src/common/fd-tracker/utils-epoll.c

   1 /*
   2  * Copyright (C) 2018 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #include <common/compat/poll.h>
  19
  20 #include "utils.h"
  21
  22 struct create_args {
  23         struct lttng_poll_event *events;
  24         int size;
  25         int flags;
  26 };
  27
  28 static
  29 int open_epoll(void *data, int *out_fd)
  30 {
  31         int ret;
  32         struct create_args *args = data;
  33
  34         ret = lttng_poll_create(args->events, args->size, args->flags);
  35         if (ret < 0) {
  36                 goto end;
  37         }
  38
  39         *out_fd = args->events->epfd;
  40 end:
  41         return ret;
  42 }
  43
  44 static
  45 int close_epoll(void *data, int *in_fd)
  46 {
  47         /* Will close the epfd. */
  48         lttng_poll_clean((struct lttng_poll_event *) data);
  49         return 0;
  50 }
  51
  52 /*
  53  * The epoll variant of the poll compat layer creates an unsuspendable fd which
  54  * must be tracked.
  55  */
  56 int fd_tracker_util_poll_create(struct fd_tracker *tracker, const char *name,
  57                 struct lttng_poll_event *events, int size, int flags)
  58 {
  59         int out_fd;
  60         struct create_args create_args = {
  61                 .events = events,
  62                 .size = size,
  63                 .flags = flags,
  64         };
  65
  66         return fd_tracker_open_unsuspendable_fd(tracker, &out_fd, &name, 1,
  67                         open_epoll, &create_args);
  68 }
  69
  70 int fd_tracker_util_poll_clean(struct fd_tracker *tracker,
  71                 struct lttng_poll_event *events)
  72 {
  73         return fd_tracker_close_unsuspendable_fd(tracker, &events->epfd, 1,
  74                         close_epoll, events);
  75 }