ACE_RW_Process_Mutex Class Reference

Wrapper for readers/writer locks that exist across processes. More...

#include <RW_Process_Mutex.h>

Collaboration diagram for ACE_RW_Process_Mutex:

Collaboration graph
[legend]
List of all members.

Public Member Functions

 ACE_RW_Process_Mutex (const ACE_TCHAR *name=0, int flags=O_CREAT|O_RDWR, mode_t mode=ACE_DEFAULT_OPEN_PERMS)
 ~ACE_RW_Process_Mutex (void)
int remove (void)
int acquire (void)
 Acquire lock ownership (wait on queue if necessary).
int tryacquire (void)
int release (void)
 Release lock and unblock a thread at head of queue.
int acquire_read (void)
 Acquire lock ownership (wait on queue if necessary).
int acquire_write (void)
 Acquire lock ownership (wait on queue if necessary).
int tryacquire_read (void)
int tryacquire_write (void)
int tryacquire_write_upgrade (void)
const ACE_File_Locklock (void) const
 Return the underlying lock.
void dump (void) const
 Dump the state of an object.

Public Attributes

 ACE_ALLOC_HOOK_DECLARE
 Declare the dynamic allocation hooks.

Private Member Functions

const ACE_TCHARunique_name (void)
 Create and return the unique name.

Private Attributes

ACE_TCHAR name_ [ACE_UNIQUE_NAME_LEN]
ACE_File_Lock lock_
 We need this to get the readers/writer semantics...

Detailed Description

Wrapper for readers/writer locks that exist across processes.

Note that because this class uses the <ACE_File_Lock> as its implementation it only can be reliably used between separate processes, rather than threads in the same process. This isn't a limitation of ACE, it's simply the file lock semantics on UNIX and Win32.

Todo:
For systems with pthread_rwlockattr_setpshared one may consider using them to make the mutex faster.


Constructor & Destructor Documentation

ACE_RW_Process_Mutex::ACE_RW_Process_Mutex const ACE_TCHAR name = 0,
int  flags = O_CREAT|O_RDWR,
mode_t  mode = ACE_DEFAULT_OPEN_PERMS
 

Create a readers/writer <Process_Mutex>, passing in the optional <name>, <flags> and <mode>

See also:
ACE_File_Lock. If not specified, a name is generated and flags and mode are set to default platform values.

ACE_RW_Process_Mutex::~ACE_RW_Process_Mutex void   ) 
 


Member Function Documentation

ACE_INLINE int ACE_RW_Process_Mutex::acquire void   ) 
 

Acquire lock ownership (wait on queue if necessary).

ACE_INLINE int ACE_RW_Process_Mutex::acquire_read void   ) 
 

Acquire lock ownership (wait on queue if necessary).

ACE_INLINE int ACE_RW_Process_Mutex::acquire_write void   ) 
 

Acquire lock ownership (wait on queue if necessary).

void ACE_RW_Process_Mutex::dump void   )  const
 

Dump the state of an object.

ACE_INLINE const ACE_File_Lock & ACE_RW_Process_Mutex::lock void   )  const
 

Return the underlying lock.

ACE_INLINE int ACE_RW_Process_Mutex::release void   ) 
 

Release lock and unblock a thread at head of queue.

ACE_INLINE int ACE_RW_Process_Mutex::remove void   ) 
 

Explicitly destroy the mutex. Note that only one thread should call this method since it doesn't protect against race conditions.

ACE_INLINE int ACE_RW_Process_Mutex::tryacquire void   ) 
 

Conditionally acquire lock (i.e., don't wait on queue). Returns -1 on failure. If we "failed" because someone else already had the lock, <errno> is set to <EBUSY>.

ACE_INLINE int ACE_RW_Process_Mutex::tryacquire_read void   ) 
 

Conditionally acquire a lock (i.e., won't block). Returns -1 on failure. If we "failed" because someone else already had the lock, <errno> is set to <EBUSY>.

ACE_INLINE int ACE_RW_Process_Mutex::tryacquire_write void   ) 
 

Conditionally acquire a lock (i.e., won't block). Returns -1 on failure. If we "failed" because someone else already had the lock, <errno> is set to <EBUSY>.

ACE_INLINE int ACE_RW_Process_Mutex::tryacquire_write_upgrade void   ) 
 

Attempt to upgrade a read lock to a write lock. Returns 0 on success, -1 on failure.

const ACE_TCHAR * ACE_RW_Process_Mutex::unique_name void   )  [private]
 

Create and return the unique name.


Member Data Documentation

ACE_RW_Process_Mutex::ACE_ALLOC_HOOK_DECLARE
 

Declare the dynamic allocation hooks.

ACE_File_Lock ACE_RW_Process_Mutex::lock_ [private]
 

We need this to get the readers/writer semantics...

ACE_TCHAR ACE_RW_Process_Mutex::name_[ACE_UNIQUE_NAME_LEN] [private]
 

If the user does not provide a name we generate a unique name in this buffer.


The documentation for this class was generated from the following files:
Generated on Wed Nov 23 15:50:17 2005 for ACE by  doxygen 1.4.5