/*
- * Copyright 2014 Facebook, Inc.
+ * Copyright 2015 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#if defined(__GNUC__) && \
(defined(__i386) || FOLLY_X64 || \
defined(ARCH_K8))
-#define RW_SPINLOCK_USE_X86_INTRINSIC_
-#include <x86intrin.h>
+# define RW_SPINLOCK_USE_X86_INTRINSIC_
+# include <x86intrin.h>
+#elif defined(_MSC_VER) && defined(FOLLY_X64)
+# define RW_SPINLOCK_USE_X86_INTRINSIC_
#else
-#undef RW_SPINLOCK_USE_X86_INTRINSIC_
+# undef RW_SPINLOCK_USE_X86_INTRINSIC_
#endif
// iOS doesn't define _mm_cvtsi64_si128 and friends
-#if defined(__SSE2__) && !TARGET_OS_IPHONE
+#if (FOLLY_SSE >= 2) && !TARGET_OS_IPHONE
#define RW_SPINLOCK_USE_SSE_INSTRUCTIONS_
#else
#undef RW_SPINLOCK_USE_SSE_INSTRUCTIONS_
private: // Some x64-specific utilities for atomic access to ticket.
template<class T> static T load_acquire(T* addr) {
T t = *addr; // acquire barrier
- asm volatile("" : : : "memory");
+ asm_volatile_memory();
return t;
}
template<class T>
static void store_release(T* addr, T v) {
- asm volatile("" : : : "memory");
+ asm_volatile_memory();
*addr = v; // release barrier
}
int count = 0;
QuarterInt val = __sync_fetch_and_add(&ticket.users, 1);
while (val != load_acquire(&ticket.write)) {
- asm volatile("pause");
+ asm_volatile_pause();
if (UNLIKELY(++count > 1000)) sched_yield();
}
}
// need to let threads that already have a shared lock complete
int count = 0;
while (!LIKELY(try_lock_shared())) {
- asm volatile("pause");
+ asm_volatile_pause();
if (UNLIKELY((++count & 1023) == 0)) sched_yield();
}
}