为什么当CFStreamCreatePairWithSocketToHost成功时CFStreamCreatePairWithSocketToCFHost失败

Question

在iOS6.1上，以下代码应该做同样的事情，但是当我忘记编写addr.sin_len = sizeof(adde)时，第一个块失败。原来的错误是：

GOT EVENT FROM INPUT Event: 8 
ERR: Error Domain=NSPOSIXErrorDomain Code=12 "The operation couldn’t be completed. Cannot allocate memory" 

在添加缺少的行来设置结构大小后，第一个块就像第二个块一样工作。其他开发人员可能会在该帖子中看到该错误消息和旅程。

的代码：

CFReadStreamRef readStream = NULL; 
    CFWriteStreamRef writeStream = NULL; 

#if 1 // LONG WAY 
    struct sockaddr_in addr; 
    memset(&addr, 0, sizeof(addr)); 
    addr.sin_len  = sizeof(addr); // ORIGINALLY WAS MISSING 
    addr.sin_family  = AF_INET; 
    addr.sin_port  = htons(5566); 
    int ret = inet_pton(AF_INET, "192.168.1.2", &(addr.sin_addr.s_addr)); // IPv4 
    assert(ret == 1); 

    NSLog(@"CONNECT"); 
    CFDataRef address = CFDataCreate(kCFAllocatorDefault, (const UInt8 *)&addr, sizeof(addr)); 
    assert(address); 

    CFHostRef macMini = CFHostCreateWithAddress(kCFAllocatorDefault, address); 
    CFRelease(address); 
    assert(macMini); 

    // (tried, makes not difference) CFHostScheduleWithRunLoop (macMini, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode); 

    CFStreamCreatePairWithSocketToCFHost(kCFAllocatorDefault, macMini, 5566, &readStream, &writeStream); 
    CFRelease(macMini); 
#else // SHORT WAY 
    CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, CFSTR("192.168.1.2"), 5566, &readStream, &writeStream); 
#endif 

    assert(readStream); 
    assert(writeStream); 

    iStream = CFBridgingRelease(readStream); 
    oStream = CFBridgingRelease(writeStream); 

    [iStream setDelegate:self]; 
    [iStream scheduleInRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode]; 
    [iStream open]; 
    NSLog(@"ISTREAM %@ status=%d", iStream, [iStream streamStatus]); 
    NSLog(@"ERR: %@", [iStream streamError]); 

    [oStream setDelegate:self]; 
    [oStream scheduleInRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode]; 
    [oStream open]; 
    NSLog(@"OSTREAM %@ status=%d", oStream, [oStream streamStatus]); 
    NSLog(@"ERR: %@", [oStream streamError]); 

Answer 1

问题是sin_len没有设置。上述两套代码的好处是你可以看到如何完成任务。