When run on cooperative threads, we need to notify the threading system
when we're going to block (in any way, sleep or spin) so that it doesn't
wake that thread up expecting it to make forward progress.
This should cover SkOnce, SkSpinlock, SkSemaphore, and by extension
SkMutex. Not sure if there are others to hit, but really the only way
to find out is by deadlocked stack traces. This CL (obviously?) does
nothing to mark synchronization primitives used by Skia's dependencies,
and in general I don't think we can do anything about them.
See cr/275261423 for more background and discussion. It's not clear to
me that marking these symbols as weak is necessary, so I figured I'd
just try not doing that and seeing what breaks. I can always follow up
with weak symbols if proven necessary.
Bug: skia:9577
Change-Id: I2c03fe92c58ad506dd8a68bdc90a09b28f965149
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/251221
Commit-Queue: Mike Klein <mtklein@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
Reviewed-by: Herb Derby <herb@google.com>
Also trim includes in SkSLCompiler while I'm there
Change-Id: I87b27199b84e5e856e0a914f44368313a6f226e4
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/242085
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Current strategy: everything from the top
Things to look at first are the manual changes:
- added tools/rewrite_includes.py
- removed -Idirectives from BUILD.gn
- various compile.sh simplifications
- tweak tools/embed_resources.py
- update gn/find_headers.py to write paths from the top
- update gn/gn_to_bp.py SkUserConfig.h layout
so that #include "include/config/SkUserConfig.h" always
gets the header we want.
No-Presubmit: true
Change-Id: I73a4b181654e0e38d229bc456c0d0854bae3363e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/209706
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Hal Canary <halcanary@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
BUG=skia:
Change-Id: Id29c47cb4bec6a6d70d6514d18fa4ab9bd31b1e2
Reviewed-on: https://skia-review.googlesource.com/6200
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reason for revert:
bust the roll
Original issue's description:
> 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/+/df02d338be8e3c1c50b48a3a9faa582703a39c07TBR=herb@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:
Review URL: https://codereview.chromium.org/1898413004
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
Review URL: https://codereview.chromium.org/1904483003
The API and implementation are very much simplified.
You may not want to bother reading the diff.
As is our trend, SkOnce now uses <atomic> directly.
Member initialization means we don't need SK_DECLARE_STATIC_ONCE.
SkSpinlock already works this same way.
All uses of the old API taking an external bool* and Lock* were pessimal,
so I have not carried this sort of API forward. It's simpler, faster,
and more space-efficient to always use this single SkOnce class interface.
SkOnce weighs 2 bytes: a done bool and an SkSpinlock, also a bool internally.
This API refactoring opens up the opportunity to fuse those into a single
three-state byte if we'd like.
No public API changes.
TBR=reed@google.com
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1894893002
Review URL: https://codereview.chromium.org/1894893002
This enables removing the more complicated atomic shims from SkAtomics.h.
TBR=reed
This doesn't actually change any API.
CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-TSAN-Trybot,Test-Ubuntu-GCC-Golo-GPU-GT610-x86_64-Release-TSAN-Trybot
Review URL: https://codereview.chromium.org/1867863002
- Use std::atomic directly.
- No more need for SkPODSpinlock or SK_DECLARE_STATIC_SPINLOCK.
Now simple code like this works as you'd hope:
static SkSpinlock gLock;
That is, it starts unlocked and there's no static initializer.
std::atomic_flag would make this terser and standard-guaranteed,
but ATOMIC_FLAG_INIT caused not-yet-implemented errors on MSVC 2013.
The generated code for this approach is identical.
It appears the implicit constructor is constexpr when all the member
initializers are. I'm hoping this way of producing constexpr constructors
without typing "constexpr" gives us a way to eliminate more SkFoo / SkBaseFoo
distinctions and SK_DECLARE_STATIC_FOO. This was certainly the easiest.
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1734383002
Review URL: https://codereview.chromium.org/1734383002
