diff options
Diffstat (limited to 'ThirdParty/SmartThreadPool/WorkItemsQueue.cs')
-rw-r--r-- | ThirdParty/SmartThreadPool/WorkItemsQueue.cs | 973 |
1 files changed, 509 insertions, 464 deletions
diff --git a/ThirdParty/SmartThreadPool/WorkItemsQueue.cs b/ThirdParty/SmartThreadPool/WorkItemsQueue.cs index af5af07..e0bc916 100644 --- a/ThirdParty/SmartThreadPool/WorkItemsQueue.cs +++ b/ThirdParty/SmartThreadPool/WorkItemsQueue.cs | |||
@@ -1,109 +1,151 @@ | |||
1 | // Ami Bar | ||
2 | // amibar@gmail.com | ||
3 | |||
4 | using System; | 1 | using System; |
2 | using System.Collections.Generic; | ||
5 | using System.Threading; | 3 | using System.Threading; |
6 | 4 | ||
7 | namespace Amib.Threading.Internal | 5 | namespace Amib.Threading.Internal |
8 | { | 6 | { |
9 | #region WorkItemsQueue class | 7 | #region WorkItemsQueue class |
10 | 8 | ||
11 | /// <summary> | 9 | /// <summary> |
12 | /// WorkItemsQueue class. | 10 | /// WorkItemsQueue class. |
13 | /// </summary> | 11 | /// </summary> |
14 | public class WorkItemsQueue : IDisposable | 12 | public class WorkItemsQueue : IDisposable |
15 | { | 13 | { |
16 | #region Member variables | 14 | #region Member variables |
17 | 15 | ||
18 | /// <summary> | 16 | /// <summary> |
19 | /// Waiters queue (implemented as stack). | 17 | /// Waiters queue (implemented as stack). |
20 | /// </summary> | 18 | /// </summary> |
21 | private WaiterEntry _headWaiterEntry = new WaiterEntry(); | 19 | private readonly WaiterEntry _headWaiterEntry = new WaiterEntry(); |
22 | 20 | ||
23 | /// <summary> | 21 | /// <summary> |
24 | /// Waiters count | 22 | /// Waiters count |
25 | /// </summary> | 23 | /// </summary> |
26 | private int _waitersCount = 0; | 24 | private int _waitersCount = 0; |
27 | 25 | ||
28 | /// <summary> | 26 | /// <summary> |
29 | /// Work items queue | 27 | /// Work items queue |
30 | /// </summary> | 28 | /// </summary> |
31 | private PriorityQueue _workItems = new PriorityQueue(); | 29 | private readonly PriorityQueue _workItems = new PriorityQueue(); |
32 | 30 | ||
33 | /// <summary> | 31 | /// <summary> |
34 | /// Indicate that work items are allowed to be queued | 32 | /// Indicate that work items are allowed to be queued |
35 | /// </summary> | 33 | /// </summary> |
36 | private bool _isWorkItemsQueueActive = true; | 34 | private bool _isWorkItemsQueueActive = true; |
37 | 35 | ||
38 | /// <summary> | ||
39 | /// Each thread in the thread pool keeps its own waiter entry. | ||
40 | /// </summary> | ||
41 | [ThreadStatic] | ||
42 | private static WaiterEntry _waiterEntry; | ||
43 | 36 | ||
44 | /// <summary> | 37 | #if (WINDOWS_PHONE) |
45 | /// A flag that indicates if the WorkItemsQueue has been disposed. | 38 | private static readonly Dictionary<int, WaiterEntry> _waiterEntries = new Dictionary<int, WaiterEntry>(); |
46 | /// </summary> | 39 | #elif (_WINDOWS_CE) |
47 | private bool _isDisposed = false; | 40 | private static LocalDataStoreSlot _waiterEntrySlot = Thread.AllocateDataSlot(); |
41 | #else | ||
48 | 42 | ||
49 | #endregion | 43 | [ThreadStatic] |
44 | private static WaiterEntry _waiterEntry; | ||
45 | #endif | ||
50 | 46 | ||
51 | #region Public properties | ||
52 | 47 | ||
53 | /// <summary> | 48 | /// <summary> |
54 | /// Returns the current number of work items in the queue | 49 | /// Each thread in the thread pool keeps its own waiter entry. |
55 | /// </summary> | 50 | /// </summary> |
56 | public int Count | 51 | private static WaiterEntry CurrentWaiterEntry |
57 | { | 52 | { |
53 | #if (WINDOWS_PHONE) | ||
58 | get | 54 | get |
59 | { | 55 | { |
60 | lock(this) | 56 | lock (_waiterEntries) |
61 | { | 57 | { |
62 | ValidateNotDisposed(); | 58 | WaiterEntry waiterEntry; |
63 | return _workItems.Count; | 59 | if (_waiterEntries.TryGetValue(Thread.CurrentThread.ManagedThreadId, out waiterEntry)) |
60 | { | ||
61 | return waiterEntry; | ||
62 | } | ||
64 | } | 63 | } |
64 | return null; | ||
65 | } | 65 | } |
66 | } | 66 | set |
67 | |||
68 | /// <summary> | ||
69 | /// Returns the current number of waiters | ||
70 | /// </summary> | ||
71 | public int WaitersCount | ||
72 | { | ||
73 | get | ||
74 | { | 67 | { |
75 | lock(this) | 68 | lock (_waiterEntries) |
76 | { | 69 | { |
77 | ValidateNotDisposed(); | 70 | _waiterEntries[Thread.CurrentThread.ManagedThreadId] = value; |
78 | return _waitersCount; | ||
79 | } | 71 | } |
80 | } | 72 | } |
73 | #elif (_WINDOWS_CE) | ||
74 | get | ||
75 | { | ||
76 | return Thread.GetData(_waiterEntrySlot) as WaiterEntry; | ||
77 | } | ||
78 | set | ||
79 | { | ||
80 | Thread.SetData(_waiterEntrySlot, value); | ||
81 | } | ||
82 | #else | ||
83 | get | ||
84 | { | ||
85 | return _waiterEntry; | ||
86 | } | ||
87 | set | ||
88 | { | ||
89 | _waiterEntry = value; | ||
90 | } | ||
91 | #endif | ||
81 | } | 92 | } |
82 | 93 | ||
94 | /// <summary> | ||
95 | /// A flag that indicates if the WorkItemsQueue has been disposed. | ||
96 | /// </summary> | ||
97 | private bool _isDisposed = false; | ||
83 | 98 | ||
84 | #endregion | 99 | #endregion |
85 | 100 | ||
86 | #region Public methods | 101 | #region Public properties |
87 | 102 | ||
88 | /// <summary> | 103 | /// <summary> |
89 | /// Enqueue a work item to the queue. | 104 | /// Returns the current number of work items in the queue |
90 | /// </summary> | 105 | /// </summary> |
91 | public bool EnqueueWorkItem(WorkItem workItem) | 106 | public int Count |
92 | { | 107 | { |
93 | // A work item cannot be null, since null is used in the | 108 | get |
94 | // WaitForWorkItem() method to indicate timeout or cancel | 109 | { |
95 | if (null == workItem) | 110 | return _workItems.Count; |
96 | { | 111 | } |
97 | throw new ArgumentNullException("workItem" , "workItem cannot be null"); | 112 | } |
98 | } | 113 | |
114 | /// <summary> | ||
115 | /// Returns the current number of waiters | ||
116 | /// </summary> | ||
117 | public int WaitersCount | ||
118 | { | ||
119 | get | ||
120 | { | ||
121 | return _waitersCount; | ||
122 | } | ||
123 | } | ||
99 | 124 | ||
100 | bool enqueue = true; | ||
101 | 125 | ||
102 | // First check if there is a waiter waiting for work item. During | 126 | #endregion |
103 | // the check, timed out waiters are ignored. If there is no | 127 | |
104 | // waiter then the work item is queued. | 128 | #region Public methods |
105 | lock(this) | 129 | |
106 | { | 130 | /// <summary> |
131 | /// Enqueue a work item to the queue. | ||
132 | /// </summary> | ||
133 | public bool EnqueueWorkItem(WorkItem workItem) | ||
134 | { | ||
135 | // A work item cannot be null, since null is used in the | ||
136 | // WaitForWorkItem() method to indicate timeout or cancel | ||
137 | if (null == workItem) | ||
138 | { | ||
139 | throw new ArgumentNullException("workItem" , "workItem cannot be null"); | ||
140 | } | ||
141 | |||
142 | bool enqueue = true; | ||
143 | |||
144 | // First check if there is a waiter waiting for work item. During | ||
145 | // the check, timed out waiters are ignored. If there is no | ||
146 | // waiter then the work item is queued. | ||
147 | lock(this) | ||
148 | { | ||
107 | ValidateNotDisposed(); | 149 | ValidateNotDisposed(); |
108 | 150 | ||
109 | if (!_isWorkItemsQueueActive) | 151 | if (!_isWorkItemsQueueActive) |
@@ -111,56 +153,55 @@ namespace Amib.Threading.Internal | |||
111 | return false; | 153 | return false; |
112 | } | 154 | } |
113 | 155 | ||
114 | while(_waitersCount > 0) | 156 | while(_waitersCount > 0) |
115 | { | 157 | { |
116 | // Dequeue a waiter. | 158 | // Dequeue a waiter. |
117 | WaiterEntry waiterEntry = PopWaiter(); | 159 | WaiterEntry waiterEntry = PopWaiter(); |
118 | 160 | ||
119 | // Signal the waiter. On success break the loop | 161 | // Signal the waiter. On success break the loop |
120 | if (waiterEntry.Signal(workItem)) | 162 | if (waiterEntry.Signal(workItem)) |
121 | { | 163 | { |
122 | enqueue = false; | 164 | enqueue = false; |
123 | break; | 165 | break; |
124 | } | 166 | } |
125 | } | 167 | } |
126 | 168 | ||
127 | if (enqueue) | 169 | if (enqueue) |
128 | { | 170 | { |
129 | // Enqueue the work item | 171 | // Enqueue the work item |
130 | _workItems.Enqueue(workItem); | 172 | _workItems.Enqueue(workItem); |
131 | } | 173 | } |
132 | } | 174 | } |
133 | return true; | 175 | return true; |
134 | } | 176 | } |
135 | 177 | ||
136 | 178 | ||
137 | /// <summary> | 179 | /// <summary> |
138 | /// Waits for a work item or exits on timeout or cancel | 180 | /// Waits for a work item or exits on timeout or cancel |
139 | /// </summary> | 181 | /// </summary> |
140 | /// <param name="millisecondsTimeout">Timeout in milliseconds</param> | 182 | /// <param name="millisecondsTimeout">Timeout in milliseconds</param> |
141 | /// <param name="cancelEvent">Cancel wait handle</param> | 183 | /// <param name="cancelEvent">Cancel wait handle</param> |
142 | /// <returns>Returns true if the resource was granted</returns> | 184 | /// <returns>Returns true if the resource was granted</returns> |
143 | public WorkItem DequeueWorkItem( | 185 | public WorkItem DequeueWorkItem( |
144 | int millisecondsTimeout, | 186 | int millisecondsTimeout, |
145 | WaitHandle cancelEvent) | 187 | WaitHandle cancelEvent) |
146 | { | 188 | { |
147 | /// This method cause the caller to wait for a work item. | 189 | // This method cause the caller to wait for a work item. |
148 | /// If there is at least one waiting work item then the | 190 | // If there is at least one waiting work item then the |
149 | /// method returns immidiately with true. | 191 | // method returns immidiately with it. |
150 | /// | 192 | // |
151 | /// If there are no waiting work items then the caller | 193 | // If there are no waiting work items then the caller |
152 | /// is queued between other waiters for a work item to arrive. | 194 | // is queued between other waiters for a work item to arrive. |
153 | /// | 195 | // |
154 | /// If a work item didn't come within millisecondsTimeout or | 196 | // If a work item didn't come within millisecondsTimeout or |
155 | /// the user canceled the wait by signaling the cancelEvent | 197 | // the user canceled the wait by signaling the cancelEvent |
156 | /// then the method returns false to indicate that the caller | 198 | // then the method returns null to indicate that the caller |
157 | /// didn't get a work item. | 199 | // didn't get a work item. |
158 | 200 | ||
159 | WaiterEntry waiterEntry = null; | 201 | WaiterEntry waiterEntry; |
160 | WorkItem workItem = null; | 202 | WorkItem workItem = null; |
161 | 203 | lock (this) | |
162 | lock(this) | 204 | { |
163 | { | ||
164 | ValidateNotDisposed(); | 205 | ValidateNotDisposed(); |
165 | 206 | ||
166 | // If there are waiting work items then take one and return. | 207 | // If there are waiting work items then take one and return. |
@@ -169,80 +210,79 @@ namespace Amib.Threading.Internal | |||
169 | workItem = _workItems.Dequeue() as WorkItem; | 210 | workItem = _workItems.Dequeue() as WorkItem; |
170 | return workItem; | 211 | return workItem; |
171 | } | 212 | } |
172 | // No waiting work items ... | ||
173 | else | ||
174 | { | ||
175 | // Get the wait entry for the waiters queue | ||
176 | waiterEntry = GetThreadWaiterEntry(); | ||
177 | |||
178 | // Put the waiter with the other waiters | ||
179 | PushWaiter(waiterEntry); | ||
180 | } | ||
181 | } | ||
182 | |||
183 | // Prepare array of wait handle for the WaitHandle.WaitAny() | ||
184 | WaitHandle [] waitHandles = new WaitHandle [] { | ||
185 | waiterEntry.WaitHandle, | ||
186 | cancelEvent }; | ||
187 | |||
188 | // Wait for an available resource, cancel event, or timeout. | ||
189 | 213 | ||
190 | // During the wait we are supposes to exit the synchronization | 214 | // No waiting work items ... |
191 | // domain. (Placing true as the third argument of the WaitAny()) | 215 | |
192 | // It just doesn't work, I don't know why, so I have lock(this) | 216 | // Get the waiter entry for the waiters queue |
193 | // statments insted of one. | 217 | waiterEntry = GetThreadWaiterEntry(); |
194 | 218 | ||
195 | int index = WaitHandle.WaitAny( | 219 | // Put the waiter with the other waiters |
196 | waitHandles, | 220 | PushWaiter(waiterEntry); |
197 | millisecondsTimeout, | 221 | } |
198 | true); | 222 | |
199 | 223 | // Prepare array of wait handle for the WaitHandle.WaitAny() | |
200 | lock(this) | 224 | WaitHandle [] waitHandles = new WaitHandle[] { |
201 | { | 225 | waiterEntry.WaitHandle, |
202 | // success is true if it got a work item. | 226 | cancelEvent }; |
203 | bool success = (0 == index); | 227 | |
204 | 228 | // Wait for an available resource, cancel event, or timeout. | |
205 | // The timeout variable is used only for readability. | 229 | |
206 | // (We treat cancel as timeout) | 230 | // During the wait we are supposes to exit the synchronization |
207 | bool timeout = !success; | 231 | // domain. (Placing true as the third argument of the WaitAny()) |
208 | 232 | // It just doesn't work, I don't know why, so I have two lock(this) | |
209 | // On timeout update the waiterEntry that it is timed out | 233 | // statments instead of one. |
210 | if (timeout) | 234 | |
211 | { | 235 | int index = STPEventWaitHandle.WaitAny( |
212 | // The Timeout() fails if the waiter has already been signaled | 236 | waitHandles, |
213 | timeout = waiterEntry.Timeout(); | 237 | millisecondsTimeout, |
214 | 238 | true); | |
215 | // On timeout remove the waiter from the queue. | 239 | |
216 | // Note that the complexity is O(1). | 240 | lock(this) |
217 | if(timeout) | 241 | { |
218 | { | 242 | // success is true if it got a work item. |
219 | RemoveWaiter(waiterEntry, false); | 243 | bool success = (0 == index); |
220 | } | 244 | |
221 | 245 | // The timeout variable is used only for readability. | |
222 | // Again readability | 246 | // (We treat cancel as timeout) |
223 | success = !timeout; | 247 | bool timeout = !success; |
224 | } | 248 | |
225 | 249 | // On timeout update the waiterEntry that it is timed out | |
226 | // On success return the work item | 250 | if (timeout) |
227 | if (success) | 251 | { |
228 | { | 252 | // The Timeout() fails if the waiter has already been signaled |
229 | workItem = waiterEntry.WorkItem; | 253 | timeout = waiterEntry.Timeout(); |
230 | 254 | ||
231 | if (null == workItem) | 255 | // On timeout remove the waiter from the queue. |
232 | { | 256 | // Note that the complexity is O(1). |
233 | workItem = _workItems.Dequeue() as WorkItem; | 257 | if(timeout) |
234 | } | 258 | { |
235 | } | 259 | RemoveWaiter(waiterEntry, false); |
236 | } | 260 | } |
237 | // On failure return null. | 261 | |
238 | return workItem; | 262 | // Again readability |
239 | } | 263 | success = !timeout; |
264 | } | ||
265 | |||
266 | // On success return the work item | ||
267 | if (success) | ||
268 | { | ||
269 | workItem = waiterEntry.WorkItem; | ||
270 | |||
271 | if (null == workItem) | ||
272 | { | ||
273 | workItem = _workItems.Dequeue() as WorkItem; | ||
274 | } | ||
275 | } | ||
276 | } | ||
277 | // On failure return null. | ||
278 | return workItem; | ||
279 | } | ||
240 | 280 | ||
241 | /// <summary> | 281 | /// <summary> |
242 | /// Cleanup the work items queue, hence no more work | 282 | /// Cleanup the work items queue, hence no more work |
243 | /// items are allowed to be queue | 283 | /// items are allowed to be queue |
244 | /// </summary> | 284 | /// </summary> |
245 | protected virtual void Cleanup() | 285 | private void Cleanup() |
246 | { | 286 | { |
247 | lock(this) | 287 | lock(this) |
248 | { | 288 | { |
@@ -271,301 +311,312 @@ namespace Amib.Threading.Internal | |||
271 | // Tell the waiters that they were timed out. | 311 | // Tell the waiters that they were timed out. |
272 | // It won't signal them to exit, but to ignore their | 312 | // It won't signal them to exit, but to ignore their |
273 | // next work item. | 313 | // next work item. |
274 | while(_waitersCount > 0) | 314 | while(_waitersCount > 0) |
275 | { | 315 | { |
276 | WaiterEntry waiterEntry = PopWaiter(); | 316 | WaiterEntry waiterEntry = PopWaiter(); |
277 | waiterEntry.Timeout(); | 317 | waiterEntry.Timeout(); |
278 | } | 318 | } |
279 | } | 319 | } |
280 | } | 320 | } |
281 | 321 | ||
282 | #endregion | 322 | public object[] GetStates() |
283 | |||
284 | #region Private methods | ||
285 | |||
286 | /// <summary> | ||
287 | /// Returns the WaiterEntry of the current thread | ||
288 | /// </summary> | ||
289 | /// <returns></returns> | ||
290 | /// In order to avoid creation and destuction of WaiterEntry | ||
291 | /// objects each thread has its own WaiterEntry object. | ||
292 | private WaiterEntry GetThreadWaiterEntry() | ||
293 | { | 323 | { |
294 | if (null == _waiterEntry) | 324 | lock (this) |
295 | { | 325 | { |
296 | _waiterEntry = new WaiterEntry(); | 326 | object[] states = new object[_workItems.Count]; |
327 | int i = 0; | ||
328 | foreach (WorkItem workItem in _workItems) | ||
329 | { | ||
330 | states[i] = workItem.GetWorkItemResult().State; | ||
331 | ++i; | ||
332 | } | ||
333 | return states; | ||
297 | } | 334 | } |
298 | _waiterEntry.Reset(); | ||
299 | return _waiterEntry; | ||
300 | } | 335 | } |
301 | 336 | ||
302 | #region Waiters stack methods | 337 | #endregion |
303 | 338 | ||
304 | /// <summary> | 339 | #region Private methods |
305 | /// Push a new waiter into the waiter's stack | 340 | |
306 | /// </summary> | 341 | /// <summary> |
307 | /// <param name="newWaiterEntry">A waiter to put in the stack</param> | 342 | /// Returns the WaiterEntry of the current thread |
308 | public void PushWaiter(WaiterEntry newWaiterEntry) | 343 | /// </summary> |
309 | { | 344 | /// <returns></returns> |
310 | // Remove the waiter if it is already in the stack and | 345 | /// In order to avoid creation and destuction of WaiterEntry |
311 | // update waiter's count as needed | 346 | /// objects each thread has its own WaiterEntry object. |
312 | RemoveWaiter(newWaiterEntry, false); | 347 | private static WaiterEntry GetThreadWaiterEntry() |
313 | 348 | { | |
314 | // If the stack is empty then newWaiterEntry is the new head of the stack | 349 | if (null == CurrentWaiterEntry) |
315 | if (null == _headWaiterEntry._nextWaiterEntry) | 350 | { |
316 | { | 351 | CurrentWaiterEntry = new WaiterEntry(); |
317 | _headWaiterEntry._nextWaiterEntry = newWaiterEntry; | 352 | } |
318 | newWaiterEntry._prevWaiterEntry = _headWaiterEntry; | 353 | CurrentWaiterEntry.Reset(); |
319 | 354 | return CurrentWaiterEntry; | |
320 | } | 355 | } |
321 | // If the stack is not empty then put newWaiterEntry as the new head | 356 | |
322 | // of the stack. | 357 | #region Waiters stack methods |
323 | else | 358 | |
324 | { | 359 | /// <summary> |
325 | // Save the old first waiter entry | 360 | /// Push a new waiter into the waiter's stack |
326 | WaiterEntry oldFirstWaiterEntry = _headWaiterEntry._nextWaiterEntry; | 361 | /// </summary> |
362 | /// <param name="newWaiterEntry">A waiter to put in the stack</param> | ||
363 | public void PushWaiter(WaiterEntry newWaiterEntry) | ||
364 | { | ||
365 | // Remove the waiter if it is already in the stack and | ||
366 | // update waiter's count as needed | ||
367 | RemoveWaiter(newWaiterEntry, false); | ||
368 | |||
369 | // If the stack is empty then newWaiterEntry is the new head of the stack | ||
370 | if (null == _headWaiterEntry._nextWaiterEntry) | ||
371 | { | ||
372 | _headWaiterEntry._nextWaiterEntry = newWaiterEntry; | ||
373 | newWaiterEntry._prevWaiterEntry = _headWaiterEntry; | ||
374 | |||
375 | } | ||
376 | // If the stack is not empty then put newWaiterEntry as the new head | ||
377 | // of the stack. | ||
378 | else | ||
379 | { | ||
380 | // Save the old first waiter entry | ||
381 | WaiterEntry oldFirstWaiterEntry = _headWaiterEntry._nextWaiterEntry; | ||
327 | 382 | ||
328 | // Update the links | 383 | // Update the links |
329 | _headWaiterEntry._nextWaiterEntry = newWaiterEntry; | 384 | _headWaiterEntry._nextWaiterEntry = newWaiterEntry; |
330 | newWaiterEntry._nextWaiterEntry = oldFirstWaiterEntry; | 385 | newWaiterEntry._nextWaiterEntry = oldFirstWaiterEntry; |
331 | newWaiterEntry._prevWaiterEntry = _headWaiterEntry; | 386 | newWaiterEntry._prevWaiterEntry = _headWaiterEntry; |
332 | oldFirstWaiterEntry._prevWaiterEntry = newWaiterEntry; | 387 | oldFirstWaiterEntry._prevWaiterEntry = newWaiterEntry; |
333 | } | 388 | } |
334 | 389 | ||
335 | // Increment the number of waiters | 390 | // Increment the number of waiters |
336 | ++_waitersCount; | 391 | ++_waitersCount; |
337 | } | 392 | } |
338 | 393 | ||
339 | /// <summary> | 394 | /// <summary> |
340 | /// Pop a waiter from the waiter's stack | 395 | /// Pop a waiter from the waiter's stack |
341 | /// </summary> | 396 | /// </summary> |
342 | /// <returns>Returns the first waiter in the stack</returns> | 397 | /// <returns>Returns the first waiter in the stack</returns> |
343 | private WaiterEntry PopWaiter() | 398 | private WaiterEntry PopWaiter() |
344 | { | 399 | { |
345 | // Store the current stack head | 400 | // Store the current stack head |
346 | WaiterEntry oldFirstWaiterEntry = _headWaiterEntry._nextWaiterEntry; | 401 | WaiterEntry oldFirstWaiterEntry = _headWaiterEntry._nextWaiterEntry; |
347 | 402 | ||
348 | // Store the new stack head | 403 | // Store the new stack head |
349 | WaiterEntry newHeadWaiterEntry = oldFirstWaiterEntry._nextWaiterEntry; | 404 | WaiterEntry newHeadWaiterEntry = oldFirstWaiterEntry._nextWaiterEntry; |
350 | 405 | ||
351 | // Update the old stack head list links and decrement the number | 406 | // Update the old stack head list links and decrement the number |
352 | // waiters. | 407 | // waiters. |
353 | RemoveWaiter(oldFirstWaiterEntry, true); | 408 | RemoveWaiter(oldFirstWaiterEntry, true); |
354 | 409 | ||
355 | // Update the new stack head | 410 | // Update the new stack head |
356 | _headWaiterEntry._nextWaiterEntry = newHeadWaiterEntry; | 411 | _headWaiterEntry._nextWaiterEntry = newHeadWaiterEntry; |
357 | if (null != newHeadWaiterEntry) | 412 | if (null != newHeadWaiterEntry) |
358 | { | 413 | { |
359 | newHeadWaiterEntry._prevWaiterEntry = _headWaiterEntry; | 414 | newHeadWaiterEntry._prevWaiterEntry = _headWaiterEntry; |
360 | } | 415 | } |
361 | 416 | ||
362 | // Return the old stack head | 417 | // Return the old stack head |
363 | return oldFirstWaiterEntry; | 418 | return oldFirstWaiterEntry; |
364 | } | 419 | } |
365 | 420 | ||
366 | /// <summary> | 421 | /// <summary> |
367 | /// Remove a waiter from the stack | 422 | /// Remove a waiter from the stack |
368 | /// </summary> | 423 | /// </summary> |
369 | /// <param name="waiterEntry">A waiter entry to remove</param> | 424 | /// <param name="waiterEntry">A waiter entry to remove</param> |
370 | /// <param name="popDecrement">If true the waiter count is always decremented</param> | 425 | /// <param name="popDecrement">If true the waiter count is always decremented</param> |
371 | private void RemoveWaiter(WaiterEntry waiterEntry, bool popDecrement) | 426 | private void RemoveWaiter(WaiterEntry waiterEntry, bool popDecrement) |
372 | { | 427 | { |
373 | // Store the prev entry in the list | 428 | // Store the prev entry in the list |
374 | WaiterEntry prevWaiterEntry = waiterEntry._prevWaiterEntry; | 429 | WaiterEntry prevWaiterEntry = waiterEntry._prevWaiterEntry; |
375 | 430 | ||
376 | // Store the next entry in the list | 431 | // Store the next entry in the list |
377 | WaiterEntry nextWaiterEntry = waiterEntry._nextWaiterEntry; | 432 | WaiterEntry nextWaiterEntry = waiterEntry._nextWaiterEntry; |
378 | 433 | ||
379 | // A flag to indicate if we need to decrement the waiters count. | 434 | // A flag to indicate if we need to decrement the waiters count. |
380 | // If we got here from PopWaiter then we must decrement. | 435 | // If we got here from PopWaiter then we must decrement. |
381 | // If we got here from PushWaiter then we decrement only if | 436 | // If we got here from PushWaiter then we decrement only if |
382 | // the waiter was already in the stack. | 437 | // the waiter was already in the stack. |
383 | bool decrementCounter = popDecrement; | 438 | bool decrementCounter = popDecrement; |
384 | 439 | ||
385 | // Null the waiter's entry links | 440 | // Null the waiter's entry links |
386 | waiterEntry._prevWaiterEntry = null; | 441 | waiterEntry._prevWaiterEntry = null; |
387 | waiterEntry._nextWaiterEntry = null; | 442 | waiterEntry._nextWaiterEntry = null; |
388 | 443 | ||
389 | // If the waiter entry had a prev link then update it. | 444 | // If the waiter entry had a prev link then update it. |
390 | // It also means that the waiter is already in the list and we | 445 | // It also means that the waiter is already in the list and we |
391 | // need to decrement the waiters count. | 446 | // need to decrement the waiters count. |
392 | if (null != prevWaiterEntry) | 447 | if (null != prevWaiterEntry) |
393 | { | 448 | { |
394 | prevWaiterEntry._nextWaiterEntry = nextWaiterEntry; | 449 | prevWaiterEntry._nextWaiterEntry = nextWaiterEntry; |
395 | decrementCounter = true; | 450 | decrementCounter = true; |
396 | } | 451 | } |
397 | 452 | ||
398 | // If the waiter entry had a next link then update it. | 453 | // If the waiter entry had a next link then update it. |
399 | // It also means that the waiter is already in the list and we | 454 | // It also means that the waiter is already in the list and we |
400 | // need to decrement the waiters count. | 455 | // need to decrement the waiters count. |
401 | if (null != nextWaiterEntry) | 456 | if (null != nextWaiterEntry) |
402 | { | 457 | { |
403 | nextWaiterEntry._prevWaiterEntry = prevWaiterEntry; | 458 | nextWaiterEntry._prevWaiterEntry = prevWaiterEntry; |
404 | decrementCounter = true; | 459 | decrementCounter = true; |
405 | } | 460 | } |
406 | 461 | ||
407 | // Decrement the waiters count if needed | 462 | // Decrement the waiters count if needed |
408 | if (decrementCounter) | 463 | if (decrementCounter) |
409 | { | 464 | { |
410 | --_waitersCount; | 465 | --_waitersCount; |
411 | } | 466 | } |
412 | } | 467 | } |
413 | 468 | ||
414 | #endregion | 469 | #endregion |
415 | 470 | ||
416 | #endregion | 471 | #endregion |
417 | 472 | ||
418 | #region WaiterEntry class | 473 | #region WaiterEntry class |
419 | 474 | ||
420 | // A waiter entry in the _waiters queue. | 475 | // A waiter entry in the _waiters queue. |
421 | public class WaiterEntry : IDisposable | 476 | public sealed class WaiterEntry : IDisposable |
422 | { | 477 | { |
423 | #region Member variables | 478 | #region Member variables |
424 | 479 | ||
425 | /// <summary> | 480 | /// <summary> |
426 | /// Event to signal the waiter that it got the work item. | 481 | /// Event to signal the waiter that it got the work item. |
427 | /// </summary> | 482 | /// </summary> |
428 | private AutoResetEvent _waitHandle = new AutoResetEvent(false); | 483 | //private AutoResetEvent _waitHandle = new AutoResetEvent(false); |
429 | 484 | private AutoResetEvent _waitHandle = EventWaitHandleFactory.CreateAutoResetEvent(); | |
430 | /// <summary> | 485 | |
431 | /// Flag to know if this waiter already quited from the queue | 486 | /// <summary> |
432 | /// because of a timeout. | 487 | /// Flag to know if this waiter already quited from the queue |
433 | /// </summary> | 488 | /// because of a timeout. |
434 | private bool _isTimedout = false; | 489 | /// </summary> |
435 | 490 | private bool _isTimedout = false; | |
436 | /// <summary> | 491 | |
437 | /// Flag to know if the waiter was signaled and got a work item. | 492 | /// <summary> |
438 | /// </summary> | 493 | /// Flag to know if the waiter was signaled and got a work item. |
439 | private bool _isSignaled = false; | 494 | /// </summary> |
495 | private bool _isSignaled = false; | ||
440 | 496 | ||
441 | /// <summary> | 497 | /// <summary> |
442 | /// A work item that passed directly to the waiter withou going | 498 | /// A work item that passed directly to the waiter withou going |
443 | /// through the queue | 499 | /// through the queue |
444 | /// </summary> | 500 | /// </summary> |
445 | private WorkItem _workItem = null; | 501 | private WorkItem _workItem = null; |
446 | 502 | ||
447 | private bool _isDisposed = false; | 503 | private bool _isDisposed = false; |
448 | 504 | ||
449 | // Linked list members | 505 | // Linked list members |
450 | internal WaiterEntry _nextWaiterEntry = null; | 506 | internal WaiterEntry _nextWaiterEntry = null; |
451 | internal WaiterEntry _prevWaiterEntry = null; | 507 | internal WaiterEntry _prevWaiterEntry = null; |
452 | 508 | ||
453 | #endregion | 509 | #endregion |
454 | 510 | ||
455 | #region Construction | 511 | #region Construction |
456 | 512 | ||
457 | public WaiterEntry() | 513 | public WaiterEntry() |
458 | { | 514 | { |
459 | Reset(); | 515 | Reset(); |
460 | } | 516 | } |
461 | 517 | ||
462 | #endregion | 518 | #endregion |
463 | 519 | ||
464 | #region Public methods | 520 | #region Public methods |
465 | 521 | ||
466 | public WaitHandle WaitHandle | 522 | public WaitHandle WaitHandle |
467 | { | 523 | { |
468 | get { return _waitHandle; } | 524 | get { return _waitHandle; } |
469 | } | 525 | } |
470 | 526 | ||
471 | public WorkItem WorkItem | 527 | public WorkItem WorkItem |
472 | { | 528 | { |
473 | get | 529 | get |
474 | { | 530 | { |
475 | lock(this) | 531 | return _workItem; |
476 | { | 532 | } |
477 | return _workItem; | 533 | } |
478 | } | 534 | |
479 | } | 535 | /// <summary> |
480 | } | 536 | /// Signal the waiter that it got a work item. |
481 | 537 | /// </summary> | |
482 | /// <summary> | 538 | /// <returns>Return true on success</returns> |
483 | /// Signal the waiter that it got a work item. | 539 | /// The method fails if Timeout() preceded its call |
484 | /// </summary> | 540 | public bool Signal(WorkItem workItem) |
485 | /// <returns>Return true on success</returns> | 541 | { |
486 | /// The method fails if Timeout() preceded its call | 542 | lock(this) |
487 | public bool Signal(WorkItem workItem) | 543 | { |
488 | { | 544 | if (!_isTimedout) |
489 | lock(this) | 545 | { |
490 | { | 546 | _workItem = workItem; |
491 | if (!_isTimedout) | 547 | _isSignaled = true; |
492 | { | 548 | _waitHandle.Set(); |
493 | _workItem = workItem; | 549 | return true; |
494 | _isSignaled = true; | 550 | } |
495 | _waitHandle.Set(); | 551 | } |
496 | return true; | 552 | return false; |
497 | } | 553 | } |
498 | } | 554 | |
499 | return false; | 555 | /// <summary> |
500 | } | 556 | /// Mark the wait entry that it has been timed out |
501 | 557 | /// </summary> | |
502 | /// <summary> | 558 | /// <returns>Return true on success</returns> |
503 | /// Mark the wait entry that it has been timed out | 559 | /// The method fails if Signal() preceded its call |
504 | /// </summary> | 560 | public bool Timeout() |
505 | /// <returns>Return true on success</returns> | 561 | { |
506 | /// The method fails if Signal() preceded its call | 562 | lock(this) |
507 | public bool Timeout() | 563 | { |
508 | { | 564 | // Time out can happen only if the waiter wasn't marked as |
509 | lock(this) | 565 | // signaled |
566 | if (!_isSignaled) | ||
567 | { | ||
568 | // We don't remove the waiter from the queue, the DequeueWorkItem | ||
569 | // method skips _waiters that were timed out. | ||
570 | _isTimedout = true; | ||
571 | return true; | ||
572 | } | ||
573 | } | ||
574 | return false; | ||
575 | } | ||
576 | |||
577 | /// <summary> | ||
578 | /// Reset the wait entry so it can be used again | ||
579 | /// </summary> | ||
580 | public void Reset() | ||
581 | { | ||
582 | _workItem = null; | ||
583 | _isTimedout = false; | ||
584 | _isSignaled = false; | ||
585 | _waitHandle.Reset(); | ||
586 | } | ||
587 | |||
588 | /// <summary> | ||
589 | /// Free resources | ||
590 | /// </summary> | ||
591 | public void Close() | ||
592 | { | ||
593 | if (null != _waitHandle) | ||
594 | { | ||
595 | _waitHandle.Close(); | ||
596 | _waitHandle = null; | ||
597 | } | ||
598 | } | ||
599 | |||
600 | #endregion | ||
601 | |||
602 | #region IDisposable Members | ||
603 | |||
604 | public void Dispose() | ||
605 | { | ||
606 | lock (this) | ||
510 | { | 607 | { |
511 | // Time out can happen only if the waiter wasn't marked as | 608 | if (!_isDisposed) |
512 | // signaled | ||
513 | if (!_isSignaled) | ||
514 | { | 609 | { |
515 | // We don't remove the waiter from the queue, the DequeueWorkItem | 610 | Close(); |
516 | // method skips _waiters that were timed out. | ||
517 | _isTimedout = true; | ||
518 | return true; | ||
519 | } | 611 | } |
520 | } | ||
521 | return false; | ||
522 | } | ||
523 | |||
524 | /// <summary> | ||
525 | /// Reset the wait entry so it can be used again | ||
526 | /// </summary> | ||
527 | public void Reset() | ||
528 | { | ||
529 | _workItem = null; | ||
530 | _isTimedout = false; | ||
531 | _isSignaled = false; | ||
532 | _waitHandle.Reset(); | ||
533 | } | ||
534 | |||
535 | /// <summary> | ||
536 | /// Free resources | ||
537 | /// </summary> | ||
538 | public void Close() | ||
539 | { | ||
540 | if (null != _waitHandle) | ||
541 | { | ||
542 | _waitHandle.Close(); | ||
543 | _waitHandle = null; | ||
544 | } | ||
545 | } | ||
546 | |||
547 | #endregion | ||
548 | |||
549 | #region IDisposable Members | ||
550 | |||
551 | public void Dispose() | ||
552 | { | ||
553 | if (!_isDisposed) | ||
554 | { | ||
555 | Close(); | ||
556 | _isDisposed = true; | 612 | _isDisposed = true; |
557 | } | 613 | } |
558 | } | 614 | } |
559 | 615 | ||
560 | ~WaiterEntry() | 616 | #endregion |
561 | { | 617 | } |
562 | Dispose(); | ||
563 | } | ||
564 | 618 | ||
565 | #endregion | 619 | #endregion |
566 | } | ||
567 | |||
568 | #endregion | ||
569 | 620 | ||
570 | #region IDisposable Members | 621 | #region IDisposable Members |
571 | 622 | ||
@@ -574,14 +625,8 @@ namespace Amib.Threading.Internal | |||
574 | if (!_isDisposed) | 625 | if (!_isDisposed) |
575 | { | 626 | { |
576 | Cleanup(); | 627 | Cleanup(); |
577 | _isDisposed = true; | ||
578 | GC.SuppressFinalize(this); | ||
579 | } | 628 | } |
580 | } | 629 | _isDisposed = true; |
581 | |||
582 | ~WorkItemsQueue() | ||
583 | { | ||
584 | Cleanup(); | ||
585 | } | 630 | } |
586 | 631 | ||
587 | private void ValidateNotDisposed() | 632 | private void ValidateNotDisposed() |
@@ -595,6 +640,6 @@ namespace Amib.Threading.Internal | |||
595 | #endregion | 640 | #endregion |
596 | } | 641 | } |
597 | 642 | ||
598 | #endregion | 643 | #endregion |
599 | } | 644 | } |
600 | 645 | ||