1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <stdlib.h>
18#include <unistd.h>
19
20#include <pagemap/pagemap.h>
21
22#define SIMPLEQ_INSERT_SIMPLEQ_TAIL(head_a, head_b)             \
23    do {                                                        \
24        if (!SIMPLEQ_EMPTY(head_b)) {                           \
25            if ((head_a)->sqh_first == NULL)                    \
26                (head_a)->sqh_first = (head_b)->sqh_first;      \
27            *(head_a)->sqh_last = (head_b)->sqh_first;          \
28            (head_a)->sqh_last = (head_b)->sqh_last;            \
29        }                                                       \
30    } while (/*CONSTCOND*/0)
31
32/* We use an array of int to store the references to a given offset in the swap
33   1 GiB swap means 512KiB size array: offset are the index */
34typedef unsigned short pm_pswap_refcount_t;
35struct pm_proportional_swap {
36    unsigned int array_size;
37    pm_pswap_refcount_t *offset_array;
38};
39
40void pm_memusage_zero(pm_memusage_t *mu) {
41    mu->vss = mu->rss = mu->pss = mu->uss = mu->swap = 0;
42    mu->p_swap = NULL;
43    SIMPLEQ_INIT(&mu->swap_offset_list);
44}
45
46void pm_memusage_pswap_init_handle(pm_memusage_t *mu, pm_proportional_swap_t *p_swap) {
47    mu->p_swap = p_swap;
48}
49
50void pm_memusage_add(pm_memusage_t *a, pm_memusage_t *b) {
51    a->vss += b->vss;
52    a->rss += b->rss;
53    a->pss += b->pss;
54    a->uss += b->uss;
55    a->swap += b->swap;
56    SIMPLEQ_INSERT_SIMPLEQ_TAIL(&a->swap_offset_list, &b->swap_offset_list);
57}
58
59pm_proportional_swap_t * pm_memusage_pswap_create(int swap_size)
60{
61    pm_proportional_swap_t *p_swap = NULL;
62
63    p_swap = malloc(sizeof(pm_proportional_swap_t));
64    if (p_swap == NULL) {
65        fprintf(stderr, "Error allocating proportional swap.\n");
66    } else {
67        p_swap->array_size = swap_size / getpagesize();
68        p_swap->offset_array = calloc(p_swap->array_size, sizeof(pm_pswap_refcount_t));
69        if (p_swap->offset_array == NULL) {
70            fprintf(stderr, "Error allocating proportional swap offset array.\n");
71            free(p_swap);
72            p_swap = NULL;
73        }
74    }
75
76    return p_swap;
77}
78
79void pm_memusage_pswap_destroy(pm_proportional_swap_t *p_swap) {
80    if (p_swap) {
81        free(p_swap->offset_array);
82        free(p_swap);
83    }
84}
85
86void pm_memusage_pswap_add_offset(pm_memusage_t *mu, unsigned int offset) {
87    pm_swap_offset_t *soff;
88
89    if (mu->p_swap == NULL)
90        return;
91
92    if (offset >= mu->p_swap->array_size) {
93        fprintf(stderr, "SWAP offset %d is out of swap bounds.\n", offset);
94        return;
95    }
96
97    if (mu->p_swap->offset_array[offset] == USHRT_MAX) {
98        fprintf(stderr, "SWAP offset %d ref. count if overflowing ushort type.\n", offset);
99    } else {
100        mu->p_swap->offset_array[offset]++;
101    }
102
103    soff = malloc(sizeof(pm_swap_offset_t));
104    if (soff) {
105        soff->offset = offset;
106        SIMPLEQ_INSERT_TAIL(&mu->swap_offset_list, soff, simpleqe);
107    }
108}
109
110void pm_memusage_pswap_get_usage(pm_memusage_t *mu, pm_swapusage_t *su) {
111
112    int pagesize = getpagesize();
113    pm_swap_offset_t *elem;
114
115    if (su == NULL)
116        return;
117
118    su->proportional = su->unique = 0;
119    SIMPLEQ_FOREACH(elem, &mu->swap_offset_list, simpleqe) {
120        su->proportional += pagesize / mu->p_swap->offset_array[elem->offset];
121        su->unique += mu->p_swap->offset_array[elem->offset] == 1 ? pagesize : 0;
122    }
123}
124
125void pm_memusage_pswap_free(pm_memusage_t *mu) {
126    pm_swap_offset_t *elem = SIMPLEQ_FIRST(&mu->swap_offset_list);
127    while (elem) {
128        SIMPLEQ_REMOVE_HEAD(&mu->swap_offset_list, simpleqe);
129        free(elem);
130        elem = SIMPLEQ_FIRST(&mu->swap_offset_list);
131    }
132}
133