TerminateExecution can lead to crashes

[Paul Harris]

Hi,

I run my JS code in a v8 Isolate,

In another thread, I cancel the running JS program at any time using V8::TerminateExecution(isolate);

As I understand it, the TerminateExecution() raises an exception in the running isolate/context, which causes the running JS script to fail and stop.

If I run a tight while loop, like so:

while (1) {

   print('hello');

}

which calls my Native_Print() C++ function, often the native function is running when things start to fail.

eg, the first time I call

String::New("whatnot");

it returns an empty handle because of the terminate exception.

When my Native_Print() detects the empty handle, it tries to throw an exception, which involves generating a new exception message, which calls String::New()

It seems that the second call to a V8 function (in this case, ToString()) triggers a fatal crash, like so:

#

# Fatal error in ../src/api.cc, line 2325

# CHECK(!(isolate)->external_caught_exception()) failed

#

I was able to work-around this problem by checking V8::IsExecutionTerminating() in my native function, BUT now I am hitting the same problem in the V8 core.

I am running a remote debugger (the Eclipse one).  I start the script, pause it using the 'debugger;' command, then connect to it with Eclipse.

THEN, I cancel the execution using V8::TerminateExecution() via the second thread method within the program.

The script is still suspended and connected to the debugger.

THEN, in Eclipse, I click Step/continue/anything, and the host program crashes with the same Fatal error.

Am I terminating the javascript incorrectly?

Any ideas?

thanks very much,

Paul

[Paul Harris]

I had thought about calling DisableAgent() before I call TerminateExecution, but DisableAgent uses CurrentIsolate() so therefore it can't be used in a different thread from the running process...