xref: /linux/tools/lib/api/fd/array.c (revision 1b85337d0685d1dc5a6f9061434ba4316d69f3b8)
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->nr		 = fda->nr_alloc = 0;
17 	fda->nr_autogrow = nr_autogrow;
18 }
19 
20 int fdarray__grow(struct fdarray *fda, int nr)
21 {
22 	int nr_alloc = fda->nr_alloc + nr;
23 	size_t size  = sizeof(struct pollfd) * nr_alloc;
24 	struct pollfd *entries = realloc(fda->entries, size);
25 
26 	if (entries == NULL)
27 		return -ENOMEM;
28 
29 	fda->nr_alloc = nr_alloc;
30 	fda->entries  = entries;
31 	return 0;
32 }
33 
34 struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow)
35 {
36 	struct fdarray *fda = calloc(1, sizeof(*fda));
37 
38 	if (fda != NULL) {
39 		if (fdarray__grow(fda, nr_alloc)) {
40 			free(fda);
41 			fda = NULL;
42 		} else {
43 			fda->nr_autogrow = nr_autogrow;
44 		}
45 	}
46 
47 	return fda;
48 }
49 
50 void fdarray__exit(struct fdarray *fda)
51 {
52 	free(fda->entries);
53 	fdarray__init(fda, 0);
54 }
55 
56 void fdarray__delete(struct fdarray *fda)
57 {
58 	fdarray__exit(fda);
59 	free(fda);
60 }
61 
62 int fdarray__add(struct fdarray *fda, int fd, short revents)
63 {
64 	if (fda->nr == fda->nr_alloc &&
65 	    fdarray__grow(fda, fda->nr_autogrow) < 0)
66 		return -ENOMEM;
67 
68 	fda->entries[fda->nr].fd     = fd;
69 	fda->entries[fda->nr].events = revents;
70 	fda->nr++;
71 	return 0;
72 }
73 
74 int fdarray__filter(struct fdarray *fda, short revents)
75 {
76 	int fd, nr = 0;
77 
78 	if (fda->nr == 0)
79 		return 0;
80 
81 	for (fd = 0; fd < fda->nr; ++fd) {
82 		if (fda->entries[fd].revents & revents)
83 			continue;
84 
85 		if (fd != nr)
86 			fda->entries[nr] = fda->entries[fd];
87 
88 		++nr;
89 	}
90 
91 	return fda->nr = nr;
92 }
93 
94 int fdarray__poll(struct fdarray *fda, int timeout)
95 {
96 	return poll(fda->entries, fda->nr, timeout);
97 }
98 
99 int fdarray__fprintf(struct fdarray *fda, FILE *fp)
100 {
101 	int fd, printed = fprintf(fp, "%d [ ", fda->nr);
102 
103 	for (fd = 0; fd < fda->nr; ++fd)
104 		printed += fprintf(fp, "%s%d", fd ? ", " : "", fda->entries[fd].fd);
105 
106 	return printed + fprintf(fp, " ]");
107 }
108