tools/lib/api/fd/array.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2014, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
   4  */
   5 #include "array.h"
   6 #include <errno.h>
   7 #include <fcntl.h>
   8 #include <poll.h>
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11
  12 void fdarray__init(struct fdarray *fda, int nr_autogrow)
  13 {
  14         fda->entries     = NULL;
  15         fda->priv        = NULL;
  16         fda->nr          = fda->nr_alloc = 0;
  17         fda->nr_autogrow = nr_autogrow;
  18 }
  19
  20 int fdarray__grow(struct fdarray *fda, int nr)
  21 {
  22         void *priv;
  23         int nr_alloc = fda->nr_alloc + nr;
  24         size_t psize = sizeof(fda->priv[0]) * nr_alloc;
  25         size_t size  = sizeof(struct pollfd) * nr_alloc;
  26         struct pollfd *entries = realloc(fda->entries, size);
  27
  28         if (entries == NULL)
  29                 return -ENOMEM;
  30
  31         priv = realloc(fda->priv, psize);
  32         if (priv == NULL) {
  33                 free(entries);
  34                 return -ENOMEM;
  35         }
  36
  37         fda->nr_alloc = nr_alloc;
  38         fda->entries  = entries;
  39         fda->priv     = priv;
  40         return 0;
  41 }
  42
  43 struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow)
  44 {
  45         struct fdarray *fda = calloc(1, sizeof(*fda));
  46
  47         if (fda != NULL) {
  48                 if (fdarray__grow(fda, nr_alloc)) {
  49                         free(fda);
  50                         fda = NULL;
  51                 } else {
  52                         fda->nr_autogrow = nr_autogrow;
  53                 }
  54         }
  55
  56         return fda;
  57 }
  58
  59 void fdarray__exit(struct fdarray *fda)
  60 {
  61         free(fda->entries);
  62         free(fda->priv);
  63         fdarray__init(fda, 0);
  64 }
  65
  66 void fdarray__delete(struct fdarray *fda)
  67 {
  68         fdarray__exit(fda);
  69         free(fda);
  70 }
  71
  72 int fdarray__add(struct fdarray *fda, int fd, short revents)
  73 {
  74         int pos = fda->nr;
  75
  76         if (fda->nr == fda->nr_alloc &&
  77             fdarray__grow(fda, fda->nr_autogrow) < 0)
  78                 return -ENOMEM;
  79
  80         fda->entries[fda->nr].fd     = fd;
  81         fda->entries[fda->nr].events = revents;
  82         fda->nr++;
  83         return pos;
  84 }
  85
  86 int fdarray__filter(struct fdarray *fda, short revents,
  87                     void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
  88                     void *arg)
  89 {
  90         int fd, nr = 0;
  91
  92         if (fda->nr == 0)
  93                 return 0;
  94
  95         for (fd = 0; fd < fda->nr; ++fd) {
  96                 if (fda->entries[fd].revents & revents) {
  97                         if (entry_destructor)
  98                                 entry_destructor(fda, fd, arg);
  99
 100                         continue;
 101                 }
 102
 103                 if (fd != nr) {
 104                         fda->entries[nr] = fda->entries[fd];
 105                         fda->priv[nr]    = fda->priv[fd];
 106                 }
 107
 108                 ++nr;
 109         }
 110
 111         return fda->nr = nr;
 112 }
 113
 114 int fdarray__poll(struct fdarray *fda, int timeout)
 115 {
 116         return poll(fda->entries, fda->nr, timeout);
 117 }
 118
 119 int fdarray__fprintf(struct fdarray *fda, FILE *fp)
 120 {
 121         int fd, printed = fprintf(fp, "%d [ ", fda->nr);
 122
 123         for (fd = 0; fd < fda->nr; ++fd)
 124                 printed += fprintf(fp, "%s%d", fd ? ", " : "", fda->entries[fd].fd);
 125
 126         return printed + fprintf(fp, " ]");
 127 }