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Diffstat (limited to 'ThirdParty/SmartThreadPool/WorkItemsQueue.cs')
-rw-r--r-- | ThirdParty/SmartThreadPool/WorkItemsQueue.cs | 1245 |
1 files changed, 645 insertions, 600 deletions
diff --git a/ThirdParty/SmartThreadPool/WorkItemsQueue.cs b/ThirdParty/SmartThreadPool/WorkItemsQueue.cs index af5af07..156a131 100644 --- a/ThirdParty/SmartThreadPool/WorkItemsQueue.cs +++ b/ThirdParty/SmartThreadPool/WorkItemsQueue.cs | |||
@@ -1,600 +1,645 @@ | |||
1 | // Ami Bar | 1 | using System; |
2 | // amibar@gmail.com | 2 | using System.Collections.Generic; |
3 | 3 | using System.Threading; | |
4 | using System; | 4 | |
5 | using System.Threading; | 5 | namespace Amib.Threading.Internal |
6 | 6 | { | |
7 | namespace Amib.Threading.Internal | 7 | #region WorkItemsQueue class |
8 | { | 8 | |
9 | #region WorkItemsQueue class | 9 | /// <summary> |
10 | 10 | /// WorkItemsQueue class. | |
11 | /// <summary> | 11 | /// </summary> |
12 | /// WorkItemsQueue class. | 12 | public class WorkItemsQueue : IDisposable |
13 | /// </summary> | 13 | { |
14 | public class WorkItemsQueue : IDisposable | 14 | #region Member variables |
15 | { | 15 | |
16 | #region Member variables | 16 | /// <summary> |
17 | 17 | /// Waiters queue (implemented as stack). | |
18 | /// <summary> | 18 | /// </summary> |
19 | /// Waiters queue (implemented as stack). | 19 | private readonly WaiterEntry _headWaiterEntry = new WaiterEntry(); |
20 | /// </summary> | 20 | |
21 | private WaiterEntry _headWaiterEntry = new WaiterEntry(); | 21 | /// <summary> |
22 | 22 | /// Waiters count | |
23 | /// <summary> | 23 | /// </summary> |
24 | /// Waiters count | 24 | private int _waitersCount = 0; |
25 | /// </summary> | 25 | |
26 | private int _waitersCount = 0; | 26 | /// <summary> |
27 | 27 | /// Work items queue | |
28 | /// <summary> | 28 | /// </summary> |
29 | /// Work items queue | 29 | private readonly PriorityQueue _workItems = new PriorityQueue(); |
30 | /// </summary> | 30 | |
31 | private PriorityQueue _workItems = new PriorityQueue(); | 31 | /// <summary> |
32 | 32 | /// Indicate that work items are allowed to be queued | |
33 | /// <summary> | 33 | /// </summary> |
34 | /// Indicate that work items are allowed to be queued | 34 | private bool _isWorkItemsQueueActive = true; |
35 | /// </summary> | 35 | |
36 | private bool _isWorkItemsQueueActive = true; | 36 | |
37 | 37 | #if (WINDOWS_PHONE) | |
38 | /// <summary> | 38 | private static readonly Dictionary<int, WaiterEntry> _waiterEntries = new Dictionary<int, WaiterEntry>(); |
39 | /// Each thread in the thread pool keeps its own waiter entry. | 39 | #elif (_WINDOWS_CE) |
40 | /// </summary> | 40 | private static LocalDataStoreSlot _waiterEntrySlot = Thread.AllocateDataSlot(); |
41 | [ThreadStatic] | 41 | #else |
42 | private static WaiterEntry _waiterEntry; | 42 | |
43 | 43 | [ThreadStatic] | |
44 | /// <summary> | 44 | private static WaiterEntry _waiterEntry; |
45 | /// A flag that indicates if the WorkItemsQueue has been disposed. | 45 | #endif |
46 | /// </summary> | 46 | |
47 | private bool _isDisposed = false; | 47 | |
48 | 48 | /// <summary> | |
49 | #endregion | 49 | /// Each thread in the thread pool keeps its own waiter entry. |
50 | 50 | /// </summary> | |
51 | #region Public properties | 51 | private static WaiterEntry CurrentWaiterEntry |
52 | 52 | { | |
53 | /// <summary> | 53 | #if (WINDOWS_PHONE) |
54 | /// Returns the current number of work items in the queue | 54 | get |
55 | /// </summary> | 55 | { |
56 | public int Count | 56 | lock (_waiterEntries) |
57 | { | 57 | { |
58 | get | 58 | WaiterEntry waiterEntry; |
59 | { | 59 | if (_waiterEntries.TryGetValue(Thread.CurrentThread.ManagedThreadId, out waiterEntry)) |
60 | lock(this) | 60 | { |
61 | { | 61 | return waiterEntry; |
62 | ValidateNotDisposed(); | 62 | } |
63 | return _workItems.Count; | 63 | } |
64 | } | 64 | return null; |
65 | } | 65 | } |
66 | } | 66 | set |
67 | 67 | { | |
68 | /// <summary> | 68 | lock (_waiterEntries) |
69 | /// Returns the current number of waiters | 69 | { |
70 | /// </summary> | 70 | _waiterEntries[Thread.CurrentThread.ManagedThreadId] = value; |
71 | public int WaitersCount | 71 | } |
72 | { | 72 | } |
73 | get | 73 | #elif (_WINDOWS_CE) |
74 | { | 74 | get |
75 | lock(this) | 75 | { |
76 | { | 76 | return Thread.GetData(_waiterEntrySlot) as WaiterEntry; |
77 | ValidateNotDisposed(); | 77 | } |
78 | return _waitersCount; | 78 | set |
79 | } | 79 | { |
80 | } | 80 | Thread.SetData(_waiterEntrySlot, value); |
81 | } | 81 | } |
82 | 82 | #else | |
83 | 83 | get | |
84 | #endregion | 84 | { |
85 | 85 | return _waiterEntry; | |
86 | #region Public methods | 86 | } |
87 | 87 | set | |
88 | /// <summary> | 88 | { |
89 | /// Enqueue a work item to the queue. | 89 | _waiterEntry = value; |
90 | /// </summary> | 90 | } |
91 | public bool EnqueueWorkItem(WorkItem workItem) | 91 | #endif |
92 | { | 92 | } |
93 | // A work item cannot be null, since null is used in the | 93 | |
94 | // WaitForWorkItem() method to indicate timeout or cancel | 94 | /// <summary> |
95 | if (null == workItem) | 95 | /// A flag that indicates if the WorkItemsQueue has been disposed. |
96 | { | 96 | /// </summary> |
97 | throw new ArgumentNullException("workItem" , "workItem cannot be null"); | 97 | private bool _isDisposed = false; |
98 | } | 98 | |
99 | 99 | #endregion | |
100 | bool enqueue = true; | 100 | |
101 | 101 | #region Public properties | |
102 | // First check if there is a waiter waiting for work item. During | 102 | |
103 | // the check, timed out waiters are ignored. If there is no | 103 | /// <summary> |
104 | // waiter then the work item is queued. | 104 | /// Returns the current number of work items in the queue |
105 | lock(this) | 105 | /// </summary> |
106 | { | 106 | public int Count |
107 | ValidateNotDisposed(); | 107 | { |
108 | 108 | get | |
109 | if (!_isWorkItemsQueueActive) | 109 | { |
110 | { | 110 | return _workItems.Count; |
111 | return false; | 111 | } |
112 | } | 112 | } |
113 | 113 | ||
114 | while(_waitersCount > 0) | 114 | /// <summary> |
115 | { | 115 | /// Returns the current number of waiters |
116 | // Dequeue a waiter. | 116 | /// </summary> |
117 | WaiterEntry waiterEntry = PopWaiter(); | 117 | public int WaitersCount |
118 | 118 | { | |
119 | // Signal the waiter. On success break the loop | 119 | get |
120 | if (waiterEntry.Signal(workItem)) | 120 | { |
121 | { | 121 | return _waitersCount; |
122 | enqueue = false; | 122 | } |
123 | break; | 123 | } |
124 | } | 124 | |
125 | } | 125 | |
126 | 126 | #endregion | |
127 | if (enqueue) | 127 | |
128 | { | 128 | #region Public methods |
129 | // Enqueue the work item | 129 | |
130 | _workItems.Enqueue(workItem); | 130 | /// <summary> |
131 | } | 131 | /// Enqueue a work item to the queue. |
132 | } | 132 | /// </summary> |
133 | return true; | 133 | public bool EnqueueWorkItem(WorkItem workItem) |
134 | } | 134 | { |
135 | 135 | // A work item cannot be null, since null is used in the | |
136 | 136 | // WaitForWorkItem() method to indicate timeout or cancel | |
137 | /// <summary> | 137 | if (null == workItem) |
138 | /// Waits for a work item or exits on timeout or cancel | 138 | { |
139 | /// </summary> | 139 | throw new ArgumentNullException("workItem" , "workItem cannot be null"); |
140 | /// <param name="millisecondsTimeout">Timeout in milliseconds</param> | 140 | } |
141 | /// <param name="cancelEvent">Cancel wait handle</param> | 141 | |
142 | /// <returns>Returns true if the resource was granted</returns> | 142 | bool enqueue = true; |
143 | public WorkItem DequeueWorkItem( | 143 | |
144 | int millisecondsTimeout, | 144 | // First check if there is a waiter waiting for work item. During |
145 | WaitHandle cancelEvent) | 145 | // the check, timed out waiters are ignored. If there is no |
146 | { | 146 | // waiter then the work item is queued. |
147 | /// This method cause the caller to wait for a work item. | 147 | lock(this) |
148 | /// If there is at least one waiting work item then the | 148 | { |
149 | /// method returns immidiately with true. | 149 | ValidateNotDisposed(); |
150 | /// | 150 | |
151 | /// If there are no waiting work items then the caller | 151 | if (!_isWorkItemsQueueActive) |
152 | /// is queued between other waiters for a work item to arrive. | 152 | { |
153 | /// | 153 | return false; |
154 | /// If a work item didn't come within millisecondsTimeout or | 154 | } |
155 | /// the user canceled the wait by signaling the cancelEvent | 155 | |
156 | /// then the method returns false to indicate that the caller | 156 | while(_waitersCount > 0) |
157 | /// didn't get a work item. | 157 | { |
158 | 158 | // Dequeue a waiter. | |
159 | WaiterEntry waiterEntry = null; | 159 | WaiterEntry waiterEntry = PopWaiter(); |
160 | WorkItem workItem = null; | 160 | |
161 | 161 | // Signal the waiter. On success break the loop | |
162 | lock(this) | 162 | if (waiterEntry.Signal(workItem)) |
163 | { | 163 | { |
164 | ValidateNotDisposed(); | 164 | enqueue = false; |
165 | 165 | break; | |
166 | // If there are waiting work items then take one and return. | 166 | } |
167 | if (_workItems.Count > 0) | 167 | } |
168 | { | 168 | |
169 | workItem = _workItems.Dequeue() as WorkItem; | 169 | if (enqueue) |
170 | return workItem; | 170 | { |
171 | } | 171 | // Enqueue the work item |
172 | // No waiting work items ... | 172 | _workItems.Enqueue(workItem); |
173 | else | 173 | } |
174 | { | 174 | } |
175 | // Get the wait entry for the waiters queue | 175 | return true; |
176 | waiterEntry = GetThreadWaiterEntry(); | 176 | } |
177 | 177 | ||
178 | // Put the waiter with the other waiters | 178 | |
179 | PushWaiter(waiterEntry); | 179 | /// <summary> |
180 | } | 180 | /// Waits for a work item or exits on timeout or cancel |
181 | } | 181 | /// </summary> |
182 | 182 | /// <param name="millisecondsTimeout">Timeout in milliseconds</param> | |
183 | // Prepare array of wait handle for the WaitHandle.WaitAny() | 183 | /// <param name="cancelEvent">Cancel wait handle</param> |
184 | WaitHandle [] waitHandles = new WaitHandle [] { | 184 | /// <returns>Returns true if the resource was granted</returns> |
185 | waiterEntry.WaitHandle, | 185 | public WorkItem DequeueWorkItem( |
186 | cancelEvent }; | 186 | int millisecondsTimeout, |
187 | 187 | WaitHandle cancelEvent) | |
188 | // Wait for an available resource, cancel event, or timeout. | 188 | { |
189 | 189 | // This method cause the caller to wait for a work item. | |
190 | // During the wait we are supposes to exit the synchronization | 190 | // If there is at least one waiting work item then the |
191 | // domain. (Placing true as the third argument of the WaitAny()) | 191 | // method returns immidiately with it. |
192 | // It just doesn't work, I don't know why, so I have lock(this) | 192 | // |
193 | // statments insted of one. | 193 | // If there are no waiting work items then the caller |
194 | 194 | // is queued between other waiters for a work item to arrive. | |
195 | int index = WaitHandle.WaitAny( | 195 | // |
196 | waitHandles, | 196 | // If a work item didn't come within millisecondsTimeout or |
197 | millisecondsTimeout, | 197 | // the user canceled the wait by signaling the cancelEvent |
198 | true); | 198 | // then the method returns null to indicate that the caller |
199 | 199 | // didn't get a work item. | |
200 | lock(this) | 200 | |
201 | { | 201 | WaiterEntry waiterEntry; |
202 | // success is true if it got a work item. | 202 | WorkItem workItem = null; |
203 | bool success = (0 == index); | 203 | lock (this) |
204 | 204 | { | |
205 | // The timeout variable is used only for readability. | 205 | ValidateNotDisposed(); |
206 | // (We treat cancel as timeout) | 206 | |
207 | bool timeout = !success; | 207 | // If there are waiting work items then take one and return. |
208 | 208 | if (_workItems.Count > 0) | |
209 | // On timeout update the waiterEntry that it is timed out | 209 | { |
210 | if (timeout) | 210 | workItem = _workItems.Dequeue() as WorkItem; |
211 | { | 211 | return workItem; |
212 | // The Timeout() fails if the waiter has already been signaled | 212 | } |
213 | timeout = waiterEntry.Timeout(); | 213 | |
214 | 214 | // No waiting work items ... | |
215 | // On timeout remove the waiter from the queue. | 215 | |
216 | // Note that the complexity is O(1). | 216 | // Get the waiter entry for the waiters queue |
217 | if(timeout) | 217 | waiterEntry = GetThreadWaiterEntry(); |
218 | { | 218 | |
219 | RemoveWaiter(waiterEntry, false); | 219 | // Put the waiter with the other waiters |
220 | } | 220 | PushWaiter(waiterEntry); |
221 | 221 | } | |
222 | // Again readability | 222 | |
223 | success = !timeout; | 223 | // Prepare array of wait handle for the WaitHandle.WaitAny() |
224 | } | 224 | WaitHandle [] waitHandles = new WaitHandle[] { |
225 | 225 | waiterEntry.WaitHandle, | |
226 | // On success return the work item | 226 | cancelEvent }; |
227 | if (success) | 227 | |
228 | { | 228 | // Wait for an available resource, cancel event, or timeout. |
229 | workItem = waiterEntry.WorkItem; | 229 | |
230 | 230 | // During the wait we are supposes to exit the synchronization | |
231 | if (null == workItem) | 231 | // domain. (Placing true as the third argument of the WaitAny()) |
232 | { | 232 | // It just doesn't work, I don't know why, so I have two lock(this) |
233 | workItem = _workItems.Dequeue() as WorkItem; | 233 | // statments instead of one. |
234 | } | 234 | |
235 | } | 235 | int index = STPEventWaitHandle.WaitAny( |
236 | } | 236 | waitHandles, |
237 | // On failure return null. | 237 | millisecondsTimeout, |
238 | return workItem; | 238 | true); |
239 | } | 239 | |
240 | 240 | lock(this) | |
241 | /// <summary> | 241 | { |
242 | /// Cleanup the work items queue, hence no more work | 242 | // success is true if it got a work item. |
243 | /// items are allowed to be queue | 243 | bool success = (0 == index); |
244 | /// </summary> | 244 | |
245 | protected virtual void Cleanup() | 245 | // The timeout variable is used only for readability. |
246 | { | 246 | // (We treat cancel as timeout) |
247 | lock(this) | 247 | bool timeout = !success; |
248 | { | 248 | |
249 | // Deactivate only once | 249 | // On timeout update the waiterEntry that it is timed out |
250 | if (!_isWorkItemsQueueActive) | 250 | if (timeout) |
251 | { | 251 | { |
252 | return; | 252 | // The Timeout() fails if the waiter has already been signaled |
253 | } | 253 | timeout = waiterEntry.Timeout(); |
254 | 254 | ||
255 | // Don't queue more work items | 255 | // On timeout remove the waiter from the queue. |
256 | _isWorkItemsQueueActive = false; | 256 | // Note that the complexity is O(1). |
257 | 257 | if(timeout) | |
258 | foreach(WorkItem workItem in _workItems) | 258 | { |
259 | { | 259 | RemoveWaiter(waiterEntry, false); |
260 | workItem.DisposeOfState(); | 260 | } |
261 | } | 261 | |
262 | 262 | // Again readability | |
263 | // Clear the work items that are already queued | 263 | success = !timeout; |
264 | _workItems.Clear(); | 264 | } |
265 | 265 | ||
266 | // Note: | 266 | // On success return the work item |
267 | // I don't iterate over the queue and dispose of work items's states, | 267 | if (success) |
268 | // since if a work item has a state object that is still in use in the | 268 | { |
269 | // application then I must not dispose it. | 269 | workItem = waiterEntry.WorkItem; |
270 | 270 | ||
271 | // Tell the waiters that they were timed out. | 271 | if (null == workItem) |
272 | // It won't signal them to exit, but to ignore their | 272 | { |
273 | // next work item. | 273 | workItem = _workItems.Dequeue() as WorkItem; |
274 | while(_waitersCount > 0) | 274 | } |
275 | { | 275 | } |
276 | WaiterEntry waiterEntry = PopWaiter(); | 276 | } |
277 | waiterEntry.Timeout(); | 277 | // On failure return null. |
278 | } | 278 | return workItem; |
279 | } | 279 | } |
280 | } | 280 | |
281 | 281 | /// <summary> | |
282 | #endregion | 282 | /// Cleanup the work items queue, hence no more work |
283 | 283 | /// items are allowed to be queue | |
284 | #region Private methods | 284 | /// </summary> |
285 | 285 | private void Cleanup() | |
286 | /// <summary> | 286 | { |
287 | /// Returns the WaiterEntry of the current thread | 287 | lock(this) |
288 | /// </summary> | 288 | { |
289 | /// <returns></returns> | 289 | // Deactivate only once |
290 | /// In order to avoid creation and destuction of WaiterEntry | 290 | if (!_isWorkItemsQueueActive) |
291 | /// objects each thread has its own WaiterEntry object. | 291 | { |
292 | private WaiterEntry GetThreadWaiterEntry() | 292 | return; |
293 | { | 293 | } |
294 | if (null == _waiterEntry) | 294 | |
295 | { | 295 | // Don't queue more work items |
296 | _waiterEntry = new WaiterEntry(); | 296 | _isWorkItemsQueueActive = false; |
297 | } | 297 | |
298 | _waiterEntry.Reset(); | 298 | foreach(WorkItem workItem in _workItems) |
299 | return _waiterEntry; | 299 | { |
300 | } | 300 | workItem.DisposeOfState(); |
301 | 301 | } | |
302 | #region Waiters stack methods | 302 | |
303 | 303 | // Clear the work items that are already queued | |
304 | /// <summary> | 304 | _workItems.Clear(); |
305 | /// Push a new waiter into the waiter's stack | 305 | |
306 | /// </summary> | 306 | // Note: |
307 | /// <param name="newWaiterEntry">A waiter to put in the stack</param> | 307 | // I don't iterate over the queue and dispose of work items's states, |
308 | public void PushWaiter(WaiterEntry newWaiterEntry) | 308 | // since if a work item has a state object that is still in use in the |
309 | { | 309 | // application then I must not dispose it. |
310 | // Remove the waiter if it is already in the stack and | 310 | |
311 | // update waiter's count as needed | 311 | // Tell the waiters that they were timed out. |
312 | RemoveWaiter(newWaiterEntry, false); | 312 | // It won't signal them to exit, but to ignore their |
313 | 313 | // next work item. | |
314 | // If the stack is empty then newWaiterEntry is the new head of the stack | 314 | while(_waitersCount > 0) |
315 | if (null == _headWaiterEntry._nextWaiterEntry) | 315 | { |
316 | { | 316 | WaiterEntry waiterEntry = PopWaiter(); |
317 | _headWaiterEntry._nextWaiterEntry = newWaiterEntry; | 317 | waiterEntry.Timeout(); |
318 | newWaiterEntry._prevWaiterEntry = _headWaiterEntry; | 318 | } |
319 | 319 | } | |
320 | } | 320 | } |
321 | // If the stack is not empty then put newWaiterEntry as the new head | 321 | |
322 | // of the stack. | 322 | public object[] GetStates() |
323 | else | 323 | { |
324 | { | 324 | lock (this) |
325 | // Save the old first waiter entry | 325 | { |
326 | WaiterEntry oldFirstWaiterEntry = _headWaiterEntry._nextWaiterEntry; | 326 | object[] states = new object[_workItems.Count]; |
327 | 327 | int i = 0; | |
328 | // Update the links | 328 | foreach (WorkItem workItem in _workItems) |
329 | _headWaiterEntry._nextWaiterEntry = newWaiterEntry; | 329 | { |
330 | newWaiterEntry._nextWaiterEntry = oldFirstWaiterEntry; | 330 | states[i] = workItem.GetWorkItemResult().State; |
331 | newWaiterEntry._prevWaiterEntry = _headWaiterEntry; | 331 | ++i; |
332 | oldFirstWaiterEntry._prevWaiterEntry = newWaiterEntry; | 332 | } |
333 | } | 333 | return states; |
334 | 334 | } | |
335 | // Increment the number of waiters | 335 | } |
336 | ++_waitersCount; | 336 | |
337 | } | 337 | #endregion |
338 | 338 | ||
339 | /// <summary> | 339 | #region Private methods |
340 | /// Pop a waiter from the waiter's stack | 340 | |
341 | /// </summary> | 341 | /// <summary> |
342 | /// <returns>Returns the first waiter in the stack</returns> | 342 | /// Returns the WaiterEntry of the current thread |
343 | private WaiterEntry PopWaiter() | 343 | /// </summary> |
344 | { | 344 | /// <returns></returns> |
345 | // Store the current stack head | 345 | /// In order to avoid creation and destuction of WaiterEntry |
346 | WaiterEntry oldFirstWaiterEntry = _headWaiterEntry._nextWaiterEntry; | 346 | /// objects each thread has its own WaiterEntry object. |
347 | 347 | private static WaiterEntry GetThreadWaiterEntry() | |
348 | // Store the new stack head | 348 | { |
349 | WaiterEntry newHeadWaiterEntry = oldFirstWaiterEntry._nextWaiterEntry; | 349 | if (null == CurrentWaiterEntry) |
350 | 350 | { | |
351 | // Update the old stack head list links and decrement the number | 351 | CurrentWaiterEntry = new WaiterEntry(); |
352 | // waiters. | 352 | } |
353 | RemoveWaiter(oldFirstWaiterEntry, true); | 353 | CurrentWaiterEntry.Reset(); |
354 | 354 | return CurrentWaiterEntry; | |
355 | // Update the new stack head | 355 | } |
356 | _headWaiterEntry._nextWaiterEntry = newHeadWaiterEntry; | 356 | |
357 | if (null != newHeadWaiterEntry) | 357 | #region Waiters stack methods |
358 | { | 358 | |
359 | newHeadWaiterEntry._prevWaiterEntry = _headWaiterEntry; | 359 | /// <summary> |
360 | } | 360 | /// Push a new waiter into the waiter's stack |
361 | 361 | /// </summary> | |
362 | // Return the old stack head | 362 | /// <param name="newWaiterEntry">A waiter to put in the stack</param> |
363 | return oldFirstWaiterEntry; | 363 | public void PushWaiter(WaiterEntry newWaiterEntry) |
364 | } | 364 | { |
365 | 365 | // Remove the waiter if it is already in the stack and | |
366 | /// <summary> | 366 | // update waiter's count as needed |
367 | /// Remove a waiter from the stack | 367 | RemoveWaiter(newWaiterEntry, false); |
368 | /// </summary> | 368 | |
369 | /// <param name="waiterEntry">A waiter entry to remove</param> | 369 | // If the stack is empty then newWaiterEntry is the new head of the stack |
370 | /// <param name="popDecrement">If true the waiter count is always decremented</param> | 370 | if (null == _headWaiterEntry._nextWaiterEntry) |
371 | private void RemoveWaiter(WaiterEntry waiterEntry, bool popDecrement) | 371 | { |
372 | { | 372 | _headWaiterEntry._nextWaiterEntry = newWaiterEntry; |
373 | // Store the prev entry in the list | 373 | newWaiterEntry._prevWaiterEntry = _headWaiterEntry; |
374 | WaiterEntry prevWaiterEntry = waiterEntry._prevWaiterEntry; | 374 | |
375 | 375 | } | |
376 | // Store the next entry in the list | 376 | // If the stack is not empty then put newWaiterEntry as the new head |
377 | WaiterEntry nextWaiterEntry = waiterEntry._nextWaiterEntry; | 377 | // of the stack. |
378 | 378 | else | |
379 | // A flag to indicate if we need to decrement the waiters count. | 379 | { |
380 | // If we got here from PopWaiter then we must decrement. | 380 | // Save the old first waiter entry |
381 | // If we got here from PushWaiter then we decrement only if | 381 | WaiterEntry oldFirstWaiterEntry = _headWaiterEntry._nextWaiterEntry; |
382 | // the waiter was already in the stack. | 382 | |
383 | bool decrementCounter = popDecrement; | 383 | // Update the links |
384 | 384 | _headWaiterEntry._nextWaiterEntry = newWaiterEntry; | |
385 | // Null the waiter's entry links | 385 | newWaiterEntry._nextWaiterEntry = oldFirstWaiterEntry; |
386 | waiterEntry._prevWaiterEntry = null; | 386 | newWaiterEntry._prevWaiterEntry = _headWaiterEntry; |
387 | waiterEntry._nextWaiterEntry = null; | 387 | oldFirstWaiterEntry._prevWaiterEntry = newWaiterEntry; |
388 | 388 | } | |
389 | // If the waiter entry had a prev link then update it. | 389 | |
390 | // It also means that the waiter is already in the list and we | 390 | // Increment the number of waiters |
391 | // need to decrement the waiters count. | 391 | ++_waitersCount; |
392 | if (null != prevWaiterEntry) | 392 | } |
393 | { | 393 | |
394 | prevWaiterEntry._nextWaiterEntry = nextWaiterEntry; | 394 | /// <summary> |
395 | decrementCounter = true; | 395 | /// Pop a waiter from the waiter's stack |
396 | } | 396 | /// </summary> |
397 | 397 | /// <returns>Returns the first waiter in the stack</returns> | |
398 | // If the waiter entry had a next link then update it. | 398 | private WaiterEntry PopWaiter() |
399 | // It also means that the waiter is already in the list and we | 399 | { |
400 | // need to decrement the waiters count. | 400 | // Store the current stack head |
401 | if (null != nextWaiterEntry) | 401 | WaiterEntry oldFirstWaiterEntry = _headWaiterEntry._nextWaiterEntry; |
402 | { | 402 | |
403 | nextWaiterEntry._prevWaiterEntry = prevWaiterEntry; | 403 | // Store the new stack head |
404 | decrementCounter = true; | 404 | WaiterEntry newHeadWaiterEntry = oldFirstWaiterEntry._nextWaiterEntry; |
405 | } | 405 | |
406 | 406 | // Update the old stack head list links and decrement the number | |
407 | // Decrement the waiters count if needed | 407 | // waiters. |
408 | if (decrementCounter) | 408 | RemoveWaiter(oldFirstWaiterEntry, true); |
409 | { | 409 | |
410 | --_waitersCount; | 410 | // Update the new stack head |
411 | } | 411 | _headWaiterEntry._nextWaiterEntry = newHeadWaiterEntry; |
412 | } | 412 | if (null != newHeadWaiterEntry) |
413 | 413 | { | |
414 | #endregion | 414 | newHeadWaiterEntry._prevWaiterEntry = _headWaiterEntry; |
415 | 415 | } | |
416 | #endregion | 416 | |
417 | 417 | // Return the old stack head | |
418 | #region WaiterEntry class | 418 | return oldFirstWaiterEntry; |
419 | 419 | } | |
420 | // A waiter entry in the _waiters queue. | 420 | |
421 | public class WaiterEntry : IDisposable | 421 | /// <summary> |
422 | { | 422 | /// Remove a waiter from the stack |
423 | #region Member variables | 423 | /// </summary> |
424 | 424 | /// <param name="waiterEntry">A waiter entry to remove</param> | |
425 | /// <summary> | 425 | /// <param name="popDecrement">If true the waiter count is always decremented</param> |
426 | /// Event to signal the waiter that it got the work item. | 426 | private void RemoveWaiter(WaiterEntry waiterEntry, bool popDecrement) |
427 | /// </summary> | 427 | { |
428 | private AutoResetEvent _waitHandle = new AutoResetEvent(false); | 428 | // Store the prev entry in the list |
429 | 429 | WaiterEntry prevWaiterEntry = waiterEntry._prevWaiterEntry; | |
430 | /// <summary> | 430 | |
431 | /// Flag to know if this waiter already quited from the queue | 431 | // Store the next entry in the list |
432 | /// because of a timeout. | 432 | WaiterEntry nextWaiterEntry = waiterEntry._nextWaiterEntry; |
433 | /// </summary> | 433 | |
434 | private bool _isTimedout = false; | 434 | // A flag to indicate if we need to decrement the waiters count. |
435 | 435 | // If we got here from PopWaiter then we must decrement. | |
436 | /// <summary> | 436 | // If we got here from PushWaiter then we decrement only if |
437 | /// Flag to know if the waiter was signaled and got a work item. | 437 | // the waiter was already in the stack. |
438 | /// </summary> | 438 | bool decrementCounter = popDecrement; |
439 | private bool _isSignaled = false; | 439 | |
440 | 440 | // Null the waiter's entry links | |
441 | /// <summary> | 441 | waiterEntry._prevWaiterEntry = null; |
442 | /// A work item that passed directly to the waiter withou going | 442 | waiterEntry._nextWaiterEntry = null; |
443 | /// through the queue | 443 | |
444 | /// </summary> | 444 | // If the waiter entry had a prev link then update it. |
445 | private WorkItem _workItem = null; | 445 | // It also means that the waiter is already in the list and we |
446 | 446 | // need to decrement the waiters count. | |
447 | private bool _isDisposed = false; | 447 | if (null != prevWaiterEntry) |
448 | 448 | { | |
449 | // Linked list members | 449 | prevWaiterEntry._nextWaiterEntry = nextWaiterEntry; |
450 | internal WaiterEntry _nextWaiterEntry = null; | 450 | decrementCounter = true; |
451 | internal WaiterEntry _prevWaiterEntry = null; | 451 | } |
452 | 452 | ||
453 | #endregion | 453 | // If the waiter entry had a next link then update it. |
454 | 454 | // It also means that the waiter is already in the list and we | |
455 | #region Construction | 455 | // need to decrement the waiters count. |
456 | 456 | if (null != nextWaiterEntry) | |
457 | public WaiterEntry() | 457 | { |
458 | { | 458 | nextWaiterEntry._prevWaiterEntry = prevWaiterEntry; |
459 | Reset(); | 459 | decrementCounter = true; |
460 | } | 460 | } |
461 | 461 | ||
462 | #endregion | 462 | // Decrement the waiters count if needed |
463 | 463 | if (decrementCounter) | |
464 | #region Public methods | 464 | { |
465 | 465 | --_waitersCount; | |
466 | public WaitHandle WaitHandle | 466 | } |
467 | { | 467 | } |
468 | get { return _waitHandle; } | 468 | |
469 | } | 469 | #endregion |
470 | 470 | ||
471 | public WorkItem WorkItem | 471 | #endregion |
472 | { | 472 | |
473 | get | 473 | #region WaiterEntry class |
474 | { | 474 | |
475 | lock(this) | 475 | // A waiter entry in the _waiters queue. |
476 | { | 476 | public sealed class WaiterEntry : IDisposable |
477 | return _workItem; | 477 | { |
478 | } | 478 | #region Member variables |
479 | } | 479 | |
480 | } | 480 | /// <summary> |
481 | 481 | /// Event to signal the waiter that it got the work item. | |
482 | /// <summary> | 482 | /// </summary> |
483 | /// Signal the waiter that it got a work item. | 483 | //private AutoResetEvent _waitHandle = new AutoResetEvent(false); |
484 | /// </summary> | 484 | private AutoResetEvent _waitHandle = EventWaitHandleFactory.CreateAutoResetEvent(); |
485 | /// <returns>Return true on success</returns> | 485 | |
486 | /// The method fails if Timeout() preceded its call | 486 | /// <summary> |
487 | public bool Signal(WorkItem workItem) | 487 | /// Flag to know if this waiter already quited from the queue |
488 | { | 488 | /// because of a timeout. |
489 | lock(this) | 489 | /// </summary> |
490 | { | 490 | private bool _isTimedout = false; |
491 | if (!_isTimedout) | 491 | |
492 | { | 492 | /// <summary> |
493 | _workItem = workItem; | 493 | /// Flag to know if the waiter was signaled and got a work item. |
494 | _isSignaled = true; | 494 | /// </summary> |
495 | _waitHandle.Set(); | 495 | private bool _isSignaled = false; |
496 | return true; | 496 | |
497 | } | 497 | /// <summary> |
498 | } | 498 | /// A work item that passed directly to the waiter withou going |
499 | return false; | 499 | /// through the queue |
500 | } | 500 | /// </summary> |
501 | 501 | private WorkItem _workItem = null; | |
502 | /// <summary> | 502 | |
503 | /// Mark the wait entry that it has been timed out | 503 | private bool _isDisposed = false; |
504 | /// </summary> | 504 | |
505 | /// <returns>Return true on success</returns> | 505 | // Linked list members |
506 | /// The method fails if Signal() preceded its call | 506 | internal WaiterEntry _nextWaiterEntry = null; |
507 | public bool Timeout() | 507 | internal WaiterEntry _prevWaiterEntry = null; |
508 | { | 508 | |
509 | lock(this) | 509 | #endregion |
510 | { | 510 | |
511 | // Time out can happen only if the waiter wasn't marked as | 511 | #region Construction |
512 | // signaled | 512 | |
513 | if (!_isSignaled) | 513 | public WaiterEntry() |
514 | { | 514 | { |
515 | // We don't remove the waiter from the queue, the DequeueWorkItem | 515 | Reset(); |
516 | // method skips _waiters that were timed out. | 516 | } |
517 | _isTimedout = true; | 517 | |
518 | return true; | 518 | #endregion |
519 | } | 519 | |
520 | } | 520 | #region Public methods |
521 | return false; | 521 | |
522 | } | 522 | public WaitHandle WaitHandle |
523 | 523 | { | |
524 | /// <summary> | 524 | get { return _waitHandle; } |
525 | /// Reset the wait entry so it can be used again | 525 | } |
526 | /// </summary> | 526 | |
527 | public void Reset() | 527 | public WorkItem WorkItem |
528 | { | 528 | { |
529 | _workItem = null; | 529 | get |
530 | _isTimedout = false; | 530 | { |
531 | _isSignaled = false; | 531 | return _workItem; |
532 | _waitHandle.Reset(); | 532 | } |
533 | } | 533 | } |
534 | 534 | ||
535 | /// <summary> | 535 | /// <summary> |
536 | /// Free resources | 536 | /// Signal the waiter that it got a work item. |
537 | /// </summary> | 537 | /// </summary> |
538 | public void Close() | 538 | /// <returns>Return true on success</returns> |
539 | { | 539 | /// The method fails if Timeout() preceded its call |
540 | if (null != _waitHandle) | 540 | public bool Signal(WorkItem workItem) |
541 | { | 541 | { |
542 | _waitHandle.Close(); | 542 | lock(this) |
543 | _waitHandle = null; | 543 | { |
544 | } | 544 | if (!_isTimedout) |
545 | } | 545 | { |
546 | 546 | _workItem = workItem; | |
547 | #endregion | 547 | _isSignaled = true; |
548 | 548 | _waitHandle.Set(); | |
549 | #region IDisposable Members | 549 | return true; |
550 | 550 | } | |
551 | public void Dispose() | 551 | } |
552 | { | 552 | return false; |
553 | if (!_isDisposed) | 553 | } |
554 | { | 554 | |
555 | Close(); | 555 | /// <summary> |
556 | _isDisposed = true; | 556 | /// Mark the wait entry that it has been timed out |
557 | } | 557 | /// </summary> |
558 | } | 558 | /// <returns>Return true on success</returns> |
559 | 559 | /// The method fails if Signal() preceded its call | |
560 | ~WaiterEntry() | 560 | public bool Timeout() |
561 | { | 561 | { |
562 | Dispose(); | 562 | lock(this) |
563 | } | 563 | { |
564 | 564 | // Time out can happen only if the waiter wasn't marked as | |
565 | #endregion | 565 | // signaled |
566 | } | 566 | if (!_isSignaled) |
567 | 567 | { | |
568 | #endregion | 568 | // We don't remove the waiter from the queue, the DequeueWorkItem |
569 | 569 | // method skips _waiters that were timed out. | |
570 | #region IDisposable Members | 570 | _isTimedout = true; |
571 | 571 | return true; | |
572 | public void Dispose() | 572 | } |
573 | { | 573 | } |
574 | if (!_isDisposed) | 574 | return false; |
575 | { | 575 | } |
576 | Cleanup(); | 576 | |
577 | _isDisposed = true; | 577 | /// <summary> |
578 | GC.SuppressFinalize(this); | 578 | /// Reset the wait entry so it can be used again |
579 | } | 579 | /// </summary> |
580 | } | 580 | public void Reset() |
581 | 581 | { | |
582 | ~WorkItemsQueue() | 582 | _workItem = null; |
583 | { | 583 | _isTimedout = false; |
584 | Cleanup(); | 584 | _isSignaled = false; |
585 | } | 585 | _waitHandle.Reset(); |
586 | 586 | } | |
587 | private void ValidateNotDisposed() | 587 | |
588 | { | 588 | /// <summary> |
589 | if(_isDisposed) | 589 | /// Free resources |
590 | { | 590 | /// </summary> |
591 | throw new ObjectDisposedException(GetType().ToString(), "The SmartThreadPool has been shutdown"); | 591 | public void Close() |
592 | } | 592 | { |
593 | } | 593 | if (null != _waitHandle) |
594 | 594 | { | |
595 | #endregion | 595 | _waitHandle.Close(); |
596 | } | 596 | _waitHandle = null; |
597 | 597 | } | |
598 | #endregion | 598 | } |
599 | } | 599 | |
600 | 600 | #endregion | |
601 | |||
602 | #region IDisposable Members | ||
603 | |||
604 | public void Dispose() | ||
605 | { | ||
606 | lock (this) | ||
607 | { | ||
608 | if (!_isDisposed) | ||
609 | { | ||
610 | Close(); | ||
611 | } | ||
612 | _isDisposed = true; | ||
613 | } | ||
614 | } | ||
615 | |||
616 | #endregion | ||
617 | } | ||
618 | |||
619 | #endregion | ||
620 | |||
621 | #region IDisposable Members | ||
622 | |||
623 | public void Dispose() | ||
624 | { | ||
625 | if (!_isDisposed) | ||
626 | { | ||
627 | Cleanup(); | ||
628 | } | ||
629 | _isDisposed = true; | ||
630 | } | ||
631 | |||
632 | private void ValidateNotDisposed() | ||
633 | { | ||
634 | if(_isDisposed) | ||
635 | { | ||
636 | throw new ObjectDisposedException(GetType().ToString(), "The SmartThreadPool has been shutdown"); | ||
637 | } | ||
638 | } | ||
639 | |||
640 | #endregion | ||
641 | } | ||
642 | |||
643 | #endregion | ||
644 | } | ||
645 | |||