G3D::AtomicInt32 Class Reference

#include <AtomicInt32.h>

Public Member Functions
	AtomicInt32 ()
	AtomicInt32 (const int32 x)
	AtomicInt32 (const AtomicInt32 &x)
const AtomicInt32 &	operator= (const int32 x)
void	operator= (const AtomicInt32 &x)
int32	value () const
int32	add (const int32 x)
int32	sub (const int32 x)
void	increment ()
int32	decrement ()
int32	compareAndSet (const int32 comperand, const int32 exchange)

Private Attributes
volatile int32	m_value

Detailed Description

An integer that may safely be used on different threads without external locking.

On Win32, Linux, FreeBSD, and Mac OS X this is implemented without locks.

BETA API This is unsupported and may change

Constructor & Destructor Documentation

G3D::AtomicInt32::AtomicInt32 ( )

inline

Initial value is undefined.

{}

G3D::AtomicInt32::AtomicInt32 ( const int32  x )

inlineexplicit

Atomic set

 {
 m_value = x;
 }

G3D::AtomicInt32::AtomicInt32 ( const AtomicInt32 &  x )

inline

Atomic set

 {
 m_value = x.m_value;
 }

Member Function Documentation

int32 G3D::AtomicInt32::add ( const int32  x )

inline

Returns the old value, before the add.

 {
# if defined(G3D_WINDOWS)

 return InterlockedExchangeAdd(&m_value, x);

# elif defined(G3D_LINUX) || defined(G3D_FREEBSD)

 int32 old;
 asm volatile ("lock; xaddl %0,%1"
 : "=r"(old), "=m"(m_value) /* outputs */
 : "0"(x), "m"(m_value) /* inputs */
 : "memory", "cc");
 return old;
 
# elif defined(G3D_OSX)

 int32 old = m_value;
 OSAtomicAdd32(x, &m_value);
 return old;

# endif
 }

Here is the caller graph for this function:

int32 G3D::AtomicInt32::compareAndSet ( const int32  comperand, const int32  exchange  )

inline

Atomic test-and-set: if *this == comperand then *this := exchange else do nothing. In both cases, returns the old value of *this.

Performs an atomic comparison of this with the Comperand value. If this is equal to the Comperand value, the Exchange value is stored in this. Otherwise, no operation is performed.

Under VC6 the sign bit may be lost.

 {
# if defined(G3D_WINDOWS)
 return InterlockedCompareExchange(&m_value, exchange, comperand);
# elif defined(G3D_LINUX) || defined(G3D_FREEBSD) || defined(G3D_OSX)
 // Based on Apache Portable Runtime
 // http://koders.com/c/fid3B6631EE94542CDBAA03E822CA780CBA1B024822.aspx
 int32 ret;
 asm volatile ("lock; cmpxchgl %1, %2"
 : "=a" (ret)
 : "r" (exchange), "m" (m_value), "0"(comperand)
 : "memory", "cc");
 return ret;

 // Note that OSAtomicCompareAndSwap32 does not return a useful value for us
 // so it can't satisfy the cmpxchgl contract.
# endif
 }

Here is the caller graph for this function:

int32 G3D::AtomicInt32::decrement ( )

inline

Returns zero if the result is zero after decrement, non-zero otherwise.

 {
# if defined(G3D_WINDOWS)
 // Note: returns the newly decremented value
 return InterlockedDecrement(&m_value);
# elif defined(G3D_LINUX) || defined(G3D_FREEBSD)
 unsigned char nz;

 asm volatile ("lock; decl %1;\n\t"
 "setnz %%al"
 : "=a" (nz)
 : "m" (m_value)
 : "memory", "cc");
 return nz;
# elif defined(G3D_OSX)
 // Note: returns the newly decremented value
 return OSAtomicDecrement32(&m_value);
# endif
 }

Here is the caller graph for this function:

void G3D::AtomicInt32::increment ( )

inline

 {
# if defined(G3D_WINDOWS)
 // Note: returns the newly incremented value
 InterlockedIncrement(&m_value);
# elif defined(G3D_LINUX) || defined(G3D_FREEBSD)
 add(1);
# elif defined(G3D_OSX)
 // Note: returns the newly incremented value
 OSAtomicIncrement32(&m_value);
# endif
 }

Here is the call graph for this function:

Here is the caller graph for this function:

const AtomicInt32& G3D::AtomicInt32::operator= ( const int32  x )

inline

Atomic set

 {
 m_value = x;
 return *this;
 }

void G3D::AtomicInt32::operator= ( const AtomicInt32 &  x )

inline

Atomic set

 {
 m_value = x.m_value;
 }

int32 G3D::AtomicInt32::sub ( const int32  x )

inline

Returns old value.

 {
 return add(-x);
 }

Here is the call graph for this function:

int32 G3D::AtomicInt32::value ( ) const

inline

Returns the current value

 {
 return m_value;
 }

Here is the caller graph for this function:

Member Data Documentation

volatile int32 G3D::AtomicInt32::m_value

private

---

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

• dep/g3dlite/include/G3D/AtomicInt32.h