ACE_Guard< ACE_LOCK > Class Template Reference

This data structure is meant to be used within a method or function... It performs automatic acquisition and release of a parameterized synchronization object ACE_LOCK. More...

#include <Guard_T.h>

Inheritance diagram for ACE_Guard< ACE_LOCK >:

List of all members.

Public Member Functions
	ACE_Guard (ACE_LOCK &l)
	ACE_Guard (ACE_LOCK &l, bool block)
	ACE_Guard (ACE_LOCK &l, bool block, int become_owner)
	~ACE_Guard (void)
	Implicitly release the lock.
int	acquire (void)
	Explicitly acquire the lock.
int	tryacquire (void)
	Conditionally acquire the lock (i.e., won't block).
int	release (void)
	Explicitly release the lock, but only if it is held!
void	disown (void)
bool	locked (void) const
int	remove (void)
	Explicitly remove the lock.
void	dump (void) const
	Dump the state of an object.
Protected Member Functions
	ACE_Guard (ACE_LOCK *lock)
	Helper, meant for subclass only.
Protected Attributes
ACE_LOCK *	lock_
	Pointer to the ACE_LOCK we're guarding.
int	owner_
	Keeps track of whether we acquired the lock or failed.
Private Member Functions
void	operator= (const ACE_Guard< ACE_LOCK > &)
	ACE_Guard (const ACE_Guard< ACE_LOCK > &)

---

Detailed Description

template<class ACE_LOCK>
class ACE_Guard< ACE_LOCK >

This data structure is meant to be used within a method or function... It performs automatic acquisition and release of a parameterized synchronization object ACE_LOCK.

The ACE_LOCK class given as an actual parameter must provide, at the very least the acquire(), tryacquire(), release(), and remove() methods.

Warning:

A successfully constructed ACE_Guard does NOT mean that the lock was acquired! It is the caller's responsibility, after constructing an ACE_Guard, to check whether the lock was successfully acquired. Code like this is dangerous: { ACE_Guard<ACE_Lock> g(lock); ... perform critical operation requiring lock to be held ... } Instead, one must do something like this: { ACE_Guard<ACE_Lock> g(lock); if (! g.locked()) { ... handle error ... } else { ... perform critical operation requiring lock to be held ... } } The ACE_GUARD_RETURN() and ACE_GUARD_REACTION() macros are designed to to help with this.

---

Constructor & Destructor Documentation

template<class ACE_LOCK >

ACE_Guard< ACE_LOCK >::ACE_Guard

(

ACE_LOCK &

l

)

[inline]

template<class ACE_LOCK >

ACE_Guard< ACE_LOCK >::ACE_Guard	(	ACE_LOCK &	l,
		bool	block
	)		[inline]

Implicitly and automatically acquire (or try to acquire) the lock. If block is non-0 then acquire() the ACE_LOCK, else tryacquire() it.

template<class ACE_LOCK >

ACE_Guard< ACE_LOCK >::ACE_Guard	(	ACE_LOCK &	l,
		bool	block,
		int	become_owner
	)		[inline]

Initialize the guard without implicitly acquiring the lock. The become_owner parameter indicates whether the guard should release the lock implicitly on destruction. The block parameter is ignored and is used here to disambiguate with the preceding constructor.

template<class ACE_LOCK >

ACE_Guard< ACE_LOCK >::~ACE_Guard

(

void

)

[inline]

Implicitly release the lock.

template<class ACE_LOCK>

ACE_Guard< ACE_LOCK >::ACE_Guard

(

ACE_LOCK *

lock

)

[inline, protected]

Helper, meant for subclass only.

template<class ACE_LOCK>

ACE_Guard< ACE_LOCK >::ACE_Guard

(

const ACE_Guard< ACE_LOCK > &

)

[private]

---

Member Function Documentation

template<class ACE_LOCK >

int ACE_Guard< ACE_LOCK >::acquire

(

void

)

[inline]

Explicitly acquire the lock.

Reimplemented in ACE_Read_Guard< ACE_LOCK >, and ACE_Write_Guard< ACE_LOCK >.

template<class ACE_LOCK >

void ACE_Guard< ACE_LOCK >::disown

(

void

)

[inline]

Relinquish ownership of the lock so that it is not released implicitly in the destructor.

template<class ACE_LOCK >

void ACE_Guard< ACE_LOCK >::dump

(

void

)

const

Dump the state of an object.

Reimplemented in ACE_Read_Guard< ACE_LOCK >, and ACE_Write_Guard< ACE_LOCK >.

template<class ACE_LOCK >

bool ACE_Guard< ACE_LOCK >::locked

(

void

)

const [inline]

true if locked, false if couldn't acquire the lock (errno will contain the reason for this).

template<class ACE_LOCK>

void ACE_Guard< ACE_LOCK >::operator=

(

const ACE_Guard< ACE_LOCK > &

)

[private]

template<class ACE_LOCK >

int ACE_Guard< ACE_LOCK >::release

(

void

)

[inline]

Explicitly release the lock, but only if it is held!

template<class ACE_LOCK >

int ACE_Guard< ACE_LOCK >::remove

(

void

)

[inline]

Explicitly remove the lock.

template<class ACE_LOCK >

int ACE_Guard< ACE_LOCK >::tryacquire

(

void

)

[inline]

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

Reimplemented in ACE_Read_Guard< ACE_LOCK >, and ACE_Write_Guard< ACE_LOCK >.

---

Member Data Documentation

template<class ACE_LOCK>

ACE_LOCK* ACE_Guard< ACE_LOCK >::lock_ [protected]

Pointer to the ACE_LOCK we're guarding.

template<class ACE_LOCK>

int ACE_Guard< ACE_LOCK >::owner_ [protected]

Keeps track of whether we acquired the lock or failed.

---

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

• Guard_T.h
• Guard_T.cpp
• Guard_T.inl