cpureserve.hxx

C++ 编写的EROS RTOS

#ifndef __CPURESERVE_HXX__
#define __CPURESERVE_HXX__
/*
 * Copyright (C) 1998, 1999, Jonathan S. Shapiro.
 *
 * This file is part of the EROS Operating System.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2,
 * or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/* Data structures for CPU reserve management.  The current kernel
 * implementation uses a fixed-priority strategy for implementing
 * cpu reserves.
 */

#include <kerninc/Link.hxx>
#include <kerninc/SysTimer.hxx>

struct CpuReserve {
  /* Following two items MUST be first, because they are directly
   * manipulated by the low-level interrupt logic.
   */
  
  uint64_t residQuanta;		/* remaining duration this quanta */
  bool    expired;		/* set TRUE when quanta has expired */
  
  uint64_t residDuration;	/* remaining duration this period */
  
  uint64_t quanta;		/* ticks till expiration */
  uint64_t duration;		/* in ticks */
  uint64_t period;		/* in ticks */
  uint64_t start;		/* when to start this reserve */

  bool active;			/* true if running under reserved cycles */
  int curPrio;			/* priority at which we are currently running. */
  
  int normPrio;			/* priority when reserve NOT active */
  int rsrvPrio;			/* priority when reserve is active */

  Timer reserveTimer;		/* reserve period timer */

  Link threadChain;		/* circularly linked list of threads
		 */
				/* under this reserve 
				 */

  void OnQuantaExpiration();	/* called whenever residQuanta goes to
	 */
				/* zero
				 */

  void Deplenish();		/* called when duration of active
		 */
				/* reserve is exhausted.
				 */
  void Replenish();		/* called at start of each period */

  CpuReserve();
  CpuReserve(int inactivePrio);
  
  static void Replenish(Timer*); /* used by timer logic. */

  void AddUserThread(Thread *t);
  void AddKernelThread(Thread *t);
  
  void QuantaExpired();

  static CpuReserve *CpuReserveTable;
  static CpuReserve KernIdleCpuReserve;
  static CpuReserve KernThreadCpuReserve;
  static CpuReserve InactiveReserve;

  static CpuReserve *Current;

  static void AllocUserCpuReserves();

  void Reset();
  
  static CpuReserve& GetReserve(const Key& k);

  inline static CpuReserve& GetHighestReserve()
  {
    return CpuReserveTable[Prio::High];
  }

private:
  void AdjustCurPrio(int prio);
};

#endif /* __CPURESERVE_HXX__ */