xref: /openbmc/linux/tools/lib/api/fd/array.h (revision f21e49be)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __API_FD_ARRAY__
3 #define __API_FD_ARRAY__
4 
5 #include <stdio.h>
6 
7 struct pollfd;
8 
9 /**
10  * struct fdarray: Array of file descriptors
11  *
12  * @priv: Per array entry priv area, users should access just its contents,
13  *	  not set it to anything, as it is kept in synch with @entries, being
14  *	  realloc'ed, * for instance, in fdarray__{grow,filter}.
15  *
16  *	  I.e. using 'fda->priv[N].idx = * value' where N < fda->nr is ok,
17  *	  but doing 'fda->priv = malloc(M)' is not allowed.
18  */
19 struct fdarray {
20 	int	       nr;
21 	int	       nr_alloc;
22 	int	       nr_autogrow;
23 	struct pollfd *entries;
24 	struct priv {
25 		union {
26 			int    idx;
27 			void   *ptr;
28 		};
29 		unsigned int flags;
30 	} *priv;
31 };
32 
33 enum fdarray_flags {
34 	fdarray_flag__default	    = 0x00000000,
35 	fdarray_flag__nonfilterable = 0x00000001
36 };
37 
38 void fdarray__init(struct fdarray *fda, int nr_autogrow);
39 void fdarray__exit(struct fdarray *fda);
40 
41 struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow);
42 void fdarray__delete(struct fdarray *fda);
43 
44 int fdarray__add(struct fdarray *fda, int fd, short revents, enum fdarray_flags flags);
45 int fdarray__poll(struct fdarray *fda, int timeout);
46 int fdarray__filter(struct fdarray *fda, short revents,
47 		    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
48 		    void *arg);
49 int fdarray__grow(struct fdarray *fda, int extra);
50 int fdarray__fprintf(struct fdarray *fda, FILE *fp);
51 
52 static inline int fdarray__available_entries(struct fdarray *fda)
53 {
54 	return fda->nr_alloc - fda->nr;
55 }
56 
57 #endif /* __API_FD_ARRAY__ */
58