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59 lines
1.8 KiB
C
59 lines
1.8 KiB
C
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#ifndef _LINUX_PRIO_HEAP_H
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#define _LINUX_PRIO_HEAP_H
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/*
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* Simple insertion-only static-sized priority heap containing
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* pointers, based on CLR, chapter 7
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*/
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#include <linux/gfp.h>
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/**
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* struct ptr_heap - simple static-sized priority heap
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* @ptrs - pointer to data area
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* @max - max number of elements that can be stored in @ptrs
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* @size - current number of valid elements in @ptrs (in the range 0..@size-1
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* @gt: comparison operator, which should implement "greater than"
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*/
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struct ptr_heap {
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void **ptrs;
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int max;
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int size;
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int (*gt)(void *, void *);
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};
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/**
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* heap_init - initialize an empty heap with a given memory size
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* @heap: the heap structure to be initialized
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* @size: amount of memory to use in bytes
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* @gfp_mask: mask to pass to kmalloc()
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* @gt: comparison operator, which should implement "greater than"
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*/
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extern int heap_init(struct ptr_heap *heap, size_t size, gfp_t gfp_mask,
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int (*gt)(void *, void *));
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/**
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* heap_free - release a heap's storage
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* @heap: the heap structure whose data should be released
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*/
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void heap_free(struct ptr_heap *heap);
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/**
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* heap_insert - insert a value into the heap and return any overflowed value
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* @heap: the heap to be operated on
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* @p: the pointer to be inserted
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*
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* Attempts to insert the given value into the priority heap. If the
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* heap is full prior to the insertion, then the resulting heap will
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* consist of the smallest @max elements of the original heap and the
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* new element; the greatest element will be removed from the heap and
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* returned. Note that the returned element will be the new element
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* (i.e. no change to the heap) if the new element is greater than all
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* elements currently in the heap.
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*/
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extern void *heap_insert(struct ptr_heap *heap, void *p);
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#endif /* _LINUX_PRIO_HEAP_H */
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