stt::system::csemp Class Reference

Synchronization tool class encapsulating System V semaphores. More...

#include <sttnet_English.h>

Public Member Functions
	csemp ()
	Constructor, initializes internal state. More...
bool	init (key_t key, unsigned short value=1, short sem_flg=SEM_UNDO)
	Initialize the semaphore. More...
bool	wait (short value=-1)
	P operation (wait), attempts to subtract value from the semaphore. More...
bool	post (short value=1)
	V operation (release), attempts to add value to the semaphore. More...
int	getvalue ()
	Get the current value of the semaphore. More...
bool	destroy ()
	Destroy the current semaphore. More...
	~csemp ()
	Destructor, does not automatically destroy the semaphore. More...

Detailed Description

Synchronization tool class encapsulating System V semaphores.

csemp provides a mutual exclusion mechanism, supporting inter-process synchronization operations. By encapsulating system calls such as semget, semop, semctl, it implements semaphore initialization, P (wait), V (release), destruction, and current value reading.

Copy construction and assignment operators are disabled to ensure resource uniqueness.

Constructor & Destructor Documentation

stt::system::csemp::csemp ( )

inline

Constructor, initializes internal state.

stt::system::csemp::~csemp

(

)

Destructor, does not automatically destroy the semaphore.

Member Function Documentation

bool stt::system::csemp::destroy

(

)

Destroy the current semaphore.

Generally used to clean up resources before the main process holding the semaphore exits.

Returns

true on success; false on failure.

int stt::system::csemp::getvalue

(

)

Get the current value of the semaphore.

Returns

The value of the semaphore; -1 on failure.

bool stt::system::csemp::init	(	key_t	key,
		unsigned short	value = 1,
		short	sem_flg = SEM_UNDO
	)

Initialize the semaphore.

If the semaphore already exists, it is obtained; otherwise, an attempt is made to create and set the initial value.

Parameters

key	Unique key of the semaphore.
value	Initial value of the semaphore (default 1, representing a mutex).
sem_flg	Semaphore operation flags, default SEM_UNDO, operations are automatically revoked when the process terminates.

Returns

true on success; false on failure.

bool stt::system::csemp::post

(

short

value = 1

)

V operation (release), attempts to add value to the semaphore.

Releases resources or wakes up waiting processes.

Parameters

value

Release value (must be greater than 0, default 1).

Returns

true on success; false on failure.

bool stt::system::csemp::wait

(

short

value = -1

)

P operation (wait), attempts to subtract value from the semaphore.

If the current value is insufficient, it will block until available.

Parameters

value

Wait value (must be less than 0, default -1).

Returns

true on success; false on failure.

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

• include/sttnet_English.h