named_lock_schedule_rewrite_controller.h

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// Copyright 2015 Google Inc.

#ifndef PAGESPEED_CONTROLLER_NAMED_LOCK_SCHEDULE_REWRITE_CONTROLLER_H_
#define PAGESPEED_CONTROLLER_NAMED_LOCK_SCHEDULE_REWRITE_CONTROLLER_H_

#include <unordered_set>

#include "pagespeed/kernel/base/abstract_mutex.h"
#include "pagespeed/controller/schedule_rewrite_controller.h"
#include "pagespeed/kernel/base/basictypes.h"
#include "pagespeed/kernel/base/function.h"
#include "pagespeed/kernel/base/rde_hash_map.h"
#include "pagespeed/kernel/base/statistics.h"
#include "pagespeed/kernel/base/string.h"
#include "pagespeed/kernel/base/string_hash.h"
#include "pagespeed/kernel/base/scoped_ptr.h"
#include "pagespeed/kernel/base/named_lock_manager.h"
#include "pagespeed/kernel/base/thread_annotations.h"
#include "pagespeed/kernel/base/thread_system.h"

namespace net_instaweb {

class NamedLockScheduleRewriteController : public ScheduleRewriteController {
 public:
  static const char kLocksGranted[];
  static const char kLocksDenied[];
  static const char kLocksStolen[];
  static const char kLocksReleasedWhenNotHeld[];
  static const char kLocksCurrentlyHeld[];

  static const int kStealMs;

  NamedLockScheduleRewriteController(NamedLockManager* lock_manager,
                                     ThreadSystem* thread_system,
                                     Statistics* statistics);
  virtual ~NamedLockScheduleRewriteController();

  virtual void ScheduleRewrite(const GoogleString& key, Function* callback);
  virtual void NotifyRewriteComplete(const GoogleString& key);
  virtual void NotifyRewriteFailed(const GoogleString& key);

  void ShutDown() override;

  static void InitStats(Statistics* stats);

 private:
  struct LockInfo {
    LockInfo() : pin_count(0) { }
    scoped_ptr<NamedLock> lock;

    std::unordered_set<Function*> pending_callbacks;

    int pin_count;

   private:
    
  };

  typedef rde::hash_map<GoogleString, LockInfo*, CasePreserveStringHash>
      LockMap;

  void LockObtained(Function* callback, const GoogleString key, NamedLock* lock)
      LOCKS_EXCLUDED(mutex_);
  void LockFailed(Function* callback, const GoogleString key, NamedLock* lock)
      LOCKS_EXCLUDED(mutex_);

  LockInfo* GetLockInfo(const GoogleString& key)
      EXCLUSIVE_LOCKS_REQUIRED(mutex_);
  void DeleteInfoIfUnused(LockInfo* info, const GoogleString& key)
      EXCLUSIVE_LOCKS_REQUIRED(mutex_);

  scoped_ptr<AbstractMutex> mutex_;
  NamedLockManager* lock_manager_;
  LockMap locks_ GUARDED_BY(mutex_);
  bool shut_down_ GUARDED_BY(mutex_);

  TimedVariable* locks_granted_;
  TimedVariable* locks_denied_;
  TimedVariable* locks_stolen_;
  TimedVariable* locks_released_when_not_held_;
  UpDownCounter* locks_currently_held_;

  
};

}  

#endif