xref: /kernel/linux/linux-5.10/tools/lib/api/fd/array.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2014, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
4 */
5#include "array.h"
6#include <errno.h>
7#include <fcntl.h>
8#include <poll.h>
9#include <stdlib.h>
10#include <unistd.h>
11#include <string.h>
12
13void fdarray__init(struct fdarray *fda, int nr_autogrow)
14{
15	fda->entries	 = NULL;
16	fda->priv	 = NULL;
17	fda->nr		 = fda->nr_alloc = 0;
18	fda->nr_autogrow = nr_autogrow;
19}
20
21int fdarray__grow(struct fdarray *fda, int nr)
22{
23	struct priv *priv;
24	int nr_alloc = fda->nr_alloc + nr;
25	size_t psize = sizeof(fda->priv[0]) * nr_alloc;
26	size_t size  = sizeof(struct pollfd) * nr_alloc;
27	struct pollfd *entries = realloc(fda->entries, size);
28
29	if (entries == NULL)
30		return -ENOMEM;
31
32	priv = realloc(fda->priv, psize);
33	if (priv == NULL) {
34		free(entries);
35		return -ENOMEM;
36	}
37
38	memset(&entries[fda->nr_alloc], 0, sizeof(struct pollfd) * nr);
39	memset(&priv[fda->nr_alloc], 0, sizeof(fda->priv[0]) * nr);
40
41	fda->nr_alloc = nr_alloc;
42	fda->entries  = entries;
43	fda->priv     = priv;
44	return 0;
45}
46
47struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow)
48{
49	struct fdarray *fda = calloc(1, sizeof(*fda));
50
51	if (fda != NULL) {
52		if (fdarray__grow(fda, nr_alloc)) {
53			free(fda);
54			fda = NULL;
55		} else {
56			fda->nr_autogrow = nr_autogrow;
57		}
58	}
59
60	return fda;
61}
62
63void fdarray__exit(struct fdarray *fda)
64{
65	free(fda->entries);
66	free(fda->priv);
67	fdarray__init(fda, 0);
68}
69
70void fdarray__delete(struct fdarray *fda)
71{
72	fdarray__exit(fda);
73	free(fda);
74}
75
76int fdarray__add(struct fdarray *fda, int fd, short revents, enum fdarray_flags flags)
77{
78	int pos = fda->nr;
79
80	if (fda->nr == fda->nr_alloc &&
81	    fdarray__grow(fda, fda->nr_autogrow) < 0)
82		return -ENOMEM;
83
84	fda->entries[fda->nr].fd     = fd;
85	fda->entries[fda->nr].events = revents;
86	fda->priv[fda->nr].flags = flags;
87	fda->nr++;
88	return pos;
89}
90
91int fdarray__filter(struct fdarray *fda, short revents,
92		    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
93		    void *arg)
94{
95	int fd, nr = 0;
96
97	if (fda->nr == 0)
98		return 0;
99
100	for (fd = 0; fd < fda->nr; ++fd) {
101		if (!fda->entries[fd].events)
102			continue;
103
104		if (fda->entries[fd].revents & revents) {
105			if (entry_destructor)
106				entry_destructor(fda, fd, arg);
107
108			fda->entries[fd].revents = fda->entries[fd].events = 0;
109			continue;
110		}
111
112		if (!(fda->priv[fd].flags & fdarray_flag__nonfilterable))
113			++nr;
114	}
115
116	return nr;
117}
118
119int fdarray__poll(struct fdarray *fda, int timeout)
120{
121	return poll(fda->entries, fda->nr, timeout);
122}
123
124int fdarray__fprintf(struct fdarray *fda, FILE *fp)
125{
126	int fd, printed = fprintf(fp, "%d [ ", fda->nr);
127
128	for (fd = 0; fd < fda->nr; ++fd)
129		printed += fprintf(fp, "%s%d", fd ? ", " : "", fda->entries[fd].fd);
130
131	return printed + fprintf(fp, " ]");
132}
133