iOS开发-常见内存泄漏

最近使用Leaks工具对项目进行了一波内存泄漏的检测，发现的问题及解决方式总结如下

1. 使用class_copyPropertyList 或者 class_copyPropertyList 之后没有释放

    unsigned int outCount;
    Ivar *ivars = class_copyIvarList([self class], &outCount);
    ...
    ...
    // 释放 防止内存泄漏
    free(ivars);

2.以下代码会检测到内存泄漏

+ (id)load:(NSString *)service
{
    id ret = nil;
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    //Configure the search setting
    [keychainQuery setObject:(id)kCFBooleanTrue forKey:(__bridge_transfer id)kSecReturnData];
    [keychainQuery setObject:(__bridge_transfer id)kSecMatchLimitOne forKey:(__bridge_transfer id)kSecMatchLimit];
    CFDataRef keyData = NULL;
    if (SecItemCopyMatching((__bridge_retained CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
        @try {
            ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge_transfer NSData *)keyData];
        } @catch (NSException *e) {
            NSLog(@"Unarchive of %@ failed: %@", service, e);
        } @finally {
        }
    }
    return ret;
}

修改方式 （释放掉被SecItemCopyMatching引用的CFDictionaryRef）

+ (id)load:(NSString *)service
{
    id ret = nil;
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    //Configure the search setting
    [keychainQuery setObject:(id)kCFBooleanTrue forKey:(__bridge_transfer id)kSecReturnData];
    [keychainQuery setObject:(__bridge_transfer id)kSecMatchLimitOne forKey:(__bridge_transfer id)kSecMatchLimit];
    CFDataRef keyData = NULL;
    CFDictionaryRef cf_query = (__bridge_retained CFDictionaryRef)keychainQuery;
    if (SecItemCopyMatching(cf_query, (CFTypeRef *)&keyData) == noErr) {
        @try {
            ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge_transfer NSData *)keyData];
        } @catch (NSException *e) {
            NSLog(@"Unarchive of %@ failed: %@", service, e);
        } @finally {
        }
    }
    CFRelease(cf_query);
    return ret;
}

3.GoogleDataTransport 中内存泄漏,源代码如下

image.png

该问题在8.3.1中已经解决，遇到此问题的可以更新下GoogleDataTransport SDK至最新版本试一下

image.png