LOCK_TIMEOUT
The SQLITE_FCNTL_LOCK_TIMEOUT opcode is used to configure a VFS to block for up to M milliseconds before failing when attempting to obtain a file lock using the xLock or xShmLock methods of the VFS. The parameter is a pointer to a 32-bit signed integer that contains the value that M is to be set to. Before returning, the 32-bit signed integer is overwritten with the previous value of M.