use MacOSX atomic(3) and barrier(3) operations
diff --git a/src/os/unix/ngx_atomic.h b/src/os/unix/ngx_atomic.h
index 7919826..593f671 100644
--- a/src/os/unix/ngx_atomic.h
+++ b/src/os/unix/ngx_atomic.h
@@ -12,6 +12,62 @@
#include <ngx_core.h>
+#if (NGX_DARWIN)
+
+/*
+ * use MacOSX atomic(3) and barrier(3) operations
+ * optimized at run time for UP and SMP
+ */
+
+#include <libkern/OSAtomic.h>
+
+/* "bool" conflicts with perl's CORE/handy.h
+ * "true" and "false" conflict with nginx, and of course we can rename them,
+ * but we need to undef "bool" anyway
+ */
+#undef bool
+#undef true
+#undef false
+
+
+#define NGX_HAVE_ATOMIC_OPS 1
+
+#if (NGX_PTR_SIZE == 8)
+
+typedef int64_t ngx_atomic_int_t;
+typedef uint64_t ngx_atomic_uint_t;
+#define NGX_ATOMIC_T_LEN sizeof("-9223372036854775808") - 1
+
+#define ngx_atomic_cmp_set(lock, old, new) \
+ OSAtomicCompareAndSwap64Barrier(old, new, (int64_t *) lock)
+
+#define ngx_atomic_fetch_add(value, add) \
+ (OSAtomicAdd64(add, (int64_t *) value) - add)
+
+#else
+
+typedef int32_t ngx_atomic_int_t;
+typedef uint32_t ngx_atomic_uint_t;
+#define NGX_ATOMIC_T_LEN sizeof("-2147483648") - 1
+
+#define ngx_atomic_cmp_set(lock, old, new) \
+ OSAtomicCompareAndSwap32Barrier(old, new, (int32_t *) lock)
+
+#define ngx_atomic_fetch_add(value, add) \
+ (OSAtomicAdd32(add, (int32_t *) value) - add)
+
+#endif
+
+#define ngx_memory_barrier() OSMemoryBarrier()
+
+#define ngx_cpu_pause()
+
+typedef volatile ngx_atomic_uint_t ngx_atomic_t;
+
+
+#else /* !(NGX_DARWIN) */
+
+
#if ( __i386__ || __i386 )
typedef int32_t ngx_atomic_int_t;
@@ -141,6 +197,8 @@
#endif
+#endif
+
#if !(NGX_HAVE_ATOMIC_OPS)
@@ -181,6 +239,7 @@
#endif
+
void ngx_spinlock(ngx_atomic_t *lock, ngx_atomic_int_t value, ngx_uint_t spin);
#define ngx_trylock(lock) (*(lock) == 0 && ngx_atomic_cmp_set(lock, 0, 1))
