#pragma once

#include "envoy/extensions/resource_monitors/downstream_connections/v3/downstream_connections.pb.h"

#include "envoy/server/proactive_resource_monitor.h"

#include "source/common/common/thread_synchronizer.h"

namespace Envoy {

namespace Extensions {

namespace ResourceMonitors {

namespace DownstreamConnections {

class ActiveDownstreamConnectionsResourceMonitor : public Server::ProactiveResourceMonitor {

public:

  ActiveDownstreamConnectionsResourceMonitor(

      const envoy::extensions::resource_monitors::downstream_connections::v3::

          DownstreamConnectionsConfig& config);

  bool tryAllocateResource(int64_t increment) override;

  bool tryDeallocateResource(int64_t decrement) override;

  int64_t currentResourceUsage() const override;

  int64_t maxResourceUsage() const override;

protected:

  const int64_t max_;

  std::atomic<int64_t> current_;

  // Used for testing only.

  mutable Thread::ThreadSynchronizer synchronizer_;

  friend class ActiveDownstreamConnectionsMonitorTest;

};

} // namespace DownstreamConnections

} // namespace ResourceMonitors

} // namespace Extensions

} // namespace Envoy