Im not sure that the current situation of forced thread incompatibility is better than leaving it up to users to manage the threading. Usually it is assumed that a library is thread unsafe unless otherwise specified.
Developing multithreaded applications is difficult, i wouldnt dispute that. But i do dispute the wisdom of actively making a library incompatible with threads. Sqlite is the first example of such behaviour i have seen, it deliberately fails even if the user attempts to synchronise concurrent access. Surely it would be better to design the api so that it was either fully thread safe and blocked on every call to an sqlite_ function using its own mutexes, or to simply ensure that it was process safe using shared memory. As i mentioned in a previous reply, synchronising sqlite would be no more or less difficult or error prone than synchonising a linked list. I dont see what is gained by making it not work with threads, so i assume that it is becuase of some technical reason rather than a design decision. Anyway, as another user has pointed out. You can compile the library in such a way as to allow the thread synchronisation routines to be overridden so i think i have a solution to the problem, but perhaps not an answer as to why things are the way they are. On 12/29/06, Jay Sprenkle <[EMAIL PROTECTED]> wrote:
On 12/27/06, Emerson Clarke <[EMAIL PROTECTED]> wrote: > The first question is why database locking has been enabled on a per thread > basis instead of per process so that the normal methods of thread > synchronisation (mutexes, ciritcal sections) could not be used for > maintaining consistency within the application. The programmer can easily > ensure that no two statements are executed at the same time just as they > would ensure that no more than one operation on a linked list was performed > at the same time. Having watched a lot of people attempt to write thread safe code I would say this is an incorrect assumption. I think it only appears simple at a casual glance. -- The PixAddixImage Collector suite: http://groups-beta.google.com/group/pixaddix SqliteImporter and SqliteReplicator: Command line utilities for Sqlite http://www.reddawn.net/~jsprenkl/Sqlite Cthulhu Bucks! http://www.cthulhubucks.com ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
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