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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

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

int close (void)
 Close a ACE_SV_Semaphore, marking it as invalid for subsequent operations...

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 .

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

int 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).

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.


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
 

Enumeration values:
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 k,
int flags = ACE_SV_Semaphore_Simple::ACE_CREATE,
int initial_value = 1,
u_short n = 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 n = 1,
int perms = ACE_DEFAULT_FILE_PERMS )
 

ACE_SV_Semaphore_Simple::~ACE_SV_Semaphore_Simple ( void )
 


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 n ) 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 n = 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 .

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.


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:
Generated at Wed Nov 21 10:33:58 2001 for ACE by doxygen1.2.3 written by Dimitri van Heesch, © 1997-2000