DD::Image::Guard Class Reference

Inheritance diagram for DD::Image::Guard:

Public Member Functions
	Guard (Lock &m)
	Guard (Lock *m)
	~Guard ()

Additional Inherited Members
Protected Member Functions inherited from DD::Image::BaseLockGuard
	BaseLockGuard (Lock &m)
Protected Attributes inherited from DD::Image::BaseLockGuard
Lock &	_lock

Detailed Description

This wrapper class locks a lock in it's constructor, and unlocks it upon destruction. This is convienent if your function has many exit points or you are using exceptions, creating a Guard as a local variable will cause the compiler to insert the unlock call everywhere it is needed.

int proc() {
  static Lock thelock;
  Guard guard(thelock);
  access_protected_data();
  if (dont_need_to_do_it()) return;
  access_protected_data();
  do_stuff_that_may_throw_exceptions();
  access_protected_data();
  // lock is always unlocked even if this statement is not reached:
  return whatever;
}

Constructor & Destructor Documentation

Guard() [1/2]

DD::Image::Guard::Guard ( Lock &  m )

inline

The constructor calls m.lock()

Guard() [2/2]

DD::Image::Guard::Guard ( Lock *  m )

inline

You can also construct it with a pointer to a lock.

~Guard()

DD::Image::Guard::~Guard ( )

inline

Calls unlock() on the lock passed to the constructor.