ACE_SV_Semaphore_Simple Class Reference

This is a simple semaphore package that assumes there are no race conditions for initialization (i.e., the order of process startup must be well defined). More...

#include <SV_Semaphore_Simple.h>

Inheritance diagram for ACE_SV_Semaphore_Simple:

Public Types
enum	{ ACE_CREATE = IPC_CREAT , ACE_EXCL = IPC_EXCL , ACE_OPEN = 0 }

Public Member Functions
	ACE_SV_Semaphore_Simple ()
	ACE_SV_Semaphore_Simple (key_t key, short flags=ACE_SV_Semaphore_Simple::ACE_CREATE, int initial_value=1, u_short nsems=1, mode_t perms=ACE_DEFAULT_FILE_PERMS)
	ACE_SV_Semaphore_Simple (const char *name, short flags=ACE_SV_Semaphore_Simple::ACE_CREATE, int initial_value=1, u_short nsems=1, mode_t perms=ACE_DEFAULT_FILE_PERMS)
	ACE_SV_Semaphore_Simple (const wchar_t *name, short flags=ACE_SV_Semaphore_Simple::ACE_CREATE, int initial_value=1, u_short nsems=1, mode_t perms=ACE_DEFAULT_FILE_PERMS)
	~ACE_SV_Semaphore_Simple ()
int	open (const char *name, short flags=ACE_SV_Semaphore_Simple::ACE_CREATE, int initial_value=1, u_short nsems=1, mode_t perms=ACE_DEFAULT_FILE_PERMS)
int	open (const wchar_t *name, short flags=ACE_SV_Semaphore_Simple::ACE_CREATE, int initial_value=1, u_short nsems=1, mode_t perms=ACE_DEFAULT_FILE_PERMS)
int	open (key_t key, short flags=ACE_SV_Semaphore_Simple::ACE_CREATE, int initial_value=1, u_short nsems=1, mode_t perms=ACE_DEFAULT_FILE_PERMS)
int	close ()
int	remove () const
int	acquire (u_short n=0, short flags=0) const
int	acquire_read (u_short n=0, short flags=0) const
	Acquire a semaphore for reading.
int	acquire_write (u_short n=0, short flags=0) const
	Acquire a semaphore for writing.
int	tryacquire (u_short n=0, short flags=0) const
	Non-blocking version of <acquire>.
int	tryacquire_read (u_short n=0, short flags=0) const
	Try to acquire the semaphore for reading.
int	tryacquire_write (u_short n=0, short flags=0) const
	Try to acquire the semaphore for writing.
int	release (u_short n=0, short flags=0) const
int	op (short val, u_short semnum=0, short flags=SEM_UNDO) const
int	op (sembuf op_vec[], u_short nsems) const
	General ACE_SV_Semaphore operation on an array of SV_Semaphores.
int	control (int cmd, semun arg, u_short n=0) const
int	control (int cmd, int value=0, u_short n=0) const
int	get_id () const
	Get underlying internal id.
void	dump () const
	Dump the state of an object.

Public Attributes
	ACE_ALLOC_HOOK_DECLARE
	Declare the dynamic allocation hooks.

Protected Member Functions
key_t	name_2_key (const char *name)

Protected Attributes
key_t	key_
	Semaphore key.
int	internal_id_
	Internal ID to identify the semaphore group within this process.
int	sem_number_
	Number of semaphores we're creating.

Detailed Description

This is a simple semaphore package that assumes there are no race conditions for initialization (i.e., the order of process startup must be well defined).

Member Enumeration Documentation

anonymous enum

anonymous enum

Enumerator
ACE_CREATE
ACE_EXCL
ACE_OPEN

Constructor & Destructor Documentation

ACE_SV_Semaphore_Simple() [1/4]

ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple

(

)

ACE_SV_Semaphore_Simple() [2/4]

ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple	(	key_t	key,
		short	flags = ACE_SV_Semaphore_Simple::ACE_CREATE,
		int	initial_value = 1,
		u_short	nsems = 1,
		mode_t	perms = ACE_DEFAULT_FILE_PERMS )

ACE_SV_Semaphore_Simple() [3/4]

ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple	(	const char *	name,
		short	flags = ACE_SV_Semaphore_Simple::ACE_CREATE,
		int	initial_value = 1,
		u_short	nsems = 1,
		mode_t	perms = ACE_DEFAULT_FILE_PERMS )

ACE_SV_Semaphore_Simple() [4/4]

ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple	(	const wchar_t *	name,
		short	flags = ACE_SV_Semaphore_Simple::ACE_CREATE,
		int	initial_value = 1,
		u_short	nsems = 1,
		mode_t	perms = ACE_DEFAULT_FILE_PERMS )

~ACE_SV_Semaphore_Simple()

ACE_SV_Semaphore_Simple::~ACE_SV_Semaphore_Simple

(

)

Member Function Documentation

acquire()

int ACE_SV_Semaphore_Simple::acquire ( u_short n = 0, short flags = 0 ) const

inline

Wait until a ACE_SV_Semaphore's value is greater than 0, the decrement it by 1 and return. Dijkstra's P operation, Tannenbaums DOWN operation.

acquire_read()

int ACE_SV_Semaphore_Simple::acquire_read ( u_short n = 0, short flags = 0 ) const

inline

Acquire a semaphore for reading.

acquire_write()

int ACE_SV_Semaphore_Simple::acquire_write ( u_short n = 0, short flags = 0 ) const

inline

Acquire a semaphore for writing.

close()

int ACE_SV_Semaphore_Simple::close ( )

inline

Close a ACE_SV_Semaphore, marking it as invalid for subsequent operations...

control() [1/2]

int ACE_SV_Semaphore_Simple::control	(	int	cmd,
		int	value = 0,
		u_short	n = 0 ) const

control() [2/2]

int ACE_SV_Semaphore_Simple::control ( int cmd, semun arg, u_short n = 0 ) const

inline

dump()

void ACE_SV_Semaphore_Simple::dump

(

)

const

Dump the state of an object.

get_id()

int ACE_SV_Semaphore_Simple::get_id ( ) const

inline

Get underlying internal id.

name_2_key()

key_t ACE_SV_Semaphore_Simple::name_2_key ( const char * name )

protected

op() [1/2]

int ACE_SV_Semaphore_Simple::op ( sembuf op_vec[], u_short nsems ) const

inline

General ACE_SV_Semaphore operation on an array of SV_Semaphores.

op() [2/2]

int ACE_SV_Semaphore_Simple::op	(	short	val,
		u_short	semnum = 0,
		short	flags = SEM_UNDO ) const

General ACE_SV_Semaphore operation. Increment or decrement by a specific amount (positive or negative; amount can`t be zero).

open() [1/3]

int ACE_SV_Semaphore_Simple::open	(	const char *	name,
		short	flags = ACE_SV_Semaphore_Simple::ACE_CREATE,
		int	initial_value = 1,
		u_short	nsems = 1,
		mode_t	perms = ACE_DEFAULT_FILE_PERMS )

open() [2/3]

int ACE_SV_Semaphore_Simple::open ( const wchar_t * name, short flags = ACE_SV_Semaphore_Simple::ACE_CREATE, int initial_value = 1, u_short nsems = 1, mode_t perms = ACE_DEFAULT_FILE_PERMS )

inline

open() [3/3]

int ACE_SV_Semaphore_Simple::open	(	key_t	key,
		short	flags = ACE_SV_Semaphore_Simple::ACE_CREATE,
		int	initial_value = 1,
		u_short	nsems = 1,
		mode_t	perms = ACE_DEFAULT_FILE_PERMS )

Open or create one or more SV_Semaphores. We return 0 if all is OK, else -1.

release()

int ACE_SV_Semaphore_Simple::release ( u_short n = 0, short flags = 0 ) const

inline

Increment ACE_SV_Semaphore by one. Dijkstra's V operation, Tannenbaums UP operation.

remove()

int ACE_SV_Semaphore_Simple::remove

(

)

const

Remove all SV_Semaphores associated with a particular key. This call is intended to be called from a server, for example, when it is being shut down, as we do an IPC_RMID on the ACE_SV_Semaphore, regardless of whether other processes may be using it or not. Most other processes should use close() below.

tryacquire()

int ACE_SV_Semaphore_Simple::tryacquire ( u_short n = 0, short flags = 0 ) const

inline

Non-blocking version of <acquire>.

tryacquire_read()

int ACE_SV_Semaphore_Simple::tryacquire_read ( u_short n = 0, short flags = 0 ) const

inline

Try to acquire the semaphore for reading.

tryacquire_write()

int ACE_SV_Semaphore_Simple::tryacquire_write ( u_short n = 0, short flags = 0 ) const

inline

Try to acquire the semaphore for writing.

Member Data Documentation

ACE_ALLOC_HOOK_DECLARE

ACE_SV_Semaphore_Simple::ACE_ALLOC_HOOK_DECLARE

Declare the dynamic allocation hooks.

internal_id_

int ACE_SV_Semaphore_Simple::internal_id_

protected

Internal ID to identify the semaphore group within this process.

key_

key_t ACE_SV_Semaphore_Simple::key_

protected

Semaphore key.

sem_number_

int ACE_SV_Semaphore_Simple::sem_number_

protected

Number of semaphores we're creating.

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

• SV_Semaphore_Simple.h
• SV_Semaphore_Simple.cpp
• SV_Semaphore_Simple.inl