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author | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | 2022-06-15 21:47:18 +0000 |
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committer | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | 2022-06-15 21:47:18 +0000 |
commit | a32061b365b2d32963d08e27396cbf32e08c31cb (patch) | |
tree | cb306ffb64819f95c080c3cb6bfcdfb45a7b3a76 /third_party/abseil-cpp/absl/base/internal/periodic_sampler.cc | |
parent | 93534cddabc1dc3b7dfa5387784c6c7394f729c4 (diff) | |
parent | b7c9dafe99969a4e9d5ffa101bb9a8d6e1df69df (diff) | |
download | webrtc-a32061b365b2d32963d08e27396cbf32e08c31cb.tar.gz |
Snap for 8730993 from b7c9dafe99969a4e9d5ffa101bb9a8d6e1df69df to mainline-tzdata3-releaseaml_tz3_314012070aml_tz3_314012050aml_tz3_314012010aml_tz3_313110000aml_tz3_312511020aml_tz3_312511010aml_tz3_312410020aml_tz3_312410010android12-mainline-tzdata3-releaseaml_tz3_314012010
Change-Id: Iab4fa0d9b620eddf41ca88e1eb5547f79c316203
Diffstat (limited to 'third_party/abseil-cpp/absl/base/internal/periodic_sampler.cc')
-rw-r--r-- | third_party/abseil-cpp/absl/base/internal/periodic_sampler.cc | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/third_party/abseil-cpp/absl/base/internal/periodic_sampler.cc b/third_party/abseil-cpp/absl/base/internal/periodic_sampler.cc new file mode 100644 index 0000000000..520dabbaa0 --- /dev/null +++ b/third_party/abseil-cpp/absl/base/internal/periodic_sampler.cc @@ -0,0 +1,53 @@ +// Copyright 2019 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include "absl/base/internal/periodic_sampler.h" + +#include <atomic> + +#include "absl/base/internal/exponential_biased.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace base_internal { + +int64_t PeriodicSamplerBase::GetExponentialBiased(int period) noexcept { + return rng_.GetStride(period); +} + +bool PeriodicSamplerBase::SubtleConfirmSample() noexcept { + int current_period = period(); + + // Deal with period case 0 (always off) and 1 (always on) + if (ABSL_PREDICT_FALSE(current_period < 2)) { + stride_ = 0; + return current_period == 1; + } + + // Check if this is the first call to Sample() + if (ABSL_PREDICT_FALSE(stride_ == 1)) { + stride_ = static_cast<uint64_t>(-GetExponentialBiased(current_period)); + if (static_cast<int64_t>(stride_) < -1) { + ++stride_; + return false; + } + } + + stride_ = static_cast<uint64_t>(-GetExponentialBiased(current_period)); + return true; +} + +} // namespace base_internal +ABSL_NAMESPACE_END +} // namespace absl |