On Sun, Mar 18, 2012 at 11:19 AM, Dan Kennedy <[email protected]> wrote:
> On 03/18/2012 11:26 AM, Arnav Aggarwal wrote: > >> On Sat, Mar 17, 2012 at 12:07 PM, Arnav Aggarwal< >> [email protected]> wrote: >> >> >>> >>> On Sat, Mar 17, 2012 at 11:51 AM, Roger Binns<[email protected]>** >>> wrote: >>> >>> -----BEGIN PGP SIGNED MESSAGE----- >>>> Hash: SHA1 >>>> >>>> On 16/03/12 22:50, Arnav Aggarwal wrote: >>>> >>>>> I don't have any choice of using a different filesystem.. >>>>> >>>> >>>> I'd suggest you write your own VFS then. You can choose exactly how >>>> locking is done. It isn't that much work and you can map to the exact >>>> semantics of the filesystem rather than pretending it is unix which it >>>> evidently isn't. >>>> >>>> >>>> My system behaves quite similar to that of unix and mostly POSIX >>> compliant. But, "fcntl" locks are not supported. >>> Is there any known problem using a "unix-dotfile" vfs ? >>> >>> >>> In such a scenario, can I safely delete the lock file and journal file >>>>> (if size 0) ? >>>>> >>>> >>>> Depends on why they are size zero. If your crummy filesystem doesn't >>>> implement barriers correctly then it is quite possible that they >>>> shouldn't >>>> be zero length. >>>> >>>> (I'm assuming your want your database to survive unexpected power >>>> failures) >>>> >>>> >>>> May be I can leave the journal files as it is. I believe sqlite code can >>> take care of them. >>> But, lock directories must be deleted else the application fails to >>> start. >>> Can these be safely deleted at apllication start up before opening the >>> database ? >>> >>> >>> >>> Guys, Sorry for being impatient and posting this again. >> Any comments on this issue ? >> >> Just to summarize, I am using "dotfile" locking. Only one instance of >> application will run (it may be multithreaded). The sqlite code is >> statically linked with the application. This is the only application that >> can access the database file. >> On application crash, lockfiles are sometimes not removed due to which >> application fail to restart. >> >> My question, can I safely remove the lockfile on application startup >> before >> opening the database and before creating any thread ? >> > > If, at some point, you are sure that no processes have > the database file open, you can safely delete any old > lock files. > > Don't ever delete a journal or wal file though of course. Thanks a lot Dan for confirming this. I will remove the code to delete the 0 byte sized journal file. _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
