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author | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | 2022-04-28 16:01:35 +0000 |
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committer | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | 2022-04-28 16:01:35 +0000 |
commit | 2ce195a4ebcb305b9320436273d9d23c717ad6f4 (patch) | |
tree | 2ce94d7f0804ccb77d1fa9b2a1bca00eecdff1e2 /third_party/abseil-cpp/absl/profiling/internal/periodic_sampler.cc | |
parent | cde6b2521fd8eb70e0fee633ec726ad687286c67 (diff) | |
parent | 7563023510bf04108a954596ea9393a4c11ac279 (diff) | |
download | webrtc-2ce195a4ebcb305b9320436273d9d23c717ad6f4.tar.gz |
Snap for 8512216 from 7563023510bf04108a954596ea9393a4c11ac279 to tm-frc-media-swcodec-releaset_frc_swc_330443040t_frc_swc_330443010android13-frc-media-swcodec-release
Change-Id: I9b0c9de1523358ec00bf7c85bb225b8f5639364b
Diffstat (limited to 'third_party/abseil-cpp/absl/profiling/internal/periodic_sampler.cc')
-rw-r--r-- | third_party/abseil-cpp/absl/profiling/internal/periodic_sampler.cc | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/third_party/abseil-cpp/absl/profiling/internal/periodic_sampler.cc b/third_party/abseil-cpp/absl/profiling/internal/periodic_sampler.cc new file mode 100644 index 0000000000..a738a82c86 --- /dev/null +++ b/third_party/abseil-cpp/absl/profiling/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/profiling/internal/periodic_sampler.h" + +#include <atomic> + +#include "absl/profiling/internal/exponential_biased.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace profiling_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 profiling_internal +ABSL_NAMESPACE_END +} // namespace absl |