Hi Partric, I am not an expert with stack traces, so I don't know if there is a better method, but I think your approach is flawed. v8::StackTrace:: CurrentStackTrace() can only work when code execution made a valid transition from JavaScript to C++, in other words, when there is an Exit frame on the stack. With a signal you transition from JavaScript code directly to the signal handling code, without an Exit frame. However, without the Exit frame V8 cannot find the beginning of the JavaScript stack, and can therefore not generate a stack trace.
You could try to request an interrupt with https://source.chromium.org/chromium/chromium/src/+/refs/heads/main:v8/include/v8-isolate.h;l=1115;drc=8d3b19d9432fa06963a1efbd8b85d5d310c3a05a, and then create the stack trace from within the callback. Maybe that works better. Cheers, Andreas On Mon, Jun 19, 2023 at 10:27 AM Patric Lemo <jiangzhan1...@gmail.com> wrote: > > Hello all: > > I am working on a project where I need to print the JS stack trace when a > JS process becomes unresponsive. My approach involves setting a periodic > alarm using the `alarm()` function, and in the timeout function, I attempt > to print the JS stack trace. > > I'm experiencing an issue where `v8::StackTrace::CurrentStackTrace` > returns a frame count of 0 when invoked within the signal handler. I > understand there could be some complications using the V8 API within a > signal handler due to its asynchronous signal-unsafe nature. > > Here is a simplified version of my current approach: > > // Assume isolate and context are correctly setup > void signalHandler(int signal) { > // Try to get stack trace and print > v8::HandleScope handleScope(isolate); > v8::Local<v8::StackTrace> stackTrace = > v8::StackTrace::CurrentStackTrace( > isolate, > 10, > v8::StackTrace::kDetailed > ); > int frameCount = stackTrace->GetFrameCount(); > printf("Frame Count: %d\n", frameCount); > // Iterate and print each frame here... > } > > int main() { > // Setup V8, isolate and context here... > signal(SIGALRM, signalHandler); > alarm(10); // Set alarm > // Rest of the program... > } > > > Is my approach flawed? Is there a safer or more effective method to > achieve what I'm trying to do? > > Thanks > > -- > -- > v8-dev mailing list > v8-dev@googlegroups.com > http://groups.google.com/group/v8-dev > --- > You received this message because you are subscribed to the Google Groups > "v8-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to v8-dev+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/v8-dev/0e06f5e3-b37b-4bcc-a293-65d152b0938fn%40googlegroups.com > <https://groups.google.com/d/msgid/v8-dev/0e06f5e3-b37b-4bcc-a293-65d152b0938fn%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- Andreas Haas Software Engineer ah...@google.com Google Germany GmbH Erika-Mann-Straße 33 80636 München Geschäftsführer: Paul Manicle, Liana Sebastian Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg Diese E-Mail ist vertraulich. Falls sie diese fälschlicherweise erhalten haben sollten, leiten Sie diese bitte nicht an jemand anderes weiter, löschen Sie alle Kopien und Anhänge davon und lassen Sie mich bitte wissen, dass die E-Mail an die falsche Person gesendet wurde. This e-mail is confidential. If you received this communication by mistake, please don't forward it to anyone else, please erase all copies and attachments, and please let me know that it has gone to the wrong person. -- -- v8-dev mailing list v8-dev@googlegroups.com http://groups.google.com/group/v8-dev --- You received this message because you are subscribed to the Google Groups "v8-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-dev+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/v8-dev/CAELSTveAc5EhxCBbKvixwHmTy1G9tfwnKPDRW%3D45S%3DPA8qPGYA%40mail.gmail.com.
