Semaphore Class Reference

A user semaphore optimized for the case where we do not block. More...

#include <semaphore.h>

Public Member Functions
	Semaphore (unsigned cap_sm=0, bool create=false)
void	down ()
void	up ()
unsigned	sm ()

Private Attributes
KernelSemaphore	_sem
long	_value

Detailed Description

A user semaphore optimized for the case where we do not block.

This semaphore implementation breaks when threads blocking on the associated kernel semaphore can be canceled, because the kernel semaphore and the shared counter might then be out-of-sync.

Constructor & Destructor Documentation

Semaphore::Semaphore ( unsigned  cap_sm = 0, bool  create = false  )

inline

Member Function Documentation

void Semaphore::down ( )

inline

unsigned Semaphore::sm ( )

inline

void Semaphore::up ( )

inline

Member Data Documentation

KernelSemaphore Semaphore::_sem

private

long Semaphore::_value

private

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

• base/include/sys/semaphore.h