Sometimes stop audio session. Process "mediaserverd" died?

• "cpa" is our VoIP application, using CallKit and audio session. (AVAudioPlayer, AVAudioSession, etc.)

• In talking, happend stop audio session (playback and recording).

• We got "sysdiagnose" and some "stacks".

• It seems that server died when audio session stopped.

Code Block 
デフォルト	2021-01-18 10:24:14.917454 +0900	cpa	AURemoteIO.cpp:1625:Stop: Stopping AURemoteIO(0x106812040)
デフォルト	2021-01-18 10:24:14.917850 +0900	cpa	AudioSessionClientManager.cpp:214:ServerDied_Priv: Server with PID 5247 died.
デフォルト	2021-01-18 10:24:14.917854 +0900	cpa	AudioSessionClientManager.cpp:394:operator(): Marking session 0x148565b for deletion. Cached server pid is 5247
デフォルト	2021-01-18 10:24:14.918070 +0900	cpa	    AVAudioSession_iOS.mm:2746  Posting AVAudioSessionMediaServicesWereLostNotification

• "PID 5247" was "mediaserverd".

Code Block 
デフォルト	2021-01-18 10:24:14.836401 +0900	osanalyticshelper	Stackshot requested by mediaserverd, code: be18d1ee, reason: <private>
デフォルト	2021-01-18 10:24:14.856735 +0900	mediaserverd	 Audio IO Overload inputs: '<private>' outputs: '<private>' cause: 'Unknown' prewarming: no recovering: no
デフォルト	2021-01-18 10:24:14.856873 +0900	mediaserverd	     CAReportingClient.mm:508   message {
    cause = Unknown;
    deadline = 422548;
    "input_device_source_list" = Unknown;
    "input_device_transport_list" = BuiltIn;
    "input_device_uid_list" = Codec;
    "io_buffer_size" = 256;
    "io_cycle" = 1649;
    "is_prewarming" = 0;
    "is_recovering" = 0;
    "issue_type" = overload;
    lateness = 143;
    "output_device_source_list" = Unknown;
    "output_device_transport_list" = BuiltIn;
    "output_device_uid_list" = Codec;
}: (
    22535693402235
)
デフォルト	2021-01-18 10:24:14.914984 +0900	osanalyticshelper	Saved type '288(288)' report (1 of max 100) at /private/var/mobile/Library/Logs/CrashReporter/stacks+mediaserverd-2021-01-18-102414.ips

• Reason is 'fig rpc timeout -- remoteXPCPlayer_RemoveFromPlayQueue' ...?

Code Block 
{"bug_type":"288","timestamp":"2021-01-18 10:24:14.84 +0900","os_version":"iPhone OS 14.3 (18C66)","incident_id":"4E4F1DA2-81F5-422F-BD64-9036AFFF210D"}
{
  "build" : "iPhone OS 14.3 (18C66)",
  "product" : "iPhone13,4",
  "kernel" : "Darwin Kernel Version 20.2.0: Fri Nov 13 01:00:14 PST 2020; root:xnu-7195.62.1~4\/RELEASE_ARM64_T8101",
  "tuning" : {
  },
  "incident" : "4E4F1DA2-81F5-422F-BD64-9036AFFF210D",
  "crashReporterKey" : "d222d231b77c6b0d5f1e81edd68e361efcd9bb70",
  "date" : "2021-01-18 10:24:14.82 +0900",
  "reason" : "mediaserverd: RPCTimeout message received to terminate [5247] from 150 (???) with reason 'fig rpc timeout -- remoteXPCPlayer_RemoveFromPlayQueue' stackshot taken",
  "frontmostPids" : [
    60
  ],
  "exception" : "0xbe18d1ee",
  "absoluteTime" : 3748681866206,
  "pid" : 5247,
  "memoryStatus" : {"compressorSize":26667,"compressions":1410695,"decompressions":715907,"busyBufferCount":0,"pageSize":16384,"memoryPressure":false,"memoryPages":{"active":117298,"throttled":0,"fileBacked":135474,"wired":44654,"purgeable":8219,"inactive":99580,"free":45453,"speculative":17613}},

• "mediaserverd" is system process?

mediaserverd
is a system process responsible for a lot of the back end of AVFoundation. It should never crash.

• In this case, we have "sysdiagnose" and some "stacks".

• Recently, it seems that similar case (stop playback and recording) happened other iPhones, but couldn't get "sysdiagnose".

• We cannot find reproducible way yet.