--- /dev/null
+/*
+ * Copyright (c) 2012-2013 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+
+#ifndef __OS_ALLOC_ONCE_IMPL__
+#define __OS_ALLOC_ONCE_IMPL__
+
+#ifndef __OS_ALLOC_INDIRECT__
+#error "Please include <os/alloc_once_private.h> instead of this file directly."
+#endif
+
+#include <Availability.h>
+#include <sys/types.h>
+#include <os/base_private.h>
+#include <os/once_private.h>
+
+__BEGIN_DECLS
+
+#define OS_ALLOC_SPI_VERSION 20120430
+
+#define OS_ALLOC_ONCE_KEY_MAX 100
+
+typedef os_once_t os_alloc_token_t;
+struct _os_alloc_once_s {
+ os_alloc_token_t once;
+ void *ptr;
+};
+
+__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0)
+extern struct _os_alloc_once_s _os_alloc_once_table[];
+
+__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0)
+OS_EXPORT OS_NONNULL1
+void*
+_os_alloc_once(struct _os_alloc_once_s *slot, size_t sz, os_function_t init);
+
+/*
+ * The region allocated by os_alloc_once is 0-filled when initially
+ * returned (or handed off to the initializer).
+ */
+OS_WARN_RESULT OS_NOTHROW OS_CONST
+__header_always_inline void*
+os_alloc_once(os_alloc_token_t token, size_t sz, os_function_t init)
+{
+ struct _os_alloc_once_s *slot = &_os_alloc_once_table[token];
+ if (OS_EXPECT(slot->once, ~0l) != ~0l) {
+ void *ptr = _os_alloc_once(slot, sz, init);
+ OS_COMPILER_CAN_ASSUME(slot->once == ~0l);
+ return ptr;
+ }
+ return slot->ptr;
+}
+
+__END_DECLS
+
+#endif // __OS_ALLOC_ONCE_IMPL__