Thank you Keith. And there are something I want to make sure. >THREADSAFE=1 means that the sqlite3 library enforces the re-entrancy requirements via mutexes attached to the CONNECTION object. This means that the library will serialize access to the sqlite3 engine for you so that only one call (entrance) per connection is permitted to proceed. Yes. That's the reason why I think my applications can use "threadsafe=1 + share one connection" directly and sqlite will meeting the entrance requirements by itself.
>Other entrances (calls) will *wait* until the in-progress call is complete before proceeding. I see the word "wait". But could you give me any advises to find the code when sqlite waiting or retrying? >THREADSAFE=2 means that the sqlite3 library WILL NOT ENFORCE the re-entrancy requirements via mutexes attatched to the CONNECTION object. Yes. So I can not use "threadsafe=2 + share one connection" in my apps, as I may have more than one call at a time. >The limitation of only ONE entrance per connection object at one time is still in effect however, so if you violate the rules then AHWBL. I want to make sure that it is not OK to read and write concurrently within the same transaction(two thread share one connection), but it is OK to read and write concurrently if I have two different connection and use WAL. Is it correct? >Therefore IF you use THREADSAFE=2 *AND* open a new connection dedicated to each thread, THEN you can be sure that you are meeting the entrance requirements provided that only calls against that connection (or objects derived therefrom) are made on the thread which owns that connection, and from NO OTHER THREAD. Sorry, I still can not understand. Um, or, is it OK to use "threadsafe=2 and 2 connections" in my apps if the 2 threads may write at the same time? thanks. -- Sent from: http://sqlite.1065341.n5.nabble.com/ _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
