reconsiderblock is prone to deadlocks when -checkblockindex=1 #16998

1. 
   Sjors commented at 2:36 pm on September 30, 2019: member

   Steps to reproduce :

   Configure with --enable-debug and run with -checkblockindex=1 .

   1. invalidateblock …
   2. reconsiderblock …

   Progress for reconsiderblock stops at some point, at least in the log. But CPU activity remains at 100%. It seems to happen shortly after it connects to new peers. Calling setnetworkactive false before reconsiderblock seems to prevent the issue.

   ctrl + c will not stop bitcoind, it doesn’t go beyond “addcon thread exit” and “net thread exit”.

   When running QT, it becomes completely unresponsive.

   bitcoin-cli stop will say “Bitcoin Core stopping”, but that’s a lie.

   In addition, calling reconsiderblock very early after start, before you see ERROR: AcceptBlockHeader: block 0000000000000000000212eb9b17aeb6e2a1527923ba79527cd8373f1d44307d is marked invalid, will prevent the chain from moving until you force-quit.

   Launching bitcoind without -checkblockindex=1 doesn’t seem to have this issue.

   Tried on master @ c3a8e097b1afe27bce2f71817fd23cb857236d9d.

2. Sjors added the label Bug on Sep 30, 2019
3. Sjors renamed this:
   reconsiderblock is prone to deadlocks
   reconsiderblock is prone to deadlocks when -checkblockindex=1
   on Sep 30, 2019
4. 
   promag commented at 7:11 pm on October 3, 2019: member

   bitcoin-cli stop will say “Bitcoin Core stopping”, but that’s a lie.

   👮

5. 
   MarcoFalke commented at 7:49 pm on October 11, 2019: member

   Can you attach gdb -p ${the_pid} and run thread apply all bt?
6. 
   Sjors commented at 12:55 pm on September 6, 2022: member

   Closing because this is too long and too many refactors ago.
7. Sjors closed this on Sep 6, 2022

   ---

8. bitcoin locked this on Sep 6, 2023

Contributors
Sjors promag MarcoFalke

Labels
Bug