Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Simple pointer stack
3 *
4 * (c) 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
5 */
6
7#include "util.h"
8#include "pstack.h"
9#include <linux/kernel.h>
10#include <stdlib.h>
11
12struct pstack {
13 unsigned short top;
14 unsigned short max_nr_entries;
15 void *entries[0];
16};
17
18struct pstack *pstack__new(unsigned short max_nr_entries)
19{
20 struct pstack *self = zalloc((sizeof(*self) +
21 max_nr_entries * sizeof(void *)));
22 if (self != NULL)
23 self->max_nr_entries = max_nr_entries;
24 return self;
25}
26
27void pstack__delete(struct pstack *self)
28{
29 free(self);
30}
31
32bool pstack__empty(const struct pstack *self)
33{
34 return self->top == 0;
35}
36
37void pstack__remove(struct pstack *self, void *key)
38{
39 unsigned short i = self->top, last_index = self->top - 1;
40
41 while (i-- != 0) {
42 if (self->entries[i] == key) {
43 if (i < last_index)
44 memmove(self->entries + i,
45 self->entries + i + 1,
46 (last_index - i) * sizeof(void *));
47 --self->top;
48 return;
49 }
50 }
51 pr_err("%s: %p not on the pstack!\n", __func__, key);
52}
53
54void pstack__push(struct pstack *self, void *key)
55{
56 if (self->top == self->max_nr_entries) {
57 pr_err("%s: top=%d, overflow!\n", __func__, self->top);
58 return;
59 }
60 self->entries[self->top++] = key;
61}
62
63void *pstack__pop(struct pstack *self)
64{
65 void *ret;
66
67 if (self->top == 0) {
68 pr_err("%s: underflow!\n", __func__);
69 return NULL;
70 }
71
72 ret = self->entries[--self->top];
73 self->entries[self->top] = NULL;
74 return ret;
75}