problem with SPV chain download (double lock?)

[mackuba]

10/11/13 5:06:54.086 PM [0x0-0xa7da7d].com.grabhive.Hive: Caused by: com.google.bitcoin.store.BlockStoreException: File size on disk does not match expected size: 0 vs 641024

This is probably because of a lock on the SPV chain file set by another instance of Hive. The problem is that sometimes there's no other instance of Hive and the lock is still set.

[mackuba]

This is appearing randomly, Wei had this a few weeks ago when her Mac crashed at some point and Hive couldn't start after reboot, and now a user reported this too.

This has nothing to do with the lock - the exception when a lock is set is the same exception class BlockStoreException, but with a different message. This happens when the memory-mapped chain file was not flushed from memory to disk for some reason (this isn't supposed to happen...).

[mackuba]

Some fixes to make it possible to detect this error and fix it by deleting the chain file:

c4cfcbd
d0e1d8a

(I don't know how to prevent this from happening yet)