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corelinux::GatewaySemaphore Class Reference

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

#include <GatewaySemaphore.hpp>

Inheritance diagram for corelinux::GatewaySemaphore

[legend]Collaboration diagram for corelinux::GatewaySemaphore:

[legend]List of all members.

Public Methods
	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. More...
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. More...
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 )
	Release the lock.
Protected Methods
	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 aRecursionFlag = false, bool aBalkingFlag = 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

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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.

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

• GatewaySemaphore.hpp
• GatewaySemaphore.cpp

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This is the CoreLinux++ reference manual
Provided by The CoreLinux Consortium