我们在 NSInputStream 中使用一个从 IMAP 服务器接收数据。我们在 Xcodes 崩溃中看到了一个无法重现的异常崩溃。InputStream 是这样初始化的(我省略了一些完整性检查):
- (void)getStreamsToServer:(NSString *)hostName
andPort:(NSUInteger)port
andInputStream:(NSInputStream **)inputStream
andOutputStream:(NSOutputStream **)outputStream
{
CFReadStreamRef readStream = NULL;
CFWriteStreamRef writeStream = NULL;
CFStreamCreatePairWithSocketToHost(NULL,
(__bridge CFStringRef)(hostName),
(unsigned int)port,
&readStream,
&writeStream);
*inputStream = (__bridge_transfer NSInputStream *)readStream;
*outputStream = (__bridge_transfer NSOutputStream *)writeStream;
}
稍后,我们将流升级到 SSL:
[_inputStream setProperty:NSStreamSocketSecurityLevelNegotiatedSSL
forKey:NSStreamSocketSecurityLevelKey];
[_outputStream setProperty:NSStreamSocketSecurityLevelNegotiatedSSL
forKey:NSStreamSocketSecurityLevelKey];
我们尝试像这样从中读取数据:
NSUInteger READ_BUFFER_LENGTH = 16 * 1024;
uint8_t readBuffer[READ_BUFFER_LENGTH];
NSInteger readBytesCount = 0;
if([_inputStream hasBytesAvailable]) {
readBytesCount = [_inputStream read:readBuffer
maxLength:READ_BUFFER_LENGTH];
if (readBytesCount > 0) {
NSData *partialData = [NSData dataWithBytes:(const void *)readBuffer
length:readBytesCount];
}
这在 99,99% 的时间内有效。但是 Xcodes 崩溃报告器让我们对这次崩溃有些头疼:
0 CoreFoundation 0x0000000184970620 CFHash + 360 (CFRuntime.c:1080)
1 CoreFoundation 0x00000001849718b8 CFBasicHashGetCountOfKey + 160 (CFBasicHash.c:455)
2 CoreFoundation 0x00000001849718b8 CFBasicHashGetCountOfKey + 160 (CFBasicHash.c:455)
3 CoreFoundation 0x0000000184971804 CFSetContainsValue + 208 (CFSet.c:405)
4 CoreFoundation 0x00000001849a0148 CFRunLoopRemoveSource + 164 (CFRunLoop.c:3542)
5 CFNetwork 0x0000000185113e78 SocketStream::read(__CFReadStream*, unsigned char*, long, CFStreamError*, unsigned char*) + 604 (SocketStream.cpp:2757)
6 CoreFoundation 0x000000018499c7c8 CFReadStreamRead + 480 (CFStream.c:1146)
这次崩溃发生在符合[NSData dataWithBytes:length:]
. 你有什么想法,如何引发、调试或修复这个错误?