1 // Copyright (c) 2008 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_FOUNDATION_UTILS_MAC_H_ 6 #define BASE_FOUNDATION_UTILS_MAC_H_ 7 #pragma once 8 9 #include <CoreFoundation/CoreFoundation.h> 10 #import <Foundation/Foundation.h> 11 12 // CFTypeRefToNSObjectAutorelease transfers ownership of a Core Foundation 13 // object (one derived from CFTypeRef) to the Foundation memory management 14 // system. In a traditional managed-memory environment, cf_object is 15 // autoreleased and returned as an NSObject. In a garbage-collected 16 // environment, cf_object is marked as eligible for garbage collection. 17 // 18 // This function should only be used to convert a concrete CFTypeRef type to 19 // its equivalent "toll-free bridged" NSObject subclass, for example, 20 // converting a CFStringRef to NSString. 21 // 22 // By calling this function, callers relinquish any ownership claim to 23 // cf_object. In a managed-memory environment, the object's ownership will be 24 // managed by the innermost NSAutoreleasePool, so after this function returns, 25 // callers should not assume that cf_object is valid any longer than the 26 // returned NSObject. 27 static inline id CFTypeRefToNSObjectAutorelease(CFTypeRef cf_object) { 28 // When GC is on, NSMakeCollectable marks cf_object for GC and autorelease 29 // is a no-op. 30 // 31 // In the traditional GC-less environment, NSMakeCollectable is a no-op, 32 // and cf_object is autoreleased, balancing out the caller's ownership claim. 33 // 34 // NSMakeCollectable returns nil when used on a NULL object. 35 return [NSMakeCollectable(cf_object) autorelease]; 36 } 37 38 #endif // BASE_FOUNDATION_UTILS_MAC_H_ 39
