Question

I am in the process of converting the available SKP_SMTP library to implement an SMTP client in my iPhone app. After a long and troubled work of bug fixing and memory checks, I have narrowed down the problems to only one. It happens that a memory leaks occurs in the call to CFStreamCreatePairWithSocketToCFHost (evidentiated by the Leaks tool in Instruments), which seems strange to me as the CFReadStreamRef parameters readStream and writeStream are either CFReleased at a later stage, or assigned to a correspondent NSStream object via __bridge_transfer (and that should eventually bring the streams memory management from CoreFoundation to ARC).
I’ve googled around but the only solutions I have found are under garbage collection(clearly not available in ARC): am I missing something or that should not happen?
Code following,
thanks a lot

@implementation NSStream (SKPSMTPExtensions)

+ (void)getStreamsToHostNamed:(NSString *)hostName port:(NSInteger)port inputStream:  (NSInputStream **)inputStream outputStream:(NSOutputStream **)outputStream
{
    CFHostRef           host;
    CFReadStreamRef     readStream;
    CFWriteStreamRef    writeStream;

    readStream = NULL;
    writeStream = NULL;

    host = CFHostCreateWithName(NULL, (__bridge_retained CFStringRef) hostName);
    if (host != NULL) 
    {
        // Memory leak at this line: strange as readStream & writeStream are either   CFReleased or _bridge_transfered to ARC 
        (void) CFStreamCreatePairWithSocketToCFHost(NULL, host, port, &readStream,   &writeStream);
        CFRelease(host);
    }

    if (inputStream == NULL) 
    {
        CFRelease(readStream);
    } 
    else 
    {
        *inputStream = (__bridge_transfer NSInputStream *) readStream;
    }
    if (outputStream == NULL) 
    {
        CFRelease(writeStream);
    } 
    else 
    {
        *outputStream = (__bridge_transfer NSOutputStream *) writeStream;
    }

}

@end

Answer 1

I think this statement leaks hostName:

host = CFHostCreateWithName(NULL, (__bridge_retained CFStringRef) hostName);

You should use a __bridge cast, not a __bridge_retained cast.