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:

[legend]

List of all members.

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

Public Member Functions
	ACE_SV_Semaphore_Simple (void)
	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 (void)
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 (void)
int	remove (void) 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 (void) const
	Get underlying internal id.
void	dump (void) const
	Dump the state of an object.

Public Attributes
	ACE_ALLOC_HOOK_DECLARE
	Declare the dynamic allocation hooks.

Protected Member Functions
int	init (key_t k=static_cast< key_t >(ACE_INVALID_SEM_KEY), int i=-1)
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

Enumerator:

ACE_CREATE
ACE_EXCL
ACE_OPEN

Constructor & Destructor Documentation

ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple ( void )

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::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::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 ( void )

Member Function Documentation

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.

Reimplemented in ACE_SV_Semaphore_Complex.

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

inline

Acquire a semaphore for reading.

Reimplemented in ACE_SV_Semaphore_Complex.

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

inline

Acquire a semaphore for writing.

Reimplemented in ACE_SV_Semaphore_Complex.

int ACE_SV_Semaphore_Simple::close ( void )

inline

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

Reimplemented in ACE_SV_Semaphore_Complex.

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

inline

Reimplemented in ACE_SV_Semaphore_Complex.

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

Reimplemented in ACE_SV_Semaphore_Complex.

void ACE_SV_Semaphore_Simple::dump ( void ) const

Dump the state of an object.

Reimplemented in ACE_SV_Semaphore_Complex.

int ACE_SV_Semaphore_Simple::get_id ( void ) const

inline

Get underlying internal id.

int ACE_SV_Semaphore_Simple::init	(	key_t	k = `static_cast<key_t> (ACE_INVALID_SEM_KEY)`,
		int	i = `-1`
	)

protected

Convert name to key This function is used internally to create keys for the semaphores. A valid name contains letters and digits only and MUST start with a letter.

The method for generating names is not very sophisticated, so caller should not pass strings which match each other for the first LUSED characters when he wants to get a different key.

key_t ACE_SV_Semaphore_Simple::name_2_key ( const char * name )

protected

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).

Reimplemented in ACE_SV_Semaphore_Complex.

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.

Reimplemented in ACE_SV_Semaphore_Complex.

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`
	)

Reimplemented in ACE_SV_Semaphore_Complex.

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

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.

Reimplemented in ACE_SV_Semaphore_Complex.

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.

Reimplemented in ACE_SV_Semaphore_Complex.

int ACE_SV_Semaphore_Simple::remove ( void ) 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.

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

inline

Non-blocking version of <acquire>.

Reimplemented in ACE_SV_Semaphore_Complex.

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

inline

Try to acquire the semaphore for reading.

Reimplemented in ACE_SV_Semaphore_Complex.

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

inline

Try to acquire the semaphore for writing.

Reimplemented in ACE_SV_Semaphore_Complex.

Member Data Documentation

ACE_SV_Semaphore_Simple::ACE_ALLOC_HOOK_DECLARE

Declare the dynamic allocation hooks.

Reimplemented in ACE_SV_Semaphore_Complex.

int ACE_SV_Semaphore_Simple::internal_id_

protected

Internal ID to identify the semaphore group within this process.

key_t ACE_SV_Semaphore_Simple::key_

protected

Semaphore key.

int ACE_SV_Semaphore_Simple::sem_number_

protected

Number of semaphores we're creating.

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

Public Types

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation