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ACE_Null_Semaphore Class Reference

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

#include <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. More...
 
int acquire (void)
 Return 0. More...
 
int acquire (ACE_Time_Value &)
 Return -1 with errno == ETIME. More...
 
int acquire (ACE_Time_Value *)
 Return -1 with errno == ETIME. More...
 
int tryacquire (void)
 Return 0. More...
 
int release (void)
 Return 0. More...
 
int release (size_t)
 Return 0. More...
 
int acquire_write (void)
 Return 0. More...
 
int tryacquire_write (void)
 Return 0. More...
 
int tryacquire_write_upgrade (void)
 Return 0. More...
 
int acquire_read (void)
 Return 0. More...
 
int tryacquire_read (void)
 Return 0. More...
 
void dump (void) const
 Dump the state of an object. More...
 

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 ( 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::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 ( void  )
inline

Return 0.

int ACE_Null_Semaphore::release ( size_t  )
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: