xref: /linux/tools/lib/api/fd/array.c (revision 7340c6df49df1b261892d287444c255d0a378063)
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 
13 void 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 
21 int 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 
47 struct 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 
63 void fdarray__exit(struct fdarray *fda)
64 {
65 	free(fda->entries);
66 	free(fda->priv);
67 	fdarray__init(fda, 0);
68 }
69 
70 void fdarray__delete(struct fdarray *fda)
71 {
72 	fdarray__exit(fda);
73 	free(fda);
74 }
75 
76 int 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 
91 int fdarray__dup_entry_from(struct fdarray *fda, int pos, struct fdarray *from)
92 {
93 	struct pollfd *entry;
94 	int npos;
95 
96 	if (pos >= from->nr)
97 		return -EINVAL;
98 
99 	entry = &from->entries[pos];
100 
101 	npos = fdarray__add(fda, entry->fd, entry->events, from->priv[pos].flags);
102 	if (npos >= 0)
103 		fda->priv[npos] = from->priv[pos];
104 
105 	return npos;
106 }
107 
108 int fdarray__filter(struct fdarray *fda, short revents,
109 		    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
110 		    void *arg)
111 {
112 	int fd, nr = 0;
113 
114 	if (fda->nr == 0)
115 		return 0;
116 
117 	for (fd = 0; fd < fda->nr; ++fd) {
118 		if (!fda->entries[fd].events)
119 			continue;
120 
121 		if (fda->entries[fd].revents & revents) {
122 			if (entry_destructor)
123 				entry_destructor(fda, fd, arg);
124 
125 			fda->entries[fd].revents = fda->entries[fd].events = 0;
126 			continue;
127 		}
128 
129 		if (!(fda->priv[fd].flags & fdarray_flag__nonfilterable))
130 			++nr;
131 	}
132 
133 	return nr;
134 }
135 
136 int fdarray__poll(struct fdarray *fda, int timeout)
137 {
138 	return poll(fda->entries, fda->nr, timeout);
139 }
140 
141 int fdarray__fprintf(struct fdarray *fda, FILE *fp)
142 {
143 	int fd, printed = fprintf(fp, "%d [ ", fda->nr);
144 
145 	for (fd = 0; fd < fda->nr; ++fd)
146 		printed += fprintf(fp, "%s%d", fd ? ", " : "", fda->entries[fd].fd);
147 
148 	return printed + fprintf(fp, " ]");
149 }
150