I don't think we need SAPI. We could consider adding a "classic" manager interface. Meanwhile, you can write the testsuite with "#define __RTEMS_VIOLATE_KERNEL_VISIBILITY__" and access the supercore freelist interface directly...
On Thu, Jul 11, 2013 at 12:25 AM, Ashi <ashi08...@gmail.com> wrote: > > And I'm adding the test case, and find we haven't the SAPI for freelist yet. > I must add it before adding test case, right? By the way, is the SAPI same > as the user-level API layer as Gedare mentioned before? I haven't realized > it before. > > > On Wed, Jul 10, 2013 at 8:31 PM, Gedare Bloom <ged...@rtems.org> wrote: >> >> You would call extend instead of calling bump, or as part of bumping. > > Thanks, I see. >> >> >> On Wed, Jul 10, 2013 at 2:30 AM, Ashi <ashi08...@gmail.com> wrote: >> > Thanks for all good explanation. >> > >> > >> > On Tue, Jul 9, 2013 at 11:24 PM, Sebastian Huber >> > <sebastian.hu...@embedded-brains.de> wrote: >> >> >> >> On 07/09/2013 05:29 AM, Ashi wrote: >> >>> >> >>> Hi, Sebastian, thanks for your review! >> >>> >> >>> 在 2013-7-7 下午9:49，"Sebastian Huber" >> >>> <sebastian.hu...@embedded-brains.de >> >>> <mailto:sebastian.hu...@embedded-brains.de>>写道： >> >>> >> >>> > >> >>> > Hello Ashi, >> >>> > >> >>> > >> >>> > On 06/07/13 09:17, Ashi wrote: >> >>> >> >> >>> >> Hi all, >> >>> >> >> >>> >> this patch adds a data structure called freelist to score, there >> >>> are >> >>> no >> >>> >> test cases yet and should be added later. >> >>> > >> >>> > >> >>> > I would appreciate to have the test for this new stuff included in >> >>> the >> >>> patch. >> >>> >> >>> >> >>> sure, I will update the patch with test cases. >> >>> > >> >>> > >> >>> >> >> >>> >> Freelist is a structure, which contains a chain of nodes. It >> >>> supports >> >>> 2 >> >>> >> operation: >> >>> >> - get node from freelist >> >>> >> - put node to freelist. >> >>> >> And when there is no enough node in freelist, it will >> >>> automatically >> >>> >> increase itself's size by allocate more nodes from heap or >> >>> workspace(which >> >>> >> is specified by user). >> >>> > >> >>> > >> >>> > What can I do if I like to get the nodes from a magic space? >> >>> >> >>> >> >>> sorry for the unclear, you can get nodes from freelist by 'get' >> >>> operation. And >> >>> if you mean get nodes from heap or workspace, it's done by >> >>> _Freelist_Get_node(), which calls _Freelist_Bump() when there is no >> >>> free >> >>> node left. >> >> >> >> >> >> Yes, the problem is that you limit your Freelist to the heap and >> >> workspace. If you use a handler function (or virtual method if you >> >> like) >> >> then you can avoid this limitation. >> >> >> >> [...] >> >> >> >>> >> +/** >> >>> >> + * @typedef freelist_callout >> >>> >> + */ >> >>> >> +typedef void (*freelist_callout)( >> >>> >> + Freelist_Control *fc, >> >>> >> + void *nodes >> >>> >> +); >> >>> >> + >> >>> >> +/** >> >>> >> + * @typedef Freelist_Control_struct >> >>> >> + * >> >>> >> + * This is used to manage each element. >> >>> >> + */ >> >>> >> +struct Freelist_Control_struct { >> >>> >> + Chain_Control Freelist; >> >>> >> + size_t free_count; >> >>> > >> >>> > >> >>> > Why do we need the free_count? >> >>> >> >>> free_count is used to keep track how many nodes there is in freelist. >> >>> And >> >>> if >> >>> free_count is 0 when you try to get node from freelist by call >> >>> _Freelist_Get_node(), _Freelist_Get_node() will call _Freelist_Bump() >> >>> to >> >>> allocate more node from heap or workspace. >> >> >> >> >> >> The list knows if it is empty. There is not need to store this >> >> information in two ways. >> >> >> >> >> >>> > >> >>> >> + size_t bump_count; >> >>> >> + size_t node_size; >> >>> > >> >>> > >> >>> >> + freelist_callout callout; >> >>> >> + bool use_workspace; >> >>> >> +}; >> >>> > >> >>> > >> >>> > I would replace this with an extend handler. >> >>> > >> >>> > /** >> >>> > * @brief Extends the freelist. >> >>> > * >> >>> > * @param[in] freelist The freelist control. >> >>> > * >> >>> > * @return The count of new nodes. >> >>> > */ >> >>> > typedef size_t ( *Freelist_Extend )( Freelist_Control *freelist ); >> >>> > >> >>> > This is much more flexible since you only specify the interface and >> >>> don't >> >>> limit this to heap/workspace. >> >>> > >> >>> > You can provide a _Freelist_Extend_with_nothing() which simply >> >>> returns >> >>> 0. >> >>> >> >>> Yeah, this Freelist_Extend is very flexible, but I feel the >> >>> Freelist_Extend is >> >>> a little complex. As it shows in _Freelist_Bump(), if users provides >> >>> their own >> >>> extension function, they have to append there new nodes to freelist's >> >>> internal >> >>> chain and call their callout function on new nodes. And since >> >>> _Freelist_Initialize() also would call Freelist_Extend(), if we >> >>> provided >> >>> _Freelist_Extend_with_nothing(), the initialization may fail. >> >> >> >> >> >> Since the Freelist_Extend gets the Freelist as a first argument it can >> >> set >> >> the extend handler to _Freelist_Extend_with_nothing() after the first >> >> invocation. >> >> >> >> Example: >> >> >> >> >> >> /** >> >> * @brief Extends the freelist. >> >> * >> >> * @param[in] freelist The freelist control. >> >> */ >> >> typedef void ( *Freelist_Extend )( Freelist_Control *freelist ); >> >> >> >> typedef struct { >> >> Objects_Control obj; >> >> int x; >> >> } my_obj; >> >> >> >> void my_extend( Freelist_Control *freelist ) >> >> { >> >> size_t bump_count = freelist->bump_count; >> >> size_t size = bump_count * sizeof(my_obj); >> >> my_obj *objs = malloc(size); >> >> >> >> _Freelist_Set_extend_handler( freelist, _Freelist_Extend_with_nothing >> >> ); >> >> _Chain_Initialize( >> >> _Freelist_Get_list( freelist ), >> >> objs, >> >> bump_count, >> >> size >> >> ); >> >> >> >> } >> > >> > I'm a little confused by my_extend() function, is it only called after >> > calling _Freelist_Initialize() by user? >> >> >> >> >> >> [...] >> >> >> >> -- >> >> Sebastian Huber, embedded brains GmbH >> >> >> >> Address : Dornierstr. 4, D-82178 Puchheim, Germany >> >> Phone : +49 89 189 47 41-16 >> >> Fax : +49 89 189 47 41-09 >> >> E-Mail : sebastian.hu...@embedded-brains.de >> >> PGP : Public key available on request. >> >> >> >> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. >> > >> > >> > Cheers, >> > Zhongwei >> > > > _______________________________________________ rtems-devel mailing list rtems-devel@rtems.org http://www.rtems.org/mailman/listinfo/rtems-devel
