38 lines
1016 B
C
38 lines
1016 B
C
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/* atomic.c -- implement shared_ptr spin lock */
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#include <yvals.h>
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#include <intrin.h>
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#pragma warning(disable: 4793)
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_STD_BEGIN
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/* SPIN LOCK FOR shared_ptr ATOMIC OPERATIONS */
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volatile long _Shared_ptr_flag;
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_CRTIMP2_PURE void __cdecl _Lock_shared_ptr_spin_lock()
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{ /* spin until _Shared_ptr_flag successfully set */
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#ifdef _M_ARM
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while (_InterlockedExchange_acq(&_Shared_ptr_flag, 1))
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__yield();
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#else /* _M_ARM */
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while (_interlockedbittestandset(&_Shared_ptr_flag, 0)) /* set bit 0 */
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;
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#endif /* _M_ARM */
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}
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_CRTIMP2_PURE void __cdecl _Unlock_shared_ptr_spin_lock()
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{ /* release previously obtained lock */
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#ifdef _M_ARM
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__dmb(_ARM_BARRIER_ISH);
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__iso_volatile_store32((volatile int *) &_Shared_ptr_flag, 0);
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#else /* _M_ARM */
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_interlockedbittestandreset(&_Shared_ptr_flag, 0); /* reset bit 0 */
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#endif /* _M_ARM */
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}
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_STD_END
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/*
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* Copyright (c) 1992-2012 by P.J. Plauger. ALL RIGHTS RESERVED.
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* Consult your license regarding permissions and restrictions.
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V6.00:0009 */
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