Paul Corke wrote: > On 10 October 2012 13:47, Richard Hipp wrote: >> We would also love to have guidance on alternative techniques for >> obtaining memory shared across multiple processes that does not >> involve mmap() of temporary files. > > In case it's any use, what we use on Linux is: > > ftok(P) -- presumably you could use the sqlite file as the first > argument > > shmget(P) -- using the id generated by ftok(), and using IPC_CREAT > if needed
With 32-bit keys, there's quite a high risk of collisions. You should rather use shm_open() (which is spec'd by POSIX and implemented by all modern Unixes except Net/OpenBSD). On Android, neither shmget nor shm_open are accessible, and the native shared memory mechanism (ashmem) would require exchanging file descriptors through RPC. There really is no alternative to mmap(). (Furthermore, there is no shared tmpfs directory, so that temp file must be created in the same directory as the DB file itself.) Regards, Clemens _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
