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
   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         union {
  25                 int    idx;
  26                 void   *ptr;
  27         } *priv;
  28 };
  29
  30 void fdarray__init(struct fdarray *fda, int nr_autogrow);
  31 void fdarray__exit(struct fdarray *fda);
  32
  33 struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow);
  34 void fdarray__delete(struct fdarray *fda);
  35
  36 int fdarray__add(struct fdarray *fda, int fd, short revents);
  37 int fdarray__poll(struct fdarray *fda, int timeout);
  38 int fdarray__filter(struct fdarray *fda, short revents,
  39                     void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
  40                     void *arg);
  41 int fdarray__grow(struct fdarray *fda, int extra);
  42 int fdarray__fprintf(struct fdarray *fda, FILE *fp);
  43
  44 static inline int fdarray__available_entries(struct fdarray *fda)
  45 {
  46         return fda->nr_alloc - fda->nr;
  47 }
  48
  49 #endif /* __API_FD_ARRAY__ */