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::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::acquire void   )  [inline]
 

Return 0.

int ACE_Null_Semaphore::acquire_read void   )  [inline]
 

Return 0.

int ACE_Null_Semaphore::acquire_write void   )  [inline]
 

Return 0.

void ACE_Null_Semaphore::dump void   )  const [inline]
 

Dump the state of an object.

int ACE_Null_Semaphore::release size_t   )  [inline]
 

Return 0.

int ACE_Null_Semaphore::release void   )  [inline]
 

Return 0.

int ACE_Null_Semaphore::remove void   )  [inline]
 

Return 0.

int ACE_Null_Semaphore::tryacquire void   )  [inline]
 

Return 0.

int ACE_Null_Semaphore::tryacquire_read 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.


The documentation for this class was generated from the following file:
Generated on Wed Nov 23 15:49:31 2005 for ACE by  doxygen 1.4.5