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
|
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2005-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.actors.scheduler
import scala.actors.threadpool.{ThreadPoolExecutor, TimeUnit, LinkedBlockingQueue,
ThreadFactory}
import scala.actors.{Debug, IScheduler}
import scala.concurrent.ManagedBlocker
/**
* This scheduler class uses a `ThreadPoolExecutor` to execute `Actor`s.
*
* The scheduler attempts to shut down itself and the underlying
* `ThreadPoolExecutor` only if `terminate` is set to true. Otherwise,
* the scheduler must be shut down explicitly.
*
* @author Philipp Haller
*/
@deprecated("Use the akka.actor package instead. For migration from the scala.actors package refer to the Actors Migration Guide.", "2.11.0")
class ResizableThreadPoolScheduler(protected val terminate: Boolean,
protected val daemon: Boolean)
extends Thread with IScheduler with TerminationMonitor {
setDaemon(daemon)
// guarded by this
private var terminating = false
// guarded by this
private var suspending = false
// this has to be a java.util.Collection, since this is what
// the ForkJoinPool returns.
@volatile
private var drainedTasks: java.util.List[_] = null
// guarded by this
private var coreSize = ThreadPoolConfig.corePoolSize
private val maxSize = ThreadPoolConfig.maxPoolSize
private val numCores = Runtime.getRuntime().availableProcessors()
protected val CHECK_FREQ = 10
private class DaemonThreadFactory extends ThreadFactory {
def newThread(r: Runnable): Thread = {
val t = new Thread(r)
t.setDaemon(daemon)
t
}
}
private val threadFac = new DaemonThreadFactory
private def makeNewPool(): ThreadPoolExecutor = {
val workQueue = new LinkedBlockingQueue
new ThreadPoolExecutor(coreSize,
maxSize,
60000L,
TimeUnit.MILLISECONDS,
workQueue,
threadFac,
new ThreadPoolExecutor.CallerRunsPolicy)
}
// guarded by this
private var executor = makeNewPool()
Debug.info(this+": corePoolSize = "+coreSize+", maxPoolSize = "+maxSize)
def this(d: Boolean) {
this(true, d)
}
def this() {
this(false)
}
private def numWorkersBlocked = {
executor.mainLock.lock()
val iter = executor.workers.iterator()
var numBlocked = 0
while (iter.hasNext()) {
val w = iter.next().asInstanceOf[ThreadPoolExecutor#Worker]
if (w.tryLock()) {
// worker is idle
w.unlock()
} else {
val s = w.thread.getState()
if (s == Thread.State.WAITING || s == Thread.State.TIMED_WAITING)
numBlocked += 1
}
}
executor.mainLock.unlock()
numBlocked
}
override def run() {
try {
while (true) {
this.synchronized {
try {
wait(CHECK_FREQ.toLong)
} catch {
case _: InterruptedException =>
}
if (terminating)
throw new QuitControl
if (!suspending) {
gc()
// check if we need more worker threads
val activeBlocked = numWorkersBlocked
if (coreSize - activeBlocked < numCores && coreSize < maxSize) {
coreSize = numCores + activeBlocked
executor.setCorePoolSize(coreSize)
} else if (terminate && allActorsTerminated) {
// if all worker threads idle terminate
if (executor.getActiveCount() == 0) {
Debug.info(this+": initiating shutdown...")
Debug.info(this+": corePoolSize = "+coreSize+", maxPoolSize = "+maxSize)
terminating = true
throw new QuitControl
}
}
} else {
drainedTasks = executor.shutdownNow()
Debug.info(this+": drained "+drainedTasks.size()+" tasks")
terminating = true
throw new QuitControl
}
} // sync
}
} catch {
case _: QuitControl =>
executor.shutdown()
// allow thread to exit
}
}
def execute(task: Runnable): Unit =
executor execute task
def execute(fun: => Unit): Unit =
executor.execute(new Runnable {
def run() { fun }
})
/** Shuts down the scheduler.
*/
def shutdown(): Unit = synchronized {
terminating = true
}
def isActive = synchronized {
!terminating && (executor ne null) && !executor.isShutdown()
}
def managedBlock(blocker: ManagedBlocker) {
blocker.block()
}
/** Suspends the scheduler. All threads that were in use by the
* scheduler and its internal thread pool are terminated.
*/
def snapshot() = synchronized {
suspending = true
}
/** Resumes the execution of the scheduler if it was previously
* suspended using `snapshot`.
*/
def restart() {
synchronized {
if (!suspending)
sys.error("snapshot has not been invoked")
else if (isActive)
sys.error("scheduler is still active")
else
suspending = false
executor = makeNewPool()
}
val iter = drainedTasks.iterator()
while (iter.hasNext()) {
executor.execute(iter.next().asInstanceOf[Runnable])
}
start()
}
}
|
