public void Init()
{
PriorityQueue pq = new PriorityQueue();
Assert.AreEqual(0, pq.Count);
Assert.IsNull(pq.Dequeue());
Assert.AreEqual(0, pq.Count);
}
public void MultipleWorkItemsMultiplePriorities()
{
// Get all the available priorities
WorkItemPriority [] priorities = Enum.GetValues(typeof(WorkItemPriority)) as WorkItemPriority [];
// Create an array of priority items
PriorityItem [] priorityItems = new PriorityItem[priorities.Length];
// Create a priority item for each priority
int i = priorities.Length;
foreach(WorkItemPriority workItemPriority in priorities)
{
--i;
priorityItems[i] = new PriorityItem(workItemPriority);
}
// Create a PermutationGenerator for the priority items
PermutationGenerator permutations = new PermutationGenerator(priorityItems);
int count = 0;
// Iterate over the permutations
foreach(object [] permutation in permutations)
{
++count;
Console.Write("Permutation #" + count + " : ");
for(int j = 0; j < permutation.Length; ++j)
{
PriorityItem pi = permutation[j] as PriorityItem;
Console.Write(pi.WorkItemPriority + ", ");
}
Console.WriteLine();
// Create a priority queue
PriorityQueue pq = new PriorityQueue();
// Enqueue each priority item according to the permutation
for(i = 0; i < permutation.Length; ++i)
{
PriorityItem priorityItem = permutation[i] as PriorityItem;
pq.Enqueue(priorityItem);
}
// Make sure all the priority items are in the queue
Assert.AreEqual(priorityItems.Length, pq.Count);
// Compare the order of the priority items
for(i = 0; i < priorityItems.Length; ++i)
{
PriorityItem priorityItem = pq.Dequeue() as PriorityItem;
Assert.AreSame(priorityItems[i], priorityItem);
}
}
}
public void MultipleWorkItemsOnePriority()
{
WorkItemPriority [] priorities = Enum.GetValues(typeof(WorkItemPriority)) as WorkItemPriority [];
foreach(WorkItemPriority wip in priorities)
{
PriorityQueue pq = new PriorityQueue();
PriorityItem [] priorityItems = new PriorityItem[10];
for(int i = 0; i < priorityItems.Length; ++i)
{
priorityItems[i] = new PriorityItem(wip);
pq.Enqueue(priorityItems[i]);
Assert.AreEqual(i+1, pq.Count, "Failed for priority {0} item count {1}", wip, i+1);
}
for(int i = 0; i < priorityItems.Length; ++i)
{
PriorityItem pi = pq.Dequeue() as PriorityItem;
Assert.AreEqual(priorityItems.Length-(i+1), pq.Count, "Failed for priority {0} item count {1}", wip, i+1);
Assert.IsNotNull(pi, "Failed for priority {0} item count {1}", wip, i+1);
Assert.AreSame(pi, priorityItems[i], "Failed for priority {0} item count {1}", wip, i+1);
}
Assert.AreEqual(0, pq.Count, "Failed for priority {0}", wip);
Assert.IsNull(pq.Dequeue());
Assert.AreEqual(0, pq.Count);
}
}
public void OneWorkItem()
{
WorkItemPriority [] priorities = Enum.GetValues(typeof(WorkItemPriority)) as WorkItemPriority [];
foreach(WorkItemPriority wip in priorities)
{
PriorityQueue pq = new PriorityQueue();
PriorityItem pi = new PriorityItem(wip);
pq.Enqueue(pi);
Assert.AreEqual(1, pq.Count, "Failed for priority {0}", wip);
PriorityItem pi2 = pq.Dequeue() as PriorityItem;
Assert.IsNotNull(pi2, "Failed for priority {0}", wip);
Assert.AreSame(pi, pi2, "Failed for priority {0}", wip);
Assert.AreEqual(0, pq.Count, "Failed for priority {0}", wip);
}
}
private void EnqueueToSTPNextWorkItem(WorkItem workItem, bool decrementWorkItemsInStpQueue)
{
lock (_lock)
{
// Got here from OnWorkItemCompletedCallback()
if (decrementWorkItemsInStpQueue)
{
--_workItemsInStpQueue;
if (_workItemsInStpQueue < 0)
{
_workItemsInStpQueue = 0;
}
--_workItemsExecutingInStp;
if (_workItemsExecutingInStp < 0)
{
_workItemsExecutingInStp = 0;
}
}
// If the work item is not null then enqueue it
if (null != workItem)
{
workItem.CanceledWorkItemsGroup = _canceledWorkItemsGroup;
RegisterToWorkItemCompletion(workItem.GetWorkItemResult());
_workItemsQueue.Enqueue(workItem);
//_stp.IncrementWorkItemsCount();
if ((1 == _workItemsQueue.Count) &&
(0 == _workItemsInStpQueue))
{
_stp.RegisterWorkItemsGroup(this);
IsIdle = false;
_isIdleWaitHandle.Reset();
}
}
// If the work items queue of the group is empty than quit
if (0 == _workItemsQueue.Count)
{
if (0 == _workItemsInStpQueue)
{
_stp.UnregisterWorkItemsGroup(this);
IsIdle = true;
_isIdleWaitHandle.Set();
if (decrementWorkItemsInStpQueue && _onIdle != null && _onIdle.GetInvocationList().Length > 0)
{
_stp.QueueWorkItem(new WorkItemCallback(FireOnIdle));
}
}
return;
}
if (!_isSuspended)
{
if (_workItemsInStpQueue < _concurrency)
{
WorkItem nextWorkItem = _workItemsQueue.Dequeue() as WorkItem;
try
{
_stp.Enqueue(nextWorkItem);
}
catch (ObjectDisposedException e)
{
e.GetHashCode();
// The STP has been shutdown
}
++_workItemsInStpQueue;
}
}
}
}
/// <summary>
/// Waits for a work item or exits on timeout or cancel
/// </summary>
/// <param name="millisecondsTimeout">Timeout in milliseconds</param>
/// <param name="cancelEvent">Cancel wait handle</param>
/// <returns>Returns true if the resource was granted</returns>
public WorkItem DequeueWorkItem(
int millisecondsTimeout,
WaitHandle cancelEvent)
{
/// This method cause the caller to wait for a work item.
/// If there is at least one waiting work item then the
/// method returns immidiately with true.
///
/// If there are no waiting work items then the caller
/// is queued between other waiters for a work item to arrive.
///
/// If a work item didn't come within millisecondsTimeout or
/// the user canceled the wait by signaling the cancelEvent
/// then the method returns false to indicate that the caller
/// didn't get a work item.
WaiterEntry waiterEntry = null;
WorkItem workItem = null;
lock (this)
{
ValidateNotDisposed();
// If there are waiting work items then take one and return.
if (_workItems.Count > 0)
{
workItem = _workItems.Dequeue() as WorkItem;
return(workItem);
}
// No waiting work items ...
else
{
// Get the wait entry for the waiters queue
waiterEntry = GetThreadWaiterEntry();
// Put the waiter with the other waiters
PushWaiter(waiterEntry);
}
}
// Prepare array of wait handle for the WaitHandle.WaitAny()
var waitHandles = new[]
{
waiterEntry.WaitHandle,
cancelEvent
};
// Wait for an available resource, cancel event, or timeout.
// During the wait we are supposes to exit the synchronization
// domain. (Placing true as the third argument of the WaitAny())
// It just doesn't work, I don't know why, so I have lock(this)
// statments insted of one.
int index = WaitHandle.WaitAny(
waitHandles,
millisecondsTimeout,
true);
lock (this)
{
// success is true if it got a work item.
bool success = (0 == index);
// The timeout variable is used only for readability.
// (We treat cancel as timeout)
bool timeout = !success;
// On timeout update the waiterEntry that it is timed out
if (timeout)
{
// The Timeout() fails if the waiter has already been signaled
timeout = waiterEntry.Timeout();
// On timeout remove the waiter from the queue.
// Note that the complexity is O(1).
if (timeout)
{
RemoveWaiter(waiterEntry, false);
}
// Again readability
success = !timeout;
}
// On success return the work item
if (success)
{
workItem = waiterEntry.WorkItem;
if (null == workItem)
{
workItem = _workItems.Dequeue() as WorkItem;
}
}
}
// On failure return null.
return(workItem);
}
private void EnqueueToSTPNextWorkItem(WorkItem workItem, bool decrementWorkItemsInStpQueue)
{
lock (_lock)
{
// Got here from OnWorkItemCompletedCallback()
if (decrementWorkItemsInStpQueue)
{
--_workItemsInStpQueue;
if (_workItemsInStpQueue < 0)
{
_workItemsInStpQueue = 0;
}
--_workItemsExecutingInStp;
if (_workItemsExecutingInStp < 0)
{
_workItemsExecutingInStp = 0;
}
}
// If the work item is not null then enqueue it
if (null != workItem)
{
workItem.CanceledWorkItemsGroup = _canceledWorkItemsGroup;
RegisterToWorkItemCompletion(workItem.GetWorkItemResult());
_workItemsQueue.Enqueue(workItem);
//_stp.IncrementWorkItemsCount();
if ((1 == _workItemsQueue.Count) &&
(0 == _workItemsInStpQueue))
{
_stp.RegisterWorkItemsGroup(this);
Trace.WriteLine("WorkItemsGroup " + Name + " is NOT idle");
_isIdleWaitHandle.Reset();
}
}
// If the work items queue of the group is empty than quit
if (0 == _workItemsQueue.Count)
{
if (0 == _workItemsInStpQueue)
{
_stp.UnregisterWorkItemsGroup(this);
Trace.WriteLine("WorkItemsGroup " + Name + " is idle");
_isIdleWaitHandle.Set();
_stp.QueueWorkItem(this.FireOnIdle);
}
return;
}
if (!_workItemsGroupStartInfo.StartSuspended)
{
if (_workItemsInStpQueue < _concurrency)
{
WorkItem nextWorkItem = _workItemsQueue.Dequeue() as WorkItem;
_stp.Enqueue(nextWorkItem, true);
++_workItemsInStpQueue;
}
}
}
}
