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/* -*- C++ -*- */
// $Id$
// ============================================================================
//
// = LIBRARY
// none
//
// = FILENAME
// ID_Generator.h
//
// = AUTHOR
// Nanbor Wang
//
// ============================================================================
#ifndef ACE_ID_GENERATOR_H
#define ACE_ID_GENERATOR_h
#include "ace/Synch.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
#define ACE_OFFER_ID_LENGTH 21
class ACE_ID_Generator
// = TITLE
// An unique ID generator.
//
// = DESCRIPTION
// Generate an offer ID according to current time and avoid
// duplicate ID. It guarantees ID uniqueness within a process,
// i.e. no two threads may get the same ID string. Using a
// similar method like the backery algorithm.
{
public:
static char *get_new_id (char *id);
// allocate a new ID string and point <id> to it.
private:
static void get_serial_id (time_t &t, size_t &s);
// Atomically get info required to generate an offer ID.
static ACE_SYNCH_MUTEX *get_lock (void);
// Get the lock instance.
static time_t last_time_;
// Record the time last offer ID generated.
static size_t last_number_;
// Record serial number of last offer ID with same
// generation time.
static ACE_SYNCH_MUTEX *lock_;
// mutex to access private member.
};
#endif /* ACE_ID_GENERATOR_H */
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