xref: /openbmc/linux/tools/lib/api/fd/array.c (revision 9cfc5c90)
1 /*
2  * Copyright (C) 2014, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
3  *
4  * Released under the GPL v2. (and only v2, not any later version)
5  */
6 #include "array.h"
7 #include <errno.h>
8 #include <fcntl.h>
9 #include <poll.h>
10 #include <stdlib.h>
11 #include <unistd.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 	void *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 	fda->nr_alloc = nr_alloc;
39 	fda->entries  = entries;
40 	fda->priv     = priv;
41 	return 0;
42 }
43 
44 struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow)
45 {
46 	struct fdarray *fda = calloc(1, sizeof(*fda));
47 
48 	if (fda != NULL) {
49 		if (fdarray__grow(fda, nr_alloc)) {
50 			free(fda);
51 			fda = NULL;
52 		} else {
53 			fda->nr_autogrow = nr_autogrow;
54 		}
55 	}
56 
57 	return fda;
58 }
59 
60 void fdarray__exit(struct fdarray *fda)
61 {
62 	free(fda->entries);
63 	free(fda->priv);
64 	fdarray__init(fda, 0);
65 }
66 
67 void fdarray__delete(struct fdarray *fda)
68 {
69 	fdarray__exit(fda);
70 	free(fda);
71 }
72 
73 int fdarray__add(struct fdarray *fda, int fd, short revents)
74 {
75 	int pos = fda->nr;
76 
77 	if (fda->nr == fda->nr_alloc &&
78 	    fdarray__grow(fda, fda->nr_autogrow) < 0)
79 		return -ENOMEM;
80 
81 	fda->entries[fda->nr].fd     = fd;
82 	fda->entries[fda->nr].events = revents;
83 	fda->nr++;
84 	return pos;
85 }
86 
87 int fdarray__filter(struct fdarray *fda, short revents,
88 		    void (*entry_destructor)(struct fdarray *fda, int fd))
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);
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