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.

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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.

Definition at line 50 of file Null_Semaphore.h.

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Constructor & Destructor Documentation

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

Definition at line 53 of file Null_Semaphore.h. References ACE_TCHAR. {}

ACE_Null_Semaphore::~ACE_Null_Semaphore (  void   )  [inline]

Definition at line 58 of file Null_Semaphore.h. {}

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Member Function Documentation

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

Return -1 with errno == ETIME. Definition at line 69 of file Null_Semaphore.h. References ETIME. {errno = ETIME; return -1;}

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

Return -1 with errno == ETIME. Definition at line 66 of file Null_Semaphore.h. References ETIME. {errno = ETIME; return -1;}

int ACE_Null_Semaphore::acquire (  void   )  [inline]

Return 0. Definition at line 63 of file Null_Semaphore.h. {return 0;}

int ACE_Null_Semaphore::acquire_read (  void   )  [inline]

Return 0. Definition at line 90 of file Null_Semaphore.h. {return 0;}

int ACE_Null_Semaphore::acquire_write (  void   )  [inline]

Return 0. Definition at line 81 of file Null_Semaphore.h. {return 0;}

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

Dump the state of an object. Definition at line 96 of file Null_Semaphore.h. {}

int ACE_Null_Semaphore::release (  size_t   )  [inline]

Return 0. Definition at line 78 of file Null_Semaphore.h. {return 0;}

int ACE_Null_Semaphore::release (  void   )  [inline]

Return 0. Definition at line 75 of file Null_Semaphore.h. {return 0;}

int ACE_Null_Semaphore::remove (  void   )  [inline]

Return 0. Definition at line 60 of file Null_Semaphore.h. {return 0;}

int ACE_Null_Semaphore::tryacquire (  void   )  [inline]

Return 0. Definition at line 72 of file Null_Semaphore.h. {return 0;}

int ACE_Null_Semaphore::tryacquire_read (  void   )  [inline]

Return 0. Definition at line 93 of file Null_Semaphore.h. {return 0;}

int ACE_Null_Semaphore::tryacquire_write (  void   )  [inline]

Return 0. Definition at line 84 of file Null_Semaphore.h. {return 0;}

int ACE_Null_Semaphore::tryacquire_write_upgrade (  void   )  [inline]

Return 0. Definition at line 87 of file Null_Semaphore.h. {return 0;}

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

• Null_Semaphore.h

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