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:

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_Lock & lock (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_TCHAR * unique_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_BEGIN_VERSIONED_NAMESPACE_DECL 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::acquire ( void )

Acquire lock ownership (wait on queue if necessary).

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::release ( void )

Release lock and unblock a thread at head of queue.

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).

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.

ACE_INLINE const ACE_File_Lock & ACE_RW_Process_Mutex::lock ( void ) const

Return the underlying lock.

void ACE_RW_Process_Mutex::dump ( void ) const

Dump the state of an object.

ACE_BEGIN_VERSIONED_NAMESPACE_DECL 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_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.

ACE_File_Lock ACE_RW_Process_Mutex::lock_ [private]

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

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


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_Lock &	lock (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_TCHAR *	unique_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...