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

   1/*
   2 * Copyright (C) 2014, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
   3 *
   4 * Released under the GPL v2. (and only v2, not any later version)
   5 */
   6#include "array.h"
   7#include <errno.h>
   8#include <fcntl.h>
   9#include <poll.h>
  10#include <stdlib.h>
  11#include <unistd.h>
  12
  13void fdarray__init(struct fdarray *fda, int nr_autogrow)
  14{
  15        fda->entries     = NULL;
  16        fda->priv        = NULL;
  17        fda->nr          = fda->nr_alloc = 0;
  18        fda->nr_autogrow = nr_autogrow;
  19}
  20
  21int fdarray__grow(struct fdarray *fda, int nr)
  22{
  23        void *priv;
  24        int nr_alloc = fda->nr_alloc + nr;
  25        size_t psize = sizeof(fda->priv[0]) * nr_alloc;
  26        size_t size  = sizeof(struct pollfd) * nr_alloc;
  27        struct pollfd *entries = realloc(fda->entries, size);
  28
  29        if (entries == NULL)
  30                return -ENOMEM;
  31
  32        priv = realloc(fda->priv, psize);
  33        if (priv == NULL) {
  34                free(entries);
  35                return -ENOMEM;
  36        }
  37
  38        fda->nr_alloc = nr_alloc;
  39        fda->entries  = entries;
  40        fda->priv     = priv;
  41        return 0;
  42}
  43
  44struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow)
  45{
  46        struct fdarray *fda = calloc(1, sizeof(*fda));
  47
  48        if (fda != NULL) {
  49                if (fdarray__grow(fda, nr_alloc)) {
  50                        free(fda);
  51                        fda = NULL;
  52                } else {
  53                        fda->nr_autogrow = nr_autogrow;
  54                }
  55        }
  56
  57        return fda;
  58}
  59
  60void fdarray__exit(struct fdarray *fda)
  61{
  62        free(fda->entries);
  63        free(fda->priv);
  64        fdarray__init(fda, 0);
  65}
  66
  67void fdarray__delete(struct fdarray *fda)
  68{
  69        fdarray__exit(fda);
  70        free(fda);
  71}
  72
  73int fdarray__add(struct fdarray *fda, int fd, short revents)
  74{
  75        int pos = fda->nr;
  76
  77        if (fda->nr == fda->nr_alloc &&
  78            fdarray__grow(fda, fda->nr_autogrow) < 0)
  79                return -ENOMEM;
  80
  81        fda->entries[fda->nr].fd     = fd;
  82        fda->entries[fda->nr].events = revents;
  83        fda->nr++;
  84        return pos;
  85}
  86
  87int fdarray__filter(struct fdarray *fda, short revents,
  88                    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
  89                    void *arg)
  90{
  91        int fd, nr = 0;
  92
  93        if (fda->nr == 0)
  94                return 0;
  95
  96        for (fd = 0; fd < fda->nr; ++fd) {
  97                if (fda->entries[fd].revents & revents) {
  98                        if (entry_destructor)
  99                                entry_destructor(fda, fd, arg);
 100
 101                        continue;
 102                }
 103
 104                if (fd != nr) {
 105                        fda->entries[nr] = fda->entries[fd];
 106                        fda->priv[nr]    = fda->priv[fd];
 107                }
 108
 109                ++nr;
 110        }
 111
 112        return fda->nr = nr;
 113}
 114
 115int fdarray__poll(struct fdarray *fda, int timeout)
 116{
 117        return poll(fda->entries, fda->nr, timeout);
 118}
 119
 120int fdarray__fprintf(struct fdarray *fda, FILE *fp)
 121{
 122        int fd, printed = fprintf(fp, "%d [ ", fda->nr);
 123
 124        for (fd = 0; fd < fda->nr; ++fd)
 125                printed += fprintf(fp, "%s%d", fd ? ", " : "", fda->entries[fd].fd);
 126
 127        return printed + fprintf(fp, " ]");
 128}
 129