In my app, I want to resolve an address with a DNS server address of my choice (the DNS isn't mine, I just want to resolve domain of my app with other dns server). i have try this code. #include <dns.h> #include <dns_sd.h> #include <sys/socket.h> static NSData * synchronousDNSQuery() { NSData * result; NSURL * confURL; dns_handle_t dns; uint8_t responseBuffer[4096]; struct sockaddr_storage fromAddr; uint32_t fromAddrLen; int32_t queryResult; confURL = [[NSBundle mainBundle] URLForResource:@"resolv" withExtension:@"conf"]; dns = dns_open(confURL.fileSystemRepresentation); fromAddrLen = sizeof(fromAddr); queryResult = dns_query( dns, "example.com.", kDNSServiceClass_IN, kDNSServiceType_A, (char *) responseBuffer, sizeof(responseBuffer), (struct sockaddr *) &fromAddr, &fromAddrLen ); if (queryResult > 0) { result = [NSData dataWithBytes:responseBuffer length:(NSUInteger) queryResult]; NSLog(@"response %@ from %@", result, [NSData dataWithBytes:&fromAddr length:(NSUInteger) fromAddrLen] ); } else { result = nil; NSLog(@"error"); } dns_free(dns); return result; } However, this code can not compile success . here is the error message Undefined symbols for architecture x86_64 _dns_free _dns_open _dns_query how to resolve this compiler error? or Is there any other way to customize dns service?

recently, i receive some feebacks There are two domain names in my app, the first domain name always reports error -1003(NRURLErrorCannotFindHost) ,at the same time the sencond domain does not report any error. what is the problem? how to resolve this problem? in documention, -1003 means host name can not be resolved. but the second domain has no error at the same thime

in my app, send request with NSURLSession. but i can not get available infomation ( eg. remoteAddress, TLS version) when request failed i want get more infomation for failed request. eg. remoteAddress, remotePort, TLS Version...

background push or background refresh can wake app in the background. according douctument About the background execution sequence, if app is not runing, system launch app an move it directy to background. however if user tap app icon when system launch app and calling didFinishLaunchingWithOptions method, then what is execution order of app lifecycle

there are some crash in my app. WatchdogVisibility: Foreground WatchdogCPUStatistics: ( "Elapsed total CPU time (seconds): 3.670 (user 2.300, system 1.370), 3% CPU", "Elapsed application CPU time (seconds): 0.404, 0% CPU" ) reportType:CrashLog maxTerminationResistance:Interactive>} Thread 0 Crashed: 0 681B06A0-7F6B-3FA3-A2CE-063DC1DA7B1B0x27e00 __ulock_wait 1 5D16936B-4E4C-3276-BA7A-69C9BC760ABA0xa0ff4 _dlock_wait 2 5D16936B-4E4C-3276-BA7A-69C9BC760ABA0xa0f24 _dispatch_once_wait 3 BFBF140A-DB1B-3B5B-ACE4-1C990763332A0x6e7c8 +[AVAudioSession sharedInstance] And i found another [AVAudioSession sharedInstance] symbol in other thread ProcessVisibility: Foreground ProcessState: Running WatchdogEvent: scene-create WatchdogVisibility: Foreground WatchdogCPUStatistics: ( "Elapsed total CPU time (seconds): 3.670 (user 2.300, system 1.370), 3% CPU", "Elapsed application CPU time (seconds): 0.404, 0% CPU" ) reportType:CrashLog maxTerminationResistance:Interactive>} 0 681B06A0-7F6B-3FA3-A2CE-063DC1DA7B1B0x272c8 mach_msg2_trap 1 681B06A0-7F6B-3FA3-A2CE-063DC1DA7B1B0x3a194 mach_msg2_internal 2 681B06A0-7F6B-3FA3-A2CE-063DC1DA7B1B0x3a46c mach_msg_overwrite 3 681B06A0-7F6B-3FA3-A2CE-063DC1DA7B1B0x27808 mach_msg 4 5D16936B-4E4C-3276-BA7A-69C9BC760ABA0xbb964 _dispatch_mach_send_and_wait_for_reply 5 5D16936B-4E4C-3276-BA7A-69C9BC760ABA0xbbcf4 dispatch_mach_send_with_result_and_wait_for_reply 6 A0D322A3-D772-3260-9690-71F28737C43C0x8ea8c xpc_connection_send_message_with_reply_sync 7 1715DE5D-0893-3AF0-B0C0-550BB14F91EC0x4dc3b4 __NSXPCCONNECTION_IS_WAITING_FOR_A_SYNCHRONOUS_REPLY__ 8 1715DE5D-0893-3AF0-B0C0-550BB14F91EC0x46f760 -[NSXPCConnection _sendInvocation:orArguments:count:methodSignature:selector:withProxy:] 9 A900B459-0127-379E-9CBA-0EAB9C5D559F0x1214a0 ___forwarding___ 10 A900B459-0127-379E-9CBA-0EAB9C5D559F0x187ef8 __forwarding_prep_0___ 11 BFBF140A-DB1B-3B5B-ACE4-1C990763332A0x7d700 -[AVAudioSession privateCreateSessionInServerUsingXPC] 12 BFBF140A-DB1B-3B5B-ACE4-1C990763332A0x7e874 -[AVAudioSession initWithSpecification:] 13 BFBF140A-DB1B-3B5B-ACE4-1C990763332A0x6e1b8 -[AVAudioSession initWithSessionType:] 14 BFBF140A-DB1B-3B5B-ACE4-1C990763332A0x6e158 __32+[AVAudioSession sharedInstance]_block_invoke 15 5D16936B-4E4C-3276-BA7A-69C9BC760ABA0xa0604 _dispatch_client_callout 16 5D16936B-4E4C-3276-BA7A-69C9BC760ABA0xa1e44 _dispatch_once_callout 17 BFBF140A-DB1B-3B5B-ACE4-1C990763332A0x6e7c8 +[AVAudioSession sharedInstance] why deadlock happend to [AVAudioSession sharedInstance]? i try get volume of [AVAudioSession sharedInstance] in my didFinishLaunchingWithOptions

{signal=SIGKILL, exceptionCode=0x00000000, virtualMemoryRegionInfo=unkown, terminationReason=<RBSTerminateContext| domain:10 code:0x8BADF00D explanation:[application<com.***.***>:3682] failed to terminate gracefully after 5.0s ProcessVisibility: Background ProcessState: Running WatchdogEvent: process-exit WatchdogVisibility: Background WatchdogCPUStatistics: ( "Elapsed total CPU time (seconds): 12.680 (user 7.120, system 5.560), 41% CPU", "Elapsed application CPU time (seconds): 1.309, 4% CPU" ) reportType:CrashLog maxTerminationResistance:Interactive>} i have no idea about this crash. who can explain this for me? what cause this problem? when does this problem occur?

i does not implementation background push notification in my app. however i found my app launch in background(applicationState is equal to background inapplicationDidFinishLaunch method) and launchOptions contained UIApplicationLaunchOptionsRemoteNotificationKey. the value of UIApplicationLaunchOptionsRemoteNotificationKey does not contained content-available : 1 is it a bug or sepcial case ?

launch due to a background fetch event does not work when debug in iOS17. it work correctly in iOS16, even though debug with xcode15.0.1