Packages

  • package root
    Definition Classes
    root
  • package io

    This is the documentation for the ThreadCSO Library.

    This is the documentation for the ThreadCSO Library. Notable packages include:

    Definition Classes
    root
  • package threadcso

    The standard threadCSO API.

    The standard threadCSO API. Most modules using CSO will need only the declaration:

    import io.threadcso._

    The present version of the ThreadCSO library API is 1.2Rr (for some number r)

    The revision number (Rr) will change if bugs are corrected but the code remains consistent with the previous API. Its minor version number will change if there is a correction to the code that breaks consistency with the previous API. Its major version will change if there is a substantial change in the semantics of an important CSO construct.

    August 2017: changes 1.1 => 1.2

    • renaming of very many internal classes and packages
    • basic channel implementations are more efficient, in some case much more so
    • alternation reliability improved
    • debugger registration of alternations is no longer needed
    • home-grown semaphores can specify which component they are part of: this makes interpreting a stack backtrace very much easier
    • there is a flexible logging system that is compatible with the debugger

    April 2016: changes 1.0 => 1.1

    • Extended rendezvous read operator is now ?? (was ?)
    • Extended rendezvous read event notation is now =??=> (was =?=>>)
    • The notation inport ? f is now equivalent to f(inport?()) This makes for a tidier layout when the function f is an explicit functional expression.

    Feb 1 2017: changes 1.1R1 => 1.1R2

    • Removed dependencies on deprecated Java->Scala functions: replaced with .asJava
    @author Bernard Sufrin, Oxford
    $Revision: 286 $
    $Date: 2017-11-18 17:41:30 +0000 (Sat, 18 Nov 2017) $
    Definition Classes
    io
  • package semaphore
    Definition Classes
    threadcso
  • package jdk
    Definition Classes
    semaphore
  • BooleanSemaphore
  • CountingSemaphore
  • FastFlag
  • Flag
  • Latch
  • Semaphore

class CountingSemaphore extends Semaphore

A counting semaphore implemented with a nonblocking queue. In principle the semaphore manages a finite collection of (identical) tokens.

The object parent (by default the semaphore itself) is used by the debugger when reporting the state of waiting processes.

The value of available may be negative, in which case it represents a deficit of tokens.

The value spin is the number of attempts the semaphore's local spinlock will make to acquire a token before a call to acquire or acquireFast causes the caller to be descheduled. The point of trying with a spinlock first is that the performance-hit of descheduling can be very high. We assume here that more than one processor is available: set spin to 0 or 1 otherwise.

The fair parameter is ignored.

To do

Make the internal spinlock adaptive

Linear Supertypes
Semaphore, AnyRef, Any
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Inherited
  1. CountingSemaphore
  2. Semaphore
  3. AnyRef
  4. Any
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Visibility
  1. Public
  2. All

Instance Constructors

  1. new CountingSemaphore(available: Int, name: String, fair: Boolean, parent: AnyRef, spin: Int = 5)

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. def acquire(): Unit

    Wait until a token is (or becomes) available.

    Wait until a token is (or becomes) available. If the acquiring thread is cancelled during the wait or the semaphore's cancel() method has been called, then rethrow the cancel.

    Definition Classes
    CountingSemaphoreSemaphore
  5. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  6. val available: Int
  7. def cancel(): Unit

    Interrupt each thread waiting to acquire this semaphore, and cause it to throw an InterruptedException.

    Interrupt each thread waiting to acquire this semaphore, and cause it to throw an InterruptedException. Mark the semaphore itself cancelled

    Definition Classes
    CountingSemaphoreSemaphore
  8. def cancelled(): Boolean

    Returns true if the semaphore was cancelled

    Returns true if the semaphore was cancelled

    Definition Classes
    CountingSemaphoreSemaphore
  9. def clone(): AnyRef
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  10. def down(): Unit

    same as acquire

    same as acquire

    Definition Classes
    Semaphore
    Annotations
    @inline()
  11. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  12. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  13. val fair: Boolean
  14. def finalize(): Unit
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  15. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
  16. def getWaiting: Seq[Thread]

    Return an (approximate) list of the threads waiting to acquire a token from this semaphore.

    Return an (approximate) list of the threads waiting to acquire a token from this semaphore. Intended for use only by diagnostic components.

    Definition Classes
    CountingSemaphoreSemaphore
  17. def hashCode(): Int
    Definition Classes
    AnyRef → Any
  18. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  19. var name: String
  20. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  21. final def notify(): Unit
    Definition Classes
    AnyRef
  22. final def notifyAll(): Unit
    Definition Classes
    AnyRef
  23. val parent: AnyRef
  24. def reInitialize(): Unit

    Reinitialize the semaphore to its as-new state.

  25. def release(): Unit

    Add a token to the collection, then permit an acquireing process to proceed if there is at least one token available.

    Add a token to the collection, then permit an acquireing process to proceed if there is at least one token available.

    Definition Classes
    CountingSemaphoreSemaphore
  26. def remaining(): Int

    Approximation to the number of acquires that could now succeed without having to wait.

    Approximation to the number of acquires that could now succeed without having to wait. Intended for use only by diagnostic components.

    Definition Classes
    CountingSemaphoreSemaphore
  27. val spin: Int
  28. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  29. def toString(): String
    Definition Classes
    CountingSemaphore → AnyRef → Any
  30. def tryAcquire(timeoutNS: Long): Boolean

    Wait until a token becomes available (returning true) or until the specified timeout has elapsed (returning false).

    Wait until a token becomes available (returning true) or until the specified timeout has elapsed (returning false). Unlike java.util.concurrent.Semaphore an invoking thread that needs to wait joins the queue of waiting threads -- threads with shorter timeouts are not prioritised over those with longer deadlines or no deadline. If the acquiring thread is cancelled during the wait or the semaphore's cancel() method has been called, then mark the semaphore as having been cancelled

    Definition Classes
    CountingSemaphoreSemaphore
  31. def up(): Unit

    same as release

    same as release

    Definition Classes
    Semaphore
    Annotations
    @inline()
  32. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  33. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  34. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Inherited from Semaphore

Inherited from AnyRef

Inherited from Any

Ungrouped