#pragma once

#include <cstdint>

#include <memory>

#include "envoy/common/pure.h"

namespace Envoy {

/**

 * Generic interface for all MutexTracer implementations. Any MutexTracer should initialize itself

 * with absl::RegisterMutexTracer() at initialization, record statistics, and deliver those

 * statistics in a thread-safe manner.

 */

class MutexTracer {

public:

  /**

   * @return resets the captured statistics.

   */

  virtual void reset() PURE;

  /**

   * @return the number of experienced mutex contentions.

   */

  virtual int64_t numContentions() const PURE;

  /**

   * @return the length of the ongoing wait cycle. Note that the wait cycles are not

   * guaranteed to correspond to core clock frequency, as per absl::base_internal::CycleClock.

   */

  virtual int64_t currentWaitCycles() const PURE;

  /**

   * @return the cumulative length of all experienced wait cycles. See the above note on wait cycles

   * v. core clock frequency.

   */

  virtual int64_t lifetimeWaitCycles() const PURE;

};

} // namespace Envoy