ACE_Null_Semaphore Class Reference

Implement a do nothing ACE_Semaphore, i.e., all the methods are no ops. More...

#include <Null_Semaphore.h>

List of all members.

Public Member Functions

ACE_Null_Semaphore (unsigned int=1, int=0, const ACE_TCHAR *=0, void *=0, int=0x7fffffff)

~ACE_Null_Semaphore (void)

int remove (void)

Return 0.

int acquire (void)

Return 0.

int acquire (ACE_Time_Value &)

Return -1 with errno == ETIME.

int acquire (ACE_Time_Value *)

Return -1 with errno == ETIME.

int tryacquire (void)

Return 0.

int release (void)

Return 0.

int release (size_t)

Return 0.

int acquire_write (void)

Return 0.

int tryacquire_write (void)

Return 0.

int tryacquire_write_upgrade (void)

Return 0.

int acquire_read (void)

Return 0.

int tryacquire_read (void)

Return 0.

void dump (void) const

Dump the state of an object.

Detailed Description

Implement a do nothing ACE_Semaphore, i.e., all the methods are no ops.

Although the methods are no-ops, the return values are different for the blocking as opposed to timed acquires. The blocking version of acquire() is often used to serialize access to a critical section, whereas the timed version is often used to wait for another thread to update some condition or change some shared state. When using an ACE_Null_Semaphore, however, there's no other thread involved to change a state or condition (otherwise, a null semaphore would be inappropriate). Returning an error value signifies that the state or condition has not been (and can't be) changed, which is consistent with the behavior of the threaded case where a timeout occurs before the state or condition is changed.

Constructor & Destructor Documentation

ACE_Null_Semaphore::ACE_Null_Semaphore	(	unsigned	int = `1`,
		int	= `0`,
		const ACE_TCHAR *	= `0`,
		void *	= `0`,
		int	= `0x7fffffff`
	)			`[inline]`

ACE_Null_Semaphore::~ACE_Null_Semaphore ( void ) [inline]

Member Function Documentation

int ACE_Null_Semaphore::remove ( void ) [inline]

Return 0.

int ACE_Null_Semaphore::acquire ( void ) [inline]

Return 0.

int ACE_Null_Semaphore::acquire ( ACE_Time_Value & ) [inline]

Return -1 with errno == ETIME.

int ACE_Null_Semaphore::acquire ( ACE_Time_Value * ) [inline]

Return -1 with errno == ETIME.

int ACE_Null_Semaphore::tryacquire ( void ) [inline]

Return 0.

int ACE_Null_Semaphore::release ( void ) [inline]

Return 0.

int ACE_Null_Semaphore::release ( size_t ) [inline]

Return 0.

int ACE_Null_Semaphore::acquire_write ( void ) [inline]

Return 0.

int ACE_Null_Semaphore::tryacquire_write ( void ) [inline]

Return 0.

int ACE_Null_Semaphore::tryacquire_write_upgrade ( void ) [inline]

Return 0.

int ACE_Null_Semaphore::acquire_read ( void ) [inline]

Return 0.

int ACE_Null_Semaphore::tryacquire_read ( void ) [inline]

Return 0.

void ACE_Null_Semaphore::dump ( void ) const [inline]

Dump the state of an object.

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

Null_Semaphore.h


Public Member Functions
	ACE_Null_Semaphore (unsigned int=1, int=0, const ACE_TCHAR =0, void =0, int=0x7fffffff)
	~ACE_Null_Semaphore (void)
int	remove (void)
	Return 0.
int	acquire (void)
	Return 0.
int	acquire (ACE_Time_Value &)
	Return -1 with `errno` == `ETIME`.
int	acquire (ACE_Time_Value *)
	Return -1 with `errno` == `ETIME`.
int	tryacquire (void)
	Return 0.
int	release (void)
	Return 0.
int	release (size_t)
	Return 0.
int	acquire_write (void)
	Return 0.
int	tryacquire_write (void)
	Return 0.
int	tryacquire_write_upgrade (void)
	Return 0.
int	acquire_read (void)
	Return 0.
int	tryacquire_read (void)
	Return 0.
void	dump (void) const
	Dump the state of an object.