POSIX: allow WaitableEvents to be deleted while watching them.

POSIX: allow WaitableEvents to be deleted while watching them.

On Windows, one can close a HANDLE which is currently being waited on. The MSDN
documentation says that the resulting behaviour is 'undefined', but it doesn't
crash. Currently, on POSIX, one couldn't use WaitableEventWatcher to watch an
event which gets deleted. This mismatch has bitten us several times now.

This patch allows WaitableEvents to be deleted while a WaitableEventWatcher is
still watching them. It applies only to watchers, the usual Wait() and
WaitMany() calls still require that all their target be valid until the end of
the call.

http://crbug.com/8809

[jeremy, 2009-03-24 23:11:57]

LGTM!

Could you reference http://crbug.com/8809 from the CL description?

http://codereview.chromium.org/53026/diff/1012/7
File base/waitable_event.h (right):

http://codereview.chromium.org/53026/diff/1012/7#newcode141
Line 141: // WaitableEventWatchers may then take a referenence and thus match
the
reference

http://codereview.chromium.org/53026/diff/1012/12
File build/SConscript.main (right):

http://codereview.chromium.org/53026/diff/1012/12#newcode485
Line 485: CCFLAGS = ['-m32', '-pthread', '-march=pentium3', '-fno-exceptions',
Is this part of the same change?

[agl, 2009-03-24 23:17:04]

http://codereview.chromium.org/53026/diff/1012/7
File base/waitable_event.h (right):

http://codereview.chromium.org/53026/diff/1012/7#newcode141
Line 141: // WaitableEventWatchers may then take a referenence and thus match
the
On 2009/03/24 23:11:57, jeremy wrote:
> reference

Done.

http://codereview.chromium.org/53026/diff/1012/12
File build/SConscript.main (right):

http://codereview.chromium.org/53026/diff/1012/12#newcode485
Line 485: CCFLAGS = ['-m32', '-pthread', '-march=pentium3', '-fno-exceptions',
On 2009/03/24 23:11:57, jeremy wrote:
> Is this part of the same change?

Opps, thanks for catching that.

[jam, 2009-03-24 23:21:04]

lgtm

I'm curious why you didn't just make WaitableEvent itself RefCounted?