1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Simple pointer stack
 4 *
 5 * (c) 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
 6 */
 7
 
 8#include "pstack.h"
 9#include "debug.h"
10#include <linux/kernel.h>
11#include <linux/zalloc.h>
12#include <stdlib.h>
13#include <string.h>
14
15struct pstack {
16	unsigned short	top;
17	unsigned short	max_nr_entries;
18	void		*entries[0];
19};
20
21struct pstack *pstack__new(unsigned short max_nr_entries)
22{
23	struct pstack *pstack = zalloc((sizeof(*pstack) +
24				       max_nr_entries * sizeof(void *)));
25	if (pstack != NULL)
26		pstack->max_nr_entries = max_nr_entries;
27	return pstack;
28}
29
30void pstack__delete(struct pstack *pstack)
31{
32	free(pstack);
33}
34
35bool pstack__empty(const struct pstack *pstack)
36{
37	return pstack->top == 0;
38}
39
40void pstack__remove(struct pstack *pstack, void *key)
41{
42	unsigned short i = pstack->top, last_index = pstack->top - 1;
43
44	while (i-- != 0) {
45		if (pstack->entries[i] == key) {
46			if (i < last_index)
47				memmove(pstack->entries + i,
48					pstack->entries + i + 1,
49					(last_index - i) * sizeof(void *));
50			--pstack->top;
51			return;
52		}
53	}
54	pr_err("%s: %p not on the pstack!\n", __func__, key);
55}
56
57void pstack__push(struct pstack *pstack, void *key)
58{
59	if (pstack->top == pstack->max_nr_entries) {
60		pr_err("%s: top=%d, overflow!\n", __func__, pstack->top);
61		return;
62	}
63	pstack->entries[pstack->top++] = key;
64}
65
66void *pstack__pop(struct pstack *pstack)
67{
68	void *ret;
69
70	if (pstack->top == 0) {
71		pr_err("%s: underflow!\n", __func__);
72		return NULL;
73	}
74
75	ret = pstack->entries[--pstack->top];
76	pstack->entries[pstack->top] = NULL;
77	return ret;
78}
79
80void *pstack__peek(struct pstack *pstack)
81{
82	if (pstack->top == 0)
83		return NULL;
84	return pstack->entries[pstack->top - 1];
85}

 
 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}