Nils O. Selåsdal
62 lines
1.5 KiB
C
62 lines
1.5 KiB
C
#ifndef UC_ATOMIC_H_
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#define UC_ATOMIC_H_
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/** @file
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* Atomic functions (macros). The ptr argument must be a pointer to
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* an integer type.
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* For gcc, see http://gcc.gnu.org/onlinedocs/gcc-4.8.1/gcc/_005f_005fsync-Builtins.html
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*/
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#ifdef __GNUC__
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/**
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* Atomically subtract val from *ptr
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* @return *ptr before the subtraction
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*/
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#define UC_ATOMIC_SUB(ptr, val) __sync_fetch_and_add((ptr), -(val))
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/**
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* Atomically add val to *ptr
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* @return *ptr before the addition
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*/
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#define UC_ATOMIC_ADD(ptr, val) __sync_fetch_and_add((ptr), (val))
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/**
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* Atomically decrement *ptr
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* @return *ptr before the decrement
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*/
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#define UC_ATOMIC_DEC(ptr) UC_ATOMIC_SUB((ptr), 1)
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/**
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* Atomically increment *ptr
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* @return *ptr before the increment
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*/
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#define UC_ATOMIC_INC(ptr) UC_ATOMIC_ADD((ptr), 1)
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/**
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* Atomic Compare-And-Swap. If *ptr is oldval, write newwal to *ptr.
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* @return *ptr that was before the operation.
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*/
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#define UC_ATOMIC_CAS(ptr, oldval, newval) __sync_val_compare_and_swap((ptr), (oldval), (newval))
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/** Issue a full (hardware) memory barrier.
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* preventing the cpu to move load/stores across
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* the barrier. (This implies a compiler barrier as well)
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* */
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#define UC_MEM_BARRIER() __sync_synchronize()
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/** Issue a full compiler/software only memory barrier
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* preventing compiler optimization to move load/stores across
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* the barrier.
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* */
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#define UC_COMPILER_BARRIER() __asm__ __volatile__("": : :"memory")
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#else
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#error "No atomic operations implemented for this compiler"
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#endif
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#endif
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