diff options
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)) |