title: iOS Pasteboard strange random crash
body: <p>Our app received the crash multi times due to use Pasteboard. Under this situation when I try to use system Notes paste the content, the system notes will block too. So I write a program try to read the pasteboard, but it will also crash when I use [UIPasteboard generalPasteboard].  </p>
  
  <p>I'm sure this seriou bug is apple's bug, all the app will crash when launch under this situation If use UIPasteboard class. When I reboot the phone, it's ok. I have report this issue to apple but no reply, very disappointed.</p>
  
  <pre><code>Date/Time: 2018-12-19 11:37:49.4053 +0800
  Launch Time: 2018-12-19 11:37:29.3603 +0800
  OS Version: iPhone OS 12.1 (16B92)
  Baseband Version: 3.11.00
  Report Version: 104
  
  Exception Type: EXC_CRASH (SIGKILL)
  Exception Codes: 0x0000000000000000, 0x0000000000000000
  Exception Note: EXC_CORPSE_NOTIFY
  Termination Reason: Namespace SPRINGBOARD, Code 0x8badf00d
  Termination Description: SPRINGBOARD, scene-create watchdog transgression: com.xxxxx.xxxx exhausted real (wall clock) time allowance of 19.86 seconds | ProcessVisibility: Background | ProcessState: Running | WatchdogEvent: scene-create | WatchdogVisibility: Foreground | WatchdogCPUStatistics: ( | "Elapsed total CPU time (seconds): 14.230 (user 14.230, system 0.000), 18% CPU", | "Elapsed application CPU time (seconds): 0.005, 0% CPU" | )
  Triggered by Thread: 0
  
  Thread 0 name: Dispatch queue: com.apple.UIKit.pasteboard.cache-queue
  Thread 0 Crashed:
  0 libsystem_kernel.dylib 0x00000001eb35bed0 mach_msg_trap + 8
  1 libsystem_kernel.dylib 0x00000001eb35b3a8 mach_msg + 72
  2 libdispatch.dylib 0x00000001eb1db614 _dispatch_mach_send_and_wait_for_reply + 500
  3 libdispatch.dylib 0x00000001eb1dbab4 dispatch_mach_send_with_result_and_wait_for_reply$VARIANT$armv81 + 56
  4 libxpc.dylib 0x00000001eb422eb4 xpc_connection_send_message_with_reply_sync + 204
  5 Foundation 0x00000001ec393a28 __NSXPCCONNECTION_IS_WAITING_FOR_A_SYNCHRONOUS_REPLY__ + 12
  6 Foundation 0x00000001ec15b4dc -[NSXPCConnection _sendInvocation:orArguments:count:methodSignature:selector:withProxy:] + 3632
  7 CoreFoundation 0x00000001eb7d5460 ___forwarding___ + 556
  8 CoreFoundation 0x00000001eb7d745c _CF_forwarding_prep_0 + 92
  9 Pasteboard 0x0000000200c29778 -[PBServerConnection pasteboardWithName:createIfNeeded:error:] + 688
  10 Pasteboard 0x0000000200c2949c -[PBServerConnection pasteboardWithName:error:] + 96
  11 UIKitCore 0x00000002187b5d90 _pasteboardCacheQueue_existingItemCollectionWithName + 896
  12 UIKitCore 0x00000002187b57d8 __59+[_UIConcretePasteboard _pasteboardNamed:createIfNotFound:]_block_invoke + 228
  13 libdispatch.dylib 0x00000001eb20a484 _dispatch_client_callout + 16
  14 libdispatch.dylib 0x00000001eb1ea754 _dispatch_lane_barrier_sync_invoke_and_complete + 56
  15 UIKitCore 0x00000002187b5630 +[_UIConcretePasteboard _pasteboardNamed:createIfNotFound:] + 332
  16 UIKitCore 0x00000002187b4b00 +[UIPasteboard _pasteboardWithName:create:] + 148
  </code></pre>