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ACE_RW_Mutex Class Reference

Wrapper for readers/writer locks. More...

#include <RW_Mutex.h>

Inheritance diagram for ACE_RW_Mutex:

Inheritance graph
[legend]
List of all members.

Public Member Functions

 ACE_RW_Mutex (int type=USYNC_THREAD, const ACE_TCHAR *name=0, void *arg=0)
 Initialize a readers/writer lock.

 ~ACE_RW_Mutex (void)
 Implicitly destroy a readers/writer lock.

int remove (void)
int acquire_read (void)
 Acquire a read lock, but block if a writer hold the lock.

int acquire_write (void)
int tryacquire_read (void)
int tryacquire_write (void)
 Conditionally acquire a write lock (i.e., won't block).

int tryacquire_write_upgrade (void)
int acquire (void)
int tryacquire (void)
int release (void)
 Unlock a readers/writer lock.

const ACE_rwlock_t & 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.


Protected Attributes

ACE_rwlock_t lock_
 Readers/writer lock.

int removed_

Private Member Functions

void operator= (const ACE_RW_Mutex &)
 ACE_RW_Mutex (const ACE_RW_Mutex &)

Detailed Description

Wrapper for readers/writer locks.

These are most useful for applications that have many more parallel readers than writers...

Definition at line 41 of file RW_Mutex.h.

Constructor & Destructor Documentation

ACE_RW_Mutex::ACE_RW_Mutex (  int  type = USYNC_THREAD,
const ACE_TCHAR *  name = 0,
void *  arg = 0
) 
 

Initialize a readers/writer lock.

Definition at line 37 of file RW_Mutex.cpp.

References ACE_ERROR, ACE_LIB_TEXT, ACE_TCHAR, LM_ERROR, and ACE_OS::rwlock_init(). 

00038   : removed_ (0)
00039 {
00040 // ACE_TRACE ("ACE_RW_Mutex::ACE_RW_Mutex");
00041   if (ACE_OS::rwlock_init (&this->lock_, type, name, arg) != 0)
00042     ACE_ERROR ((LM_ERROR,
00043                 ACE_LIB_TEXT ("%p\n"),
00044                 ACE_LIB_TEXT ("ACE_RW_Mutex::ACE_RW_Mutex")));
00045 }

ACE_RW_Mutex::~ACE_RW_Mutex (  void   ) 
 

Implicitly destroy a readers/writer lock.

Definition at line 47 of file RW_Mutex.cpp.

References remove(). 

00048 {
00049 // ACE_TRACE ("ACE_RW_Mutex::~ACE_RW_Mutex");
00050   this->remove ();
00051 }

ACE_RW_Mutex::ACE_RW_Mutex (  const ACE_RW_Mutex &   )  [private]
 

Member Function Documentation

ACE_INLINE int ACE_RW_Mutex::acquire (  void   ) 
 

Note, for interface uniformity with other synchronization wrappers we include the method. This is implemented as a write-lock to safe...

Definition at line 42 of file RW_Mutex.inl.

References ACE_OS::rw_wrlock(). 

00043 {
00044 // ACE_TRACE ("ACE_RW_Mutex::acquire");
00045   return ACE_OS::rw_wrlock (&this->lock_);
00046 }

ACE_INLINE int ACE_RW_Mutex::acquire_read (  void   ) 
 

Acquire a read lock, but block if a writer hold the lock.

Definition at line 28 of file RW_Mutex.inl.

References ACE_OS::rw_rdlock(). 

00029 {
00030 // ACE_TRACE ("ACE_RW_Mutex::acquire_read");
00031   return ACE_OS::rw_rdlock (&this->lock_);
00032 }

ACE_INLINE int ACE_RW_Mutex::acquire_write (  void   ) 
 

Acquire a write lock, but block if any readers or a writer hold the lock.

Definition at line 35 of file RW_Mutex.inl.

References ACE_OS::rw_wrlock(). 

00036 {
00037 // ACE_TRACE ("ACE_RW_Mutex::acquire_write");
00038   return ACE_OS::rw_wrlock (&this->lock_);
00039 }

ACE_BEGIN_VERSIONED_NAMESPACE_DECL void ACE_RW_Mutex::dump (  void   )  const
 

Dump the state of an object.

Reimplemented in ACE_RW_Thread_Mutex.

Definition at line 26 of file RW_Mutex.cpp.

References ACE_BEGIN_DUMP, ACE_DEBUG, ACE_END_DUMP, ACE_LIB_TEXT, and LM_DEBUG.

Referenced by ACE_RW_Thread_Mutex::dump(). 

00027 {
00028 #if defined (ACE_HAS_DUMP)
00029 // ACE_TRACE ("ACE_RW_Mutex::dump");
00030 
00031   ACE_DEBUG ((LM_DEBUG, ACE_BEGIN_DUMP, this));
00032   ACE_DEBUG ((LM_DEBUG, ACE_LIB_TEXT ("\n")));
00033   ACE_DEBUG ((LM_DEBUG, ACE_END_DUMP));
00034 #endif /* ACE_HAS_DUMP */
00035 }

ACE_BEGIN_VERSIONED_NAMESPACE_DECL ACE_INLINE const ACE_rwlock_t & ACE_RW_Mutex::lock (  void   )  const
 

Return the underlying lock.

Definition at line 8 of file RW_Mutex.inl. 

00009 {
00010 // ACE_TRACE ("ACE_RW_Mutex::lock");
00011   return this->lock_;
00012 }

void ACE_RW_Mutex::operator= (  const ACE_RW_Mutex &   )  [private]
 

ACE_INLINE int ACE_RW_Mutex::release (  void   ) 
 

Unlock a readers/writer lock.

Definition at line 77 of file RW_Mutex.inl.

References ACE_OS::rw_unlock(). 

00078 {
00079 // ACE_TRACE ("ACE_RW_Mutex::release");
00080   return ACE_OS::rw_unlock (&this->lock_);
00081 }

ACE_INLINE int ACE_RW_Mutex::remove (  void   ) 
 

Explicitly destroy a readers/writer lock. Note that only one thread should call this method since it doesn't protect against race conditions.

Definition at line 15 of file RW_Mutex.inl.

References ACE_OS::rwlock_destroy().

Referenced by ~ACE_RW_Mutex(). 

00016 {
00017 // ACE_TRACE ("ACE_RW_Mutex::remove");
00018   int result = 0;
00019   if (this->removed_ == 0)
00020     {
00021       this->removed_ = 1;
00022       result = ACE_OS::rwlock_destroy (&this->lock_);
00023     }
00024   return result;
00025 }

ACE_INLINE int ACE_RW_Mutex::tryacquire (  void   ) 
 

Note, for interface uniformity with other synchronization wrappers we include the method. This is implemented as a write-lock to be safe... Returns -1 on failure. If we "failed" because someone else already had the lock, is set to .

Definition at line 70 of file RW_Mutex.inl.

References tryacquire_write(). 

00071 {
00072 // ACE_TRACE ("ACE_RW_Mutex::tryacquire");
00073   return this->tryacquire_write ();
00074 }

ACE_INLINE int ACE_RW_Mutex::tryacquire_read (  void   ) 
 

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

Definition at line 49 of file RW_Mutex.inl.

References ACE_OS::rw_tryrdlock(). 

00050 {
00051 // ACE_TRACE ("ACE_RW_Mutex::tryacquire_read");
00052   return ACE_OS::rw_tryrdlock (&this->lock_);
00053 }

ACE_INLINE int ACE_RW_Mutex::tryacquire_write (  void   ) 
 

Conditionally acquire a write lock (i.e., won't block).

Definition at line 56 of file RW_Mutex.inl.

References ACE_OS::rw_trywrlock().

Referenced by tryacquire(). 

00057 {
00058 // ACE_TRACE ("ACE_RW_Mutex::tryacquire_write");
00059   return ACE_OS::rw_trywrlock (&this->lock_);
00060 }

ACE_INLINE int ACE_RW_Mutex::tryacquire_write_upgrade (  void   ) 
 

Conditionally upgrade a read lock to a write lock. This only works if there are no other readers present, in which case the method returns 0. Otherwise, the method returns -1 and sets to . Note that the caller of this method *must* already possess this lock as a read lock (but this condition is not checked by the current implementation).

Reimplemented in ACE_RW_Thread_Mutex.

Definition at line 63 of file RW_Mutex.inl.

References ACE_OS::rw_trywrlock_upgrade(). 

00064 {
00065 // ACE_TRACE ("ACE_RW_Mutex::tryacquire_write_upgrade");
00066   return ACE_OS::rw_trywrlock_upgrade (&this->lock_);
00067 }

Member Data Documentation

ACE_RW_Mutex::ACE_ALLOC_HOOK_DECLARE
 

Declare the dynamic allocation hooks.

Reimplemented in ACE_RW_Thread_Mutex.

Definition at line 112 of file RW_Mutex.h.

ACE_rwlock_t ACE_RW_Mutex::lock_ [protected]
 

Readers/writer lock.

Definition at line 116 of file RW_Mutex.h.

int ACE_RW_Mutex::removed_ [protected]
 

Keeps track of whether has been called yet to avoid multiple calls, e.g., explicitly and implicitly in the destructor. This flag isn't protected by a lock, so make sure that you don't have multiple threads simultaneously calling on the same object, which is a bad idea anyway...

Definition at line 123 of file RW_Mutex.h.

The documentation for this class was generated from the following files:
Generated on Thu Nov 9 11:28:21 2006 for ACE by doxygen 1.3.6