tree be9b51b339a021b4a318e39a536937cc36d62c94
parent c51616d7905a32d564e80c0190bb45ab232391f5
author Austin Eng <enga@chromium.org> 1573514156 +0000
committer Commit Bot service account <commit-bot@chromium.org> 1573514156 +0000

Make perf test tracing thread-safe

The Metal driver calls command buffer completion callbacks on a
separate thread so enqueueing these trace events needs to be made
thread-safe. In the future, Dawn will probably have other threads
that also require thread-safe tracing.

In this CL, each thread records trace events into its own buffer,
and all buffers concatenated when trace events are acquired.

Bug: dawn:254, dawn:208
Change-Id: I0f1abd404568d838091066a8f27a3bf98fa764b9
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/13080
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Austin Eng <enga@chromium.org>