Obviously i had not looked at the code. I see now that the async code is registered as a VFS... And thanks to Dan there is only one background thread and queue.
One could implement the background thread and a function, mutex and condition variable so that the function would call the sqlite3async_control setting the SQLITEASYNC_HALT_IDLE. The function would then block on the condition awaiting the running thread to complete the work. The running thread would then signal the condition causing the "waiting" function to return. --- On Thu, 5/7/09, Virgilio Alexandre Fornazin <virgilioforna...@gmail.com> wrote: > From: Virgilio Alexandre Fornazin <virgilioforna...@gmail.com> > Subject: RE: [sqlite] SQLite version 3.6.14 and async vfs > To: kennethinbox-sql...@yahoo.com, "'General Discussion of SQLite Database'" > <sqlite-users@sqlite.org>, "'Pavel Ivanov'" <paiva...@gmail.com> > Date: Thursday, May 7, 2009, 12:04 PM > This break purpose of VFS, all VFS > should work in same way, you must not > know if your VFS is asynchronous > or not. VFS close method should wait for all file I/O on > this database > handle (not all databases) to > finalize before returning, providing compatibility with all > other existing > VFS implementations. > > > -----Original Message----- > From: sqlite-users-boun...@sqlite.org > [mailto:sqlite-users-boun...@sqlite.org] > On Behalf Of Ken > Sent: quinta-feira, 7 de maio de 2009 13:47 > To: General Discussion of SQLite Database; Pavel Ivanov > Subject: Re: [sqlite] SQLite version 3.6.14 and async vfs > > > I see the confusion with the word "Shutdown". > > How about but a call that would block until the async > thread completes all > operations that are enqueued. Effectively a Close of the > async thread/queue > and db. The call could be sqlite3Async_close. > > Hope that clarifies my intent. > > > --- On Thu, 5/7/09, Pavel Ivanov <paiva...@gmail.com> > wrote: > > > From: Pavel Ivanov <paiva...@gmail.com> > > Subject: Re: [sqlite] SQLite version 3.6.14 and async > vfs > > To: kennethinbox-sql...@yahoo.com, > "General Discussion of SQLite Database" > <sqlite-users@sqlite.org> > > Date: Thursday, May 7, 2009, 11:10 AM > > Shutdown is not an option at all. I > > need vfs to continue working on > > other databases but to be notified (or have > possibility to > > check) when > > one particular database is no longer opened. > > > > Pavel > > > > On Thu, May 7, 2009 at 12:00 PM, Ken <kennethinbox-sql...@yahoo.com> > > wrote: > > > > > > --- On Thu, 5/7/09, Virgilio Alexandre Fornazin > <virgilioforna...@gmail.com> > > wrote: > > > > > >> From: Virgilio Alexandre Fornazin <virgilioforna...@gmail.com> > > >> Subject: Re: [sqlite] SQLite version 3.6.14 > and > > async vfs > > >> To: "'General Discussion of SQLite > Database'" > > <sqlite-users@sqlite.org> > > >> Date: Thursday, May 7, 2009, 10:50 AM > > >> Close should wait for all file > > >> operations complete to meet that needs. > > >> I think asynchronous VFS should take care of > > waiting in > > >> sqlite3_close() > > >> call. > > >> > > >> -----Original Message----- > > >> From: sqlite-users-boun...@sqlite.org > > >> [mailto:sqlite-users-boun...@sqlite.org] > > >> On Behalf Of Pavel Ivanov > > >> Sent: quinta-feira, 7 de maio de 2009 12:33 > > >> To: General Discussion of SQLite Database > > >> Subject: Re: [sqlite] SQLite version 3.6.14 > and > > async vfs > > >> > > >> Hi! > > >> > > >> It's great to hear about performance > improvements > > and > > >> especially about > > >> asynchronous I/O extension. Thank you very > much > > for your > > >> work! > > >> > > >> I have one question though: taking quick look > at > > the > > >> sources of async > > >> vfs I've noticed that even closing the file > is > > just a task > > >> in the > > >> async queue and thus after closing sqlite > > connection file > > >> remains > > >> opened for some time. It sounds pretty > reasonable, > > but here > > >> stands the > > >> question: what if I want to do something with > the > > database > > >> file after > > >> I close sqlite connection to it (e.g. move to > the > > archive > > >> directory, > > >> zip it etc.)? With sync vfs I could be sure > that > > after > > >> closing > > >> connection file is closed and I can do with > it > > whatever I > > >> want. Is > > >> there a way to catch the moment of actual > file > > closing with > > >> async vfs? > > >> > > >> And another question just to be sure that I > > understand it > > >> correctly: > > >> async vfs holds only one queue for all > opened > > database > > >> files, right? > > >> > > >> Pavel > > >> > > >> On Wed, May 6, 2009 at 10:36 PM, D. Richard > Hipp > > <d...@hwaci.com> > > >> wrote: > > >> > SQLite version 3.6.14 is now available > on the > > SQLite > > >> website > > >> > > > >> > http://www.sqlite.org/ > > >> > > > >> > Version 3.6.14 contains performance > enhances > > in the > > >> btree and pager > > >> > subsystems. In addition, the query > > optimizer now > > >> knows how to take > > >> > advantage of OR and IN operators on > columns > > of a > > >> virtual table. > > >> > > > >> > A new optional extension is included > that > > implements > > >> an asynchronous I/ > > >> > O backend for SQLite on either windows > or > > unix. The > > >> asynchronous I/O > > >> > backend processes all writes using a > > background > > >> thread. This gives > > >> > the appearance of faster response time > at the > > cost of > > >> durability and > > >> > additional memory usage. See http://www.sqlite.org/asyncvfs.html for > > >> > additional information. > > >> > > > >> > This release also includes many small > bug > > fixes and > > >> documentation > > >> > improvements. > > >> > > > >> > As always, please let me know if you > > encounter any > > >> difficulties. > > >> > > > >> > D. Richard Hipp > > >> > d...@hwaci.com > > >> > > > >> > > > > > > > Without actually looking at the async code I > think > > that instead of using the sqlite3_close to cause a > block > > there should be a "shutdown" that would wait for the > > shutdown of the async thread to complete. So maybe a > better > > name would be sqlite3Async_close or something > similar. > > > > > > Ken > > > > > > > > > _______________________________________________ > > > sqlite-users mailing list > > > sqlite-users@sqlite.org > > > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > > > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
