ACE  6.3.3
Public Types | Public Member Functions | Public Attributes | Protected Member Functions | Protected Attributes | List of all members
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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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. More...
 
int acquire_write (u_short n=0, short flags=0) const
 Acquire a semaphore for writing. More...
 
int tryacquire (u_short n=0, short flags=0) const
 Non-blocking version of <acquire>. More...
 
int tryacquire_read (u_short n=0, short flags=0) const
 Try to acquire the semaphore for reading. More...
 
int tryacquire_write (u_short n=0, short flags=0) const
 Try to acquire the semaphore for writing. More...
 
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. More...
 
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. More...
 
void dump (void) const
 Dump the state of an object. More...
 

Public Attributes

 ACE_ALLOC_HOOK_DECLARE
 Declare the dynamic allocation hooks. More...
 

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. More...
 
int internal_id_
 Internal ID to identify the semaphore group within this process. More...
 
int sem_number_
 Number of semaphores we're creating. More...
 

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.

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

Acquire a semaphore for reading.

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

Acquire a semaphore for writing.

int ACE_SV_Semaphore_Simple::close ( void  )
inline

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

int ACE_SV_Semaphore_Simple::control ( int  cmd,
semun  arg,
u_short  n = 0 
) const
inline
int ACE_SV_Semaphore_Simple::control ( int  cmd,
int  value = 0,
u_short  n = 0 
) const
void ACE_SV_Semaphore_Simple::dump ( void  ) const

Dump the state of an object.

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).

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.

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 
)
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.

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.

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>.

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

Try to acquire the semaphore for reading.

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_SV_Semaphore_Simple::ACE_ALLOC_HOOK_DECLARE

Declare the dynamic allocation hooks.

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: