LXR linux/tools/lib/api/fd/array.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __API_FD_ARRAY__
   3#define __API_FD_ARRAY__
   4
   5#include <stdio.h>
   6
   7struct 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 */
  19struct 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
  33enum fdarray_flags {
  34        fdarray_flag__default       = 0x00000000,
  35        fdarray_flag__nonfilterable = 0x00000001
  36};
  37
  38void fdarray__init(struct fdarray *fda, int nr_autogrow);
  39void fdarray__exit(struct fdarray *fda);
  40
  41struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow);
  42void fdarray__delete(struct fdarray *fda);
  43
  44int fdarray__add(struct fdarray *fda, int fd, short revents, enum fdarray_flags flags);
  45int fdarray__poll(struct fdarray *fda, int timeout);
  46int fdarray__filter(struct fdarray *fda, short revents,
  47                    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
  48                    void *arg);
  49int fdarray__grow(struct fdarray *fda, int extra);
  50int fdarray__fprintf(struct fdarray *fda, FILE *fp);
  51
  52static inline int fdarray__available_entries(struct fdarray *fda)
  53{
  54        return fda->nr_alloc - fda->nr;
  55}
  56
  57#endif /* __API_FD_ARRAY__ */
  58