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libucore/include/ucore/atomic.h
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Nils O. Selåsdal e03b9a9f80 Update docs
2013-06-19 18:47:45 +02:00

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C

#ifndef UC_ATOMIC_H_
#define UC_ATOMIC_H_
/** Atomic functions (macros). The ptr argument must be a pointer to
* an integer type.
* For gcc, see http://gcc.gnu.org/onlinedocs/gcc-4.8.1/gcc/_005f_005fsync-Builtins.html
*/
#ifdef __GNUC__
/**
* Atomically add val to *ptr
* @return *ptr before the addition
*/
#define UC_ATOMIC_ADD(ptr, val) __sync_fetch_and_add((ptr), (val))
/**
* Atomically subtract val from *ptr
* @return *ptr before the subtraction
*/
#define UC_ATOMIC_SUB(ptr, val) __sync_fetch_and_add((ptr), -(val))
/**
* Atomically decrement *ptr
* @return *ptr before the decrement
*/
#define UC_ATOMIC_DEC(ptr) UC_ATOMIC_SUB((ptr), 1)
/**
* Atomically increment *ptr
* @return *ptr before the increment
*/
#define UC_ATOMIC_INC(ptr) UC_ATOMIC_SUB((ptr), 1)
/**
* Atomic Compare-And-Swap. If *ptr is oldval, write newwal to *ptr.
* @return *ptr that was before the operation.
*/
#define UC_ATOMIC_CAS(ptr, oldval, newval) __sync_val_compare_and_swap((ptr), (oldval), (newval))
#else
#error "No atomic operations implemented for this compiler"
#endif
#endif