diff options
| author |  Abseil Team <absl-team@google.com> | 2019-05-15 12:21:46 -0700 |
|---|---|---|
| committer |  Andy Soffer <asoffer@google.com> | 2019-05-15 15:37:33 -0400 |
| commit | fa00c321073c7ea40a4fc3dfc8a06309eae3d025 (patch) | |
| tree | 6bd77267f450a1eedf65a5fb3858ca1c8faa44e7 /absl/base | |
| parent | 436ba6c4a0ea3a06eca6e055f9c8d296bf3bae12 (diff) | |
Export of internal Abseil changes.
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6258612abc571fa7f51f34046b410c73486505fe by Derek Mauro <dmauro@google.com>:
Rollback checking the return value of pthread functions in thread_identity.cc.
PiperOrigin-RevId: 248381230
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fda6acddab04fc53eeb84ec253de4a9655bf9a36 by CJ Johnson <johnsoncj@google.com>:
Removes too-restrictive benchmark abstraction in inlined_vector_benchmark
PiperOrigin-RevId: 248366325
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68674991e63c919de8a3eebced5adec6466ec8fe by Abseil Team <absl-team@google.com>:
Check for pthread_setmask() failure.
Log a fatal error message if pthread_setmask() fails.
PiperOrigin-RevId: 248347115
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45389e44c0d1badafb6b560cae3df99fc8bd16ac by Derek Mauro <dmauro@google.com>:
Fix a -Wredundant-move warning in GCC 9.
PiperOrigin-RevId: 248338682
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12cfbacf599084a8ac6bf4395026cbf193c85a26 by Derek Mauro <dmauro@google.com>:
Check the return value of pthread functions in thread_identity.cc.
PiperOrigin-RevId: 248327118
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2bc69998e68cfee96e812ce800e83cce7a715091 by Benjamin Barenblat <bbaren@google.com>:
Encourage judicious use of ABSL_PREDICT_{TRUE,FALSE}
Recommend that users use branch prediction annotations only on hot,
consistently mispredicted branches.
PiperOrigin-RevId: 248222450
GitOrigin-RevId: 6258612abc571fa7f51f34046b410c73486505fe
Change-Id: I09d409f9a3941ee926b8476b5473f9c4899cc3ff
Diffstat (limited to 'absl/base')
| -rw-r--r-- | absl/base/internal/low_level_alloc.cc | 5 | ||||
| -rw-r--r-- | absl/base/optimization.h | 6 |
2 files changed, 10 insertions, 1 deletions
diff --git a/absl/base/internal/low_level_alloc.cc b/absl/base/internal/low_level_alloc.cc index 5a8199e6..36e4f1ba 100644 --- a/absl/base/internal/low_level_alloc.cc +++ b/absl/base/internal/low_level_alloc.cc @@ -294,7 +294,10 @@ class SCOPED_LOCKABLE ArenaLock { arena_->mu.Unlock(); #ifndef ABSL_LOW_LEVEL_ALLOC_ASYNC_SIGNAL_SAFE_MISSING if (mask_valid_) { - pthread_sigmask(SIG_SETMASK, &mask_, nullptr); + const int err = pthread_sigmask(SIG_SETMASK, &mask_, nullptr); + if (err != 0) { + ABSL_RAW_LOG(FATAL, "pthread_sigmask failed: %d", err); + } } #endif left_ = true; diff --git a/absl/base/optimization.h b/absl/base/optimization.h index 6974f1f6..0dcbef32 100644 --- a/absl/base/optimization.h +++ b/absl/base/optimization.h @@ -163,6 +163,12 @@ // Compilers can use the information that a certain branch is not likely to be // taken (for instance, a CHECK failure) to optimize for the common case in // the absence of better information (ie. compiling gcc with `-fprofile-arcs`). +// +// Recommendation: Modern CPUs dynamically predict branch execution paths, +// typically with accuracy greater than 97%. As a result, annotating every +// branch in a codebase is likely counterproductive; however, annotating +// specific branches that are both hot and consistently mispredicted is likely +// to yield performance improvements. #if ABSL_HAVE_BUILTIN(__builtin_expect) || \ (defined(__GNUC__) && !defined(__clang__)) #define ABSL_PREDICT_FALSE(x) (__builtin_expect(x, 0)) |