"},"id":12}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":13,"method":"Log.enable"}*
>>>>>>>>>
>>>>>>>>> *Channel response: {"error":{"code":-32601,"message":"'Log.enable'
>>>>>>>>> wasn't found"},"id":13}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message:
>>>>>>>>> {"id":14,"method":"Log.startViolationsReport","params":{"config":[{"name":"longTask","threshold":200},{"name":"longLayout","threshold":30},{"name":"blockedEvent","threshold":100},{"name":"blockedParser","threshold":-1},{"name":"handler","threshold":150},{"name":"recurringHandler","threshold":50},{"name":"discouragedAPIUse","threshold":-1}]}}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Log.startViolationsReport' wasn't
>>>>>>>>> found"},"id":14}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":15,"method":"ServiceWorker.enable"}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'ServiceWorker.enable' wasn't
>>>>>>>>> found"},"id":15}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message: {"id":16,"method":"Inspector.enable"}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Inspector.enable' wasn't
>>>>>>>>> found"},"id":16}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message:
>>>>>>>>> {"id":17,"method":"Target.setAutoAttach","params":{"autoAttach":true,"waitForDebuggerOnStart":true}}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Target.setAutoAttach' wasn't
>>>>>>>>> found"},"id":17}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message:
>>>>>>>>> {"id":18,"method":"Target.setDiscoverTargets","params":{"discover":true}}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Target.setDiscoverTargets' wasn't
>>>>>>>>> found"},"id":18}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message:
>>>>>>>>> {"id":19,"method":"Target.setRemoteLocations","params":{"locations":[{"host":"localhost","port":9229}]}}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Target.setRemoteLocations' wasn't
>>>>>>>>> found"},"id":19}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message:
>>>>>>>>> {"id":20,"method":"Debugger.setBlackboxPatterns","params":{"patterns":["/main\\.js\\b"]}}*
>>>>>>>>>
>>>>>>>>> *Channel response: {"id":20,"result":{}}*
>>>>>>>>>
>>>>>>>>> *Chrome tools message:
>>>>>>>>> {"id":21,"method":"Page.getNavigationHistory","params":{}}*
>>>>>>>>>
>>>>>>>>> *Channel response:
>>>>>>>>> {"error":{"code":-32601,"message":"'Page.getNavigationHistory' wasn't
>>>>>>>>> found"},"id":21}*
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
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