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
|
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.concurrent.impl
import java.util.concurrent.{ LinkedBlockingQueue, Callable, Executor, ExecutorService, Executors, ThreadFactory, TimeUnit, ThreadPoolExecutor }
import java.util.Collection
import scala.concurrent.forkjoin._
import scala.concurrent.{ BlockContext, ExecutionContext, Awaitable, CanAwait, ExecutionContextExecutor, ExecutionContextExecutorService }
import scala.util.control.NonFatal
private[scala] class ExecutionContextImpl private[impl] (es: Executor, reporter: Throwable => Unit) extends ExecutionContextExecutor {
// Placed here since the creation of the executor needs to read this val
private[this] val uncaughtExceptionHandler: Thread.UncaughtExceptionHandler = new Thread.UncaughtExceptionHandler {
def uncaughtException(thread: Thread, cause: Throwable): Unit = reporter(cause)
}
val executor: Executor = es match {
case null => createExecutorService
case some => some
}
// Implement BlockContext on FJP threads
class DefaultThreadFactory(daemonic: Boolean) extends ThreadFactory with ForkJoinPool.ForkJoinWorkerThreadFactory {
def wire[T <: Thread](thread: T): T = {
thread.setDaemon(daemonic)
thread.setUncaughtExceptionHandler(uncaughtExceptionHandler)
thread
}
def newThread(runnable: Runnable): Thread = wire(new Thread(runnable))
def newThread(fjp: ForkJoinPool): ForkJoinWorkerThread = wire(new ForkJoinWorkerThread(fjp) with BlockContext {
override def blockOn[T](thunk: =>T)(implicit permission: CanAwait): T = {
var result: T = null.asInstanceOf[T]
ForkJoinPool.managedBlock(new ForkJoinPool.ManagedBlocker {
@volatile var isdone = false
override def block(): Boolean = {
result = try thunk finally { isdone = true }
true
}
override def isReleasable = isdone
})
result
}
})
}
def createExecutorService: ExecutorService = {
def getInt(name: String, f: String => Int): Int =
try f(System.getProperty(name)) catch { case e: Exception => Runtime.getRuntime.availableProcessors }
def range(floor: Int, desired: Int, ceiling: Int): Int =
if (ceiling < floor) range(ceiling, desired, floor) else scala.math.min(scala.math.max(desired, floor), ceiling)
val desiredParallelism = range(
getInt("scala.concurrent.context.minThreads", _.toInt),
getInt("scala.concurrent.context.numThreads", {
case null | "" => Runtime.getRuntime.availableProcessors
case s if s.charAt(0) == 'x' => (Runtime.getRuntime.availableProcessors * s.substring(1).toDouble).ceil.toInt
case other => other.toInt
}),
getInt("scala.concurrent.context.maxThreads", _.toInt))
val threadFactory = new DefaultThreadFactory(daemonic = true)
try {
new ForkJoinPool(
desiredParallelism,
threadFactory,
uncaughtExceptionHandler,
true) // Async all the way baby
} catch {
case NonFatal(t) =>
System.err.println("Failed to create ForkJoinPool for the default ExecutionContext, falling back to ThreadPoolExecutor")
t.printStackTrace(System.err)
val exec = new ThreadPoolExecutor(
desiredParallelism,
desiredParallelism,
5L,
TimeUnit.MINUTES,
new LinkedBlockingQueue[Runnable],
threadFactory
)
exec.allowCoreThreadTimeOut(true)
exec
}
}
def execute(runnable: Runnable): Unit = executor match {
case fj: ForkJoinPool =>
val fjt = runnable match {
case t: ForkJoinTask[_] => t
case runnable => new ForkJoinTask[Unit] {
final override def setRawResult(u: Unit): Unit = ()
final override def getRawResult(): Unit = ()
final override def exec(): Boolean = try { runnable.run(); true } catch {
case anything: Throwable ⇒
val t = Thread.currentThread
t.getUncaughtExceptionHandler match {
case null ⇒
case some ⇒ some.uncaughtException(t, anything)
}
throw anything
}
}
}
Thread.currentThread match {
case fjw: ForkJoinWorkerThread if fjw.getPool eq fj => fjt.fork()
case _ => fj execute fjt
}
case generic => generic execute runnable
}
def reportFailure(t: Throwable) = reporter(t)
}
private[concurrent] object ExecutionContextImpl {
def fromExecutor(e: Executor, reporter: Throwable => Unit = ExecutionContext.defaultReporter): ExecutionContextImpl = new ExecutionContextImpl(e, reporter)
def fromExecutorService(es: ExecutorService, reporter: Throwable => Unit = ExecutionContext.defaultReporter): ExecutionContextImpl with ExecutionContextExecutorService =
new ExecutionContextImpl(es, reporter) with ExecutionContextExecutorService {
final def asExecutorService: ExecutorService = executor.asInstanceOf[ExecutorService]
override def execute(command: Runnable) = executor.execute(command)
override def shutdown() { asExecutorService.shutdown() }
override def shutdownNow() = asExecutorService.shutdownNow()
override def isShutdown = asExecutorService.isShutdown
override def isTerminated = asExecutorService.isTerminated
override def awaitTermination(l: Long, timeUnit: TimeUnit) = asExecutorService.awaitTermination(l, timeUnit)
override def submit[T](callable: Callable[T]) = asExecutorService.submit(callable)
override def submit[T](runnable: Runnable, t: T) = asExecutorService.submit(runnable, t)
override def submit(runnable: Runnable) = asExecutorService.submit(runnable)
override def invokeAll[T](callables: Collection[_ <: Callable[T]]) = asExecutorService.invokeAll(callables)
override def invokeAll[T](callables: Collection[_ <: Callable[T]], l: Long, timeUnit: TimeUnit) = asExecutorService.invokeAll(callables, l, timeUnit)
override def invokeAny[T](callables: Collection[_ <: Callable[T]]) = asExecutorService.invokeAny(callables)
override def invokeAny[T](callables: Collection[_ <: Callable[T]], l: Long, timeUnit: TimeUnit) = asExecutorService.invokeAny(callables, l, timeUnit)
}
}
|