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// Session WatchDog timer

#ifndef MOZC_SESSION_SESSION_WATCH_DOG_H_
#define MOZC_SESSION_SESSION_WATCH_DOG_H_

#include "base/base.h"
#include "base/scoped_handle.h"
#include "base/thread.h"

namespace mozc {
class CPUStatsInterface;
class UnnamedEvent;
namespace client {
class ClientInterface;
}

// SessionWatchDog class sends Cleanup command to Sessionhandler
// for every some specified seconds.
class SessionWatchDog : public Thread {
 public:
  // return the interval sec of watch dog timer
  int32 interval() const {
    return interval_sec_;
  }

  // Set client interface. This method doesn't take the owership.
  // mainly for unittesting.
  void SetClientInterface(client::ClientInterface *client);

  // Set CPUStats interface. This method doesn't take the owership.
  // mainly for unittesting.
  void SetCPUStatsInterface(CPUStatsInterface *cpu_stats);

  explicit SessionWatchDog(int32 interval_sec);
  virtual ~SessionWatchDog();

  // inherited from Thread class
  void Terminate();

  // return false if the watch dog thread receives stop signal
  bool Wait(int32 timeout);

  // inherited from Thread class
  // start watch dog timer and return immediately
  // virtual void Start();


  // return true if watch dog can send CleanupCommand:
  // |cpu_loads|: An array of cpu loads.
  // |cpu_load_index|: the size of cpu loads
  // |last_cleanup_time|: the last UTC time cleanup is executed
  // TODO(taku): want to define it inside private with FRIEND_TEST
  bool CanSendCleanupCommand(const volatile float *cpu_loads,
                             int cpu_load_index,
                             uint64 current_time,
                             uint64 last_cleanup_time) const;

 private:
  virtual void Run();

  int32 interval_sec_;
  client::ClientInterface *client_;
  CPUStatsInterface *cpu_stats_;
  scoped_ptr<UnnamedEvent> event_;
};
}  // namespace mozc
#endif  // MOZC_SESSION_SESSION_WATCH_DOG_H_