##// END OF EJS Templates
DispatchPool works again, but performance is poor in some cases
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r21:6a56df4ec59e promises
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@@ -151,7 +151,7 namespace Implab.Test {
151 151 var pool = new WorkerPool(5, 20);
152 152 Assert.AreEqual(5, pool.PoolSize);
153 153 pool.Dispose();
154 Thread.Sleep(200);
154 Thread.Sleep(500);
155 155 Assert.AreEqual(0, pool.PoolSize);
156 156 pool.Dispose();
157 157 }
@@ -244,7 +244,7 namespace Implab.Test {
244 244 [TestMethod]
245 245 public void ChainedMapTest() {
246 246
247 using (var pool = new WorkerPool(0,100,0)) {
247 using (var pool = new WorkerPool(0,100,1)) {
248 248 int count = 10000;
249 249
250 250 double[] args = new double[count];
1 NO CONTENT: modified file, binary diff hidden
@@ -9,12 +9,15 namespace Implab.Parallels {
9 9 public abstract class DispatchPool<TUnit> : IDisposable {
10 10 readonly int m_minThreads;
11 11 readonly int m_maxThreads;
12 int m_createdThreads = 0;
13 int m_activeThreads = 0;
14 int m_sleepingThreads = 0;
15 int m_maxRunningThreads = 0;
16 int m_exitRequired = 0;
17 int m_releaseTimeout = 100; // timeout while the working thread will wait for the new tasks before exit
12
13 int m_createdThreads = 0; // the current size of the pool
14 int m_activeThreads = 0; // the count of threads which are active
15 int m_sleepingThreads = 0; // the count of currently inactive threads
16 int m_maxRunningThreads = 0; // the meximum reached size of the pool
17 int m_exitRequired = 0; // the pool is going to shutdown, all unused workers are released
18 int m_releaseTimeout = 100; // the timeout while the working thread will wait for the new tasks before exit
19 int m_wakeEvents = 0; // the count of wake events
20
18 21 AutoResetEvent m_hasTasks = new AutoResetEvent(false);
19 22
20 23 protected DispatchPool(int min, int max) {
@@ -72,69 +75,89 namespace Implab.Parallels {
72 75
73 76 protected abstract bool TryDequeue(out TUnit unit);
74 77
75 protected virtual bool ExtendPool() {
76 if (m_sleepingThreads == 0)
77 // no sleeping workers are available
78 // try create one
79 return StartWorker();
80 else {
81 // we can get here a race condition when several threads asks to extend pool
82 // and some sleaping threads are exited due timeout but they are still counted as sleeping
83 // in that case all of this threads could exit except one
84 WakePool();
78 #region thread execution traits
79 int SignalThread() {
80 var signals = Interlocked.Increment(ref m_wakeEvents);
81 if(signals == 1)
82 m_hasTasks.Set();
83 return signals;
84 }
85
86 bool Sleep(int timeout) {
87 Interlocked.Increment(ref m_sleepingThreads);
88 if (m_hasTasks.WaitOne(timeout)) {
89 // this is autoreset event, only one thread can run this block simultaneously
90 var sleeping = Interlocked.Decrement(ref m_sleepingThreads);
91 if (Interlocked.Decrement(ref m_wakeEvents) > 0)
92 m_hasTasks.Set(); // wake next worker
93
85 94 return true;
95 } else {
96 Interlocked.Decrement(ref m_sleepingThreads);
97 return false;
86 98 }
87
88 99 }
100 #endregion
89 101
90 102 /// <summary>
91 103 /// Запускает либо новый поток, если раньше не было ни одного потока, либо устанавливает событие пробуждение одного спящего потока
92 104 /// </summary>
93 protected void WakePool() {
94 m_hasTasks.Set(); // wake sleeping thread;
105 protected void GrowPool() {
106 if (m_exitRequired != 0)
107 return;
108 if (m_sleepingThreads > m_wakeEvents) {
109 // all sleeping threads may gone
110 SignalThread(); // wake a sleeping thread;
95 111
96 if (AllocateThreadSlot(1)) {
97 // if there were no threads in the pool
98 var worker = new Thread(this.Worker);
99 worker.IsBackground = true;
100 worker.Start();
112 // we can't check whether signal has been processed
113 // anyway it may take some time for the thread to start
114 // we will ensure that at least one thread is running
115
116 if (AllocateThreadSlot(1)) {
117 // if there were no threads in the pool
118 var worker = new Thread(this.Worker);
119 worker.IsBackground = true;
120 worker.Start();
121 }
122 } else {
123 // if there is no sleeping threads in the pool
124 StartWorker();
101 125 }
102 126 }
103 127
104 bool Sleep(int timeout) {
105 Interlocked.Increment(ref m_sleepingThreads);
106 var result = m_hasTasks.WaitOne(timeout);
107 Interlocked.Decrement(ref m_sleepingThreads);
108 return result;
109 }
110
111 protected virtual bool Suspend() {
128 private bool Suspend() {
112 129 //no tasks left, exit if the thread is no longer needed
113 130 bool last;
114 131 bool requestExit;
115 132
133
134
135 // if threads have a timeout before releasing
116 136 if (m_releaseTimeout > 0)
117 137 requestExit = !Sleep(m_releaseTimeout);
118 138 else
119 139 requestExit = true;
120
121 140
141 if (!requestExit)
142 return true;
143
144 // release unsused thread
122 145 if (requestExit && ReleaseThreadSlot(out last)) {
123 146 // in case at the moment the last thread was being released
124 147 // a new task was added to the queue, we need to try
125 148 // to revoke the thread to avoid the situation when the task is left unprocessed
126 if (last && m_hasTasks.WaitOne(0)) {
149 if (last && Sleep(0)) { // Sleep(0) will fetch pending task or will return false
127 150 if (AllocateThreadSlot(1))
128 151 return true; // spin again...
129 152 else
130 // we failed to reallocate the first slot for this thread
131 // therefore we need to release the event
132 m_hasTasks.Set();
153 SignalThread(); // since Sleep(0) has fetched the signal we neet to reschedule it
154
133 155 }
134 156
135 157 return false;
136 158 }
137 159
160 // wait till infinity
138 161 Sleep(-1);
139 162
140 163 return true;
@@ -215,7 +238,12 namespace Implab.Parallels {
215 238 }
216 239 }
217 240
218 bool FetchTask(out TUnit unit) {
241 protected abstract void InvokeUnit(TUnit unit);
242
243 void Worker() {
244 TUnit unit;
245 Interlocked.Increment(ref m_activeThreads);
246 Sleep(0); // remove wake request if the new thread is started
219 247 do {
220 248 // exit if requested
221 249 if (m_exitRequired != 0) {
@@ -224,15 +252,15 namespace Implab.Parallels {
224 252 if (ReleaseThreadSlotAnyway()) // it was the last worker
225 253 m_hasTasks.Dispose();
226 254 else
227 m_hasTasks.Set(); // wake next worker
255 SignalThread(); // wake next worker
228 256 unit = default(TUnit);
229 return false;
257 break;
230 258 }
231 259
232 260 // fetch task
233 261 if (TryDequeue(out unit)) {
234 ExtendPool();
235 return true;
262 InvokeUnit(unit);
263 continue;
236 264 }
237 265
238 266 Interlocked.Decrement(ref m_activeThreads);
@@ -240,19 +268,11 namespace Implab.Parallels {
240 268 // entering suspend state
241 269 // keep this thread and wait
242 270 if (!Suspend())
243 return false;
271 break;
244 272
245 273 Interlocked.Increment(ref m_activeThreads);
246 274 } while (true);
247 }
248
249 protected abstract void InvokeUnit(TUnit unit);
250
251 void Worker() {
252 TUnit unit;
253 Interlocked.Increment(ref m_activeThreads);
254 while (FetchTask(out unit))
255 InvokeUnit(unit);
275
256 276 }
257 277
258 278 protected virtual void Dispose(bool disposing) {
@@ -262,7 +282,10 namespace Implab.Parallels {
262 282 return;
263 283
264 284 // wake sleeping threads
265 m_hasTasks.Set();
285 if (m_createdThreads > 0)
286 SignalThread();
287 else
288 m_hasTasks.Dispose();
266 289 GC.SuppressFinalize(this);
267 290 }
268 291 }
@@ -57,15 +57,8 namespace Implab.Parallels {
57 57 var len = Interlocked.Increment(ref m_queueLength);
58 58 m_queue.Enqueue(unit);
59 59
60 ExtendPool();
61 }
62
63 protected override bool ExtendPool() {
64 if (m_queueLength <= m_threshold*ActiveThreads)
65 // in this case we are in active thread and it request for additional workers
66 // satisfy it only when queue is longer than threshold
67 return false;
68 return base.ExtendPool();
60 if (len > m_threshold*ActiveThreads)
61 GrowPool();
69 62 }
70 63
71 64 protected override bool TryDequeue(out Action unit) {
@@ -80,11 +73,5 namespace Implab.Parallels {
80 73 unit();
81 74 }
82 75
83 protected override bool Suspend() {
84 if (m_queueLength == 0)
85 return base.Suspend();
86 else
87 return true; // spin again without locks...
88 }
89 76 }
90 77 }
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