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         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__ */