ThreadRestrictions: leak the thread local variable

ThreadRestrictions: leak the thread local variable

LazyInstances are destroyed by the AtExitManager, but we have
threads that outlive the AtExitManager that could potentially
access this.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=63410

[Evan Martin, 2010-10-21 18:06:21]

I don't really know what I'm doing, so advice (including what to do about
valgrind) is welcome

[willchan no longer on Chromium, 2010-10-21 19:00:03]

LGTM

http://codereview.chromium.org/3956003/diff/1/2
File base/thread_restrictions.cc (right):

http://codereview.chromium.org/3956003/diff/1/2#newcode16
base/thread_restrictions.cc:16: struct LeakLazyInstanceTraits {
Sounds like you should put this in base/lazy_instance.h, template it, name it
LeakyLazyInstanceTraits (a la LeakySingletonTraits), and use it here.  And then
add a valgrind suppression for the traits if you see a leak.  I don't think
it'll leak, since the global pointer is still alive at process shutdown.

[Evan Martin, 2010-10-21 19:24:50]

I did some refactoring to sidestep the AtExitManager requirement.

It's a little silly that my other change required me to add an AtExitManager
just so I could have it do nothing because the object leaked.

Also, more tests!

[willchan no longer on Chromium, 2010-10-21 20:26:50]

LGTM, just had some nits which you can address if you want.

http://codereview.chromium.org/3956003/diff/4002/5003
File base/lazy_instance_unittest.cc (right):

http://codereview.chromium.org/3956003/diff/4002/5003#newcode116
base/lazy_instance_unittest.cc:116: }  // anonymous namespace
I actually don't understand why this whole file isn't in an anonymous namespace,
not that it matters too much.

http://codereview.chromium.org/3956003/diff/4002/5004
File base/thread_restrictions.cc (right):

http://codereview.chromium.org/3956003/diff/4002/5004#newcode16
base/thread_restrictions.cc:16: base::LazyInstance<base::ThreadLocalBoolean,
Why don't you just move this anonymous namespace within the base namespace, then
you can get rid of all the base:: which should make this a bit prettier.