76 lines
1.4 KiB
C
76 lines
1.4 KiB
C
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/*
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* Simple pointer stack
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*
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* (c) 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
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*/
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#include "util.h"
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#include "pstack.h"
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#include <linux/kernel.h>
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#include <stdlib.h>
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struct pstack {
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unsigned short top;
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unsigned short max_nr_entries;
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void *entries[0];
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};
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struct pstack *pstack__new(unsigned short max_nr_entries)
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{
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struct pstack *self = zalloc((sizeof(*self) +
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max_nr_entries * sizeof(void *)));
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if (self != NULL)
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self->max_nr_entries = max_nr_entries;
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return self;
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}
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void pstack__delete(struct pstack *self)
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{
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free(self);
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}
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bool pstack__empty(const struct pstack *self)
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{
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return self->top == 0;
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}
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void pstack__remove(struct pstack *self, void *key)
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{
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unsigned short i = self->top, last_index = self->top - 1;
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while (i-- != 0) {
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if (self->entries[i] == key) {
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if (i < last_index)
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memmove(self->entries + i,
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self->entries + i + 1,
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(last_index - i) * sizeof(void *));
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--self->top;
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return;
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}
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}
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pr_err("%s: %p not on the pstack!\n", __func__, key);
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}
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void pstack__push(struct pstack *self, void *key)
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{
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if (self->top == self->max_nr_entries) {
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pr_err("%s: top=%d, overflow!\n", __func__, self->top);
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return;
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}
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self->entries[self->top++] = key;
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}
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void *pstack__pop(struct pstack *self)
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{
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void *ret;
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if (self->top == 0) {
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pr_err("%s: underflow!\n", __func__);
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return NULL;
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}
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ret = self->entries[--self->top];
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self->entries[self->top] = NULL;
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return ret;
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}
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