Can I ask you why do you need to allocate memsys5 memory pool in the first place? Why don't you use standard mallocs? Or even your own allocator? I just have a feeling that you're pursuing some goals very specific to your application and this kind of functionality is not necessary to anybody else.
Pavel On Fri, Aug 28, 2009 at 12:19 AM, shankar m<shankar.mah...@gmail.com> wrote: > Its not a problem in SQLite. I need a feature enhancement. > > Currently in SQLite i can allocate memory in a block. > > Example: > 2.5MB memory for memsys5 memory pool. Here 2MB i am using for Mem Db and > 0.5MB for heap and other DB cache. > > I want flexibility such that when i close mem db, the 2MB should be freed. > For this I need to configure SQLite with 2 Memory blocks. One with 2MB and > another 0.5MB. > > For doing this I have sent the modifications that needs to be done. > > Regards > Shankar > > > > > On Thu, Aug 27, 2009 at 4:40 PM, Pavel Ivanov <paiva...@gmail.com> wrote: > >> OK. So you have allocated memsys5 memory pool and now are complaining >> that this memory is not returned to OS? >> >> Sorry, but it's not quite understandable what do you want to achieve, >> what's the problem with it and how did you find that there's a >> problem. >> >> Pavel >> >> On Thu, Aug 27, 2009 at 6:11 AM, shankar m<shankar.mah...@gmail.com> >> wrote: >> > I have allocated memory for SQLite heap and using memsys5 memory pool >> > algorithm to manage the heap. So if free is called it will be added to >> free >> > list of memsys5 memory pool. >> > >> > Regards >> > Shankar >> > >> > On Wed, Aug 26, 2009 at 7:51 PM, Pavel Ivanov <paiva...@gmail.com> >> wrote: >> > >> >> And I mean that you're wrong in this vision. SQLite doesn't keep >> >> memory in pools if it doesn't belong to cache necessary to some open >> >> connection. At least SQLite calls free() which of course doesn't >> >> necessarily mean that memory will be returned to OS. >> >> >> >> >> >> Pavel >> >> >> >> On Wed, Aug 26, 2009 at 10:02 AM, shankar m<shankar.mah...@gmail.com> >> >> wrote: >> >> > I mean to say free to the OS so that it can use for other purpose. >> >> > >> >> > SQlite frees but maintains to the memory will be present in SQLite >> memory >> >> > pool or heap. Not to the OS. >> >> > >> >> > Regards >> >> > Shankar >> >> > >> >> > On Wed, Aug 26, 2009 at 7:15 PM, Pavel Ivanov <paiva...@gmail.com> >> >> wrote: >> >> > >> >> >> > SQLite currently does not support freeing of allocated memory >> >> >> > unless it is shutdown. >> >> >> >> >> >> It seams to me that you're wrong in this conclusion or elaborate >> >> >> please how did you come to it. >> >> >> In fact SQLite always frees all memory related to connection >> >> >> (including cache) when you close it. And you can clearly see it in >> >> >> sources... >> >> >> >> >> >> >> >> >> Pavel >> >> >> >> >> >> On Wed, Aug 26, 2009 at 12:57 AM, shankar m<shankar.mah...@gmail.com >> > >> >> >> wrote: >> >> >> > Hi, >> >> >> > >> >> >> > I am using SQLite in a embedded system which has the following >> >> databases >> >> >> > 1. 64MB Flash stored Database for persistent storage >> >> >> > 2. 2 MB In-Memory Database. >> >> >> > >> >> >> > When the Memory Database is closed the 2MB should be returned to >> the >> >> >> > operating system. The 2 MB will be reallocated when the system >> wants >> >> to >> >> >> use >> >> >> > the mem db. SQLite currently does not support freeing of allocated >> >> memory >> >> >> > unless it is shutdown. >> >> >> > >> >> >> > >> >> >> > To implement the above requirement I am planning to do as follows >> >> >> > >> >> >> > In SQLite Page cache module i.e pcahe1.c handles the datbase >> buffering >> >> of >> >> >> > both persistent storage and in-memory storage. >> >> >> > To identify whether the database is mem or file there is a flag >> >> >> bPurgeable >> >> >> > in struct PCache1. >> >> >> > >> >> >> > The pages for cache are allocated in functions >> >> >> > 1. pcache1AllocPage >> >> >> > 2. pcache1FreePage >> >> >> > >> >> >> > Add 2 new configuration variables >> >> >> > 1. SQLITE_CONFIG_MEMDB - Enables separate memory DB with the >> default >> >> >> > values >> >> >> > 2. SQLITE_CONFIG_MEMSIZE- Configures the mem db with user >> specified >> >> >> > memory block. Similar to the config variable >> >> >> > SQLITE_CONFIG_PAGECACHE >> >> >> > >> >> >> > Using bPurgeable in pcache1AllocPage identify the mem db, If memdb >> >> then >> >> >> use >> >> >> > the mem block specified by the user. >> >> >> > The algorithm for the page allocation will be same as the list >> >> >> > implementation present for the SQLITE_CONFIG_PAGECACHE >> >> >> > >> >> >> > Please provide comments or suggestion. >> >> >> > >> >> >> > Thanks >> >> >> > Shankar >> >> >> > _______________________________________________ >> >> >> > 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 >> >> > >> >> _______________________________________________ >> >> 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 >> > _______________________________________________ > 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
