atomicops-inl.h

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 * The above copyright notice and this permission notice shall be included in
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#ifndef UV_WIN_ATOMICOPS_INL_H_
#define UV_WIN_ATOMICOPS_INL_H_
 
#include "uv.h"
#include "internal.h"
 
 
/* Atomic set operation on char */
#ifdef _MSC_VER /* MSVC */
 
/* _InterlockedOr8 is supported by MSVC on x32 and x64. It is slightly less
 * efficient than InterlockedExchange, but InterlockedExchange8 does not exist,
 * and interlocked operations on larger targets might require the target to be
 * aligned. */
#pragma intrinsic(_InterlockedOr8)
 
static char INLINE uv__atomic_exchange_set(char volatile* target) {
  return _InterlockedOr8(target, 1);
}
 
#else /* GCC */
 
/* Mingw-32 version, hopefully this works for 64-bit gcc as well. */
static inline char uv__atomic_exchange_set(char volatile* target) {
  const char one = 1;
  char old_value;
  __asm__ __volatile__ ("lock xchgb %0, %1\n\t"
                        : "=r"(old_value), "=m"(*target)
                        : "0"(one), "m"(*target)
                        : "memory");
  return old_value;
}
 
#endif
 
#endif /* UV_WIN_ATOMICOPS_INL_H_ */