Snap for 8570526 from d3dfe74c4025bacd9741d761815a8cb059e49c68 to mainline-scheduling-releaseaml_sch_331113000aml_sch_331111000android13-mainline-scheduling-release

Change-Id: Ic17fef21c4ad09be65415d62691ec93c0584ef6c

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