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| ///////////////////////////////////////////////////////////////////////////
// //
// Copyright (c) 2015 by Charta Software B.V. //
// All rights reserved //
// //
// Version: 1.7.0.83525 //
// Web site: https://pascal.chartasoftware.com/ //
// //
// This code and information are provided "as is" without warranty of //
// any kind. Dissemination of this information or reproduction of //
// this material is strictly forbidden unless prior written permission //
// is obtained from Charta Software B.V.. //
// //
///////////////////////////////////////////////////////////////////////////
unit Task.Scheduler;
interface
{$SCOPEDENUMS ON}
uses
Boolean,
Collection.List,
Event.Queue,
Integer._32,
Integer._32.Interval,
Task,
Task.Group,
Task.Node,
Task.Scheduled,
Task.Scheduler.Thread,
Task.Status,
Thread.Synchronization.WaitableQueue;
type
TWaitType = (DontWait, Wait);
TTaskScheduler = class(TObject)
public
class var
Instance: TTaskScheduler;
class procedure Initialize();
class procedure Finalize();
protected
TaskSchedulerThread: TTaskSchedulerThread;
procedure ExecuteScheduledTaskRecurringly(ScheduledTask: TScheduledTask; Interval: TInteger32);
public
UserInterfaceEventQueue: TEventQueue;
constructor Create(); virtual;
destructor Destroy(); override;
procedure Execute(Task: TTask; Wait: TWaitType = TWaitType.DontWait); overload;
procedure Execute(Group: TTaskGroup; Wait: TWaitType = TWaitType.DontWait); overload;
procedure ExecuteRecurringly(Task: TTask; Interval: TInteger32);
procedure Unschedule(Node: TTaskNode);
function GetStatuses(): TList<TTaskStatus>;
function HasUserInterface(): TBoolean;
procedure ExecuteInUserInterface(Task: TTask; Wait: TWaitType);
procedure CreatePool(TaskClass: TTaskClass; const ConcurrencyRange: TInteger32Interval; MaximumQueueSize: TInteger32 = MAXIMUM_QUEUE_LENGTH);
end;
implementation
uses
Exception,
Object_.List,
Reference.User,
Task.Execution.EventQueue.Event,
Task.Execution.Exception,
Task.Node.Event,
Task.Scheduled.Event,
Thread.Event,
Thread.WaitableObject,
Windows.Api.Kernel.Thread;
{ TTaskScheduler }
constructor TTaskScheduler.Create();
begin
inherited Create();
TaskSchedulerThread := TTaskSchedulerThread.Create();
TaskSchedulerThread.Resume();
end;
procedure TTaskScheduler.CreatePool(TaskClass: TTaskClass; const ConcurrencyRange: TInteger32Interval; MaximumQueueSize: TInteger32 = MAXIMUM_QUEUE_LENGTH);
var
TaskPool: TTaskThreadPool;
begin
TaskPool := TTaskThreadPool.Create(TaskClass, ConcurrencyRange, MaximumQueueSize);
TaskPool.Pool.StatusQueue := TaskSchedulerThread.EventQueue;
TaskSchedulerThread.TaskPools.Add(TaskPool);
end;
destructor TTaskScheduler.Destroy();
begin
TaskSchedulerThread.Terminate();
TaskSchedulerThread.WaitFor(TWaitableObject.INFINITE);
TaskSchedulerThread.Free();
inherited Destroy();
end;
procedure TTaskScheduler.ExecuteScheduledTaskRecurringly(ScheduledTask: TScheduledTask; Interval: TInteger32);
begin
TaskSchedulerThread.EventQueue.Queue(TRecurringTaskStartedEvent.Create(Self, ScheduledTask, Interval));
end;
procedure TTaskScheduler.Execute(Task: TTask; Wait: TWaitType = TWaitType.DontWait);
var
ScheduledTask: TScheduledTask;
begin
ScheduledTask := TScheduledTask.Create();
ScheduledTask.AddReference();
ScheduledTask.Task := Task;
TaskSchedulerThread.EventQueue.Queue(TTaskScheduledEvent.Create(Self, ScheduledTask));
if Wait = TWaitType.Wait then
ScheduledTask.ThreadEvent.WaitFor(TWaitableObject.INFINITE);
ScheduledTask.ReleaseReference();
end;
procedure TTaskScheduler.ExecuteInUserInterface(Task: TTask; Wait: TWaitType);
var
Event: TExecuteTaskInEventQueueEvent;
begin
if not HasUserInterface() or (GetCurrentThreadId() = UserInterfaceEventQueue.ThreadIdentifier) then
begin
Task.Execute();
Task.Discard();
end
else
begin
Event := TExecuteTaskInEventQueueEvent.Create(Self, Task);
Event.Wait := Wait;
case Wait of
TWaitType.Wait:
begin
UserInterfaceEventQueue.Queue(Event);
Event.ExecutedEvent.WaitFor(TWaitableObject.INFINITE);
Event.Free();
end;
TWaitType.DontWait:
UserInterfaceEventQueue.Queue(Event);
else
raise EException.Create('Unknown wait type');
end;
end;
end;
procedure TTaskScheduler.ExecuteRecurringly(Task: TTask; Interval: TInteger32);
var
ScheduledTask: TScheduledTask;
begin
ScheduledTask := TScheduledTask.Create();
ScheduledTask.AddReference();
ScheduledTask.Task := Task;
ExecuteScheduledTaskRecurringly(ScheduledTask, Interval);
ScheduledTask.ReleaseReference();
end;
procedure TTaskScheduler.Execute(Group: TTaskGroup; Wait: TWaitType);
var
ScheduledGroup: TScheduledTaskGroup;
ScheduledTask: TScheduledTask;
Registration: TTaskRegistration;
Exceptions: TList<EException>;
begin
ScheduledGroup := TScheduledTaskGroup.Create();
ScheduledGroup.AddReference();
ScheduledGroup.TaskGroup := Group;
for Registration in Group.Tasks do
begin
ScheduledTask := TScheduledTask.Create();
ScheduledTask.Task := Registration.Task;
ScheduledTask.Dependencies.AddAll(Registration.Dependencies);
ScheduledGroup.Tasks.Add(ScheduledTask);
end;
TaskSchedulerThread.EventQueue.Queue(TTaskGroupScheduledEvent.Create(Self, ScheduledGroup));
if Wait = TWaitType.Wait then
for ScheduledTask in ScheduledGroup.Tasks do
ScheduledTask.ThreadEvent.WaitFor(TWaitableObject.INFINITE);
Exceptions := TObjectList<EException>.Create();
Exceptions.ElementManager := TReferenceUser<EException>.Create();
for ScheduledTask in ScheduledGroup.Tasks do
if ScheduledTask.Exception <> nil then
Exceptions.Add(ScheduledTask.Exception);
if Exceptions.Count > 0 then
raise ETaskGroupExecutionFailed.Create(Exceptions)
else
Exceptions.Free();
ScheduledGroup.ReleaseReference();
end;
class procedure TTaskScheduler.Finalize();
begin
Instance.Free();
end;
function TTaskScheduler.GetStatuses(): TList<TTaskStatus>;
var
Status: TTaskStatus;
begin
TaskSchedulerThread.StatusLock.Acquire();
try
Result := TObjectList<TTaskStatus>.Create();
for Status in TaskSchedulerThread.Statuses do
Result.Add(Status.Copy());
finally
TaskSchedulerThread.StatusLock.Release();
end;
end;
function TTaskScheduler.HasUserInterface(): TBoolean;
begin
Result := UserInterfaceEventQueue <> nil;
end;
class procedure TTaskScheduler.Initialize();
begin
IsMultiThread := True;
Instance := TTaskScheduler.Create();
end;
procedure TTaskScheduler.Unschedule(Node: TTaskNode);
var
UnscheduleEvent: TTaskNodeUnscheduledEvent;
CompletedEvent: TThreadEvent;
begin
CompletedEvent := TThreadEvent.Create(True, False);
UnscheduleEvent := TTaskNodeUnscheduledEvent.Create(Self, Node);
UnscheduleEvent.CompletedEvent := CompletedEvent;
TaskSchedulerThread.EventQueue.Queue(UnscheduleEvent);
CompletedEvent.WaitFor(TWaitableObject.INFINITE);
CompletedEvent.Free();
end;
initialization
TTaskScheduler.Initialize();
finalization
TTaskScheduler.Finalize();
end.
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