1 /*
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14  *       derived from this software without specific prior written permission.
15  *
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26  */
27 
28 #ifndef UPB_INT_H_
29 #define UPB_INT_H_
30 
31 #include "upb/upb.h"
32 
33 struct mem_block;
34 typedef struct mem_block mem_block;
35 
36 struct upb_arena {
37   _upb_arena_head head;
38   /* Stores cleanup metadata for this arena.
39    * - a pointer to the current cleanup counter.
40    * - a boolean indicating if there is an unowned initial block.  */
41   uintptr_t cleanup_metadata;
42 
43   /* Allocator to allocate arena blocks.  We are responsible for freeing these
44    * when we are destroyed. */
45   upb_alloc *block_alloc;
46   uint32_t last_size;
47 
48   /* When multiple arenas are fused together, each arena points to a parent
49    * arena (root points to itself). The root tracks how many live arenas
50    * reference it. */
51   uint32_t refcount;  /* Only used when a->parent == a */
52   struct upb_arena *parent;
53 
54   /* Linked list of blocks to free/cleanup. */
55   mem_block *freelist, *freelist_tail;
56 };
57 
58 #endif  /* UPB_INT_H_ */
59