NSOutputStream not calling delegate's NSStreamEventHasSpaceAvailable - ios

Question

I have implemented socket by using input and output streams. The external architecture takes care of sending one request at a time to write.
However if any request does not return no HasBytesAvailable I need to remove that request from queue and inform about request timeout.
For all other requests, I am able to send/receive data correctly, but if any one of the request time outs then after that HasSpaceAvailable never gets called.
My code is as follows :
#implementation CCCommandSocket
#synthesize connectionTimeoutTimer;
#synthesize requestTimeoutTimer;
/*
* init
*
* #params
* ipAddress :ip address of camera socket
* portNumber :port address of camera socket
*
* #return
* Object of type Socket, which will send connection request to ipAddress,portNumber
*
*/
- (id)init
{
self = [super init];
if (self)
{
ip = #"192.168.42.1";
port = 7878;
[self performSelectorOnMainThread:#selector(connectToCamera) withObject:nil waitUntilDone:YES];
bytesReceivedCondition = [[NSCondition alloc] init];
requestCompletedCondition = [[NSCondition alloc] init];
requestReadyToProcess = [[NSCondition alloc] init];
isBytesReceived = false;
isRequestCompleted = false;
isRequestReadyToProcess = false;
responseString = [[NSString alloc] init];
openBracesCount = 0;
mutex = [[NSLock alloc] init];
}
return self;
}
pragma mark-
pragma establish socket communication.
/*
* connectToCamera
*
*/
- (void) connectToCamera
{
NSString *urlStr = ip;
if (![urlStr isEqualToString:#""])
{
NSURL *website = [NSURL URLWithString:urlStr];
if (!website)
{
NSString* messageString = [NSString stringWithFormat:#"%# is not a valid URL",website];
CCLog(LOG_ERROR, messageString);
return;
}
CFStreamCreatePairWithSocketToHost(NULL, (__bridge CFStringRef)(urlStr), port, &readStream, &writeStream);
//cast the CFStreams to NSStreams
inputStream = (__bridge_transfer NSInputStream *)readStream;
outputStream = (__bridge_transfer NSOutputStream *)writeStream;
//set the delegate
[inputStream setDelegate:self];
[outputStream setDelegate:self];
//schedule the stream on a run loop
[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
//open the stream
[inputStream open];
[outputStream open];
if(readStream==NULL)
{
CCLog(LOG_INFO, #"readstream NULL");
}
if(writeStream == NULL)
{
CCLog(LOG_INFO, #"writeStream NULL");
}
[self startConnectionTimeoutTimer];
}
}
pragma mark -
pragma getter methods
/*
* getIP
*
* #return
* Ip address to which socket is connected
*/
-(NSString *) getIP
{
return ip;
}
/*
* getPort
*
* #return
* Port number to which socket is connected
*/
-(int) getPort
{
return port;
}
pragma mark-
pragma Handle socket callbacks.
(void)stream:(NSStream *)stream handleEvent:(NSStreamEvent)eventCode
{
NSMutableArray *array = [[NSMutableArray alloc] init];
[array addObject:stream];
[array addObject:[NSNumber numberWithInt:eventCode]];
[self performSelectorInBackground:#selector(myStream:) withObject:array];
}
(void)myStream:(NSMutableArray*) array
{
NSNumber *number = [array objectAtIndex:1];
int eventCode = [number intValue];
switch(eventCode)
{
case NSStreamEventErrorOccurred:
{
CCLog(LOG_ERROR, #"In Command Socket NSStreamEventErrorOccurred");
//[self disconnect];
//[[ErrorDetails getInstance] reportError:NSStreamEventErrorOccurred];
break;
}
//Read from stream
case NSStreamEventHasBytesAvailable:
{
CCLog(LOG_INFO, #"In Command Socket NSStreamEventHasBytesAvailable");
[self handleCommandPortDataReceived];
break;
}
//Write to stream
case NSStreamEventHasSpaceAvailable:
{
#synchronized(self)
{
[requestReadyToProcess lock];
while (isRequestReadyToProcess == false)
{
[requestReadyToProcess wait];
}
[requestReadyToProcess unlock];
CCLog(LOG_INFO,#"In Command Socket NSStreamEventHasSpaceAvailable");
#try
{
#synchronized(requestString)
{
if(requestString != nil)
{
if(outputStream != nil)
{
int dataSent;
uint8_t* data = (uint8_t *)[requestString cStringUsingEncoding:NSUTF8StringEncoding];
responseString = #"";
//[requestReadyToProcess lock];
isRequestReadyToProcess = false;
//[requestReadyToProcess signal];
dataSent = [outputStream write:data maxLength:strlen((char*)data)];
if(dataSent != -1)
{
NSString* message = [NSString stringWithFormat:#"Bytes written %d for request\n %#",dataSent, requestString];
CCLog(LOG_REQUEST, message);
requestString = nil;
isBytesReceived = false;
[bytesReceivedCondition lock];
while (isBytesReceived ==false)
{
[bytesReceivedCondition wait];
}
[requestCompletedCondition lock];
isRequestCompleted = true;
[requestCompletedCondition signal];
[requestCompletedCondition unlock];
[bytesReceivedCondition unlock];
}
else
{
CCLog(LOG_INFO, #"Command Socket : Request not sent (dataSent == -1)");
responseString = #"{ \"rval\": -104}";
CCLog(LOG_RESPONSE, responseString);
[self removeRequestFromQueue];
}
}
else
{
CCLog(LOG_INFO, #"in else :(outputStream != nil)");
}
}
}
}
#catch (NSException *e)
{
CCLog(LOG_WARNING, e.description);
}
}
break;
}
case NSStreamEventNone:
{
CCLog(LOG_INFO, #"In Command Socket NSStreamEventNone");
break;
}
case NSStreamEventOpenCompleted:
{
CCLog(LOG_INFO, #"In Command Socket NSStreamEventOpenCompleted");
[self stopConnectionTimeoutTimer];
break;
}
case NSStreamEventEndEncountered:
{
CCLog(LOG_INFO, #"Command Socket NSStreamEventEndEncountered");
[self disconnectWithNotification:YES];
break;
}
}
}
/*
* execute
*
* #param
* request :command to be sent over socket to camera
*
* #return
* responce :response received from camera
*
*/
-(NSString *) executeRequest :(NSString *)request
{
CCLog(LOG_INFO, #"Command Socket Executing request");
[self performSelectorOnMainThread:#selector(startRequestTimeoutTimer) withObject:nil waitUntilDone:NO];
isRequestCompleted = false;
requestString = request;
responseString = #"";
[requestReadyToProcess lock];
isRequestReadyToProcess = true;
[requestReadyToProcess signal];
[requestReadyToProcess unlock];
[requestCompletedCondition lock];
while (isRequestCompleted ==false)
{
[requestCompletedCondition wait];
}
CCLog(LOG_INFO, #"Command Socket Execute request : request completed");
[requestCompletedCondition unlock];
CCLog(LOG_RESPONSE, responseString);
return responseString;
}
pragma mark-
pragma Handle connection time out
// Call this when you initiate the connection
- (void)startConnectionTimeoutTimer
{
[self stopConnectionTimeoutTimer]; // Or make sure any existing timer is stopped before this method is called
NSTimeInterval interval = 10.0; // Measured in seconds, is a double
self.connectionTimeoutTimer = [NSTimer scheduledTimerWithTimeInterval:interval
target:self
selector:#selector(handleConnectionTimeout)
userInfo:nil
repeats:NO];
}
(void)handleConnectionTimeout
{
responseString = #"{ \"rval\": -103}";
CCLog(LOG_RESPONSE, responseString);
[self removeRequestFromQueue];
[self disconnectWithNotification:YES];
[self stopConnectionTimeoutTimer];
}
// Call this when you initiate the connection
- (void)startRequestTimeoutTimer
{
[self stopRequestTimeoutTimer]; // Or make sure any existing timer is stopped before this method is called
NSTimeInterval interval = 20.0; // Measured in seconds, is a double
self.requestTimeoutTimer = [NSTimer scheduledTimerWithTimeInterval:interval
target:self
selector:#selector(handleRequestTimeout)
userInfo:nil
repeats:NO];
}
(void)handleRequestTimeout
{
responseString = #"{ \"rval\": -103}";
CCLog(LOG_RESPONSE, responseString);
[self connectToCamera];
[self stopRequestTimeoutTimer];
[self removeRequestFromQueue];
}
// Call this when you successfully connect
- (void)stopRequestTimeoutTimer
{
if (requestTimeoutTimer)
{
[requestTimeoutTimer invalidate];
requestTimeoutTimer = nil;
}
}
-(void) disconnectWithNotification:(BOOL)showNotification
{
CCLog(LOG_INFO, #"Socket Disconnected");
[inputStream close];
[inputStream setDelegate:nil];
[inputStream removeFromRunLoop:[NSRunLoop currentRunLoop]
forMode:NSDefaultRunLoopMode];
inputStream = nil;
[outputStream close];
[outputStream setDelegate:nil];
[outputStream removeFromRunLoop:[NSRunLoop currentRunLoop]
forMode:NSDefaultRunLoopMode];
outputStream = nil;
[[CCCore getInstance] disconnectWithNotification:showNotification];
}
// Call this when you successfully connect
- (void)stopConnectionTimeoutTimer
{
if (connectionTimeoutTimer)
{
[connectionTimeoutTimer invalidate];
connectionTimeoutTimer = nil;
}
if (requestTimeoutTimer)
{
[requestTimeoutTimer invalidate];
requestTimeoutTimer = nil;
}
}
-(void) handleCommandPortDataReceived
{
[mutex lock];
[self stopRequestTimeoutTimer];
#try
{
long size = 1024;
uint8_t buf[size];
unsigned int len = 0;
do
{
// read input stream into buffer
strcpy((char *)buf, "\0");
len = [inputStream read:buf maxLength:size];
//NSLog(#"Size = %ld Len = %d, Buf = %s",size, len, (char *)buf);
// Following code checks if we have received complete response by matching "{" and "}"
// from input stream. We continue to form response string unless braces are matched.
if (len > 0)
{
// Create nsdata from buffer
NSMutableData *_data = [[NSMutableData alloc] init];
[_data appendBytes:(const void *)buf length:len];
// create temporary string form nsdata
NSString* currentString = [[NSString alloc] initWithData:_data encoding:NSUTF8StringEncoding];
// check the occurances of { and } in current string
int currentOpeningBraceCount = [[currentString componentsSeparatedByString:#"{"] count] - 1;
int currentClosingBraceCount = [[currentString componentsSeparatedByString:#"}"] count] - 1;
openBracesCount = (openBracesCount + currentOpeningBraceCount) - currentClosingBraceCount;
responseString = [responseString stringByAppendingString:currentString];
// NSLog(#"Total:%d currentOpen:%d currentClose:%d\n\n",openBracesCount, currentOpeningBraceCount, currentClosingBraceCount);
// NSLog(#"Current String : %#\n\n",currentString);
// NSLog(#"Final String : %#",finalString);
// NSLog(#"+++++++++++++++++++++++++++++");
}
else
break;
} while (openBracesCount != 0);
NSRange range = [responseString rangeOfString:#"get_file_complete"];
if(range.location == NSNotFound)
{
//remove it from queue
[bytesReceivedCondition lock];
isBytesReceived = true;
[bytesReceivedCondition signal];
[bytesReceivedCondition unlock];
}
//responseString = #"";
}
#catch (NSException* e)
{
[self connectToCamera];
}
[mutex unlock];
}
-(void) removeRequestFromQueue
{
//remove it from queue
requestString = nil;
[requestReadyToProcess lock];
isRequestReadyToProcess = false;
[requestReadyToProcess unlock];
[requestCompletedCondition lock];
isRequestCompleted = true;
[requestCompletedCondition signal];
[requestCompletedCondition unlock];
}
#end

Answer 1

Which OS version are you trying this on?? I'm having the similar issue, in 10.7 and up it is all good, but on 10.6 and below I get the very same issue you are having I'm doing some debugging but so far have not come up with a good resolution yet.