Object addresses are not exposed either. You would have to build such instrumentation into V8's internals.
On Tue, Aug 29, 2017 at 12:32 PM, Hanyun Tao <taohany...@gmail.com> wrote: > Thank you Jakob! > > I can understand why it is hidden from external access. But would it be > possible for the user to get access to the instruction addresses of the > compiled code? > > We are studying the cache performance of JavaScript execution and we want > to know if it is possible to prefetch the instructions in the next event > handlers into the cache before it is executed based on the information > collected in the v8 engine. > > Best regards, > > On Tuesday, August 29, 2017 at 12:29:33 PM UTC-4, Jakob Kummerow wrote: >> >> No, compiled code is an internal implementation detail and as such is >> hidden from JavaScript and other external access. If there ever is a way >> for users to get to compiled code, then it's a (probably severe security) >> bug and we would like to hear about it! :-) >> >> On Mon, Aug 28, 2017 at 9:03 PM, Hanyun Tao <taoha...@gmail.com> wrote: >> >>> Hi Jakob, >>> >>> Thanks again! >>> >>> According to what you have said, v8 compiles the event handlers are >>> installed(compiled?) before it is executed. If it is true, then I believe >>> v8 will store the compiled code somewhere in the system. >>> Would it be possible for the user to get access to the compiled code? >>> >>> Best regards, >>> >>> On Monday, August 28, 2017 at 1:29:29 PM UTC-4, Jakob Kummerow wrote: >>>> >>>> The main API entry point for compilation is >>>> v8::ScriptCompiler::Compile(). >>>> >>>> I don't think event handling itself triggers compilation; but I'm not >>>> an expert on that part of the system. AFAIK event handlers are installed >>>> during page load (or more precisely: DOM element creation); they may still >>>> be compiled on-demand on first use but that's not controlled via the V8 >>>> API. >>>> >>>> On Mon, Aug 28, 2017 at 9:06 AM, Hanyun Tao <taoha...@gmail.com> wrote: >>>> >>>>> Hi Jakob, >>>>> >>>>> Thank you for replying! >>>>> >>>>> To be more specific, I'm looking for the point (function) that >>>>> initiate the compilation process. >>>>> >>>>> In my understanding, when handling an "event", the renderer process in >>>>> the browser will figure out the JavaScript related to the event, and ask >>>>> the V8 engine to execute it by calling some api function. >>>>> >>>>> Inside those api function, there should be a point where V8 initiate >>>>> the compilation process, and that is what I'm looking for. >>>>> >>>>> Best regards, >>>>> >>>>> >>>>> >>>>> On Sunday, August 27, 2017 at 7:58:37 PM UTC-4, Jakob Kummerow wrote: >>>>>> >>>>>> Hi Hanyun, >>>>>> >>>>>> V8 is fairly complicated, and pretty much all it does is to compile >>>>>> and execute JavaScript. Do you have a more specific question? >>>>>> >>>>>> If you just want a starting point for reading code: maybe >>>>>> "CompileTopLevel" in src/compiler.cc would be a reasonable choice. >>>>>> >>>>>> On Sun, Aug 27, 2017 at 1:06 PM, Hanyun Tao <taoha...@gmail.com> >>>>>> wrote: >>>>>> >>>>>>> Hi all, >>>>>>> >>>>>>> I'm trying to understand how V8 engine compiles and execute >>>>>>> JavaScript events. I used GDB to track the function call path when >>>>>>> handling >>>>>>> an event and it look like this. >>>>>>> >>>>>>> >>>>>>> >>>>>>> #0 v8::internal::Logger::TimerEvent (this=<optimized out>, >>>>>>> se=<optimized out>, name=<optimized out>) at ../../v8/src/log.cc:866 >>>>>>> >>>>>>> >>>>>>> #1 0x00007f0cfcb23b39 in TimerEventScope (this=<optimized out>, >>>>>>> isolate=<optimized out>) at ../../v8/src/log.h:354 >>>>>>> >>>>>>> >>>>>>> #2 v8::Function::Call (this=<optimized out>, context=..., >>>>>>> recv=..., argc=<optimized out>, argv=<optimized out>) at >>>>>>> ../../v8/src/api.cc:5094 >>>>>>> >>>>>>> >>>>>>> #3 0x00007f0cf18daa0b in blink::V8ScriptRunner::callFunction >>>>>>> (function=..., context=0x201b099829d0, receiver=..., argc=1, >>>>>>> args=0x7fffe9e1cea0, >>>>>>> isolate=0x2def318c6020) at ../../third_party/WebKit/Source/ >>>>>>> bindings/core/v8/V8ScriptRunner.cpp:658 >>>>>>> >>>>>>> >>>>>>> #4 0x00007f0cf18a1c26 in blink::V8EventListener::callListenerFunction >>>>>>> (this=0xe9381bfbea0, scriptState=0x37fa7244c710, jsEvent=..., event= >>>>>>> 0x36f97e2ba60) at ../../third_party/WebKit/Source/bindings/core/ >>>>>>> v8/V8EventListener.cpp:112 >>>>>>> >>>>>>> >>>>>>> >>>>>>> #5 0x00007f0cf1887b16 in >>>>>>> blink::V8AbstractEventListener::invokeEventHandler >>>>>>> (this=0xe9381bfbea0, scriptState=0x37fa7244c710, >>>>>>> event=0x36f97e2ba60, jsEvent=...) at ../../third_party/WebKit/ >>>>>>> Source/bindings/core/v8/V8AbstractEventListener.cpp:142 >>>>>>> >>>>>>> >>>>>>> #6 0x00007f0cf188787f in blink::V8AbstractEventListener::handleEvent >>>>>>> (this=0xe9381bfbea0, scriptState=0x37fa7244c710, event=0x36f97e2ba60) >>>>>>> at ../../third_party/WebKit/Source/bindings/core/v8/V8AbstractE >>>>>>> ventListener.cpp:101 >>>>>>> >>>>>>> >>>>>>> #7 0x00007f0cf1887689 in blink::V8AbstractEventListener::handleEvent >>>>>>> (this=0xe9381bfbea0, executionContext=0x201b099829d0, >>>>>>> event=0x36f97e2ba60) >>>>>>> at ../../third_party/WebKit/Source/bindings/core/v8/V8AbstractE >>>>>>> ventListener.cpp:89 >>>>>>> >>>>>>> >>>>>>> #8 0x00007f0cf211c596 in blink::EventTarget::fireEventListeners >>>>>>> (this=0x201b09982858, event=0x36f97e2ba60, d=0xe9381be9500, entry=...) >>>>>>> at ../../third_party/WebKit/Source/core/events/EventTarget.cpp: >>>>>>> 700 >>>>>>> >>>>>>> >>>>>>> #9 0x00007f0cf211b7cb in blink::EventTarget::fireEventListeners >>>>>>> (this=0x201b09982858, event=0x36f97e2ba60) >>>>>>> at ../../third_party/WebKit/Source/core/events/EventTarget.cpp: >>>>>>> 56 >>>>>>> >>>>>>> >>>>>>> I tried to read the source code to find out where does V8 compiles >>>>>>> the JavaScript, but unfortunately, I could not find it. >>>>>>> >>>>>>> It would be really helpful if someone can explain the process to me, >>>>>>> or let me know which files(functions) I should read. >>>>>>> >>>>>>> Best regards, >>>>>>> >>>>>>> -- >>>>>>> -- >>>>>>> v8-users mailing list >>>>>>> v8-u...@googlegroups.com >>>>>>> http://groups.google.com/group/v8-users >>>>>>> --- >>>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "v8-users" group. >>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>> send an email to v8-users+u...@googlegroups.com. >>>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>>> >>>>>> >>>>>> -- >>>>> -- >>>>> v8-users mailing list >>>>> v8-u...@googlegroups.com >>>>> http://groups.google.com/group/v8-users >>>>> --- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "v8-users" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to v8-users+u...@googlegroups.com. >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> >>>> -- >>> -- >>> v8-users mailing list >>> v8-u...@googlegroups.com >>> http://groups.google.com/group/v8-users >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "v8-users" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to v8-users+u...@googlegroups.com. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- > -- > v8-users mailing list > v8-users@googlegroups.com > http://groups.google.com/group/v8-users > --- > You received this message because you are subscribed to the Google Groups > "v8-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to v8-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. 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