DelayQueue Class Reference

#include <DelayQueue.hh>

Inheritance diagram for DelayQueue:

[legend]Collaboration diagram for DelayQueue:

[legend]

Public Member Functions
	DelayQueue ()
virtual	~DelayQueue ()
void	addEntry (DelayQueueEntry *newEntry)
void	updateEntry (DelayQueueEntry *entry, DelayInterval newDelay)
void	updateEntry (intptr_t tokenToFind, DelayInterval newDelay)
void	removeEntry (DelayQueueEntry *entry)
DelayQueueEntry *	removeEntry (intptr_t tokenToFind)
DelayInterval const &	timeToNextAlarm ()
void	handleAlarm ()
intptr_t	token ()
Protected Member Functions
virtual void	handleTimeout ()
Private Member Functions
DelayQueueEntry *	head ()
DelayQueueEntry *	findEntryByToken (intptr_t token)
void	synchronize ()
Private Attributes
EventTime	fLastSyncTime

---

Detailed Description

Definition at line 160 of file DelayQueue.hh.

---

Constructor & Destructor Documentation

DelayQueue::DelayQueue

(

)

Definition at line 110 of file DelayQueue.cpp.

References fLastSyncTime, and TimeNow().

  : DelayQueueEntry(ETERNITY) {
  fLastSyncTime = TimeNow();
}

DelayQueue::~DelayQueue

(

)

[virtual]

Definition at line 115 of file DelayQueue.cpp.

References DelayQueueEntry::fNext, and removeEntry().

                        {
  while (fNext != this) {
    DelayQueueEntry* entryToRemove = fNext;
    removeEntry(entryToRemove);
    delete entryToRemove;
  }
}

---

Member Function Documentation

void DelayQueue::addEntry

(

DelayQueueEntry *

newEntry

)

Definition at line 123 of file DelayQueue.cpp.

References DelayQueueEntry::fDeltaTimeRemaining, DelayQueueEntry::fNext, DelayQueueEntry::fPrev, head(), and synchronize().

Referenced by BasicTaskScheduler0::scheduleDelayedTask(), and updateEntry().

                                                   {
  synchronize();

  DelayQueueEntry* cur = head();
  while (newEntry->fDeltaTimeRemaining >= cur->fDeltaTimeRemaining) {
    newEntry->fDeltaTimeRemaining -= cur->fDeltaTimeRemaining;
    cur = cur->fNext;
  }

  cur->fDeltaTimeRemaining -= newEntry->fDeltaTimeRemaining;

  // Add "newEntry" to the queue, just before "cur":
  newEntry->fNext = cur;
  newEntry->fPrev = cur->fPrev;
  cur->fPrev = newEntry->fPrev->fNext = newEntry;
}

void DelayQueue::updateEntry	(	DelayQueueEntry *	entry,
		DelayInterval	newDelay
	)

Definition at line 140 of file DelayQueue.cpp.

References addEntry(), DelayQueueEntry::fDeltaTimeRemaining, NULL, and removeEntry().

Referenced by updateEntry().

                                                                           {
  if (entry == NULL) return;

  removeEntry(entry);
  entry->fDeltaTimeRemaining = newDelay;
  addEntry(entry);
}

void DelayQueue::updateEntry	(	intptr_t	tokenToFind,
		DelayInterval	newDelay
	)

Definition at line 148 of file DelayQueue.cpp.

References findEntryByToken(), and updateEntry().

                                                                         {
  DelayQueueEntry* entry = findEntryByToken(tokenToFind);
  updateEntry(entry, newDelay);
}

void DelayQueue::removeEntry

(

DelayQueueEntry *

entry

)

Definition at line 153 of file DelayQueue.cpp.

References DelayQueueEntry::fDeltaTimeRemaining, DelayQueueEntry::fNext, DelayQueueEntry::fPrev, and NULL.

Referenced by handleAlarm(), removeEntry(), BasicTaskScheduler0::unscheduleDelayedTask(), updateEntry(), and ~DelayQueue().

                                                   {
  if (entry == NULL || entry->fNext == NULL) return;

  entry->fNext->fDeltaTimeRemaining += entry->fDeltaTimeRemaining;
  entry->fPrev->fNext = entry->fNext;
  entry->fNext->fPrev = entry->fPrev;
  entry->fNext = entry->fPrev = NULL;
  // in case we should try to remove it again
}

DelayQueueEntry * DelayQueue::removeEntry

(

intptr_t

tokenToFind

)

Definition at line 163 of file DelayQueue.cpp.

References findEntryByToken(), and removeEntry().

                                                             {
  DelayQueueEntry* entry = findEntryByToken(tokenToFind);
  removeEntry(entry);
  return entry;
}

DelayInterval const & DelayQueue::timeToNextAlarm

(

)

Definition at line 169 of file DelayQueue.cpp.

References DELAY_ZERO, DelayQueueEntry::fDeltaTimeRemaining, head(), and synchronize().

Referenced by BasicTaskScheduler::SingleStep().

                                                 {
  if (head()->fDeltaTimeRemaining == DELAY_ZERO) return DELAY_ZERO; // a common case

  synchronize();
  return head()->fDeltaTimeRemaining;
}

void DelayQueue::handleAlarm

(

)

Definition at line 176 of file DelayQueue.cpp.

References DELAY_ZERO, DelayQueueEntry::fDeltaTimeRemaining, DelayQueueEntry::handleTimeout(), head(), removeEntry(), and synchronize().

Referenced by BasicTaskScheduler::SingleStep().

                             {
  if (head()->fDeltaTimeRemaining != DELAY_ZERO) synchronize();

  if (head()->fDeltaTimeRemaining == DELAY_ZERO) {
    // This event is due to be handled:
    DelayQueueEntry* toRemove = head();
    removeEntry(toRemove); // do this first, in case handler accesses queue

    toRemove->handleTimeout();
  }
}

DelayQueueEntry* DelayQueue::head

(

)

[inline, private]

Definition at line 175 of file DelayQueue.hh.

References DelayQueueEntry::fNext.

Referenced by addEntry(), findEntryByToken(), handleAlarm(), synchronize(), and timeToNextAlarm().

{ return fNext; }

DelayQueueEntry * DelayQueue::findEntryByToken

(

intptr_t

token

)

[private]

Definition at line 188 of file DelayQueue.cpp.

References DelayQueueEntry::fNext, head(), NULL, and DelayQueueEntry::token().

Referenced by removeEntry(), and updateEntry().

                                                                  {
  DelayQueueEntry* cur = head();
  while (cur != this) {
    if (cur->token() == tokenToFind) return cur;
    cur = cur->fNext;
  }

  return NULL;
}

void DelayQueue::synchronize

(

)

[private]

Definition at line 198 of file DelayQueue.cpp.

References DELAY_ZERO, DelayQueueEntry::fDeltaTimeRemaining, fLastSyncTime, DelayQueueEntry::fNext, head(), and TimeNow().

Referenced by addEntry(), handleAlarm(), and timeToNextAlarm().

                             {
  // First, figure out how much time has elapsed since the last sync:
  EventTime timeNow = TimeNow();
  if (timeNow < fLastSyncTime) {
    // The system clock has apparently gone back in time; reset our sync time and return:
    fLastSyncTime  = timeNow;
    return;
  }
  DelayInterval timeSinceLastSync = timeNow - fLastSyncTime;
  fLastSyncTime = timeNow;

  // Then, adjust the delay queue for any entries whose time is up:
  DelayQueueEntry* curEntry = head();
  while (timeSinceLastSync >= curEntry->fDeltaTimeRemaining) {
    timeSinceLastSync -= curEntry->fDeltaTimeRemaining;
    curEntry->fDeltaTimeRemaining = DELAY_ZERO;
    curEntry = curEntry->fNext;
  }
  curEntry->fDeltaTimeRemaining -= timeSinceLastSync;
}

intptr_t DelayQueueEntry::token

(

)

[inline, inherited]

Definition at line 139 of file DelayQueue.hh.

References DelayQueueEntry::fToken.

Referenced by findEntryByToken(), and BasicTaskScheduler0::scheduleDelayedTask().

                   {
    return fToken;
  }

void DelayQueueEntry::handleTimeout

(

)

[protected, virtual, inherited]

Reimplemented in AlarmHandler.

Definition at line 103 of file DelayQueue.cpp.

Referenced by handleAlarm(), and AlarmHandler::handleTimeout().

                                    {
  delete this;
}

---

Field Documentation

EventTime DelayQueue::fLastSyncTime [private]

Definition at line 179 of file DelayQueue.hh.

Referenced by DelayQueue(), and synchronize().

---

The documentation for this class was generated from the following files:

• BasicUsageEnvironment/include/DelayQueue.hh
• BasicUsageEnvironment/DelayQueue.cpp

---