Forking problems on Cygwin

[schwernbot]

From: @schwern
Date: Monday May 06, 2013 at 22:50 GMT
Orig: Test-More/test-more#379

I tried out the forking code on Cygwin and there's a problem. It will work with a parent and child, but throw a grand child process into the mix (as t/fork/events.t does) and they will hang trying to get a lock.

We need someone who understands Cygwin and fork to have a look at this problem. I've made a special branch for it, bug/fork-cygwin. It annotates the locking and forking process to make debugging easier. Any insight would be appreciated.

This is blocking 1.5.0 alpha 7.

[schwernbot]

From: @Perlover
Date: Monday Jun 10, 2013 at 11:16 GMT
Orig: Test-More/test-more#379 (comment)

Hi,
My opinion - it may be problem of flushing to tty
Here description: http://www.khngai.com/emacs/tty.php

I noticed that some tests hangs up in Test::More::ok subroutine
It creates a builder each time which makes a flushing buffers ( https://metacpan.org/source/MSCHWERN/Test-Simple-0.98/lib/Test/Builder.pm -> _dup_stdhandles )
These are my guesses only after analyzing code of Test::More

[schwernbot]

From: @Perlover
Date: Monday Jun 10, 2013 at 11:27 GMT
Orig: Test-More/test-more#379 (comment)

And here may be useful info:

http://stackoverflow.com/questions/3250749/using-windows-python-from-cygwin

[schwernbot]

From: @Perlover
Date: Monday Jun 10, 2013 at 12:57 GMT
Orig: Test-More/test-more#379 (comment)

Sorry, i think i make mistake
I see hanged up the ok sub but sometime this is not first calling of this function so $builder already created and flushed
I think now that it's not problem of flushing
I will try to do something for finding a problem

[schwernbot]

From: @Perlover
Date: Monday Jun 10, 2013 at 13:16 GMT
Orig: Test-More/test-more#379 (comment)

And i wrote to here because i have problems with Test::SharedFork module
I use Cygwin and this module hangs up in Test::More::ok()
Test::More i have v0.98
So my problem is not related with this issue may be - yes, the test t/fork/events.t from branch bug/fork-cygwin hangs up too but i tried to make test for "v0.98" git's tag - and all tests are OK
Now i don't know why tests of Test::SharedFork hang in Test::More::ok :(

---

I researched near problem with forking under Cygwin
May be this will help few

https://rt.cpan.org/Ticket/Display.html?id=79226#txn-1222540

Best regards