aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/ThirdParty/SmartThreadPool/Interfaces.cs
blob: 29c8a3e766451614c8fdcd4ff788b7279708de8e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
using System;
using System.Threading;

namespace Amib.Threading
{
	#region Delegates

	/// <summary>
	/// A delegate that represents the method to run as the work item
	/// </summary>
	/// <param name="state">A state object for the method to run</param>
	public delegate object WorkItemCallback(object state);

	/// <summary>
	/// A delegate to call after the WorkItemCallback completed
	/// </summary>
	/// <param name="wir">The work item result object</param>
    public delegate void PostExecuteWorkItemCallback(IWorkItemResult wir);

    /// <summary>
    /// A delegate to call after the WorkItemCallback completed
    /// </summary>
    /// <param name="wir">The work item result object</param>
    public delegate void PostExecuteWorkItemCallback<TResult>(IWorkItemResult<TResult> wir);

	/// <summary>
	/// A delegate to call when a WorkItemsGroup becomes idle
	/// </summary>
	/// <param name="workItemsGroup">A reference to the WorkItemsGroup that became idle</param>
	public delegate void WorkItemsGroupIdleHandler(IWorkItemsGroup workItemsGroup);

    /// <summary>
    /// A delegate to call after a thread is created, but before 
    /// it's first use.
    /// </summary>
    public delegate void ThreadInitializationHandler();

    /// <summary>
    /// A delegate to call when a thread is about to exit, after 
    /// it is no longer belong to the pool.
    /// </summary>
    public delegate void ThreadTerminationHandler();

	#endregion

	#region WorkItem Priority

    /// <summary>
    /// Defines the availeable priorities of a work item.
    /// The higher the priority a work item has, the sooner
    /// it will be executed.
    /// </summary>
	public enum WorkItemPriority
	{
		Lowest,
		BelowNormal,
		Normal,
		AboveNormal,
		Highest,
	}

	#endregion

	#region IWorkItemsGroup interface 

	/// <summary>
	/// IWorkItemsGroup interface
    /// Created by SmartThreadPool.CreateWorkItemsGroup()
	/// </summary>
	public interface IWorkItemsGroup
	{
		/// <summary>
		/// Get/Set the name of the WorkItemsGroup
		/// </summary>
		string Name { get; set; }

        /// <summary>
        /// Get/Set the maximum number of workitem that execute cocurrency on the thread pool
        /// </summary>
        int Concurrency { get; set; }

        /// <summary>
        /// Get the number of work items waiting in the queue.
        /// </summary>
        int WaitingCallbacks { get; }

        /// <summary>
        /// Get an array with all the state objects of the currently running items.
        /// The array represents a snap shot and impact performance.
        /// </summary>
        object[] GetStates();

        /// <summary>
        /// Get the WorkItemsGroup start information
        /// </summary>
        WIGStartInfo WIGStartInfo { get; }

        /// <summary>
        /// Starts to execute work items
        /// </summary>
        void Start();

        /// <summary>
        /// Cancel all the work items.
        /// Same as Cancel(false)
        /// </summary>
        void Cancel();

        /// <summary>
        /// Cancel all work items using thread abortion
        /// </summary>
        /// <param name="abortExecution">True to stop work items by raising ThreadAbortException</param>
        void Cancel(bool abortExecution);

        /// <summary>
        /// Wait for all work item to complete.
        /// </summary>
		void WaitForIdle();

        /// <summary>
        /// Wait for all work item to complete, until timeout expired
        /// </summary>
        /// <param name="timeout">How long to wait for the work items to complete</param>
        /// <returns>Returns true if work items completed within the timeout, otherwise false.</returns>
		bool WaitForIdle(TimeSpan timeout);

        /// <summary>
        /// Wait for all work item to complete, until timeout expired
        /// </summary>
        /// <param name="millisecondsTimeout">How long to wait for the work items to complete in milliseconds</param>
        /// <returns>Returns true if work items completed within the timeout, otherwise false.</returns>
        bool WaitForIdle(int millisecondsTimeout);

        /// <summary>
        /// IsIdle is true when there are no work items running or queued.
        /// </summary>
        bool IsIdle { get; }

        /// <summary>
        /// This event is fired when all work items are completed.
        /// (When IsIdle changes to true)
        /// This event only work on WorkItemsGroup. On SmartThreadPool
        /// it throws the NotImplementedException.
        /// </summary>
        event WorkItemsGroupIdleHandler OnIdle;

        #region QueueWorkItem

        /// <summary>
        /// Queue a work item
        /// </summary>
        /// <param name="callback">A callback to execute</param>
        /// <returns>Returns a work item result</returns>        
        IWorkItemResult QueueWorkItem(WorkItemCallback callback);

        /// <summary>
        /// Queue a work item
        /// </summary>
        /// <param name="callback">A callback to execute</param>
        /// <param name="workItemPriority">The priority of the work item</param>
        /// <returns>Returns a work item result</returns>
        IWorkItemResult QueueWorkItem(WorkItemCallback callback, WorkItemPriority workItemPriority);

        /// <summary>
        /// Queue a work item
        /// </summary>
        /// <param name="callback">A callback to execute</param>
        /// <param name="state">
        /// The context object of the work item. Used for passing arguments to the work item. 
        /// </param>
        /// <returns>Returns a work item result</returns>
        IWorkItemResult QueueWorkItem(WorkItemCallback callback, object state);

        /// <summary>
        /// Queue a work item
        /// </summary>
        /// <param name="callback">A callback to execute</param>
        /// <param name="state">
        /// The context object of the work item. Used for passing arguments to the work item. 
        /// </param>
        /// <param name="workItemPriority">The work item priority</param>
        /// <returns>Returns a work item result</returns>
        IWorkItemResult QueueWorkItem(WorkItemCallback callback, object state, WorkItemPriority workItemPriority);

        /// <summary>
        /// Queue a work item
        /// </summary>
        /// <param name="callback">A callback to execute</param>
        /// <param name="state">
        /// The context object of the work item. Used for passing arguments to the work item. 
        /// </param>
        /// <param name="postExecuteWorkItemCallback">
        /// A delegate to call after the callback completion
        /// </param>
        /// <returns>Returns a work item result</returns>
        IWorkItemResult QueueWorkItem(WorkItemCallback callback, object state, PostExecuteWorkItemCallback postExecuteWorkItemCallback);

        /// <summary>
        /// Queue a work item
        /// </summary>
        /// <param name="callback">A callback to execute</param>
        /// <param name="state">
        /// The context object of the work item. Used for passing arguments to the work item. 
        /// </param>
        /// <param name="postExecuteWorkItemCallback">
        /// A delegate to call after the callback completion
        /// </param>
        /// <param name="workItemPriority">The work item priority</param>
        /// <returns>Returns a work item result</returns>
        IWorkItemResult QueueWorkItem(WorkItemCallback callback, object state, PostExecuteWorkItemCallback postExecuteWorkItemCallback, WorkItemPriority workItemPriority);

        /// <summary>
        /// Queue a work item
        /// </summary>
        /// <param name="callback">A callback to execute</param>
        /// <param name="state">
        /// The context object of the work item. Used for passing arguments to the work item. 
        /// </param>
        /// <param name="postExecuteWorkItemCallback">
        /// A delegate to call after the callback completion
        /// </param>
        /// <param name="callToPostExecute">Indicates on which cases to call to the post execute callback</param>
        /// <returns>Returns a work item result</returns>
        IWorkItemResult QueueWorkItem(WorkItemCallback callback, object state, PostExecuteWorkItemCallback postExecuteWorkItemCallback, CallToPostExecute callToPostExecute);

        /// <summary>
        /// Queue a work item
        /// </summary>
        /// <param name="callback">A callback to execute</param>
        /// <param name="state">
        /// The context object of the work item. Used for passing arguments to the work item. 
        /// </param>
        /// <param name="postExecuteWorkItemCallback">
        /// A delegate to call after the callback completion
        /// </param>
        /// <param name="callToPostExecute">Indicates on which cases to call to the post execute callback</param>
        /// <param name="workItemPriority">The work item priority</param>
        /// <returns>Returns a work item result</returns>
        IWorkItemResult QueueWorkItem(WorkItemCallback callback, object state, PostExecuteWorkItemCallback postExecuteWorkItemCallback, CallToPostExecute callToPostExecute, WorkItemPriority workItemPriority);

        /// <summary>
        /// Queue a work item
        /// </summary>
        /// <param name="workItemInfo">Work item info</param>
        /// <param name="callback">A callback to execute</param>
        /// <returns>Returns a work item result</returns>
        IWorkItemResult QueueWorkItem(WorkItemInfo workItemInfo, WorkItemCallback callback);

        /// <summary>
        /// Queue a work item
        /// </summary>
        /// <param name="workItemInfo">Work item information</param>
        /// <param name="callback">A callback to execute</param>
        /// <param name="state">
        /// The context object of the work item. Used for passing arguments to the work item. 
        /// </param>
        /// <returns>Returns a work item result</returns>
        IWorkItemResult QueueWorkItem(WorkItemInfo workItemInfo, WorkItemCallback callback, object state);

        #endregion

        #region QueueWorkItem(Action<...>)

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult object, but its GetResult() will always return null</returns>
        IWorkItemResult QueueWorkItem(Action action);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult object, but its GetResult() will always return null</returns>
        IWorkItemResult QueueWorkItem (Action action, WorkItemPriority priority);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult object, but its GetResult() will always return null</returns>
        IWorkItemResult QueueWorkItem<T> (Action<T> action, T arg, WorkItemPriority priority);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult object, but its GetResult() will always return null</returns>
        IWorkItemResult QueueWorkItem<T> (Action<T> action, T arg);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult object, but its GetResult() will always return null</returns>
        IWorkItemResult QueueWorkItem<T1, T2>(Action<T1, T2> action, T1 arg1, T2 arg2);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult object, but its GetResult() will always return null</returns>
        IWorkItemResult QueueWorkItem<T1, T2> (Action<T1, T2> action, T1 arg1, T2 arg2, WorkItemPriority priority);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult object, but its GetResult() will always return null</returns>
        IWorkItemResult QueueWorkItem<T1, T2, T3>(Action<T1, T2, T3> action, T1 arg1, T2 arg2, T3 arg3);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult object, but its GetResult() will always return null</returns>
        IWorkItemResult QueueWorkItem<T1, T2, T3> (Action<T1, T2, T3> action, T1 arg1, T2 arg2, T3 arg3, WorkItemPriority priority);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult object, but its GetResult() will always return null</returns>
        IWorkItemResult QueueWorkItem<T1, T2, T3, T4>(Action<T1, T2, T3, T4> action, T1 arg1, T2 arg2, T3 arg3, T4 arg4);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult object, but its GetResult() will always return null</returns>
        IWorkItemResult QueueWorkItem<T1, T2, T3, T4> (Action<T1, T2, T3, T4> action, T1 arg1, T2 arg2, T3 arg3, T4 arg4, WorkItemPriority priority);

        #endregion

        #region QueueWorkItem(Func<...>)

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult&lt;TResult&gt; object. 
        /// its GetResult() returns a TResult object</returns>
        IWorkItemResult<TResult> QueueWorkItem<TResult>(Func<TResult> func);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult&lt;TResult&gt; object. 
        /// its GetResult() returns a TResult object</returns>
        IWorkItemResult<TResult> QueueWorkItem<T, TResult>(Func<T, TResult> func, T arg);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult&lt;TResult&gt; object. 
        /// its GetResult() returns a TResult object</returns>
        IWorkItemResult<TResult> QueueWorkItem<T1, T2, TResult>(Func<T1, T2, TResult> func, T1 arg1, T2 arg2);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult&lt;TResult&gt; object. 
        /// its GetResult() returns a TResult object</returns>
        IWorkItemResult<TResult> QueueWorkItem<T1, T2, T3, TResult>(Func<T1, T2, T3, TResult> func, T1 arg1, T2 arg2, T3 arg3);

        /// <summary>
        /// Queue a work item.
        /// </summary>
        /// <returns>Returns a IWorkItemResult&lt;TResult&gt; object. 
        /// its GetResult() returns a TResult object</returns>
        IWorkItemResult<TResult> QueueWorkItem<T1, T2, T3, T4, TResult>(Func<T1, T2, T3, T4, TResult> func, T1 arg1, T2 arg2, T3 arg3, T4 arg4);

        #endregion
    }

	#endregion

	#region CallToPostExecute enumerator

	[Flags]
	public enum CallToPostExecute
	{
        /// <summary>
        /// Never call to the PostExecute call back
        /// </summary>
		Never                    = 0x00,

        /// <summary>
        /// Call to the PostExecute only when the work item is cancelled
        /// </summary>
		WhenWorkItemCanceled     = 0x01,

        /// <summary>
        /// Call to the PostExecute only when the work item is not cancelled
        /// </summary>
		WhenWorkItemNotCanceled  = 0x02,

        /// <summary>
        /// Always call to the PostExecute
        /// </summary>
		Always                   = WhenWorkItemCanceled | WhenWorkItemNotCanceled,
	}

	#endregion

	#region IWorkItemResult interface

    /// <summary>
    /// The common interface of IWorkItemResult and IWorkItemResult&lt;T&gt;
    /// </summary>
    public interface IWaitableResult
    {
        /// <summary>
        /// This method intent is for internal use.
        /// </summary>
        /// <returns></returns>
        IWorkItemResult GetWorkItemResult();

        /// <summary>
        /// This method intent is for internal use.
        /// </summary>
        /// <returns></returns>
        IWorkItemResult<TResult> GetWorkItemResultT<TResult>();
    }

    /// <summary>
    /// IWorkItemResult interface.
    /// Created when a WorkItemCallback work item is queued.
    /// </summary>
    public interface IWorkItemResult : IWorkItemResult<object>
    {
    }

	/// <summary>
    /// IWorkItemResult&lt;TResult&gt; interface.
    /// Created when a Func&lt;TResult&gt; work item is queued.
	/// </summary>
    public interface IWorkItemResult<TResult> : IWaitableResult
	{
		/// <summary>
		/// Get the result of the work item.
		/// If the work item didn't run yet then the caller waits.
		/// </summary>
		/// <returns>The result of the work item</returns>
        TResult GetResult();

		/// <summary>
		/// Get the result of the work item.
		/// If the work item didn't run yet then the caller waits until timeout.
		/// </summary>
		/// <returns>The result of the work item</returns>
		/// On timeout throws WorkItemTimeoutException
        TResult GetResult(
			int millisecondsTimeout,
			bool exitContext);

		/// <summary>
		/// Get the result of the work item.
		/// If the work item didn't run yet then the caller waits until timeout.
		/// </summary>
		/// <returns>The result of the work item</returns>
		/// On timeout throws WorkItemTimeoutException
        TResult GetResult(			
			TimeSpan timeout,
			bool exitContext);

		/// <summary>
		/// Get the result of the work item.
		/// If the work item didn't run yet then the caller waits until timeout or until the cancelWaitHandle is signaled.
		/// </summary>
		/// <param name="millisecondsTimeout">Timeout in milliseconds, or -1 for infinite</param>
		/// <param name="exitContext">
		/// true to exit the synchronization domain for the context before the wait (if in a synchronized context), and reacquire it; otherwise, false. 
		/// </param>
		/// <param name="cancelWaitHandle">A cancel wait handle to interrupt the blocking if needed</param>
		/// <returns>The result of the work item</returns>
		/// On timeout throws WorkItemTimeoutException
		/// On cancel throws WorkItemCancelException
        TResult GetResult(			
			int millisecondsTimeout,
			bool exitContext,
			WaitHandle cancelWaitHandle);

		/// <summary>
		/// Get the result of the work item.
		/// If the work item didn't run yet then the caller waits until timeout or until the cancelWaitHandle is signaled.
		/// </summary>
		/// <returns>The result of the work item</returns>
		/// On timeout throws WorkItemTimeoutException
		/// On cancel throws WorkItemCancelException
        TResult GetResult(			
			TimeSpan timeout,
			bool exitContext,
			WaitHandle cancelWaitHandle);

		/// <summary>
		/// Get the result of the work item.
		/// If the work item didn't run yet then the caller waits.
		/// </summary>
		/// <param name="e">Filled with the exception if one was thrown</param>
		/// <returns>The result of the work item</returns>
        TResult GetResult(out Exception e);

		/// <summary>
		/// Get the result of the work item.
		/// If the work item didn't run yet then the caller waits until timeout.
		/// </summary>
		/// <param name="millisecondsTimeout"></param>
		/// <param name="exitContext"></param>
		/// <param name="e">Filled with the exception if one was thrown</param>
		/// <returns>The result of the work item</returns>
		/// On timeout throws WorkItemTimeoutException
        TResult GetResult(
			int millisecondsTimeout,
			bool exitContext,
			out Exception e);

		/// <summary>
		/// Get the result of the work item.
		/// If the work item didn't run yet then the caller waits until timeout.
		/// </summary>
		/// <param name="exitContext"></param>
		/// <param name="e">Filled with the exception if one was thrown</param>
		/// <param name="timeout"></param>
		/// <returns>The result of the work item</returns>
		/// On timeout throws WorkItemTimeoutException
        TResult GetResult(			
			TimeSpan timeout,
			bool exitContext,
			out Exception e);

		/// <summary>
		/// Get the result of the work item.
		/// If the work item didn't run yet then the caller waits until timeout or until the cancelWaitHandle is signaled.
		/// </summary>
		/// <param name="millisecondsTimeout">Timeout in milliseconds, or -1 for infinite</param>
		/// <param name="exitContext">
		/// true to exit the synchronization domain for the context before the wait (if in a synchronized context), and reacquire it; otherwise, false. 
		/// </param>
		/// <param name="cancelWaitHandle">A cancel wait handle to interrupt the blocking if needed</param>
		/// <param name="e">Filled with the exception if one was thrown</param>
		/// <returns>The result of the work item</returns>
		/// On timeout throws WorkItemTimeoutException
		/// On cancel throws WorkItemCancelException
        TResult GetResult(			
			int millisecondsTimeout,
			bool exitContext,
			WaitHandle cancelWaitHandle,
			out Exception e);

		/// <summary>
		/// Get the result of the work item.
		/// If the work item didn't run yet then the caller waits until timeout or until the cancelWaitHandle is signaled.
		/// </summary>
		/// <returns>The result of the work item</returns>
		/// <param name="cancelWaitHandle"></param>
		/// <param name="e">Filled with the exception if one was thrown</param>
		/// <param name="timeout"></param>
		/// <param name="exitContext"></param>
		/// On timeout throws WorkItemTimeoutException
		/// On cancel throws WorkItemCancelException
        TResult GetResult(			
			TimeSpan timeout,
			bool exitContext,
			WaitHandle cancelWaitHandle,
			out Exception e);

		/// <summary>
		/// Gets an indication whether the asynchronous operation has completed.
		/// </summary>
		bool IsCompleted { get; }

		/// <summary>
		/// Gets an indication whether the asynchronous operation has been canceled.
		/// </summary>
		bool IsCanceled { get; }

		/// <summary>
		/// Gets the user-defined object that contains context data 
        /// for the work item method.
		/// </summary>
		object State { get; }

		/// <summary>
        /// Same as Cancel(false).
		/// </summary>
        bool Cancel();

        /// <summary>
        /// Cancel the work item execution.
        /// If the work item is in the queue then it won't execute
        /// If the work item is completed, it will remain completed
        /// If the work item is in progress then the user can check the SmartThreadPool.IsWorkItemCanceled
        ///   property to check if the work item has been cancelled. If the abortExecution is set to true then
        ///   the Smart Thread Pool will send an AbortException to the running thread to stop the execution 
        ///   of the work item. When an in progress work item is canceled its GetResult will throw WorkItemCancelException.
        /// If the work item is already cancelled it will remain cancelled
        /// </summary>
        /// <param name="abortExecution">When true send an AbortException to the executing thread.</param>
        /// <returns>Returns true if the work item was not completed, otherwise false.</returns>
        bool Cancel(bool abortExecution);

		/// <summary>
		/// Get the work item's priority
		/// </summary>
		WorkItemPriority WorkItemPriority { get; }

		/// <summary>
		/// Return the result, same as GetResult()
		/// </summary>
        TResult Result { get; }

		/// <summary>
		/// Returns the exception if occured otherwise returns null.
		/// </summary>
		object Exception { get; }
	}

	#endregion

    #region .NET 3.5

    // All these delegate are built-in .NET 3.5
    // Comment/Remove them when compiling to .NET 3.5 to avoid ambiguity.

    public delegate void Action();
    public delegate void Action<T1, T2>(T1 arg1, T2 arg2);
    public delegate void Action<T1, T2, T3>(T1 arg1, T2 arg2, T3 arg3);
    public delegate void Action<T1, T2, T3, T4>(T1 arg1, T2 arg2, T3 arg3, T4 arg4);

    public delegate TResult Func<TResult>();
    public delegate TResult Func<T, TResult>(T arg1);
    public delegate TResult Func<T1, T2, TResult>(T1 arg1, T2 arg2);
    public delegate TResult Func<T1, T2, T3, TResult>(T1 arg1, T2 arg2, T3 arg3);
    public delegate TResult Func<T1, T2, T3, T4, TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4);

    #endregion
}