diff options
Diffstat (limited to 'absl/container')
-rw-r--r-- | absl/container/internal/hashtablez_sampler.cc | 20 | ||||
-rw-r--r-- | absl/container/internal/hashtablez_sampler.h | 2 | ||||
-rw-r--r-- | absl/container/internal/hashtablez_sampler_force_weak_definition.cc | 5 |
3 files changed, 23 insertions, 4 deletions
diff --git a/absl/container/internal/hashtablez_sampler.cc b/absl/container/internal/hashtablez_sampler.cc index d03dd82e7fd5..054e89817815 100644 --- a/absl/container/internal/hashtablez_sampler.cc +++ b/absl/container/internal/hashtablez_sampler.cc @@ -228,8 +228,26 @@ int64_t HashtablezSampler::Iterate( return dropped_samples_.load(std::memory_order_relaxed); } +static bool ShouldForceSampling() { + enum ForceState { + kDontForce, + kForce, + kUninitialized + }; + ABSL_CONST_INIT static std::atomic<ForceState> global_state{ + kUninitialized}; + ForceState state = global_state.load(std::memory_order_relaxed); + if (ABSL_PREDICT_TRUE(state == kDontForce)) return false; + + if (state == kUninitialized) { + state = AbslContainerInternalSampleEverything() ? kForce : kDontForce; + global_state.store(state, std::memory_order_relaxed); + } + return state == kForce; +} + HashtablezInfo* SampleSlow(int64_t* next_sample) { - if (kAbslContainerInternalSampleEverything) { + if (ABSL_PREDICT_FALSE(ShouldForceSampling())) { *next_sample = 1; return HashtablezSampler::Global().Register(); } diff --git a/absl/container/internal/hashtablez_sampler.h b/absl/container/internal/hashtablez_sampler.h index 4112175449ef..53996bb9fa4c 100644 --- a/absl/container/internal/hashtablez_sampler.h +++ b/absl/container/internal/hashtablez_sampler.h @@ -280,7 +280,7 @@ void SetHashtablezMaxSamples(int32_t max); // initialization of static storage duration objects. // The definition of this constant is weak, which allows us to inject a // different value for it at link time. -extern "C" const bool kAbslContainerInternalSampleEverything; +extern "C" bool AbslContainerInternalSampleEverything(); } // namespace container_internal } // namespace absl diff --git a/absl/container/internal/hashtablez_sampler_force_weak_definition.cc b/absl/container/internal/hashtablez_sampler_force_weak_definition.cc index 4ca6ffdadd7d..984dce5dd992 100644 --- a/absl/container/internal/hashtablez_sampler_force_weak_definition.cc +++ b/absl/container/internal/hashtablez_sampler_force_weak_definition.cc @@ -20,8 +20,9 @@ namespace absl { namespace container_internal { // See hashtablez_sampler.h for details. -extern "C" ABSL_ATTRIBUTE_WEAK const bool - kAbslContainerInternalSampleEverything = false; +extern "C" ABSL_ATTRIBUTE_WEAK bool AbslContainerInternalSampleEverything() { + return false; +} } // namespace container_internal } // namespace absl |