corelinux::GatewaySemaphore Class Reference

GatewaySemphore enables a depth of resource indicator. More...

#include <GatewaySemaphore.hpp>

Inheritance diagram for corelinux::GatewaySemaphore:

List of all members.

Public Member Functions
	GatewaySemaphore (SemaphoreGroupPtr, SemaphoreIdentifierRef, Count, bool Recursive=false, bool Balking=false) throw ( NullPointerException )
	Default constructor requires the identifier of the semaphore in the semaphore group and a count of resources for control.
virtual	~GatewaySemaphore (void)
	Virtual Destructor.
virtual bool	isLocked (void)
	Ask if AbstractSemaphore instance is locked.
virtual bool	isAnOwner (void)
	Returns true if calling thread owns a resource.
virtual Counter	getOwnerRecursionQueueLength (void)
	Returns the recursion depth for the calling thread.
virtual SemaphoreOperationStatus	lockWithWait (void) throw ( SemaphoreException )
	Request the lock, wait for availability.
virtual SemaphoreOperationStatus	lockWithNoWait (void) throw ( SemaphoreException )
	Request the lock without waiting.
virtual SemaphoreOperationStatus	release (void) throw ( SemaphoreException )
	Request the AbstractSemaphore but timeout if not available.
Protected Member Functions
	GatewaySemaphore (void) throw ( Assertion )
	Default construct throws assert.
	GatewaySemaphore (GatewaySemaphoreCref) throw ( Assertion )
	Copy constructor throws assertion.
GatewaySemaphoreRef	operator= (GatewaySemaphoreCref) throw ( Assertion )
	Assignment operator throws assertion.
SemaphoreOperationStatus	lockAndAdd (ThreadIdentifierRef aTid, Int aFlag=0)

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Detailed Description

GatewaySemphore enables a depth of resource indicator.

Unlike the tradition boolean semaphore (locked,unlocked), this type assumes a finite number of threads/processes can be granted access up to theResourceMaximum. The semantics regarding semaphore and recursion in relationship to the GatewaySemaphore is as follows:

With recursion enabled:

• Semaphore::getOwningThreadIdentifier returns the ThreadIdentifier of the thread that pushed the value to zero(0).
• Semaphore::getRecursionQueueLength returns the depth of recursion by Semaphore::getOwningThreadIdentifier
• GatewaySemaphore::isAnOwner returns true if the current thread is in the set of threads that own a resource.
• GatewaySemaphore::getOwnerRecursionQueueLength returns either -1 if the current thread does not control a resource, 0 if the current thread does own a resource, but has not recursed, or returns the depth of recursion for the calling thread.

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Constructor & Destructor Documentation

corelinux::GatewaySemaphore::GatewaySemaphore	(	SemaphoreGroupPtr	aGroup,
		SemaphoreIdentifierRef	aIdentifier,
		Count	aValue,
		bool	Recursive = false,
		bool	Balking = false
	)			throw ( NullPointerException )

Default constructor requires the identifier of the semaphore in the semaphore group and a count of resources for control.

Parameters:

	SemaphoreGroupPtr	The owning SemaphoreGroup
	SemaphoreIdentifier	The identifier for the Semaphore from the SemaphoreGroup
	Count	number of resources the semaphore controls
	bool	true if recursion enabled
	bool	true if balking enabled

References corelinux::AbstractSemaphore::setValue().

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Member Function Documentation

Counter corelinux::GatewaySemaphore::getOwnerRecursionQueueLength

(

void

)

[virtual]

Returns the recursion depth for the calling thread.

Returns:

Counter -1 if not an owner, 0 if owner but not recursed, or > 0 for recursion depth.

References corelinux::Thread::getThreadIdentifier(), and isAnOwner().

SemaphoreOperationStatus corelinux::GatewaySemaphore::release

(

void

)

throw ( SemaphoreException ) [virtual]

Request the AbstractSemaphore but timeout if not available.

Release the lock

Implements corelinux::AbstractSemaphore.

References corelinux::Semaphore::getOwnerId(), corelinux::Thread::getThreadIdentifier(), corelinux::Semaphore::isRecursionEnabled(), corelinux::Semaphore::resetOwnerId(), corelinux::AbstractSemaphore::setUnlock(), corelinux::SUCCESS, and corelinux::UNAVAILABLE.

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The documentation for this class was generated from the following files:

• GatewaySemaphore.hpp
• GatewaySemaphore.cpp