mirror of
https://github.com/ddnet/ddnet.git
synced 2024-09-20 09:34:19 +00:00
reworked the ringbuffer. should work like it should now.
This commit is contained in:
Magnus Auvinen
parent
03f6d24ba1
commit
07fc7ec8f8
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@ -2,33 +2,29 @@
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#include "e_ringbuffer.h"
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enum
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typedef struct RBITEM
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{
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RBFLAG_FREE=1
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};
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struct RBITEM *prev;
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struct RBITEM *next;
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int free;
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int size;
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} RBITEM;
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/*
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*/
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struct RINGBUFFER
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{
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struct RBITEM_t *next_alloc;
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struct RBITEM_t *last_alloc;
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struct RBITEM_t *first;
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struct RBITEM_t *last;
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RBITEM *produce;
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RBITEM *consume;
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RBITEM *first;
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RBITEM *last;
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void *memory;
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int size;
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int flags;
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};
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typedef struct RBITEM_t
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{
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struct RBITEM_t *prev;
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struct RBITEM_t *next;
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int flags;
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int size;
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} RBITEM;
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RINGBUFFER *ringbuf_init(void *memory, int size, int flags)
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{
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RINGBUFFER *rb = (RINGBUFFER *)memory;
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@ -37,115 +33,80 @@ RINGBUFFER *ringbuf_init(void *memory, int size, int flags)
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rb->memory = rb+1;
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rb->size = (size-sizeof(RINGBUFFER))/sizeof(RBITEM)*sizeof(RBITEM);
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rb->first = (RBITEM *)rb->memory;
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rb->first->flags = RBFLAG_FREE;
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rb->first->free = 1;
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rb->first->size = rb->size;
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rb->last = rb->first;
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rb->next_alloc = rb->first;
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rb->produce = rb->first;
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rb->consume = rb->first;
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rb->flags = flags;
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return rb;
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}
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static RBITEM *ringbuf_free(RINGBUFFER *rb, RBITEM *item)
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static RBITEM *ringbuf_nextblock(RINGBUFFER *rb, RBITEM *item)
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{
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dbg_assert(!(item->flags&RBFLAG_FREE), "trying to free element that is already freed");
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item->flags |= RBFLAG_FREE;
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/* TODO: this should be handled better */
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if(item == rb->last_alloc)
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rb->last_alloc = 0;
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/* merge with all free items backwards */
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while(item->prev && (item->prev->flags&RBFLAG_FREE))
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{
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item->prev->size += item->size;
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item->prev->next = item->next;
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item = item->prev;
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if(item->next)
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item->next->prev = item;
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}
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/* merge with all free items forwards */
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while(item->next && (item->next->flags&RBFLAG_FREE))
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{
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item->size += item->next->size;
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item->next = item->next->next;
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if(item->next)
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item->next->prev = item;
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}
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if(!item->next)
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rb->last = item;
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return item;
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if(item->next)
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return item->next;
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return rb->first;
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}
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void ringbuf_validate(RINGBUFFER *rb)
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static RBITEM *ringbuf_prevblock(RINGBUFFER *rb, RBITEM *item)
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{
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RBITEM *prev = 0;
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RBITEM *cur = rb->first;
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int freechunks = 0;
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while(cur)
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{
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if(cur->flags&RBFLAG_FREE)
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freechunks++;
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dbg_assert(freechunks <= 2, "too many free chunks");
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dbg_assert(cur->prev == prev, "pointers doesn't match");
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dbg_assert(!prev || prev->next == cur, "pointers doesn't match");
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dbg_assert(cur->next || cur == rb->last, "last isn't last");
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prev = cur;
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cur = cur->next;
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}
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if(item->prev)
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return item->prev;
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return rb->last;
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}
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static RBITEM *ringbuf_try_allocate(RINGBUFFER *rb, int wanted_size)
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static RBITEM *ringbuf_mergeback(RINGBUFFER *rb, RBITEM *item)
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{
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RBITEM *item = rb->next_alloc;
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/* check for space */
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if(!(item->flags&RBFLAG_FREE) || item->size < wanted_size)
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return 0x0;
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/* split the block if needed */
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if(item->size > wanted_size)
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{
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RBITEM *new_item = (RBITEM *)((char *)item + wanted_size);
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new_item->prev = item;
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new_item->next = item->next;
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if(new_item->next)
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new_item->next->prev = new_item;
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item->next = new_item;
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new_item->flags = RBFLAG_FREE;
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new_item->size = item->size - wanted_size;
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item->size = wanted_size;
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if(!new_item->next)
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rb->last = new_item;
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}
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item->flags &= ~RBFLAG_FREE;
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rb->next_alloc = item->next;
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if(!rb->next_alloc)
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rb->next_alloc = rb->first;
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rb->last_alloc = item;
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return item;
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}
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/* make sure that this block and previous block is free */
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if(!item->free || !item->prev || !item->prev->free)
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return item;
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void ringbuf_popfirst(RINGBUFFER *rb)
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{
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if(rb->next_alloc->next)
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rb->next_alloc = ringbuf_free(rb, rb->next_alloc->next);
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/* merge the blocks */
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item->prev->size += item->size;
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item->prev->next = item->next;
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/* fixup pointers */
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if(item->next)
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item->next->prev = item->prev;
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else
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rb->last = item->prev;
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if(item == rb->produce)
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rb->produce = item->prev;
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if(item == rb->consume)
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rb->consume = item->prev;
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/* return the current block */
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return item->prev;
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}
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int ringbuf_popfirst(RINGBUFFER *rb)
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{
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if(rb->consume->free)
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return 0;
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/* set the free flag */
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rb->consume->free = 1;
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/* previous block is also free, merge them */
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rb->consume = ringbuf_mergeback(rb, rb->consume);
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/* advance the consume pointer */
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rb->consume = ringbuf_nextblock(rb, rb->consume);
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while(rb->consume->free && rb->consume != rb->produce)
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{
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rb->next_alloc = rb->first;
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rb->next_alloc = ringbuf_free(rb, rb->next_alloc);
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rb->consume = ringbuf_mergeback(rb, rb->consume);
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rb->consume = ringbuf_nextblock(rb, rb->consume);
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}
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/* in the case that we have catched up with the produce pointer */
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/* we might stand on a free block so merge em */
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ringbuf_mergeback(rb, rb->consume);
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return 1;
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}
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void *ringbuf_allocate(RINGBUFFER *rb, int size)
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@ -157,87 +118,245 @@ void *ringbuf_allocate(RINGBUFFER *rb, int size)
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if(wanted_size > rb->size)
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return 0;
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/* free the block if it is in use */
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if(!(rb->next_alloc->flags&RBFLAG_FREE))
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rb->next_alloc = ringbuf_free(rb, rb->next_alloc);
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/* first attempt */
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block = ringbuf_try_allocate(rb, wanted_size);
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if(block)
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return block+1;
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/* check if we just should return null */
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if(!(rb->flags&RINGBUF_FLAG_RECYCLE))
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return 0;
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/* ok, we need to wipe some blocks in order to get space */
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while(1)
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while(1)
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{
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/* pop one */
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ringbuf_popfirst(rb);
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/* try allocate again */
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block = ringbuf_try_allocate(rb, wanted_size);
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/* check for space */
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if(rb->produce->free)
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{
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if(rb->produce->size >= wanted_size)
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block = rb->produce;
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else
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{
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/* wrap around to try to find a block */
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if(rb->first->free && rb->first->size >= wanted_size)
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block = rb->first;
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}
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}
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if(block)
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return block+1;
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break;
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else
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{
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/* we have no block, check our policy and see what todo */
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if(rb->flags&RINGBUF_FLAG_RECYCLE)
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{
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if(!ringbuf_popfirst(rb))
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return 0;
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}
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else
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return 0;
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}
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}
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/* okey, we have our block */
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/* split the block if needed */
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if(block->size > wanted_size)
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{
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RBITEM *new_item = (RBITEM *)((char *)block + wanted_size);
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new_item->prev = block;
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new_item->next = block->next;
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if(new_item->next)
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new_item->next->prev = new_item;
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block->next = new_item;
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new_item->free = 1;
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new_item->size = block->size - wanted_size;
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block->size = wanted_size;
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if(!new_item->next)
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rb->last = new_item;
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}
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/* set next block */
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rb->produce = ringbuf_nextblock(rb, block);
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/* set as used and return the item pointer */
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block->free = 0;
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return block+1;
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}
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void *ringbuf_prev(RINGBUFFER *rb, void *current)
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{
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RBITEM *item = ((RBITEM *)current) - 1;
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while(1)
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{
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/* back up one step */
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item = item->prev;
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if(!item)
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item = rb->last;
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/* we have gone around */
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if(item == rb->last_alloc)
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item = ringbuf_prevblock(rb, item);
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if(item == rb->produce)
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return 0;
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if(!(item->flags&RBFLAG_FREE))
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if(!item->free)
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return item+1;
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}
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}
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void *ringbuf_next(RINGBUFFER *rb, void *current)
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{
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RBITEM *item = ((RBITEM *)current) - 1;
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/* we have gone around */
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if(item == rb->last_alloc)
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return 0;
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while(1)
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{
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/* back up one step */
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item = item->next;
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if(!item)
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item = rb->first;
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if(!(item->flags&RBFLAG_FREE))
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item = ringbuf_nextblock(rb, item);
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if(item == rb->produce)
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return 0;
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if(!item->free)
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return item+1;
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}
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}
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void *ringbuf_item_ptr(void *p)
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{
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return ((RBITEM *)p) - 1;
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}
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void *ringbuf_first(RINGBUFFER *rb)
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{
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if(rb->last_alloc && rb->last_alloc->next)
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return ringbuf_next(rb, rb->last_alloc->next+1);
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return 0x0;
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if(rb->consume->free)
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return 0;
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return rb->consume+1;
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}
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void *ringbuf_last(RINGBUFFER *rb)
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{
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if(rb->last_alloc == 0)
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return 0;
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return rb->last_alloc+1;
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if(!rb->produce->free)
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return rb->produce+1;
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return ringbuf_prev(rb, rb->produce+1);
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}
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/* debugging and testing stuff */
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static void ringbuf_debugdump(RINGBUFFER *rb, const char *msg)
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{
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RBITEM *cur = rb->first;
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dbg_msg("ringbuf", "-- dumping --");
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while(cur)
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{
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char flags[4] = " ";
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if(cur->free)
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flags[0] = 'F';
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if(cur == rb->consume)
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flags[1] = '>';
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if(cur == rb->produce)
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flags[2] = '<';
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dbg_msg("ringbuf", "%s %d", flags, cur->size);
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cur = cur->next;
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}
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dbg_msg("ringbuf", "-- --");
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if(msg)
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dbg_assert(0, msg);
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}
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static void ringbuf_validate(RINGBUFFER *rb)
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{
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RBITEM *prev = 0;
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RBITEM *cur = rb->first;
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int freechunks = 0;
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int got_consume = 0;
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int got_produce = 0;
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while(cur)
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{
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if(cur->free)
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freechunks++;
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if(freechunks > 2) ringbuf_debugdump(rb, "too many free chunks");
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if(prev && prev->free && cur->free) ringbuf_debugdump(rb, "two free chunks next to each other");
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if(cur == rb->consume) got_consume = 1;
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if(cur == rb->produce) got_produce = 1;
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dbg_assert(cur->prev == prev, "prev pointers doesn't match");
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dbg_assert(!prev || prev->next == cur, "next pointers doesn't match");
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dbg_assert(cur->next || cur == rb->last, "last isn't last");
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prev = cur;
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cur = cur->next;
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}
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if(!got_consume) ringbuf_debugdump(rb, "consume pointer isn't pointing at a valid block");
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if(!got_produce) ringbuf_debugdump(rb, "produce pointer isn't pointing at a valid block");
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}
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int ringbuf_test()
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{
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char buffer[256];
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RINGBUFFER *rb;
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int i, s, k, m;
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int count;
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int testcount = 0;
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void *item;
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int before;
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for(k = 100; k < sizeof(buffer); k++)
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{
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if((k%10) == 0)
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dbg_msg("ringbuf", "testing at %d", k);
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rb = ringbuf_init(buffer, k, 0);
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count = 0;
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for(s = 1; s < sizeof(buffer); s++)
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{
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for(i = 0; i < k*8; i++, testcount++)
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{
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for(m = 0, item = ringbuf_first(rb); item; item = ringbuf_next(rb, item), m++);
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before = m;
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if(ringbuf_allocate(rb, s))
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{
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count++;
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for(m = 0, item = ringbuf_first(rb); item; item = ringbuf_next(rb, item), m++);
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if(before+1 != m) ringbuf_debugdump(rb, "alloc error");
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if(count != m) ringbuf_debugdump(rb, "count error");
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}
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else
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{
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if(ringbuf_popfirst(rb))
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{
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count--;
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for(m = 0, item = ringbuf_first(rb); item; item = ringbuf_next(rb, item), m++);
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if(before-1 != m) dbg_msg("", "popping error %d %d", before, m);
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if(count != m) ringbuf_debugdump(rb, "count error");
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}
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}
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/* remove an item every 10 */
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if((i%10) == 0)
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{
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for(m = 0, item = ringbuf_first(rb); item; item = ringbuf_next(rb, item), m++);
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before = m;
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if(ringbuf_popfirst(rb))
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{
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count--;
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for(m = 0, item = ringbuf_first(rb); item; item = ringbuf_next(rb, item), m++);
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if(before-1 != m) dbg_msg("", "popping error %d %d", before, m);
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dbg_assert(count == m, "count error");
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}
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}
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/* count items */
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for(m = 0, item = ringbuf_first(rb); item; item = ringbuf_next(rb, item), m++);
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if(m != count) ringbuf_debugdump(rb, "wrong number of items during forward count");
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for(m = 0, item = ringbuf_last(rb); item; item = ringbuf_prev(rb, item), m++);
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if(m != count) ringbuf_debugdump(rb, "wrong number of items during backward count");
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ringbuf_validate(rb);
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}
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/* empty the ring buffer */
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while(ringbuf_first(rb))
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ringbuf_popfirst(rb);
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ringbuf_validate(rb);
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count = 0;
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}
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}
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return 0;
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}
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@ -12,15 +12,12 @@ enum
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RINGBUFFER *ringbuf_init(void *memory, int size, int flags);
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void ringbuf_clear(RINGBUFFER *rb);
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||||
void *ringbuf_allocate(RINGBUFFER *rb, int size);
|
||||
void ringbuf_validate(RINGBUFFER *rb);
|
||||
|
||||
void *ringbuf_item_ptr(void *p);
|
||||
|
||||
void *ringbuf_prev(RINGBUFFER *rb, void *current);
|
||||
void *ringbuf_next(RINGBUFFER *rb, void *current);
|
||||
void *ringbuf_first(RINGBUFFER *rb);
|
||||
void *ringbuf_last(RINGBUFFER *rb);
|
||||
|
||||
void ringbuf_popfirst(RINGBUFFER *rb);
|
||||
int ringbuf_popfirst(RINGBUFFER *rb);
|
||||
|
||||
#endif
|
||||
|
|
|
|||
Loading…
Reference in a new issue