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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:

[legend]List of all members.

Public Types
enum	{ ACE_CREATE = IPC_CREAT, ACE_EXCL = IPC_EXCL, ACE_OPEN = 0 }
Public Methods
	ACE_SV_Semaphore_Simple (void)
	ACE_SV_Semaphore_Simple (key_t key, int flags=ACE_SV_Semaphore_Simple::ACE_CREATE, int initial_value=1, u_short nsems=1, int perms=ACE_DEFAULT_FILE_PERMS)
	ACE_SV_Semaphore_Simple (const char *name, int flags=ACE_SV_Semaphore_Simple::ACE_CREATE, int initial_value=1, u_short nsems=1, int perms=ACE_DEFAULT_FILE_PERMS)
	~ACE_SV_Semaphore_Simple (void)
int	open (const char *name, int flags=ACE_SV_Semaphore_Simple::ACE_CREATE, int initial_value=1, u_short nsems=1, int perms=ACE_DEFAULT_FILE_PERMS)
int	open (key_t key, int flags=ACE_SV_Semaphore_Simple::ACE_CREATE, int initial_value=1, u_short nsems=1, int perms=ACE_DEFAULT_FILE_PERMS)
int	close (void)
int	remove (void) const
int	acquire (u_short n=0, int flags=0) const
int	acquire_read (u_short n=0, int flags=0) const
	Acquire a semaphore for reading.
int	acquire_write (u_short n=0, int flags=0) const
	Acquire a semaphore for writing.
int	tryacquire (u_short n=0, int flags=0) const
	Non-blocking version of <acquire>.
int	tryacquire_read (u_short n=0, int flags=0) const
	Try to acquire the semaphore for reading.
int	tryacquire_write (u_short n=0, int flags=0) const
	Try to acquire the semaphore for writing.
int	release (u_short n=0, int flags=0) const
int	op (int val, u_short semnum=0, int 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 Methods
int	init (key_t k=ACE_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.

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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).

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Member Enumeration Documentation

anonymous enum

Enumeration values: ACE_CREATE  ACE_EXCL  ACE_OPEN

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Constructor & Destructor Documentation

ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple (  void    )

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

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

ACE_SV_Semaphore_Simple::~ACE_SV_Semaphore_Simple (  void    )

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Member Function Documentation

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

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.

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

Acquire a semaphore for reading. Reimplemented in ACE_SV_Semaphore_Complex.

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

Acquire a semaphore for writing. Reimplemented in ACE_SV_Semaphore_Complex.

ASYS_INLINE int ACE_SV_Semaphore_Simple::close (  void    )

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, int    value = 0, u_short    n = 0 )  const

Reimplemented in ACE_SV_Semaphore_Complex.

ASYS_INLINE int ACE_SV_Semaphore_Simple::control (  int    cmd, semun    arg, 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.

ASYS_INLINE int ACE_SV_Semaphore_Simple::get_id (  void    )  const

Get underlying internal id.

int ACE_SV_Semaphore_Simple::init (  key_t    k = ACE_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]

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

General ACE_SV_Semaphore operation on an array of SV_Semaphores. Reimplemented in ACE_SV_Semaphore_Complex.

int ACE_SV_Semaphore_Simple::op (  int    val, u_short    semnum = 0, int    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::open (  key_t    key, int    flags = ACE_SV_Semaphore_Simple::ACE_CREATE, int    initial_value = 1, u_short    nsems = 1, int    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::open (  const char *    name, int    flags = ACE_SV_Semaphore_Simple::ACE_CREATE, int    initial_value = 1, u_short    nsems = 1, int    perms = ACE_DEFAULT_FILE_PERMS )

Reimplemented in ACE_SV_Semaphore_Complex.

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

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.

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

Non-blocking version of <acquire>. Reimplemented in ACE_SV_Semaphore_Complex.

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

Try to acquire the semaphore for reading. Reimplemented in ACE_SV_Semaphore_Complex.

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

Try to acquire the semaphore for writing. Reimplemented in ACE_SV_Semaphore_Complex.

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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.

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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.i

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