@ -617,107 +617,39 @@ static void __attribute__((destructor)) fini_##rwlock(void) \
# define pthread_create __use_ast_pthread_create_instead__
# endif
/*
* Support for atomic instructions .
* For platforms that have it , use the native cpu instruction to
* implement them . For other platforms , resort to a ' slow ' version
* ( defined in utils . c ) that protects the atomic instruction with
* a single lock .
* The slow versions is always available , for testing purposes ,
* as ast_atomic_fetchadd_int_slow ( )
*/
int ast_atomic_fetchadd_int_slow ( volatile int * p , int v ) ;
/* Support for atomic instructions. */
# include "asterisk/inline_api.h"
# if defined(HAVE_OSX_ATOMICS)
# include "libkern/OSAtomic.h"
# if defined(HAVE_C_ATOMICS)
# define ast_atomic_fetch_add(p, v, memorder) __atomic_fetch_add(p, v, memorder)
# define ast_atomic_sub_fetch(p, v, memorder) __atomic_sub_fetch(p, v, memorder)
# elif defined(HAVE_GCC_ATOMICS)
# define ast_atomic_fetch_add(p, v, memorder) __sync_fetch_and_add(p, v)
# define ast_atomic_sub_fetch(p, v, memorder) __sync_sub_and_fetch(p, v)
# else
# error "Atomics not available."
# endif
/*! \brief Atomically add v to *p and return * the previous value of *p.
/*!
* \ brief Atomically add v to * p and return the previous value of * p .
*
* This can be used to handle reference counts , and the return value
* can be used to generate unique identifiers .
*/
# if defined(HAVE_C_ATOMICS)
AST_INLINE_API ( int ast_atomic_fetchadd_int ( volatile int * p , int v ) ,
{
return _ _atomic_fetch_add( p , v , __ATOMIC_RELAXED ) ;
return ast _atomic_fetch_add( p , v , __ATOMIC_RELAXED ) ;
} )
# elif defined(HAVE_GCC_ATOMICS)
AST_INLINE_API ( int ast_atomic_fetchadd_int ( volatile int * p , int v ) ,
{
return __sync_fetch_and_add ( p , v ) ;
} )
# elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 4)
AST_INLINE_API ( int ast_atomic_fetchadd_int ( volatile int * p , int v ) ,
{
return OSAtomicAdd32 ( v , ( int32_t * ) p ) - v ;
} )
# elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 8)
AST_INLINE_API ( int ast_atomic_fetchadd_int ( volatile int * p , int v ) ,
{
return OSAtomicAdd64 ( v , ( int64_t * ) p ) - v ;
} )
# elif defined (__i386__) || defined(__x86_64__)
# ifdef sun
AST_INLINE_API ( int ast_atomic_fetchadd_int ( volatile int * p , int v ) ,
{
__asm __volatile (
" lock; xaddl %0, %1 ; "
: " +r " ( v ) , /* 0 (result) */
" =m " ( * p ) /* 1 */
: " m " ( * p ) ) ; /* 2 */
return ( v ) ;
} )
# else /* ifndef sun */
AST_INLINE_API ( int ast_atomic_fetchadd_int ( volatile int * p , int v ) ,
{
__asm __volatile (
" lock xaddl %0, %1 ; "
: " +r " ( v ) , /* 0 (result) */
" =m " ( * p ) /* 1 */
: " m " ( * p ) ) ; /* 2 */
return ( v ) ;
} )
# endif
# else /* low performance version in utils.c */
AST_INLINE_API ( int ast_atomic_fetchadd_int ( volatile int * p , int v ) ,
{
return ast_atomic_fetchadd_int_slow ( p , v ) ;
} )
# endif
/*! \brief decrement *p by 1 and return true if the variable has reached 0.
/*!
* \ brief decrement * p by 1 and return true if the variable has reached 0.
*
* Useful e . g . to check if a refcount has reached 0.
*/
# if defined(HAVE_C_ATOMICS)
AST_INLINE_API ( int ast_atomic_dec_and_test ( volatile int * p ) ,
{
return __atomic_sub_fetch ( p , 1 , __ATOMIC_RELAXED ) = = 0 ;
} )
# elif defined(HAVE_GCC_ATOMICS)
AST_INLINE_API ( int ast_atomic_dec_and_test ( volatile int * p ) ,
{
return __sync_sub_and_fetch ( p , 1 ) = = 0 ;
} )
# elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 4)
AST_INLINE_API ( int ast_atomic_dec_and_test ( volatile int * p ) ,
{
return OSAtomicAdd32 ( - 1 , ( int32_t * ) p ) = = 0 ;
} )
# elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 8)
AST_INLINE_API ( int ast_atomic_dec_and_test ( volatile int * p ) ,
{
return OSAtomicAdd64 ( - 1 , ( int64_t * ) p ) = = 0 ;
} )
# else
AST_INLINE_API ( int ast_atomic_dec_and_test ( volatile int * p ) ,
{
int a = ast_atomic_fetchadd_int ( p , - 1 ) ;
return a = = 1 ; /* true if the value is 0 now (so it was 1 previously) */
return ast_atomic_sub_fetch ( p , 1 , __ATOMIC_RELAXED ) = = 0 ;
} )
# endif
# endif /* _ASTERISK_LOCK_H */
Corey Farrell
7 years ago