| commit | 650f9e9a2630026d578970c6d031d7d4644f63b4 | [log] [tgz] |
|---|---|---|
| author | mtklein <mtklein@chromium.org> | Wed Apr 20 13:49:15 2016 -0700 |
| committer | Commit bot <commit-bot@chromium.org> | Wed Apr 20 13:49:15 2016 -0700 |
| tree | 05443d78fb7d26fefeddd0efa5919b3b962553fe | |
| parent | 9134686fd9ce384e9163b44942538d033b5bff11 [diff] |
SkOnce: 2 bytes -> 1 byte This uses the same logic we worked out for SkOncePtr to reduce the memory footprint of SkOnce from a done byte and lock byte to a single 3-state byte: - NotStarted: no thread has tried to run fn() yet - Active: a thread is running fn() - Done: fn() is complete Threads which see Done return immediately. Threads which see NotStarted try to move to Active, run fn(), then move to Done. Threads which see Active spin until the active thread moves to Done. This additionally fixes a too-weak memory order bug in SkOncePtr, and adds a big note to explain. BUG=skia: GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1904483003 Committed: https://skia.googlesource.com/skia/+/df02d338be8e3c1c50b48a3a9faa582703a39c07 Review URL: https://codereview.chromium.org/1904483003