677333 - Assert on exit after starting a worker and immediately exiting.

Status: RESOLVED WONTFIX

(Tamarin Graveyard :: Workers, defect, P3)

Description

[Chris Peyer]

Run attached testcase.

Results in:

ReferenceError: Error #1065: Variable not_defined is not defined.
Assertion failed: "((incChannel->gc() != __null))" ("../core/WorkerGlue.cpp":317)
Trace/BPT trap

The ReferenceError is expected, but code should not assert on exit.

Comment 1

[Chris Peyer]

ReferenceError is actually not relevant to the assert.  Testcase has been updated to simplest testcase.

Comment 2

[Chris Peyer]

Attachment: testcase

Comment 3

[Dan Schaffer]

I did not reproduce the bug with the current workers code.  If I use the code:
import flash.system.*
var w:Worker = WorkerDomain.current.createWorkerFromPrimordial();
print(w);
var p:Promise = w.start();
w.exit();

after 32 workers on my macbook I reach the worker limit and on _d builds I get an assertion.   
Error: Worker limit reached
Assertion failed: "((!m_roots))" ("../MMgc/GC.cpp":420)
Trace/BPT trap: 5

On release builds after the Worker limit is reached the shell exits with exit code 0.

If I exit immediately after start I do not see any problems, the test works as expected.
import flash.system.*

var w:Worker = WorkerDomain.current.createWorkerFromPrimordial();
if (Worker.current.isPrimordial()) {
   var p:Promise = w.start();
   w.exit();
}

Comment 4

[Adam Welc]

The reason for the assertion firing was that the worker was being asked to shutdown before it was fully initialized. The assertion has been augmented with a check for shutdown request.

Comment 5

[Dan Schaffer]

in debug builds I still see the assertion:
Error: Worker limit reached
Assertion failed: "((!m_roots))" ("../MMgc/GC.cpp":420)
Trace/BPT trap: 5

I'm using the code:

var w:Worker = WorkerDomain.current.createWorkerFromPrimordial();
var promise:Promise = w.start();
var result;
try {
    result = not_defined.local::receive();
} catch (e) {
    result = e.toString();
}

Comment 6

[Adam Welc]

I am reassigning this bug to Krzysztof as it seems to have something to do with the worker's lifecycle. I believe that the assertion is triggered because after the exception is thrown by the background worker, worker cleanup is not performed correctly resulting in some GC roots still remaining at the point of GC destruction. I tried explicitly cleaning up worker's channels but it does not seem to be enough.

Comment 7

[Adam Welc]

Attachment: test to trigger the GC assertion

Comment 8

[Krzysztof Palacz]

After recent changes to the worker lifecycle the assert is not triggered any more

Comment 9

[Dan Schaffer]

windows 64 exits with exit code 1 intermittently...

Comment 10

[Tamarin Bot]

changeset: 7397:f09b425761b5
user:      Dan Schaffer <[e-mail]>
summary:   bug 677333: regression test in failing intermittently on win64

http://hg.mozilla.org/tamarin-redux/rev/f09b425761b5

Comment 11

[Tamarin Bot]

changeset: 7411:0415347eefb5
user:      Brent Baker <[e-mail]>
summary:   bug 677333: previous change (CL@1064610) to skip test had the path incorrect, this will correctly skip the testcase on all x64-win runs (p=brbaker)

http://hg.mozilla.org/tamarin-redux/rev/0415347eefb5

Comment 12

[Sylvestre Ledru [:Sylvestre]]

Tamarin is a dead project now. Mass WONTFIX.

Comment 13

[Sylvestre Ledru [:Sylvestre]]

Tamarin isn't maintained anymore. WONTFIX remaining bugs.