Semaphore Class Reference

A classic semaphore synchronization primitive. More...

#include "psemaphore.h"

Public Member Functions
	Semaphore (int initial_count=1)
	Semaphore (const Semaphore &copy)=delete
void	acquire ()
	Decrements the internal count. More...
int	get_count () const
	Returns the current semaphore count. More...
Semaphore &	operator= (const Semaphore &copy)=delete
void	output (std::ostream &out) const
int	release ()
	Increments the semaphore's internal count. More...
bool	try_acquire ()
	If the semaphore can be acquired without blocking, does so and returns true. More...

Detailed Description

A classic semaphore synchronization primitive.

A semaphore manages an internal counter which is decremented by each acquire() call and incremented by each release() call. The counter can never go below zero; when acquire() finds that it is zero, it blocks, waiting until some other thread calls release().

Definition at line 30 of file psemaphore.h.

Member Function Documentation

acquire()

void Semaphore::acquire ( )

inline

Decrements the internal count.

If the count was already at zero, blocks until the count is nonzero, then decrements it.

Definition at line 31 of file psemaphore.I.

get_count()

int Semaphore::get_count ( ) const

inline

Returns the current semaphore count.

Note that this call is not thread- safe (the count may change at any time).

Definition at line 77 of file psemaphore.I.

release()

int Semaphore::release ( )

inline

Increments the semaphore's internal count.

This may wake up another thread blocked on acquire().

Returns the count of the semaphore upon release.

Definition at line 64 of file psemaphore.I.

try_acquire()

bool Semaphore::try_acquire ( )

inline

If the semaphore can be acquired without blocking, does so and returns true.

Otherwise, returns false.

Definition at line 46 of file psemaphore.I.

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

• panda/src/pipeline/psemaphore.h
• panda/src/pipeline/psemaphore.cxx
• panda/src/pipeline/psemaphore.I