syntax = "proto3";

package envoy.admin.v4alpha;

import "udpa/annotations/status.proto";
import "udpa/annotations/versioning.proto";

option java_package = "io.envoyproxy.envoy.admin.v4alpha";
option java_outer_classname = "MutexStatsProto";
option java_multiple_files = true;
option (udpa.annotations.file_status).package_version_status = NEXT_MAJOR_VERSION_CANDIDATE;

// [#protodoc-title: MutexStats]

// Proto representation of the statistics collected upon absl::Mutex contention, if Envoy is run
// under :option:`--enable-mutex-tracing`. For more information, see the `absl::Mutex`
// [docs](https://abseil.io/about/design/mutex#extra-features).
//
// *NB*: The wait cycles below are measured by `absl::base_internal::CycleClock`, and may not
// correspond to core clock frequency. For more information, see the `CycleClock`
// [docs](https://github.com/abseil/abseil-cpp/blob/master/absl/base/internal/cycleclock.h).
message MutexStats {
  option (udpa.annotations.versioning).previous_message_type = "envoy.admin.v3.MutexStats";

  // The number of individual mutex contentions which have occurred since startup.
  uint64 num_contentions = 1;

  // The length of the current contention wait cycle.
  uint64 current_wait_cycles = 2;

  // The lifetime total of all contention wait cycles.
  uint64 lifetime_wait_cycles = 3;
}