I'm trying to communicate my xpc service from LaunchDaemon.
LaunchDaemon is command line executable and LaunchAgent is xpc service.
Initiating my connection from main service(LaunchDaemon) like this:
NSXPCConnection * _connectionToService;
_connectionToService = [[NSXPCConnection alloc] initWithMachServiceName:#"com.XpcService" options:NSXPCConnectionPrivileged];
_connectionToService.remoteObjectInterface = [NSXPCInterface interfaceWithProtocol:#protocol(XpcServiceProtocol)];
_connectionToService.interruptionHandler = ^{ NSLog(#"Connection Terminated"); };
_connectionToService.invalidationHandler = ^{ NSLog(#"Connection Invalidated"); };
[_connectionToService resume];
//here calling required functions
Xpc-service listening like this:
#interface ServiceDelegate : NSObject <NSXPCListenerDelegate>
#end
#implementation ServiceDelegate
-(BOOL)listener:(NSXPCListener *)listener shouldAcceptNewConnection: (NSXPCConnection *)newConnection {
newConnection.exportedInterface = [NSXPCInterface interfaceWithProtocol:#protocol(XpcServiceProtocol)];
XpcService *exportedObject = [XpcService new];
newConnection.exportedObject = exportedObject;
[newConnection resume];
return YES;
}
#end
int main(int argc, const char *argv[]) {
ServiceDelegate *delegate = [ServiceDelegate new];
NSXPCListener *listener = [[NSXPCListener alloc] initWithMachServiceName:#"com.XpcService"];
listener.delegate = delegate;
[listener resume];
return 0;
}
In my case i'm getting Connection Invalidated error, my xpc couldn't even be started.
LaunchAgent & LaunchDaemon loaded perfectly, code signing was also be done. help me to find out what might be caused the problem? Thanks in advance.
Related
I am trying to run a program in a background process that will register every shutdown event in the system.
Doing so by registering to NSWorkspaceWillPowerOffNotification as show below:
#import <AppKit/AppKit.h>
#interface ShutDownHandler : NSObject <NSApplicationDelegate>
- (void)computerWillShutDownNotification:(NSNotification *)notification;
#end
int main(int argc, char* argv[]) {
NSNotificationCenter *notCenter;
notCenter = [[NSWorkspace sharedWorkspace] notificationCenter];
ShutDownHandler* sdh = [ShutDownHandler new];
[NSApplication sharedApplication].delegate = sdh;
[notCenter addObserver:sdh
selector:#selector(computerWillShutDownNotification:)
name:NSWorkspaceWillPowerOffNotification
object:nil];
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
[[NSFileManager defaultManager] createFileAtPath:#"./output.txt" contents:nil attributes:nil];
});
[[NSRunLoop currentRunLoop] run];
return 0;
}
#implementation ShutDownHandler
- (void)computerWillShutDownNotification:(NSNotification *)notification {
NSFileHandle* file = [NSFileHandle fileHandleForUpdatingAtPath: #"./output.txt"];
[file seekToEndOfFile];
NSDateFormatter* fmt = [NSDateFormatter new];
[fmt setDateFormat:#"yyyy-MM-dd HH:mm:ss"];
NSDate* current = [NSDate date];
NSString* dateStr = [fmt stringFromDate:current];
[dateStr writeToFile:#"./output.txt" atomically:YES encoding:NSUTF8StringEncoding error:nil];
}
- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
{
return NSTerminateCancel;
}
#end
For some reason that I cannot understand, the NSWorkspaceWillPowerOffNotification handler is never called!
Also added the following to my .plist:
<key>NSSupportsSuddenTermination</key>
<false/>
but still no notification is register when shutting down my system.
Any idea as to why??
For future reference:
I was not able to register to the above event and see it fire.
Finally, I went with a different approach:
apple open-source power management
Here, you can see we have notifications names such as:
"com.apple.system.loginwindow.logoutNoReturn"
You can register to those, and that will do the trick.
Hope this will help someone one day :)
When you say you've ran your code as a background process, do you mean that it's based on launchd daemon handled according to plist file in /Library/LaunchDeamon ? In this case, the notification will not be sent. Try running it under Cocoa application
Seems like this notification doesn't work on LaunchDaemon linked against AppKit.
I'm still looking for a way to get these notifications on background deamon process.
i can make NSWorkspaceWillPowerOffNotification and applicationShouldTerminate: to work by adding NSApplicationActivationPolicyAccessory and replacing the run loop with [NSApp run]. it still won't be very useful if you want to continue to monitor all logouts (and/or power off attempts) since it only works if the process is launched while the user has already logged in, and it can only detect the current UI login session's power-off/logout notification and "app should terminate" delegate.
"apps" that belong to the current UI login session get terminated by the OS when the user logs out. non-app (no [NSApp run]) processes will continue to run even after the user logs out.
so, if you wan to continue to monitor the user logouts (or power off attempts), you would need a non-app (no [NSApp run]) process.
NSWorkspaceSessionDidBecomeActiveNotification and NSWorkspaceSessionDidResignActiveNotification work without [NSApp run] if you want to monitor if the user switched out or back in.
or you can try the System Configuration APIs if it works for your use case.
"Technical Q&A QA1133: Determining console user login status" https://developer.apple.com/library/archive/qa/qa1133/_index.html
sounds like com.apple.system.loginwindow.logoutNoReturn was the best option for whatever you wanted to do. good to know!
here is the updated code (although it's not really useful):
// cc powreoff-notification.m -o poweroff-notification -framework AppKit
#import <AppKit/AppKit.h>
#interface ShutDownHandler : NSObject <NSApplicationDelegate>
- (void)computerWillShutDownNotification:(NSNotification *)notification;
#end
int main(int argc, char* argv[]) {
#autoreleasepool {
NSLog(#"%s", __func__);
NSNotificationCenter* notCenter = [[NSWorkspace sharedWorkspace] notificationCenter];
ShutDownHandler* sdh = [ShutDownHandler new];
[NSApplication sharedApplication].delegate = sdh;
[notCenter addObserver:sdh
selector:#selector(computerWillShutDownNotification:)
name:NSWorkspaceWillPowerOffNotification
object:nil];
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
[[NSFileManager defaultManager] createFileAtPath:#"./output.txt" contents:nil attributes:nil];
});
// without NSApplicationActivationPolicyAccessory, the [NSApp run] process gets killed on
// poweroff/logout instead of getting the power off notification or applicationShouldTerminate:.
[NSApp setActivationPolicy:NSApplicationActivationPolicyAccessory];
// without [NSApp run], you won't get the power off notification or applicationShouldTerminate:.
//[[NSRunLoop currentRunLoop] run];
[NSApp run];
// this process needs to be launched while the user has already logged in. otherwise,
// you won't get the power off notification or applicationShouldTerminate:.
}
return 0;
}
#implementation ShutDownHandler
- (void)computerWillShutDownNotification:(NSNotification *)notification {
NSLog(#"%s", __func__);
NSFileHandle* file = [NSFileHandle fileHandleForUpdatingAtPath: #"./output.txt"];
[file seekToEndOfFile];
NSDateFormatter* fmt = [NSDateFormatter new];
[fmt setDateFormat:#"yyyy-MM-dd HH:mm:ss\n"];
NSDate* current = [NSDate date];
NSString* dateStr = [fmt stringFromDate:current];
[dateStr writeToFile:#"./output.txt" atomically:YES encoding:NSUTF8StringEncoding error:nil];
}
- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
{
NSLog(#"%s", __func__);
return NSTerminateCancel;
}
#end
I have two Cocoa Applications, one is going to be the sender and another the receiver in this XPC relationship.
In the applicationDidFinishLaunching in the sender, I first open the second receiver application
NSError* error = nil;
NSURL* url = [[NSBundle mainBundle] bundleURL];
url = [url URLByAppendingPathComponent:#"Contents" isDirectory:YES];
url = [url URLByAppendingPathComponent:#"MacOS" isDirectory:YES];
url = [url URLByAppendingPathComponent:#"TestXPCHelper.app" isDirectory:YES];
[[NSWorkspace sharedWorkspace] launchApplicationAtURL:url
options:NSWorkspaceLaunchWithoutActivation
configuration:[NSDictionary dictionary]
error:&error];
if ( error )
{
NSLog(#"launchApplicationAtURL:%# error = %#", url, error);
[[NSAlert alertWithError:error] runModal];
}
Then I create my NSXPCConnection
assert([NSThread isMainThread]);
if (self.testConnection == nil) {
self.testConnection = [[NSXPCConnection alloc] initWithMachServiceName:NEVER_TRANSLATE(#"com.TechSmith.TestXPCHelper") options:NSXPCConnectionPrivileged];
self.testConnection.remoteObjectInterface = [NSXPCInterface interfaceWithProtocol:#protocol(TestXPCProtocol)];
self.testConnection.interruptionHandler = ^{
NSLog(#"Connection Terminated");
};
self.testConnection.invalidationHandler = ^{
self.testConnection.invalidationHandler = nil;
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
self.testConnection = nil;
}];
};
[self.testConnection resume];
}
Then I try to send a message over the connection (the connection is already invalidated by here)
id<TestXPCProtocol> testRemoteObject= [self.testConnection remoteObjectProxy];
[testRemoteObject testXPCMethod2];
[[self.testConnection remoteObjectProxyWithErrorHandler:^(NSError * proxyError){
NSLog(#"%#", proxyError);
}] testXPCMethod:^(NSString* reply) {
NSLog(#"%#", reply);
}];
And here is the app delegate for my receiver application:
#interface AppDelegate () <NSXPCListenerDelegate, TestXPCProtocol>
#property (weak) IBOutlet NSWindow *window;
#property NSXPCListener *xpcListener;
#end
#implementation AppDelegate
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
// Insert code here to initialize your application
NSLog(#"TESTING123");
self.xpcListener = [[NSXPCListener alloc] initWithMachServiceName:#"com.TechSmith.TestXPCHelper"];
self.xpcListener.delegate = self;
[self.xpcListener resume];
}
- (void)applicationDidBecomeActive:(NSNotification *)notification {
NSLog(#"ACTIVE234");
}
- (void)applicationWillTerminate:(NSNotification *)aNotification {
// Insert code here to tear down your application
}
- (void)run
{
NSLog(#"RUNNING");
// Tell the XPC listener to start processing requests.
[self.xpcListener resume];
// Run the run loop forever.
[[NSRunLoop currentRunLoop] run];
}
- (BOOL)listener:(NSXPCListener *)listener shouldAcceptNewConnection:(NSXPCConnection *)newConnection
{
NSLog(#"LISTENING");
assert(listener == self.xpcListener);
#pragma unused(listener)
assert(newConnection != nil);
newConnection.exportedInterface = [NSXPCInterface interfaceWithProtocol:#protocol(TestXPCProtocol)];
newConnection.exportedObject = self;
[newConnection resume];
return YES;
}
- (void)testXPCMethod:(void(^)(NSString * version))reply
{
NSLog(#"HEY");
reply(#"REPLY HERE");
}
- (void)testXPCMethod2
{
NSLog(#"TWO!");
}
Here is the proxyError when I try to send a message over the connection:
Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service
named com.TechSmith.TestXPCHelper was invalidated." UserInfo={NSDebugDescription=The
connection to service named com.TechSmith.TestXPCHelper was invalidated.}
So I think I am doing something wrong with my instantiation of the NSXPCConnection. I can't find a good example of two applications speaking to eachother-- it's always one application and a service. Is that what my problem is? I need a service inbetween the applications talking?
Is there any way to get more information on why this connection is being invalidated? That would also help a lot
So pretty straight forward problem here,
Turns out initWithMachServiceName is explicitly looking for a mach service. I was using an identifier of another application process.
If I actually use an identifier of a valid mach service, there is no issue
Note that there are two other ways to create an NSXPCConnection,
with an NSXPCEndpoint or with a XPCService identifier
I was successful in creating XPC service and communicating with XPC service by sending messages from main application. But what I want to know is, whether its possible to initiate a communication from XPC service to the main application. The Apple documentation says XPC is bidirectional. It would be much appreciated if someone can point me in right direction with an example.
Please note,
I want to launch the XPC from main application.
communicate with XPC from main application.
when some events occur, XPC should send a message to main application.
I succeeded in first two, but couldn't find any resource on the third one.
Thanks. :)
Figured everything out. The following should be a decent example:
ProcessorListener.h (included in both client and server):
#protocol Processor
- (void) doProcessing: (void (^)(NSString *response))reply;
#end
#protocol Progress
- (void) updateProgress: (double) currentProgress;
- (void) finished;
#end
#interface ProcessorListener : NSObject<NSXPCListenerDelegate, Processor>
#property (weak) NSXPCConnection *xpcConnection;
#end
ProcessorListener.m: (Included in just the server)
#import "ProcessorListener.h"
#implementation ProcessorListener
- (BOOL)listener:(NSXPCListener *)listener shouldAcceptNewConnection:(NSXPCConnection *)newConnection
{
[newConnection setExportedInterface: [NSXPCInterface interfaceWithProtocol:#protocol(Processor)]];
[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) doProcessing: (void (^)(NSString *g))reply
{
dispatch_async(dispatch_get_global_queue(0,0), ^{
for(int index = 0; index < 60; ++index)
{
[NSThread sleepWithTimeInterval: 1];
[[self.xpcConnection remoteObjectProxy] updateProgress: (double)index / (double)60 * 100];
}
[[self.xpcConnection remoteObjectProxy] finished];
}
// nil is a valid return value.
reply(#"This is a reply!");
}
#end
MainApplication.m (your main app):
#import "ProcessorListener.h"
- (void) executeRemoteProcess
{
// Create our connection
NSXPCInterface * myCookieInterface = [NSXPCInterface interfaceWithProtocol: #protocol(Processor)];
NSXPCConnection * connection = [[NSXPCConnection alloc] initWithServiceName: kServiceName];
[connection setRemoteObjectInterface: myCookieInterface];
connection.exportedInterface = [NSXPCInterface interfaceWithProtocol:#protocol(Progress)];
connection.exportedObject = self;
[connection resume];
id<Processor> theProcessor = [connection remoteObjectProxyWithErrorHandler:^(NSError *err)
{
NSAlert *alert = [[NSAlert alloc] init];
[alert addButtonWithTitle: #"OK"];
[alert setMessageText: err.localizedDescription];
[alert setAlertStyle: NSWarningAlertStyle];
[alert performSelectorOnMainThread: #selector(runModal) withObject: nil waitUntilDone: YES];
}];
[theProcessor doProcessing: ^(NSString * response)
{
NSLog(#"Received response: %#", response);
}];
}
#pragma mark -
#pragma mark Progress
- (void) updateProgress: (double) currentProgress
{
NSLog(#"In progress: %f", currentProgress);
}
- (void) finished
{
NSLog(#"Has finished!");
}
#end
Note that this code is is a condensed version based on my working code. It may not compile 100% but shows the key concepts used. In the example, the doProcessing runs async to show that the callbacks defined in the Progress protocol still get executed even after the initial method has return and the Received response: This is a reply! has been logged.
I can observe NSWorkspaceWillPowerOffNotification notifications in the application delegate of a GUI program, but not in a command line utility. Any ideas why the following does not work? Or is there a different approach I should consider?
Edit: Cold it be that NSWorkspace's notification center doesn't work for a GUI-less program? (I have verified that |notificationCenter| is not nil)
#interface Helper : NSObject
-(void)userLogout:(NSNotification*)notification;
#end
#implementation Helper
-(void)userLogout:(NSNotification*)notification
{
NSLog(#"Notification Received");
}
#end
int main(int argc, const char * argv[])
{
#autoreleasepool {
Helper* helper = [[Helper alloc] init];
NSNotificationCenter* notificationCenter = [[NSWorkspace sharedWorkspace] notificationCenter];
[notificationCenter addObserver:helper
selector:#selector(userLogout:)
name:NSWorkspaceWillPowerOffNotification
object:nil];
NSRunLoop* runLoop = [NSRunLoop currentRunLoop];
[runLoop run];
}
return 0;
}
I'm trying to load image date for person entries in the shared ABAddressBook. In particular, I'm calling
-[ABPerson beginLoadingImageDataForClient:]
and passing as the argument an object which adopts ABImageClient and implements
-[<ABPersonClient> consumeImageData:forTag:]
The approach I'm using works fine on Mountain Lion, but fails on Snow Leopard. In particular, -consumeImageData:forTag: never gets called.
The following sample command line program demonstrates my approach:
#import <Foundation/Foundation.h>
#import <AddressBook/AddressBook.h>
#interface ImageConsumer : NSObject <ABImageClient>
#property (nonatomic, strong) NSMutableDictionary *imagesForNumbers;
#end
#implementation ImageConsumer
- (id)init
{
self = [super init];
if (self) {
self.imagesForNumbers = [NSMutableDictionary dictionary];
}
return self;
}
- (void)consumeImageData:(NSData *)data forTag:(NSInteger)tag
{
[self.imagesForNumbers setObject:data forKey:[NSNumber numberWithInteger:tag]];
NSLog(#"%s: loaded data of length %zu for tag %zd", __PRETTY_FUNCTION__, data.length, tag);
}
#end
int main(int argc, const char * argv[])
{
#autoreleasepool {
NSArray *persons = [[ABAddressBook sharedAddressBook] people];
ImageConsumer *imageConsumer = [[ImageConsumer alloc] init];
for (ABPerson *person in persons) {
NSInteger loadingKey = [person beginLoadingImageDataForClient:imageConsumer];
NSLog(#"requested data person named %# %# and received tag %zd", [person valueForProperty:kABFirstNameProperty], [person valueForProperty:kABLastNameProperty], loadingKey);
}
[[NSRunLoop mainRunLoop] run];
}
return 0;
}
Am I misusing the ABAddressBook calls for loading image data for instances of ABPerson? Is this a bug with ABAddressBook on Snow Leopard? If so, is there a work-around?