G3D::Spinlock Class Reference

A mutual exclusion lock that busy-waits when locking. More...

#include <GMutex.h>

Public Member Functions
	Spinlock ()
bool	lock ()
void	unlock ()

Private Attributes
AtomicInt32	x

Detailed Description

A mutual exclusion lock that busy-waits when locking.

On a machine with one (significant) thread per processor core, a Spinlock may be substantially faster than a mutex.

See also

G3D::GThread, G3D::GMutex, G3D::AtomicInt32

Constructor & Destructor Documentation

G3D::Spinlock::Spinlock ( )

inline

: x(0) {}

Member Function Documentation

bool G3D::Spinlock::lock ( )

inline

Busy waits until the lock is unlocked, then locks it exclusively. Returns true if the lock succeeded on the first try (indicating no contention).

Unlike a G3D::GMutex, a single thread cannot re-enter Spinlock::lock() that it already locked.

 {
 bool first = true;
 while (x.compareAndSet(0, 1) == 1) {
 first = false;
# ifdef G3D_WINDOWS
 Sleep(0);
# else
 usleep(0);
# endif
 }
 return first;
 }

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void G3D::Spinlock::unlock ( )

inline

 {
 x.compareAndSet(1, 0);
 }

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Member Data Documentation

AtomicInt32 G3D::Spinlock::x

private

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

• dep/g3dlite/include/G3D/GMutex.h