cdev-1.7.2n

include/cdevTimerQueue.h

@@ -0,0 +1,128 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 1994,1995 Southeastern Universities Research Association,
+//                         Continuous Electron Beam Accelerator Facility
+//
+// This software was developed under a United States Government license
+// described in the NOTICE file included as part of this distribution.
+//
+//-----------------------------------------------------------------------------
+//
+// Description:
+//      cdevTimerQueue Class
+//
+// Author:  Jie Chen
+//
+// Revision History:
+//   cdevTimerQueue.h,v
+// Revision 1.1  1998/02/10  18:04:58  chen
+// add cdevSystem timer handler
+//
+//
+//
+#ifndef _CDEV_TIMER_QUEUE_H
+#define _CDEV_TIMER_QUEUE_H
+
+#include <stdio.h>
+#include <cdevTimerHandler.h>
+#include <cdevSlist.h>
+
+class cdevTimerQueue;
+
+class cdevTimerQNode
+{
+private:
+
+  friend class cdevTimerQueue;
+
+  cdevTimerQNode (cdevTimerHandler* h,
+		  const void* arg,
+		  const cdevTimeValue& t,
+		  const cdevTimeValue& i,
+		  int   id);
+
+  // data area
+  cdevTimerHandler* handler_;
+
+  // user argument
+  const void*       arg_;
+
+  // first time interval to expire
+  cdevTimeValue     timer_;
+
+  // timer interval: if this is not zero this holds the time until the next
+  // timeout
+  cdevTimeValue     interval_;
+
+  // int timer id
+  int               tid_;
+};
+
+
+class CDEV_CLASS_SPEC cdevTimerQueue
+{
+public:
+  // constructor
+  cdevTimerQueue (void);
+  // destructor
+  virtual ~cdevTimerQueue (void);
+
+  int isEmpty    (void) const;
+  // PURPOSE: check whether this queue is empty or not
+  // REQUIRE: nothing
+  // PROMISE: return 1, empty, 0, not empty
+
+  const cdevTimeValue& earliestTime (void) const;
+  // PURPOSE: return earliestTime in the timer queue
+  // REQUIRE: nothing
+  // PROMISE: time value denoted the earliest time in the queue
+
+  int   scheduleTimer (cdevTimerHandler* handler,
+		       const void* arg,
+		       const cdevTimeValue& delay,
+		       const cdevTimeValue& interval = cdevTimeValue::zero);
+  // PURPOSE: Schedule an <cdevTimerHandler> that will expire after <delay>
+  // amount of time.  If it expires then <arg> is passed in as the value to
+  // the <cdevTimerHandler>'s <timerCallback> callback method.  If
+  // <interval> is != to <cdevTimeValue::zero> then it is used to
+  // reschedule the <cdevTimerHandler> automatically.  This method
+  // returns a timer handle that uniquely identifies the
+  // <cdevTimerhandler> in an internal list.  This timer handle can be
+  // used to cancel an <cdevTimerhandler> before it expires.  The
+  // cancellation ensures that timer_ids are unique up to values of
+  // greater than 2 billion timers.  As long as timers don't stay
+  // around longer than this there should be no problems with
+  // accidentally deleting the wrong timer.
+  
+  int   cancel        (cdevTimerHandler* handler);
+  // PURPOSE: cancel all timers associated with handler
+  // REQUIRE: handler != 0
+  // PROMISE: all timer is canceled. return 0
+
+  int   cancel        (int id);
+  // PURPOSE: cancel a single timer with id
+  // REQUIRE: id must be valid
+  // PROMISE: if id is found, the timer is canceled.
+
+  int   expire        (const cdevTimeValue& current_time);
+  // PURPOSE: run the <timerCallback> method for all timers whose values are
+  //          <= current_time
+  
+private:
+  void  reschedule    (cdevTimerQNode* node);
+  // reschedule a "interval" timer
+
+  cdevSlist   queue_;
+  // real linked list as a queue
+
+  int         timerId_;
+  // run time timer id
+};
+#endif
+  
+		       
+
+  
+  
+
+		  
+