xref: /openbmc/linux/tools/lib/api/fd/array.c (revision a44e4f3a)
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 
12 void fdarray__init(struct fdarray *fda, int nr_autogrow)
13 {
14 	fda->entries	 = NULL;
15 	fda->priv	 = NULL;
16 	fda->nr		 = fda->nr_alloc = 0;
17 	fda->nr_autogrow = nr_autogrow;
18 }
19 
20 int fdarray__grow(struct fdarray *fda, int nr)
21 {
22 	void *priv;
23 	int nr_alloc = fda->nr_alloc + nr;
24 	size_t psize = sizeof(fda->priv[0]) * nr_alloc;
25 	size_t size  = sizeof(struct pollfd) * nr_alloc;
26 	struct pollfd *entries = realloc(fda->entries, size);
27 
28 	if (entries == NULL)
29 		return -ENOMEM;
30 
31 	priv = realloc(fda->priv, psize);
32 	if (priv == NULL) {
33 		free(entries);
34 		return -ENOMEM;
35 	}
36 
37 	fda->nr_alloc = nr_alloc;
38 	fda->entries  = entries;
39 	fda->priv     = priv;
40 	return 0;
41 }
42 
43 struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow)
44 {
45 	struct fdarray *fda = calloc(1, sizeof(*fda));
46 
47 	if (fda != NULL) {
48 		if (fdarray__grow(fda, nr_alloc)) {
49 			free(fda);
50 			fda = NULL;
51 		} else {
52 			fda->nr_autogrow = nr_autogrow;
53 		}
54 	}
55 
56 	return fda;
57 }
58 
59 void fdarray__exit(struct fdarray *fda)
60 {
61 	free(fda->entries);
62 	free(fda->priv);
63 	fdarray__init(fda, 0);
64 }
65 
66 void fdarray__delete(struct fdarray *fda)
67 {
68 	fdarray__exit(fda);
69 	free(fda);
70 }
71 
72 int fdarray__add(struct fdarray *fda, int fd, short revents)
73 {
74 	int pos = fda->nr;
75 
76 	if (fda->nr == fda->nr_alloc &&
77 	    fdarray__grow(fda, fda->nr_autogrow) < 0)
78 		return -ENOMEM;
79 
80 	fda->entries[fda->nr].fd     = fd;
81 	fda->entries[fda->nr].events = revents;
82 	fda->nr++;
83 	return pos;
84 }
85 
86 int fdarray__filter(struct fdarray *fda, short revents,
87 		    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
88 		    void *arg)
89 {
90 	int fd, nr = 0;
91 
92 	if (fda->nr == 0)
93 		return 0;
94 
95 	for (fd = 0; fd < fda->nr; ++fd) {
96 		if (fda->entries[fd].revents & revents) {
97 			if (entry_destructor)
98 				entry_destructor(fda, fd, arg);
99 
100 			continue;
101 		}
102 
103 		if (fd != nr) {
104 			fda->entries[nr] = fda->entries[fd];
105 			fda->priv[nr]	 = fda->priv[fd];
106 		}
107 
108 		++nr;
109 	}
110 
111 	return fda->nr = nr;
112 }
113 
114 int fdarray__poll(struct fdarray *fda, int timeout)
115 {
116 	return poll(fda->entries, fda->nr, timeout);
117 }
118 
119 int fdarray__fprintf(struct fdarray *fda, FILE *fp)
120 {
121 	int fd, printed = fprintf(fp, "%d [ ", fda->nr);
122 
123 	for (fd = 0; fd < fda->nr; ++fd)
124 		printed += fprintf(fp, "%s%d", fd ? ", " : "", fda->entries[fd].fd);
125 
126 	return printed + fprintf(fp, " ]");
127 }
128