internal override void Execute()
{
TaskMetadata taskMetadata;
Task task;
lock (scheduler.resourcesLock)
{
if (!scheduler.tokenToTask.ContainsKey(taskToken))
{
return;
}
task = scheduler.tokenToTask[taskToken];
taskMetadata = scheduler.taskToMetadata[task];
}
if (!scheduler.resourceToTask.ContainsKey(resource))
{
return;
}
//In case task is not locking the resource, do nothing
if (scheduler.resourceToTask[resource] != task)
{
return;
}
else if (scheduler.resourceToTask[resource] == task)
{
//Change state of task
taskMetadata.taskState = TaskMetadata.TaskState.Executing;
//In case task is locking the resource, unlock it and notify the caller
scheduler.resourceToTask.Remove(resource);
//Give resource to first task waiting for it
if (scheduler.tasksWaitingOnResources.ContainsKey(resource) && scheduler.tasksWaitingOnResources[resource].Count > 0)
{
(Task taskWaitingOnResource, EventWaitHandle taskWaitingOnResourceNotifier) = scheduler.FindLowestPriorityTaskWaitingOnResource(resource);
scheduler.tasksWaitingOnResources[resource].Remove((taskWaitingOnResource, taskWaitingOnResourceNotifier));
lock (scheduler.resourcesLock)
{
if (scheduler.taskToToken.ContainsKey(taskWaitingOnResource))
{
scheduler.eventQueue.Add(new TaskWantsToLockResourceEvent(scheduler, scheduler.taskToToken[taskWaitingOnResource], taskWaitingOnResourceNotifier, resource));
}
}
}
//Set priority back to normal
taskMetadata.VirtualPriority = taskMetadata.InitialPriority;
taskMetadata.waitingOnResource = null;
scheduler.Graph.RemoveEdge(resource, task);
scheduler.taskHoldingResources[task].Remove(resource);
//Notify our caller that he has released the resource successfully
taskNotifier.Set();
//Queue new event for scheduling, because the virtual priority is dropping
scheduler.eventQueue.Add(new ScheduleTasksEvent(scheduler));
}
}
