xref: /openbmc/linux/tools/lib/api/fd/array.h (revision 3db55767)
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 	fdarray_flag__non_perf_event	= 0x00000002,
37 };
38 
39 void fdarray__init(struct fdarray *fda, int nr_autogrow);
40 void fdarray__exit(struct fdarray *fda);
41 
42 struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow);
43 void fdarray__delete(struct fdarray *fda);
44 
45 int fdarray__add(struct fdarray *fda, int fd, short revents, enum fdarray_flags flags);
46 int fdarray__dup_entry_from(struct fdarray *fda, int pos, struct fdarray *from);
47 int fdarray__poll(struct fdarray *fda, int timeout);
48 int fdarray__filter(struct fdarray *fda, short revents,
49 		    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
50 		    void *arg);
51 int fdarray__grow(struct fdarray *fda, int extra);
52 int fdarray__fprintf(struct fdarray *fda, FILE *fp);
53 
54 static inline int fdarray__available_entries(struct fdarray *fda)
55 {
56 	return fda->nr_alloc - fda->nr;
57 }
58 
59 #endif /* __API_FD_ARRAY__ */
60