Hello, my app crashed on iOS 12.x, it only crashed on iOS 12.x system, I don’t know what to do? I use NSURLSession to download remote image. Please help me thanks
I have tried to look out and explore but can't find the reason or nor reproduce it yet.
Date/Time: 2021-08-10 04:28:44.855 +0800
OS Version: iOS 12.4 (16G77)
Report Version: 104
Monitor Type: Unix Signal
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x00000000 at 0x0000000190b530dc
Crashed Thread: 40
Pthread id: 1160889
Thread 0:
0 libsystem_kernel.dylib mach_msg_trap + 8
1 libsystem_kernel.dylib mach_msg + 72
2 CoreFoundation __CFRunLoopServiceMachPort + 236
3 CoreFoundation __CFRunLoopRun + 1360
4 CoreFoundation CFRunLoopRunSpecific + 436
5 GraphicsServices GSEventRunModal + 104
6 UIKitCore UIApplicationMain + 212
7 MyAPP main + 300
8 libdyld.dylib start + 4
Pthread id: 1166811
Thread 40 Crashed:
0 libsystem_kernel.dylib __pthread_kill + 8
1 libsystem_pthread.dylib pthread_kill$VARIANT$armv81 + 296
2 libsystem_c.dylib abort + 140
3 libsystem_c.dylib __assert_rtn + 312
4 CFNetwork invocation function for block in TCPIOConnection::_tlsValidateServerTrust(nw_tls_context*) + 0
5 CFNetwork TCPIOConnection::_handleConnectionEvent(unsigned int, void const*) + 980
6 CFNetwork invocation function for block in TCPIOConnection::_startConnection() + 108
7 libnetwork.dylib __tcp_connection_start_block_invoke + 1020
8 libdispatch.dylib _dispatch_client_callout + 16
9 libdispatch.dylib _dispatch_block_invoke_direct$VARIANT$armv81 + 216
10 MyAPP __innerBlockOnce_block_invoke + 148
11 libdispatch.dylib _dispatch_call_block_and_release + 24
12 libdispatch.dylib _dispatch_client_callout + 16
13 libdispatch.dylib _dispatch_lane_serial_drain$VARIANT$armv81 + 548
14 libdispatch.dylib _dispatch_lane_invoke$VARIANT$armv81 + 464
15 libdispatch.dylib _dispatch_workloop_invoke$VARIANT$armv81 + 1900
16 libdispatch.dylib _dispatch_workloop_worker_thread + 584
17 libsystem_pthread.dylib _pthread_wqthread + 304
Enqueue thread backtrace:
0 MyAPP innerBlockOnce + 36
1 MyAPP _dispatch_async + 44
2 libnetwork.dylib nw_connection_report_state_with_handler_locked + 1196
3 libnetwork.dylib nw_connection_endpoint_report + 7392
4 libnetwork.dylib nw_endpoint_handler_report + 180
5 libnetwork.dylib nw_endpoint_resolver_update + 8220
6 libnetwork.dylib __nw_resolver_update_client_block_invoke + 104
7 MyAPP __innerBlockOnce_block_invoke + 148
8 libdispatch.dylib _dispatch_call_block_and_release + 24
9 libdispatch.dylib _dispatch_client_callout + 16
10 libdispatch.dylib _dispatch_workloop_invoke$VARIANT$armv81 + 2200
11 libdispatch.dylib _dispatch_workloop_worker_thread + 584
12 libsystem_pthread.dylib _pthread_wqthread + 304
13 libsystem_pthread.dylib start_wqthread + 4
Enqueue thread backtrace:
0 MyAPP innerBlockOnce + 36
1 MyAPP _dispatch_async + 44
2 libnetwork.dylib nw_queue_context_async + 88
3 libnetwork.dylib nw_resolver_update_client + 316
4 libnetwork.dylib nw_resolver_update_status_locked + 632
5 libnetwork.dylib nw_resolver_host_resolve_callback + 2472
6 libsystem_dnssd.dylib handle_addrinfo_response + 412
7 libsystem_dnssd.dylib DNSServiceProcessResult + 596
8 MyAPP __innerBlock_block_invoke + 140
9 libdispatch.dylib _dispatch_client_callout + 16
10 libdispatch.dylib _dispatch_continuation_pop$VARIANT$armv81 + 404
11 libdispatch.dylib _dispatch_source_invoke$VARIANT$armv81 + 1232
12 libdispatch.dylib _dispatch_workloop_invoke$VARIANT$armv81 + 1900
13 libdispatch.dylib _dispatch_workloop_worker_thread + 584
14 libsystem_pthread.dylib _pthread_wqthread + 304
15 libsystem_pthread.dylib start_wqthread + 4
Enqueue thread backtrace:
0 MyAPP innerBlock + 36
1 MyAPP _dispatch_source_set_event_handler + 44
2 libsystem_dnssd.dylib DNSServiceSetDispatchQueue + 236
3 libnetwork.dylib nw_resolver_create_dns_service_locked + 1836
4 libnetwork.dylib __nw_resolver_set_update_handler_block_invoke + 96
5 libnetwork.dylib nw_queue_context_async_if_needed + 100
6 libnetwork.dylib nw_resolver_set_update_handler + 328
7 libnetwork.dylib -[NWConcrete_nw_endpoint_resolver startWithHandler:] + 1696
8 libnetwork.dylib nw_endpoint_handler_path_change + 11544
9 libnetwork.dylib __nw_endpoint_handler_initialize_association_block_invoke + 172
10 libnetwork.dylib __nw_association_update_paths_block_invoke.73 + 64
11 libnetwork.dylib nw_hash_table_apply + 316
12 libnetwork.dylib nw_association_update_paths + 320
13 libnetwork.dylib nw_path_necp_update_evaluator + 1224
14 libnetwork.dylib nw_path_necp_check_for_updates + 908
15 libdispatch.dylib _dispatch_client_callout + 16
16 libdispatch.dylib _dispatch_continuation_pop$VARIANT$armv81 + 404
17 libdispatch.dylib _dispatch_source_invoke$VARIANT$armv81 + 1232
18 libdispatch.dylib _dispatch_workloop_invoke$VARIANT$armv81 + 1900
19 libdispatch.dylib _dispatch_workloop_worker_thread + 584
20 libsystem_pthread.dylib _pthread_wqthread + 304
21 libsystem_pthread.dylib start_wqthread + 4
Using the Apple crash report I was able to track down the assertion that’s causing this crash. Unfortunately that doesn’t help you very much. The assertion is related to internal state within the TCPIOConnection subsystem.
For context, TCPIOConnection is the way that older versions of CFNetwork interact with TCP connection. This code has changed a lot in recent releases, with the roll out of Network framework, which probably explains why you’re not seeing it on iOS 13 and later.
I don’t think there’s much you can do about this. If you’re seeing this crash a lot, your best option would be to drop iOS 12 support. This isn’t that unusual; most iOS apps don’t support that far back. OTOH, if you’re seeing this infrequently then you may just want to live with it )-:
Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"