Add noBarrierStore to WTF and use it for spinlocks

Add noBarrierStore to WTF and use it for spinlocks

This will eliminate TSAN warnings on some benign races,
and help ensure that they remain benign.

BUG=556469
Committed: https://crrev.com/12678ed8e9f993cbe343ddd3d08ee174244b6552
Cr-Commit-Position: refs/heads/master@{#360481}

[jschuh, 2015-11-18 21:45:59]

Description was changed from

==========
Add noBarrierStore to WTf and use it for spinlocks

This will eliminate TSAN warnings on some benign races,
and ensure that they remain benign.

BUG=556469
==========

to

==========
Add noBarrierStore to WTF and use it for spinlocks

This will eliminate TSAN warnings on some benign races,
and ensure that they remain benign.

BUG=556469
==========

[jschuh, 2015-11-18 21:46:08]

Description was changed from

==========
Add noBarrierStore to WTF and use it for spinlocks

This will eliminate TSAN warnings on some benign races,
and ensure that they remain benign.

BUG=556469
==========

to

==========
Add noBarrierStore to WTF and use it for spinlocks

This will eliminate TSAN warnings on some benign races,
and help ensure that they remain benign.

BUG=556469
==========

[jschuh, 2015-11-18 21:50:21]

jschuh@chromium.org changed reviewers:
+ haraken@chromium.org

[jschuh, 2015-11-18 21:50:21]

ptal

[haraken, 2015-11-18 23:38:38]

LGTM

[haraken, 2015-11-18 23:38:47]

The CQ bit was checked by haraken@chromium.org

[commit-bot: I haz the power, 2015-11-18 23:39:24]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1461743002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1461743002/20001

[commit-bot: I haz the power, 2015-11-19 02:08:20]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-11-19 02:09:08]

Patchset 2 (id:??) landed as
https://crrev.com/12678ed8e9f993cbe343ddd3d08ee174244b6552
Cr-Commit-Position: refs/heads/master@{#360481}

[Alexander Potapenko, 2015-11-19 09:10:14]

On 2015/11/19 02:09:08, commit-bot: I haz the power wrote:
> Patchset 2 (id:??) landed as
> https://crrev.com/12678ed8e9f993cbe343ddd3d08ee174244b6552
> Cr-Commit-Position: refs/heads/master@{#360481}

Did this help?
I'm pretty sure it didn't, because you forgot to add the TSan version of
noBarrierLoad.
Unfortunately we must have those until all atomic operations in WTF are
converted to proper C++ atomics.

[Alexander Potapenko, 2015-11-19 11:23:01]

This CL had also introduced a compilation failure on the TSan bot:

FAILED: /mnt/data/b/build/goma/gomacc
../../third_party/llvm-build/Release+Asserts/bin/clang++ -MMD -MF
obj/third_party/WebKit/Source/wtf/wtf.SpinLock.o.d -DV8_DEPRECATION_WARNINGS
-DCLD_VERSION=2 -D_FILE_OFFSET_BITS=64 -DNO_TCMALLOC -DDISABLE_NACL
-DCHROMIUM_BUILD -DCR_CLANG_REVISION=247874-1 -DUI_COMPOSITOR_IMAGE_TRANSPORT
-DUSE_AURA=1 -DUSE_ASH=1 -DUSE_PANGO=1 -DUSE_CAIRO=1
-DUSE_DEFAULT_RENDER_THEME=1 -DUSE_LIBJPEG_TURBO=1 -DUSE_X11=1
-DUSE_CLIPBOARD_AURAX11=1 -DENABLE_ONE_CLICK_SIGNIN -DENABLE_PRE_SYNC_BACKUP
-DENABLE_WEBRTC=1 -DENABLE_MEDIA_ROUTER=1 -DENABLE_PEPPER_CDMS
-DENABLE_CONFIGURATION_POLICY -DENABLE_NOTIFICATIONS -DENABLE_HIDPI=1
-DENABLE_TOPCHROME_MD=1 -DUSE_UDEV -DDONT_EMBED_BUILD_METADATA
-DFIELDTRIAL_TESTING_ENABLED -DENABLE_TASK_MANAGER=1 -DENABLE_EXTENSIONS=1
-DENABLE_PDF=1 -DENABLE_PLUGINS=1 -DENABLE_SESSION_SERVICE=1 -DENABLE_THEMES=1
-DENABLE_AUTOFILL_DIALOG=1 -DENABLE_BACKGROUND=1 -DENABLE_GOOGLE_NOW=1
-DENABLE_PRINTING=1 -DENABLE_BASIC_PRINTING=1 -DENABLE_PRINT_PREVIEW=1
-DENABLE_SPELLCHECK=1 -DENABLE_CAPTIVE_PORTAL_DETECTION=1 -DENABLE_APP_LIST=1
-DENABLE_SETTINGS_APP=1 -DENABLE_SUPERVISED_USERS=1 -DENABLE_MDNS=1
-DENABLE_SERVICE_DISCOVERY=1 -DV8_USE_EXTERNAL_STARTUP_DATA -DFULL_SAFE_BROWSING
-DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DWTF_IMPLEMENTATION=1
-DENABLE_LAYOUT_UNIT_IN_INLINE_BOXES=0
-DWTF_USE_CONCATENATED_IMPULSE_RESPONSES=1 -DENABLE_INPUT_MULTIPLE_FIELDS_UI=1
-DENABLE_WEB_AUDIO=1 -DWTF_USE_WEBAUDIO_FFMPEG=1
-DWTF_USE_DEFAULT_RENDER_THEME=1 -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0
-DU_STATIC_IMPLEMENTATION -DUSE_LIBPCI=1 -DUSE_OPENSSL=1 -DUSE_GLIB=1
-DUSE_NSS_CERTS=1 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS
-DMEMORY_TOOL_REPLACES_ALLOCATOR -DMEMORY_SANITIZER_INITIAL_SIZE
-DTHREAD_SANITIZER -DDYNAMIC_ANNOTATIONS_EXTERNAL_IMPL=1
-DWTF_USE_DYNAMIC_ANNOTATIONS_NOIMPL=1 -DNDEBUG -DDYNAMIC_ANNOTATIONS_ENABLED=1
-DWTF_USE_DYNAMIC_ANNOTATIONS=1 -Igen -I../../third_party/WebKit/Source
-I../../third_party/WebKit -I../../third_party/icu/source/i18n
-I../../third_party/icu/source/common
'-I../../buildtools/third_party/libc++/trunk/include'
'-I../../buildtools/third_party/libc++abi/trunk/include' -fstack-protector
--param=ssp-buffer-size=4 -Werror -pthread -fno-strict-aliasing -Wall
-Wno-unused-parameter -Wno-missing-field-initializers -fvisibility=hidden -pipe
-fPIC -Wno-reserved-user-defined-literal -Xclang -load -Xclang
/mnt/data/b/build/slave/Chromium_Linux_TSan_Builder/build/src/third_party/llvm-build/Release+Asserts/lib/libFindBadConstructs.so
-Xclang -add-plugin -Xclang find-bad-constructs -Xclang
-plugin-arg-find-bad-constructs -Xclang check-templates -fcolor-diagnostics
-B/mnt/data/b/build/slave/Chromium_Linux_TSan_Builder/build/src/third_party/binutils/Linux_x64/Release/bin
-Wheader-hygiene -Wno-char-subscripts -Wno-unneeded-internal-declaration
-Wno-covered-switch-default -Wstring-conversion -Wno-c++11-narrowing
-Wno-deprecated-register -Wno-inconsistent-missing-override
-Wno-shift-negative-value -Wno-bitfield-width -Wglobal-constructors -Xclang
-load -Xclang
/mnt/data/b/build/slave/Chromium_Linux_TSan_Builder/build/src/third_party/llvm-build/Release+Asserts/lib/libBlinkGCPlugin.so
-Xclang -add-plugin -Xclang blink-gc-plugin -m64 -march=x86-64
-fno-omit-frame-pointer -gline-tables-only -fsanitize=thread
-fsanitize-blacklist=../../tools/memory/tsan_v2/ignores.txt -O2 -fno-ident
-fdata-sections -ffunction-sections -funwind-tables -fno-exceptions -fno-rtti
-fno-threadsafe-statics -fvisibility-inlines-hidden -Wsign-compare -std=gnu++11
-nostdinc++  -c ../../third_party/WebKit/Source/wtf/SpinLock.cpp -o
obj/third_party/WebKit/Source/wtf/wtf.SpinLock.o
../../third_party/WebKit/Source/wtf/SpinLock.cpp:65:22: error: no matching
function for call to 'noBarrierLoad'
                if (!noBarrierLoad(lock) &&
LIKELY(!atomicTestAndSetToOne(lock)))
                     ^~~~~~~~~~~~~
../../third_party/WebKit/Source/wtf/Atomics.h:198:21: note: candidate function
not viable: no known conversion from 'volatile int *' to 'const volatile float
*' for 1st argument
ALWAYS_INLINE float noBarrierLoad(volatile const float* ptr)
                    ^
../../third_party/WebKit/Source/wtf/SpinLock.cpp:71:18: error: no matching
function for call to 'noBarrierLoad'
        } while (noBarrierLoad(lock));
                 ^~~~~~~~~~~~~
../../third_party/WebKit/Source/wtf/Atomics.h:198:21: note: candidate function
not viable: no known conversion from 'volatile int *' to 'const volatile float
*' for 1st argument
ALWAYS_INLINE float noBarrierLoad(volatile const float* ptr)
                    ^

Reverting.

[Alexander Potapenko, 2015-11-19 11:24:02]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/1457843003/ by glider@chromium.org.

The reason for reverting is: This CL broke compilation on the TSan bot.
Please consider using the linux_clang_tsan trybot or building locally with
GYP_DEFINES=tsan=1 next time..