ANR in SendRelayedMessageUtil.sendMultipleMsgs

[adbenitez]

dc_send_msg blocks the main thread:

  
      #00  pc 0x000000000005823c  /apex/com.android.runtime/lib64/bionic/libc.so (syscall+28)
    
  
      #01  pc 0x0000000000cd0088  /data/app/~~0Q154b6xQGDTLUevPLXoUw==/chat.delta-o1eYDjDpzVMHK5_--aqNQg==/lib/arm64/libnative-utils.so (BuildId: 9a945705947528941f50411cc3e0b13821e656fb)
    
  
      #02  pc 0x0000000000ccfba8  /data/app/~~0Q154b6xQGDTLUevPLXoUw==/chat.delta-o1eYDjDpzVMHK5_--aqNQg==/lib/arm64/libnative-utils.so (BuildId: 9a945705947528941f50411cc3e0b13821e656fb)
    
  
      #03  pc 0x0000000000e1e8f0  /data/app/~~0Q154b6xQGDTLUevPLXoUw==/chat.delta-o1eYDjDpzVMHK5_--aqNQg==/lib/arm64/libnative-utils.so (BuildId: 9a945705947528941f50411cc3e0b13821e656fb)
    
  
      #04  pc 0x0000000000e1f1ec  /data/app/~~0Q154b6xQGDTLUevPLXoUw==/chat.delta-o1eYDjDpzVMHK5_--aqNQg==/lib/arm64/libnative-utils.so (BuildId: 9a945705947528941f50411cc3e0b13821e656fb)
    
  
      #05  pc 0x00000000008171cc  /data/app/~~0Q154b6xQGDTLUevPLXoUw==/chat.delta-o1eYDjDpzVMHK5_--aqNQg==/lib/arm64/libnative-utils.so (dc_send_msg+424) (BuildId: 9a945705947528941f50411cc3e0b13821e656fb)
    
  
      at com.b44t.messenger.DcContext.sendMsg (Native method)
    
  
      at org.thoughtcrime.securesms.util.SendRelayedMessageUtil.sendMultipleMsgs (SendRelayedMessageUtil.java:76)
    
  
      at org.thoughtcrime.securesms.ConversationActivity.lambda$onActivityResult$0$org-thoughtcrime-securesms-ConversationActivity (ConversationActivity.java:366)
    
  
      at org.thoughtcrime.securesms.ConversationActivity$$ExternalSyntheticLambda12.run (unavailable:4)
    
  
      at org.thoughtcrime.securesms.ConversationActivity.lambda$askSendingFiles$8 (ConversationActivity.java:689)
    
  
      at org.thoughtcrime.securesms.ConversationActivity$$ExternalSyntheticLambda0.onClick (unavailable:2)
    
  
      at androidx.appcompat.app.AlertController$ButtonHandler.handleMessage (AlertController.java:167)
    
  
      at android.os.Handler.dispatchMessage (Handler.java:106)
    
  
      at android.os.Looper.loopOnce (Looper.java:243)
    
  
      at android.os.Looper.loop (Looper.java:338)
    
  
      at android.app.ActivityThread.main (ActivityThread.java:8470)
    
  
      at java.lang.reflect.Method.invoke (Native method)
    
  
      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:600)
    
  
      at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1064)
    
  

[Hocuri]

Also here, I think we can just do that on a background thread.