ABRecordSetValue返回的CFErrorRef的内存管理

考虑一些涉及error handling的典型CF代码，比如说：

ABRecordRef aRecord = ABPersonCreate(); CFErrorRef anError = NULL; ABRecordSetValue(aRecord, kABPersonFirstNameProperty, CFSTR("Joe"), &anError); 

在此代码之后如何处理anError ？ 我是否必须保留它，以确保它不会消失，然后再释放它？ 或者我已经是主人了，我只需要稍后发布它？

Answer 1

在Core Foundation框架中，调用者始终有责任释放通过CFErrorRef *参数返回的错误。 例如，这是来自CFBundle.h的头文件注释：

 CF_EXPORT Boolean CFBundlePreflightExecutable(CFBundleRef bundle, CFErrorRef *error) CF_AVAILABLE(10_5, 2_0); /* This function will return true if the bundle is loaded, or if the bundle appears to be */ /* loadable upon inspection. This does not mean that the bundle is definitively loadable, */ /* since it may fail to load due to link errors or other problems not readily detectable. */ /* If this function detects problems, it will return false, and return a CFError by reference. */ /* It is the responsibility of the caller to release the CFError. */ 

机会是AB框架使用相同的约定。

Answer 2

根据“CFError.h”，其中定义了CFErrorRef：即

 typedef struct __CFError * CFErrorRef; // line 43 in CFError.h 

如果你滚动到顶部，你会在第14行到第22行看到这个：

 CFError *error; if (!ReadFromFile(fd, &error)) { ... process error ... CFRelease(error); // If an error occurs, the returned CFError must be released. } It is the responsibility of anyone returning CFErrors this way to: - Not touch the error argument if no error occurs - Create and assign the error for return only if the error argument is non-NULL 

因此我们似乎需要自己发布CFErrorRef！