Cocoa中打开读取流的Posix错误14 (错误地址)。暗示？

Question

我遵循CFNetwork编程指南中的示例代码，特别是关于在使用时防止阻塞的部分。我的代码与他们的(下面)几乎相同，但是，当我连接到我的服务器时，我得到了posix错误14 (错误的地址-这个IP地址是坏的(除非它不是)吗？我打的电话的记忆地址不好吗？不然呢？！

我不知道如何调试这个。我对整个CFNetworking非常陌生，从一开始我从来就不是网络方面的专家(我最喜欢的一点是:轻松网络！:D)

无论如何，日志如下，下面是代码。任何提示都将不胜感激。

日志：

[6824:20b] [DEBUG] Compat version: 30000011
[6824:20b] [DEBUG] resovled host.
[6824:20b] [DEBUG] writestream opened.
[6824:20b] [DEBUG] readstream client assigned.
[6824:20b] [DEBUG] readstream opened.
[6824:20b] [DEBUG] *** Read stream reported kCFStreamEventErrorOccurred
[6824:20b] [DEBUG] *** POSIX error: 14 - Bad address
[6824:20b] Error closing readstream
[6824:20b] [DEBUG] Writing int: 0x09000000 (0x00000009)

代码：

+ (BOOL) connectToServerNamed:(NSString*)name atPort:(int)port {
    CFHostRef theHost = CFHostCreateWithName (NULL, (CFStringRef)name);
    CFStreamError error;

    if (CFHostStartInfoResolution (theHost, kCFHostReachability, &error))
    {
        NSLog (@"[DEBUG] resovled host.");
        CFStreamCreatePairWithSocketToCFHost (NULL, theHost, port, &readStream, &writeStream);
        if (CFWriteStreamOpen(writeStream))
        {
            NSLog (@"[DEBUG] writestream opened.");

            CFStreamClientContext myContext = { 0, self, NULL, NULL, NULL };
            CFOptionFlags registeredEvents = kCFStreamEventHasBytesAvailable |
                    kCFStreamEventErrorOccurred | kCFStreamEventEndEncountered;
            if (CFReadStreamSetClient (readStream, registeredEvents, readCallBack, &myContext))
            {
                NSLog (@"[DEBUG] readstream client assigned.");
                CFReadStreamScheduleWithRunLoop(readStream, CFRunLoopGetCurrent(),
                                                kCFRunLoopCommonModes);
                if (CFReadStreamOpen(readStream))
                {
                    NSLog (@"[DEBUG] readstream opened.");
                    CFRunLoopRun();
         // Lots of error condition handling snipped.
        [...]
    return YES;
}


void readCallBack (CFReadStreamRef stream, CFStreamEventType event, void *myPtr)
{
    switch (event)
    {
        case kCFStreamEventHasBytesAvailable:
        {
            CFIndex bytesRead = CFReadStreamRead(stream, buffer, kNetworkyBitsBufferSize); // won't block
            if (bytesRead > 0)                                                  // <= 0 leads to additional events
            {
                if (listener)
                {
                    UInt8 *tmpBuffer = malloc (sizeof (UInt8) * bytesRead);
                    memcpy (buffer, tmpBuffer, bytesRead);
                    NSLog(@"[DEBUG] reveived %d bytes", bytesRead);
                    [listener networkDataArrived:tmpBuffer count:bytesRead];
                }
                NSLog(@"[DEBUG] reveived %d bytes; no listener", bytesRead);
            }
        }
            break;

        case kCFStreamEventErrorOccurred:
            NSLog(@"[DEBUG] *** Read stream reported kCFStreamEventErrorOccurred");
            CFStreamError error = CFReadStreamGetError(stream);
            logError(error);
            [NetworkyBits shutDownRead];
            break;

        case kCFStreamEventEndEncountered:
            NSLog(@"[DEBUG] *** Read stream reported kCFStreamEventEndEncountered");
            [NetworkyBits shutDownRead];
            break;
    }
}

void logError (CFStreamError error)
{
    if (error.domain == kCFStreamErrorDomainPOSIX)                              // Interpret error.error as a UNIX errno.
    {
        NSLog (@"[DEBUG] *** POSIX error: %d - %s", (int) error.error, strerror(error.error));
    }
    else if (error.domain == kCFStreamErrorDomainMacOSStatus)
    {
        NSLog (@"[DEBUG] *** MacOS error: %d", (int) error.error);
    }
    else
    {
        NSLog (@"[DEBUG] *** Stream error domain: %d, error: %d", (int) error.error);
    }
}

Answer 1

奥利，你在哪里

buffer

你提供给

CFReadStreamRead()

来自?EFAULT是一个糟糕的缓冲地址..。你确定你真的已经初始化这个缓冲区来指向有效的东西吗？很明显是全球性的或者某个时候..。这本身就是个坏主意。您应该在您的函数中分配它，或者它应该是ivar (如果您使用的是Obj-C)。

Answer 2

我不熟悉Cocoa或Objective，但我可以告诉您，POSIX错误代码14名为埃弗尔特，这意味着您使用无效的指针值进行了系统调用。这几乎可以肯定是一些用户提供的缓冲区指针，指向某种类型的读或写系统调用。检查所有的缓冲区指针，确保它们不是空的。检查malloc()的返回值--您可能无法分配缓冲区。