asyncdeferredpowermanagerp.nc

tinyos-2.x.rar

/*
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/*
 * - Revision -------------------------------------------------------------
 * $Revision: 1.5 $
 * $Date: 2007/02/04 19:55:23 $ 
 * ======================================================================== 
 */
 
/**
 * Please refer to TEP 115 for more information about this component and its
 * intended use.<br><br>
 *
 * This is the internal implementation of the deffered power management
 * policy for managing the power states of non-virtualized devices.
 * Non-virtualized devices are shared using a parameterized Resource
 * interface, and are powered down according to some policy whenever there
 * are no more pending requests to that Resource.  The policy implemented
 * by this component is to delay the power down of a device by some contant
 * factor.  Such a policy is useful whenever a device has a long wake-up
 * latency.  The cost of waiting for the device to power up can be
 * avoided if the device is requested again before some predetermined
 * amount of time.
 *
 * @param <b>delay</b> -- The amount of time the power manager should wait
 *                        before shutting down the device once it is free.
 * 
 * @author Kevin Klues ([e-mail])
 */
 
generic module AsyncDeferredPowerManagerP(uint32_t delay) {
  uses {
    interface AsyncStdControl;

    interface PowerDownCleanup;
    interface ResourceDefaultOwner;
    interface ArbiterInfo;
    interface Timer<TMilli> as TimerMilli;
  }
}
implementation {

  norace bool stopTimer = FALSE;

  task void stopTimerTask() {
    call TimerMilli.stop();
    stopTimer = FALSE;
  }

  task void timerTask() {
    if(stopTimer == FALSE)
      call TimerMilli.startOneShot(delay);
  }

  async event void ResourceDefaultOwner.requested() {
    stopTimer = TRUE;
    post stopTimerTask();
    call AsyncStdControl.start();
    call ResourceDefaultOwner.release();
  }

  async event void ResourceDefaultOwner.immediateRequested() {
    stopTimer = TRUE;
    post stopTimerTask();
    call AsyncStdControl.start();
    call ResourceDefaultOwner.release();
  }

  async event void ResourceDefaultOwner.granted() {
      post timerTask();
  }

  event void TimerMilli.fired() {
    if(stopTimer == FALSE) {
      call PowerDownCleanup.cleanup();
      call AsyncStdControl.stop();
    }
  }

  default async command void PowerDownCleanup.cleanup() {
  }
}