Add a unit test for ProcessWatcher::EnsureProcessTerminated().

Add a unit test for ProcessWatcher::EnsureProcessTerminated().

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=21259

[agl, 2009-07-21 20:10:38]

Why do we need to allow ECHILD? That's a sign of a programming error on our
part.

(I'm beginning to think that the whole child reaping thing needs a total
rewrite.)

[Lei Zhang, 2009-07-21 20:36:21]

On 2009/07/21 20:10:38, agl wrote:
> Why do we need to allow ECHILD? That's a sign of a programming error on our
> part.
> 
> (I'm beginning to think that the whole child reaping thing needs a total
> rewrite.)

In the test case I wrote, I used base::CrashAwareSleep() to see if the process
is still alive. CrashAwareSleep() and just about everything else in base that
checks on processes end up calling waitpid(). So there seems to be a race
between the CrashAwareSleep() thread and the EnsureProcessTerminated() thread.

It's not clear from the comments in the ProcessWatcher header what's the proper
usage for EnsureProcessTerminated() is. Is it that once you call
EnsureProcessTerminated() with handle foo, then you don't ever touch that handle
again? If that's the case, then the test case has used EnsureProcessTerminated()
incorrectly. OTOH, if the program that calls EnsureProcessTerminated() is
allowed to touch that handle afterwards, then EnsureProcessTerminated() should
not hit NOTREACHED() if the process goes away from underneath it.

[agl, 2009-07-21 20:41:58]

On Tue, Jul 21, 2009 at 8:36 PM, <thestig@chromium.org> wrote:
> It's not clear from the comments in the ProcessWatcher header what's the
> proper usage for EnsureProcessTerminated() is. Is it that once you call
> EnsureProcessTerminated() with handle foo, then you don't ever touch
> that handle again?

Correct. EnsureProcessTerminated is a fire-and-forget call. It takes
ownership of the PID.


http://codereview.chromium.org/155799

[Lei Zhang, 2009-07-22 00:00:51]

Ok, here's a couple simple tests for EnsureProcessTerminated(). I still need to
check the handle, but I only do it after I know the EnsureProcessTerminated
thread has finished.

[agl, 2009-07-22 02:03:55]

LGTM