68 lines
1.5 KiB
Scala
68 lines
1.5 KiB
Scala
package examples.pilib
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import scala.concurrent.pilib._
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/** Two-place buffer specification and implementation. */
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object twoPlaceBuffer extends Application {
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/**
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* Specification.
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*/
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def Spec[A](in: Chan[A], out: Chan[A]) {
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def B0: Unit = choice (
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in * (x => B1(x))
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)
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def B1(x: A): Unit = choice (
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out(x) * (B0),
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in * (y => B2(x, y))
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)
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def B2(x: A, y: A): Unit = choice (
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out(x) * (B1(y))
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)
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B0
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}
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/**
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* Implementation using two one-place buffers.
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*/
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def Impl[A](in: Chan[A], out: Chan[A]) {
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///- ... complete here ...
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// one-place buffer
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def OnePlaceBuffer[A](in: Chan[A], out: Chan[A]) {
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def B0: Unit = choice ( in * (x => B1(x)) )
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def B1(x: A): Unit = choice ( out(x) * (B0))
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B0
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}
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val hidden = new Chan[A]
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spawn < OnePlaceBuffer(in, hidden) | OnePlaceBuffer(hidden, out) >
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///+
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}
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val random = new util.Random()
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def Producer(n: Int, in: Chan[String]) {
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Thread.sleep(random.nextInt(1000))
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val msg = "" + n
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choice (in(msg) * {})
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Producer(n + 1, in)
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}
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def Consumer(out: Chan[String]) {
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Thread.sleep(random.nextInt(1000))
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choice (out * { msg => () })
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Consumer(out)
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}
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val in = new Chan[String]
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in.attach(s => println("put " + s))
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val out = new Chan[String]
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out.attach(s => println("get " + s))
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//spawn < Producer(0, in) | Consumer(out) | Spec(in, out) >
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spawn < Producer(0, in) | Consumer(out) | Impl(in, out) >
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}
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