sqlite can be non-reenterant

[sergeych]

Just found that running a resultset in one thread and executeQuery in another often causes crash in the sqlite code. Typical crash stack is:

Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libsqlite3.dylib 0x3265929c sqlite3_extended_errcode + 18104
1 libsqlite3.dylib 0x32659342 sqlite3_extended_errcode + 18270
2 libsqlite3.dylib 0x3266cc08 sqlite3_column_bytes16 + 7160
3 libsqlite3.dylib 0x32687002 sqlite3_open16 + 42242
4 libsqlite3.dylib 0x32644954 sqlite3_step + 56
5 iGlomp 0x00010d46 -FMResultSet next

Well, it might depend on the sqlite version, but I'd better add a mutex to all sqlite calls. Does a new thread contain a workaround fot it already?

[ccgus]

Check out the threadtests branch:
https://github.com/ccgus/fmdb/tree/threadtests

Instead of using the same FMDatabase instance, make a pool and use that for thread safety.

[sergeych]

thanks, it works.