TSAN: use somewhat pithier SK_ANNOTATE_UNPROTECTED_READ.

TSAN: use somewhat pithier SK_ANNOTATE_UNPROTECTED_READ.

This is a little bit better practice to be i than the existing SK_ANNOTATE_BENIGN_RACE, as UNPROTECTED_READ will only ignore reads, not writes.

Tag SkRefCnt::unique() as a safe unprotected read like SkOnce's double-checked locking.

BUG=skia:

Committed: http://code.google.com/p/skia/source/detail?r=13309

[reed1, 2014-02-04 14:57:55]

lgtm w/ dox request

https://codereview.chromium.org/144953005/diff/1/include/core/SkDynamicAnnota...
File include/core/SkDynamicAnnotations.h (right):

https://codereview.chromium.org/144953005/diff/1/include/core/SkDynamicAnnota...
include/core/SkDynamicAnnotations.h:12: // we check the same define.  Add other
macros you use here.
I have no idea what this stuff does. Can we also nab some dox from the other
file?

[bungeman-skia, 2014-02-04 15:20:53]

https://codereview.chromium.org/144953005/diff/1/include/core/SkRefCnt.h
File include/core/SkRefCnt.h (right):

https://codereview.chromium.org/144953005/diff/1/include/core/SkRefCnt.h#newc...
include/core/SkRefCnt.h:52: // We believe we're reading fRefCnt in a safe way
here, so we stifle the TSAN warning.
Which TSAN warning?

https://codereview.chromium.org/144953005/diff/1/include/core/SkRefCnt.h#newc...
include/core/SkRefCnt.h:58: //TODO: issue the barrier.
Note that until this is fixed we are still broken on ARM.

[mtklein, 2014-02-04 17:11:44]

ptal

[bungeman-skia, 2014-02-04 17:21:39]

lgtm

https://codereview.chromium.org/144953005/diff/110001/include/core/SkRefCnt.h
File include/core/SkRefCnt.h (right):

https://codereview.chromium.org/144953005/diff/110001/include/core/SkRefCnt.h...
include/core/SkRefCnt.h:53: // an unproctected read.  Generally, don't read
fRefCnt, and don't stifle this warning.
nit: two spaces after the period.

[mtklein, 2014-02-04 17:43:36]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2014-02-04 17:43:44]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/mtklein@google.com/144953005/110001

[commit-bot: I haz the power, 2014-02-04 18:00:26]

Change committed as 13309