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

   1 /*
   2  * Copyright (C) 2018 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #include <common/compat/poll.h>
   9
  10 #include "utils.h"
  11
  12 struct create_args {
  13         struct lttng_poll_event *events;
  14         int size;
  15         int flags;
  16 };
  17
  18 static int open_epoll(void *data, int *out_fd)
  19 {
  20         int ret;
  21         struct create_args *args = data;
  22
  23         ret = lttng_poll_create(args->events, args->size, args->flags);
  24         if (ret < 0) {
  25                 goto end;
  26         }
  27
  28         *out_fd = args->events->epfd;
  29 end:
  30         return ret;
  31 }
  32
  33 static int close_epoll(void *data, int *in_fd)
  34 {
  35         /* Will close the epfd. */
  36         lttng_poll_clean((struct lttng_poll_event *) data);
  37         return 0;
  38 }
  39
  40 /*
  41  * The epoll variant of the poll compat layer creates an unsuspendable fd which
  42  * must be tracked.
  43  */
  44 int fd_tracker_util_poll_create(struct fd_tracker *tracker,
  45                 const char *name,
  46                 struct lttng_poll_event *events,
  47                 int size,
  48                 int flags)
  49 {
  50         int out_fd;
  51         struct create_args create_args = {
  52                 .events = events,
  53                 .size = size,
  54                 .flags = flags,
  55         };
  56
  57         return fd_tracker_open_unsuspendable_fd(
  58                         tracker, &out_fd, &name, 1, open_epoll, &create_args);
  59 }
  60
  61 int fd_tracker_util_poll_clean(
  62                 struct fd_tracker *tracker, struct lttng_poll_event *events)
  63 {
  64         return fd_tracker_close_unsuspendable_fd(
  65                         tracker, &events->epfd, 1, close_epoll, events);
  66 }