Posix Shared memory with linked list
in [Unix Programming]
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From: Bin Chen on 27 Feb 2007 07:09 On 2ÔÂ27ÈÕ, ÉÏÎç12ʱ03·Ö, "queengambit" <cbp...(a)cs.york.ac.uk> wrote: > I'm sorry but i can't think of even a simple way to implement my own > allocator & deallocator working on shared memory with items in the > linked list are of the same size sizeof(struct my_ringnode_st). Use an array to do the management, you can refer to: https://gro.clinux.org/scm/cvsweb.php/%7echeckout%7e/Lingix/mm/memory.c?rev=1.3&contenttype=text/plain&cvsroot=lingix > > I thought of defining a new struct with two arrays, one for holding > offset in shared memory of each item of the linked list and the other > for the actual items. The problem with this approach is how to keep > track of free slots in the second array so that new item can be > allocated as any item can be removed from the linked list. > > struct my_shm{ > long ringnode_off[PTHREAD_THREADS_MAX]; > my_ringnode_t ringnodes_array[PTHREAD_THREADS_MAX*sizeof(struct > my_ringnode_st)]} > > Please advise me on how to implement the allocator/deallocator for my > shared memory of linked list. > > Thank you
From: Bin Chen on 27 Feb 2007 07:12
On 2ÔÂ27ÈÕ, ÏÂÎç8ʱ09·Ö, "Bin Chen" <binary.c...(a)gmail.com> wrote: > On 2ÔÂ27ÈÕ, ÉÏÎç12ʱ03·Ö, "queengambit" <cbp...(a)cs.york.ac.uk> wrote: > > > I'm sorry but i can't think of even a simple way to implement my own > > allocator & deallocator working on shared memory with items in the > > linked list are of the same size sizeof(struct my_ringnode_st). > > Use an array to do the management, you can refer to: > > https://gro.clinux.org/scm/cvsweb.php/%7echeckout%7e/Lingix/mm/memory... > BTW: This is done when I was a college student and have many defects, just for illustration purpose, don't laugh at it. > > > > I thought of defining a new struct with two arrays, one for holding > > offset in shared memory of each item of the linked list and the other > > for the actual items. The problem with this approach is how to keep > > track of free slots in the second array so that new item can be > > allocated as any item can be removed from the linked list. > > > struct my_shm{ > > long ringnode_off[PTHREAD_THREADS_MAX]; > > my_ringnode_t ringnodes_array[PTHREAD_THREADS_MAX*sizeof(struct > > my_ringnode_st)]} > > > Please advise me on how to implement the allocator/deallocator for my > > shared memory of linked list. > > > Thank you |