base: Add discardable memory test that check behavior when creating enough instances that could use…

base: Add discardable memory test that check behavior when creating enough instances that could use up a 32-bit address space.

BUG=422953
TEST=base_unittests --gtest_filter=DiscardableMemoryTests/DiscardableMemoryTest.AddressSpace/*

Committed: https://crrev.com/b2dd79c61e4fc3ffe8fc6226576f2a5ddd5ec61b
Cr-Commit-Position: refs/heads/master@{#300028}

[reveman, 2014-10-15 20:47:01]

reveman@chromium.org changed reviewers:
+ avi@chromium.org

[reveman, 2014-10-15 20:47:02]

It's a bit nasty to churn through 4GB of discardable memory to test this but I
not sure how else to make sure this works correctly.

After landing this, I'll upload a patch that removes the 512MB per-process limit
for DiscardableMemoryMach and we'll see how the bots feel about that.

[Avi (use Gerrit), 2014-10-15 21:11:27]

I think it's an interesting test, and look forward to seeing how things behave.

LGTM with nits.

https://codereview.chromium.org/655003003/diff/1/base/memory/discardable_memo...
File base/memory/discardable_memory_unittest.cc (right):

https://codereview.chromium.org/655003003/diff/1/base/memory/discardable_memo...
base/memory/discardable_memory_unittest.cc:110: const size_t kNumberOfInstances
= 1024 + 1;  // >4GiB total.
Why "4MB" on the line above, and "4GiB" here? Either use "MiB"/"GiB" or
"MB"/"GB".

https://codereview.chromium.org/655003003/diff/1/base/memory/discardable_memo...
base/memory/discardable_memory_unittest.cc:117:
ASSERT_NE(static_cast<void*>(NULL), addr);
nullptr, plus you shouldn't need a cast with it.

[reveman, 2014-10-16 20:50:34]

reveman@chromium.org changed reviewers:
+ danakj@chromium.org

[reveman, 2014-10-16 20:50:34]

+danakj

https://codereview.chromium.org/655003003/diff/1/base/memory/discardable_memo...
File base/memory/discardable_memory_unittest.cc (right):

https://codereview.chromium.org/655003003/diff/1/base/memory/discardable_memo...
base/memory/discardable_memory_unittest.cc:110: const size_t kNumberOfInstances
= 1024 + 1;  // >4GiB total.
On 2014/10/15 21:11:27, Avi wrote:
> Why "4MB" on the line above, and "4GiB" here? Either use "MiB"/"GiB" or
> "MB"/"GB".

Done.

https://codereview.chromium.org/655003003/diff/1/base/memory/discardable_memo...
base/memory/discardable_memory_unittest.cc:117:
ASSERT_NE(static_cast<void*>(NULL), addr);
On 2014/10/15 21:11:27, Avi wrote:
> nullptr, plus you shouldn't need a cast with it.

Done.

[danakj, 2014-10-16 20:52:08]

LGTM

[reveman, 2014-10-16 22:32:01]

The CQ bit was checked by reveman@chromium.org

[commit-bot: I haz the power, 2014-10-16 22:32:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/655003003/20001

[commit-bot: I haz the power, 2014-10-17 00:38:36]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-10-17 00:40:24]

Patchset 2 (id:??) landed as
https://crrev.com/b2dd79c61e4fc3ffe8fc6226576f2a5ddd5ec61b
Cr-Commit-Position: refs/heads/master@{#300028}