id_generator.cpp

ACE自适配通信环境（ADAPTIVE Communication Environment）是可以自由使用、开放源码的面向对象（OO）框架（Framework）

// ID_Generator.cpp,v 1.4 1998/07/31 23:36:45 gonzo Exp

#if !defined (ACE_ID_GENERATOR_C)
#define ACE_ID_GENERATOR_C

#include "ace/Object_Manager.h"
#include "ID_Generator.h"

ACE_RCSID(Caching, ID_Generator, "ID_Generator.cpp,v 1.4 1998/07/31 23:36:45 gonzo Exp")

time_t ACE_ID_Generator::last_time_ = 0;

size_t ACE_ID_Generator::last_number_ = 0;

ACE_SYNCH_MUTEX *ACE_ID_Generator::lock_ = 0;

char *
ACE_ID_Generator::get_new_id (char *id)
{
  time_t t;
  size_t sn;

  ACE_ID_Generator::get_serial_id (t, sn);
  ACE_NEW_RETURN (id, char [ACE_OFFER_ID_LENGTH], 0);
  
  ACE_OS::sprintf (id, "%014d%06d", t, sn);
  return id;
}

void
ACE_ID_Generator::get_serial_id (time_t &t, size_t &s)
{
  ACE_MT (ACE_GUARD (ACE_SYNCH_MUTEX, ace_mon, *ACE_ID_Generator::get_lock ()));
  ACE_OS::time (&t);

  if (t != ACE_ID_Generator::last_time_)
    {
      ACE_ID_Generator::last_time_ = t;
      s = ACE_ID_Generator::last_number_ = 0;
    }
  else
      s = ACE_ID_Generator::last_number_++;
}

ACE_SYNCH_MUTEX *
ACE_ID_Generator::get_lock (void)
{
#if defined (ACE_HAS_THREADS)
  if (ACE_ID_Generator::lock_ == 0)
    {
      ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, *ACE_Static_Object_Lock::instance (), 0));

      // Double-checked Locking Optimization.
      if (ACE_ID_Generator::lock_ == 0)
	ACE_NEW_RETURN (ACE_ID_Generator::lock_, ACE_SYNCH_MUTEX, 0);
    }
#endif /* ACE_HAS_THREADS */
  return ACE_ID_Generator::lock_;
}

#endif /* ACE_ID_GENERATOR_C */