I'm trying to send some small data over UDP using the AsyncUdpSocket library. There is a lot of docs for the TCP connection but none for the UDP connection.
I wrote this class to send 5 bytes to a remote host but it looks like nothing is actually going to the wire. I'm monitoring the network using wireshark but I see no outgoing packets. The delegate method "didSendDataWithTag" is never called :(
Any ideas what I forgot ?
#import "UDPController.h"
#implementation UDPController
- (id)init
{
self = [super init];
if (self) {
socket = [[AsyncUdpSocket alloc] initWithDelegate:self];
}
return self;
}
- (void) sendUDPTest {
NSLog(#"%s", __PRETTY_FUNCTION__);
NSString * string = #"R/103";
NSString * address = #"192.168.1.130";
UInt16 port = 21001;
NSData * data = [string dataUsingEncoding:NSUTF8StringEncoding];
[socket sendData:data toHost:address port:port withTimeout:-1 tag:1];
}
/**
* Called when the datagram with the given tag has been sent.
**/
- (void)onUdpSocket:(AsyncUdpSocket *)sock didSendDataWithTag:(long)tag {
NSLog(#"%s", __PRETTY_FUNCTION__);
}
- (void)dealloc
{
[socket release];
[super dealloc];
}
#end
cheers
The problem here was that this code was not running in an "application loop" and the main was exiting before the AsyncUdpSocket had time to send the packet.
The same code works fine if it's put in an application.
Related
I'm trying to write a simple pair of "client app" & "XPC service". I was able to launch xpc service from client (i.e I can see service running in the Activity monitor processes list), but when I try to send any request, that has a response block, I get an error: "Couldn’t communicate with a helper application."
The worst thing here is that error doesn't give me any info about what went wrong. And I'm also unable to debug the service properly. As I understand, the correct way to do this is to attach a debugger to process (Debug->Attach to process, also see here). I have both client and service projects in a single workspace.
When I run client from xcode and try to attach debugger to launched service, that ends with a "Could not attach to pid : X" error.
If I archive the client app run it from app file and then try to attach debugger to service the result is the same.
The only way to record something from the service I could imagine is to write a logger class, that would write data to some file. Haven't tried this approach yet, however that looks insane to me.
So my question is:
a) How to find out what went wrong, when receiving such non-informative response like: "Couldn’t communicate with a helper application"?
b) And also, what's the correct way to debug the xpc service in the first place? The link above is 5 years old from now, however I can see that some people were saying that "attach to debugger" wasn't working.
The code itself is fairly simple:
XPC service, listener implementation:
#import "ProcessorListener.h"
#implementation ProcessorListener
- (BOOL)listener:(NSXPCListener *)listener shouldAcceptNewConnection:(NSXPCConnection *)newConnection
{
[newConnection setExportedInterface: [NSXPCInterface interfaceWithProtocol:#protocol(TestServiceProtocol)]];
[newConnection setExportedObject: self];
self.xpcConnection = newConnection;
newConnection.remoteObjectInterface = [NSXPCInterface interfaceWithProtocol: #protocol(Progress)];
// connections start suspended by default, so resume and start receiving them
[newConnection resume];
return YES;
}
- (void) sendMessageWithResponse:(NSString *)receivedString reply:(void (^)(NSString *))reply
{
reply = #"This is a response";
}
- (void) sendMessageWithNoResponse:(NSString *)mString
{
// no response here, dummy method
NSLog(#"%#", mString);
}
And the main file for service:
#import <Foundation/Foundation.h>
#import "TestService.h"
#interface ServiceDelegate : NSObject <NSXPCListenerDelegate>
#end
#implementation ServiceDelegate
- (BOOL)listener:(NSXPCListener *)listener shouldAcceptNewConnection:(NSXPCConnection *)newConnection {
// This method is where the NSXPCListener configures, accepts, and resumes a new incoming NSXPCConnection.
// Configure the connection.
// First, set the interface that the exported object implements.
newConnection.exportedInterface = [NSXPCInterface interfaceWithProtocol:#protocol(TestServiceProtocol)];
// Next, set the object that the connection exports. All messages sent on the connection to this service will be sent to the exported object to handle. The connection retains the exported object.
TestService *exportedObject = [TestService new];
newConnection.exportedObject = exportedObject;
// Resuming the connection allows the system to deliver more incoming messages.
[newConnection resume];
// Returning YES from this method tells the system that you have accepted this connection. If you want to reject the connection for some reason, call -invalidate on the connection and return NO.
return YES;
}
#end
int main(int argc, const char *argv[])
{
// [NSThread sleepForTimeInterval:10.0];
// Create the delegate for the service.
ServiceDelegate *delegate = [ServiceDelegate new];
// Set up the one NSXPCListener for this service. It will handle all incoming connections.
NSXPCListener *listener = [NSXPCListener serviceListener];
listener.delegate = delegate;
// Resuming the serviceListener starts this service. This method does not return.
[listener resume];
return 0;
}
For client app, the UI contains a bunch of buttons:
- (IBAction)buttonSendMessageTap:(id)sender {
if ([daemonController running])
{
[self executeRemoteProcessWithName:#"NoResponse"];
}
else
{
[[self.labelMessageResult cell] setTitle: #"Error"];
}
}
- (IBAction)buttonSendMessage2:(id)sender {
if ([daemonController running])
{
[self executeRemoteProcessWithName:#"WithResponse"];
}
else
{
[[self.labelMessageResult cell] setTitle: #"Error"];
}
}
- (void) executeRemoteProcessWithName: (NSString*) processName
{
// Create connection
NSXPCInterface * myCookieInterface = [NSXPCInterface interfaceWithProtocol: #protocol(Processor)];
NSXPCConnection * connection = [[NSXPCConnection alloc] initWithServiceName: #"bunldeID"]; // there's a correct bundle id there, really
[connection setRemoteObjectInterface: myCookieInterface];
connection.exportedInterface = [NSXPCInterface interfaceWithProtocol:#protocol(Progress)];
connection.exportedObject = self;
[connection resume];
// NOTE that this error handling code is not called, when debugging client, i.e connection seems to be established
id<Processor> theProcessor = [connection remoteObjectProxyWithErrorHandler:^(NSError *err)
{
NSAlert *alert = [[NSAlert alloc] init];
[alert addButtonWithTitle: #"OK"];
[alert setMessageText: err.localizedDescription];
[alert setAlertStyle: NSAlertStyleWarning];
[alert performSelectorOnMainThread: #selector(runModal) withObject: nil waitUntilDone: YES];
}];
if ([processName containsString:#"NoResponse"])
{
[theProcessor sendMessageWithNoResponse:#"message"];
}
else if ([processName containsString:#"WithResponse"])
{
[theProcessor sendMessageWithResponse:#"message" reply:^(NSString* replyString)
{
[[self.labelMessageResult cell] setTitle: replyString];
}];
}
}
Jonathan Levin's XPoCe tool is helpful when you can't attach a debugger.
You can add logging NSLog() or fprintf(stderr,...) to your service and clients, specifically around the status codes. You just have to specify the path of the file to write stdout and stderr. <key>StandardErrorPath</key> <string>/tmp/mystderr.log</string>
There's a section on Debugging Daemons at this article on objc.io .
I am new to Cocoa programming...I am learning IPC with Distributed Objects.
I have made a simple example where I am vending objects from the server and calling them in the client.I am successful in passing messages from client object to the server But I want to pass messages from server to client[Bidirectional]...How do I do that?
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
MYMessageServer *server = [[MYMessageServer alloc] init];
NSConnection *defaultConnection=[NSConnection defaultConnection];
[defaultConnection setRootObject:server];
if ([defaultConnection registerName:#"server"] == NO)
{
NSLog(#"Error registering server");
}
else
NSLog(#"Connected");
[[NSRunLoop currentRunLoop] configureAsServer];
}
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
// Insert code here to initialize your application
//Getting an Vended Object
server = [NSConnection rootProxyForConnectionWithRegisteredName:#"server" host:nil];
if(nil == server)
{
NSLog(#"Error: Failed to connect to server.");
}
else
{
//setProtocolForProxy is a method of NSDistantObject
[server setProtocolForProxy:#protocol(MYMessageServerProtocol)];
[server addMessageClient:self];
[server broadcastMessageString:[NSString stringWithFormat:#"Connected: %# %d\n",
[[NSProcessInfo processInfo] processName],
[[NSProcessInfo processInfo] processIdentifier]]];
}
}
- (void)appendMessageString:(NSString *)aString
{
NSRange appendRange = NSMakeRange([[_messageView string] length], 0);
// Append text and scroll if neccessary
[_messageView replaceCharactersInRange:appendRange withString:aString];
[_messageView scrollRangeToVisible:appendRange];
}
- (void)addMessageClient:(id)aClient
{
if(nil == _myListOfClients)
{
_myListOfClients = [[NSMutableArray alloc] init];
}
[_myListOfClients addObject:aClient];
NSLog(#"Added client");
}
- (BOOL)removeMessageClient:(id)aClient
{
[_myListOfClients removeObject:aClient];
NSLog(#"Removed client");
return YES;
}
- (void)broadcastMessageString:(NSString *)aString
{
NSLog(#"Msg is %#",aString);
self.logStatement = aString;
[_myListOfClients makeObjectsPerformSelector:#selector(appendMessageString:)
withObject:aString];
}
#protocol MYMessageServerProtocol
- (void)addMessageClient:(id)aClient;
- (BOOL)removeMessageClient:(id)aClient;
- (void)broadcastMessageString:(NSString *)aString;
You haven't shown the code for MYMessageServer or MYMessageServerProtocol, specifically the -addMessageClient: method. However, once you have passed the server a reference to an object in the client, the server can message that object like normal and that message will be sent over D.O. to the client.
So, the client is sending self (its application delegate) to the server via -addMessageClient:. The server can simply call methods on the object it receives in its implementation of -addMessageClient: and that will call methods on the client's application delegate object. The server can keep that reference somewhere, such as an array of clients in an instance variable, and continue to message the client at later times, too, if it wants. The server will want to clear that reference out when the connection closes, which it can detect from notifications that NSConnection posts.
I'm writing a mac app that runs its own web server, using the GCDWebServer library (https://github.com/swisspol/GCDWebServer). My app delegate handles GET requests like so:
__weak typeof(self) weakSelf = self;
[webServer addDefaultHandlerForMethod:#"GET"
requestClass:[GCDWebServerRequest class]
processBlock:^GCDWebServerResponse *(GCDWebServerRequest* request) {
return [weakSelf handleRequest:request];
}];
And then the handleRequest method returns the response data, something like:
return [GCDWebServerDataResponse responseWithHTML:#"<html><body><p>Hello World!</p></body></html>"];
So far so good. Except now I want the handleRequest method to use NSSpeechSynthesizer to create an audio file with some spoken text in it, and then wait for the speechSynthesizer:didFinishSpeaking method to be called before returning to the processBlock.
// NSSpeechSynthesizerDelegate method:
- (void)speechSynthesizer:(NSSpeechSynthesizer *)sender didFinishSpeaking:(BOOL)success
{
NSLog(#"did finish speaking, success: %d", success);
// return to processBlock...
}
Problem is, I have no idea how to do this. Is there a way to return from the speechSynthesizer:didFinishSpeaking method into the processBlock defined above?
You need to run the speech synthesizer on a separate thread with its own run loop, and use a lock to allow your request thread to wait for the operation to complete on the speech thread.
Assuming the web server maintains its own thread(s) and runloop, you can use your app's main thread to run the speech synthesizer, and you can use NSCondition to signal completion to the web response thread.
A basic (untested) example (without error handling):
#interface SynchroSpeaker : NSObject<NSSpeechSynthesizerDelegate>
- (id)initWithText:(NSString*)text outputUrl:(NSURL*)url;
- (void)run;
#end
#implementation SynchroSpeaker
{
NSCondition* _lock;
NSString* _text;
NSURL* _url;
NSSpeechSynthesizer* _synth;
}
- (id)initWithText:(NSString*)text outputUrl:(NSURL*)url
{
if (self = [super init])
{
_text = text;
_url = url;
_lock = [NSCondition new];
}
return self;
}
- (void)run
{
NSAssert(![NSThread isMainThread], #"This method cannot execute on the main thread.");
[_lock lock];
[self performSelectorOnMainThread:#selector(startOnMainThread) withObject:nil waitUntilDone:NO];
[_lock wait];
[_lock unlock];
}
- (void)startOnMainThread
{
NSAssert([NSThread isMainThread], #"This method must execute on the main thread.");
[_lock lock];
//
// Set up your speech synethsizer and start speaking
//
}
- (void)speechSynthesizer:(NSSpeechSynthesizer *)sender didFinishSpeaking:(BOOL)success
{
//
// Signal waiting thread that speaking has completed
//
[_lock signal];
[_lock unlock];
}
#end
It's used like so:
- (id)handleRequest:(id)request
{
SynchroSpeaker* speaker = [[SynchroSpeaker alloc] initWithText:#"Hello World" outputUrl:[NSURL fileURLWithPath:#"/tmp/foo.dat"]];
[speaker run];
////
return response;
}
GCDWebServer does run into its own threads (I guess 2 of them) - not in the main one. My solution needed to run code in Main Thread when calling the ProcessBlock.
I found this way that suits my needs:
First declare a weak storage for my AppDelegate: __weak AppDelegate *weakSelf = self;. Doing so I can access all my properties within the block.
Declare a strong reference to AppDelegate from within the block like so: __strong AppDelegate* strongSelf = weakSelf;
Use NSOperationQueue to align the operation on mainThread:
[[NSOperationQueue mainQueue] addOperationWithBlock:^ {
//Your code goes in here
NSLog(#"Main Thread Code");
[strongSelf myMethodOnMainThread];
}];
In this way myMethodOnMainThread surely will run where it's supposed to.
For sake of clarity I quote my relevant code section:
webServer = [[GCDWebServer alloc] init];
webServer.delegate = self;
__weak AppDelegate *weakSelf = self;
// Add a handler to respond to GET requests
[webServer addDefaultHandlerForMethod:#"GET"
requestClass:[GCDWebServerRequest class]
asyncProcessBlock:^(GCDWebServerRequest* request, GCDWebServerCompletionBlock completionBlock) {
__strong AppDelegate* strongSelf = weakSelf;
[[NSOperationQueue mainQueue] addOperationWithBlock:^ {
//Your code goes in here
NSLog(#"Main Thread Code");
[strongSelf myMethodOnMainThread];
}];
GCDWebServerDataResponse* response = [GCDWebServerDataResponse responseWithJSONObject:packet];
completionBlock(response);
}];
GCWebServer supports fully asynchronous responses as of version 3.0 and later [1].
[webServer addDefaultHandlerForMethod:#"GET"
requestClass:[GCDWebServerRequest class]
asyncProcessBlock:^(GCDWebServerRequest* request, GCDWebServerCompletionBlock completionBlock) {
// 1. Trigger speech synthesizer on main thread (or whatever thread it has to run on) and save "completionBlock"
// 2. Have the delegate from the speech synthesizer call "completionBlock" when done passing an appropriate response
}];
[1] https://github.com/swisspol/GCDWebServer#asynchronous-http-responses
I am really stuck at the moment trying to get the grasp of invites in the MultipeerConnectivityFramework.
Right now I have an ipad App acting as the Advertiser and an iphone App acting as Browser.
I have implemented a sharedService for the MultipeerFramework and did the following:
Advertiser
#implementation MultipeerConnectivityService {
MCNearbyServiceAdvertiser *_advertiser;
MCSession *_session;
MCNearbyServiceBrowser *_browser;
}
- (void)automaticAdvertiseWithName:(NSString *)name {
MCPeerID *peerID = [[MCPeerID alloc] initWithDisplayName:name];
_session = [[MCSession alloc] initWithPeer:peerID];
_session.delegate = self;
_advertiser = [[MCNearbyServiceAdvertiser alloc] initWithPeer:peerID discoveryInfo:nil serviceType:kServiceType];
_advertiser.delegate = self;
[_advertiser startAdvertisingPeer];
}
- (void)advertiser:(MCNearbyServiceAdvertiser *)advertiser didReceiveInvitationFromPeer:(MCPeerID *)peerID withContext:(NSData *)context invitationHandler:(void (^)(BOOL, MCSession *))invitationHandler {
invitationHandler([#YES boolValue], _session);
NSLog(#"Invitation accepted");
}
Browser
- (void)automaticBrowsingWithName:(NSString *)name {
MCPeerID *peerID = [[MCPeerID alloc] initWithDisplayName:name];
_browser = [[MCNearbyServiceBrowser alloc] initWithPeer:peerID serviceType:kServiceType];
_browser.delegate = self;
[_browser startBrowsingForPeers];
}
- (void)browser:(MCNearbyServiceBrowser *)browser didNotStartBrowsingForPeers:(NSError *)error {
if ([_delegate respondsToSelector:#selector(browser:didNotStartBrowsingForPeers:)]) {
[_delegate browserDidNotStartBrowsingForPeers];
}
}
- (void)browser:(MCNearbyServiceBrowser *)browser foundPeer:(MCPeerID *)peerID withDiscoveryInfo:(NSDictionary *)info {
[browser invitePeer:peerID toSession:[self getMCSession] withContext:nil timeout:10];
if ([_delegate respondsToSelector:#selector(browser:foundPeer:)]) {
[_delegate browser:browser foundPeer:peerID];
}
}
- (void)browser:(MCNearbyServiceBrowser *)browser lostPeer:(MCPeerID *)peerID {
if ([_delegate respondsToSelector:#selector(browserLostPeer:)]) {
[_delegate browserLostPeer:peerID];
}
}
- (MCSession *) getMCSession {
return _session;
}
But then I am getting as feedback in the console:
-[MCNearbyServiceBrowser invitePeer:toSession:withContext:timeout:] Bad argument session=nil
When I check for the found Advertisers, everything is OK. My advertiser ipad is being found. But how can I manage the invite?
So I don't get it right now... When I send an invitation by the browser, what session do I have to use? On the iPad I set up the session like you can see in the "automaticAdvertiseWithName" method. but on the iphone I don't do this when calling "automaticBrowsingWithName"... Is that the problem? And don't they have to be the same session to successfully connect them? And how can I successfully invite my advertiser ipad to the browser?
I am confused by the notion of creating a new session when one has already been created by the advertiser.
I am actually not sure, if the delegate didReceiveInvitation is adding the peer to the connectedPeers at all.
- (void)automaticAdvertiseWithName:(NSString *)name {
MCPeerID *peerID = [[MCPeerID alloc] initWithDisplayName:name];
self.session = [[MCSession alloc] initWithPeer:peerID];
self.session.delegate = self;
_advertiser = [[MCNearbyServiceAdvertiser alloc] initWithPeer:peerID discoveryInfo:nil serviceType:kServiceType];
_advertiser.delegate = self;
[_advertiser startAdvertisingPeer];
}
- (void)advertiser:(MCNearbyServiceAdvertiser *)advertiser didReceiveInvitationFromPeer:(MCPeerID *)peerID withContext:(NSData *)context invitationHandler:(void (^)(BOOL, MCSession *))invitationHandler {
BOOL accept = YES;
invitationHandler(accept, self.session);
NSLog(#"Invitation accepted: %#", self.session);
}
And when I call the property "connectedPeers" on my session, there are no connected peers at all, even though the delegate found one. Did I make a mistake there?
Your problem is that your session is null at the time you call invitePeer:toSession:withContext:timeout...Anyway you have two options to fix this.
You have two options :
Option 1
- move the peerID creation, session creation and session delegate assignment in a place where its executed at all time. For example in the init code for MultipeerConnectivityService class of if its a UIViewController in the viewDidLoad.
Option 2
- add the following snippet before you call "invitePeer:toSession:withContext:timeout:"
if (!_session) {
MCPeerID *peerID = [[MCPeerID alloc] initWithDisplayName:#"Browser"]; // you can customize the name here
_session = [[MCSession alloc] initWithPeer:peerID];
_session.delegate = self;
}
Hope this helps ...good luck!
I have been trying to develop an app for my ipad which i can use to connect to my local network devices in order to get files and so on without any progress.
What i want to do is to first detect the devices on the network and then select which i want to browse files from by connecting to it.
What i got so far is
#import "BrowseForNetworkDevices.h"
#implementation BrowseForNetworkDevices
- (id)init
{
self = [super init];
if (self)
{
services = [[NSMutableArray alloc] init];
serviceBrowser = [[NSNetServiceBrowser alloc] init];
[serviceBrowser setDelegate: delegateObject];
searching = NO;
}
return self;
}
- (void)dealloc
{
[services release];
[serviceBrowser release];
[super dealloc];
}
// Sent when browsing begins
- (void)netServiceBrowserWillSearch:(NSNetServiceBrowser *)browser
{
searching = YES;
[serviceBrowser searchForServicesOfType:#" " inDomain:#"local."];
[self updateUI];
}
// Sent when browsing stops
- (void)netServiceBrowserDidStopSearch:(NSNetServiceBrowser *)browser
{
searching = NO;
[self updateUI];
}
// Sent if browsing fails
- (void)netServiceBrowser:(NSNetServiceBrowser *)browser
didNotSearch:(NSDictionary *)errorDict
{
searching = NO;
[self handleError:[errorDict objectForKey:NSNetServicesErrorCode]];
}
// Sent when a service appears
- (void)netServiceBrowser:(NSNetServiceBrowser *)browser
didFindService:(NSNetService *)aNetService
moreComing:(BOOL)moreComing
{
//[services addObject:aNetService];
if (![services containsObject:aNetService]) {
[self willChangeValueForKey:#"services"];
[services addObject:aNetService];
[self didChangeValueForKey:#"service"];
}
if(!moreComing)
{
[self updateUI];
}
}
// Sent when a service disappears
- (void)netServiceBrowser:(NSNetServiceBrowser *)browser
didRemoveService:(NSNetService *)aNetService
moreComing:(BOOL)moreComing
{
//[services removeObject:aNetService];
if ([services containsObject:aNetService]) {
[self willChangeValueForKey:#"service"];
[services removeObject:aNetService];
[self didChangeValueForKey:#"service"];
}
if(!moreComing)
{
[self updateUI];
}
}
// Error handling code
- (void)handleError:(NSNumber *)error
{
NSLog(#"An error occurred. Error code = %d", [error intValue]);
// Handle error here
}
// UI update code
- (void)updateUI
{
if(searching)
{
// Update the user interface to indicate searching
for(Class obj in services){
NSLog(#"service found %#", obj);
}
// Also update any UI that lists available services
}
else
{
// Update the user interface to indicate not searching
}
}
#end
Any good tutorials on how to perform such task?
Thanks in advance for all the help
You will need both the network devices and your iPad to be speaking the same protocol. You will need to pick an appropriate protocol. It sounds like what you want to do is file transfer - there are many protocols that can handle this that are implemented in libraries for iOS:
- WebDAV
- HTTP
- FTP
- SFTP
- AFP
- SAMBA
In order for the devices to detect one another you will need to use something like Apple's Bonjour