src/common/fd-tracker/utils-poll.cpp

   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 "utils.hpp"
   9
  10 #ifdef HAVE_EPOLL
  11
  12 namespace {
  13 struct create_args {
  14         struct lttng_poll_event *events;
  15         int size;
  16         int flags;
  17 };
  18 } /* namespace */
  19
  20 static int open_epoll(void *data, int *out_fd)
  21 {
  22         int ret;
  23         struct create_args *args = (create_args *) data;
  24
  25         ret = lttng_poll_create(args->events, args->size, args->flags);
  26         if (ret < 0) {
  27                 goto end;
  28         }
  29
  30         *out_fd = args->events->epfd;
  31 end:
  32         return ret;
  33 }
  34
  35 static int close_epoll(void *data, int *in_fd __attribute__((unused)))
  36 {
  37         /* Will close the epfd. */
  38         lttng_poll_clean((struct lttng_poll_event *) data);
  39         return 0;
  40 }
  41
  42 /*
  43  * The epoll variant of the poll compat layer creates an unsuspendable fd which
  44  * must be tracked.
  45  */
  46 int fd_tracker_util_poll_create(struct fd_tracker *tracker,
  47                                 const char *name,
  48                                 struct lttng_poll_event *events,
  49                                 int size,
  50                                 int flags)
  51 {
  52         int out_fd;
  53         struct create_args create_args = {
  54                 .events = events,
  55                 .size = size,
  56                 .flags = flags,
  57         };
  58
  59         return fd_tracker_open_unsuspendable_fd(
  60                 tracker, &out_fd, &name, 1, open_epoll, &create_args);
  61 }
  62
  63 int fd_tracker_util_poll_clean(struct fd_tracker *tracker, struct lttng_poll_event *events)
  64 {
  65         return fd_tracker_close_unsuspendable_fd(tracker, &events->epfd, 1, close_epoll, events);
  66 }
  67
  68 #else /* HAVE_EPOLL */
  69
  70 /*
  71  * The epoll variant of the poll compat layer creates an unsuspendable fd which
  72  * must be tracked.
  73  */
  74 int fd_tracker_util_poll_create(struct fd_tracker *tracker __attribute__((unused)),
  75                                 const char *name __attribute__((unused)),
  76                                 struct lttng_poll_event *events,
  77                                 int size,
  78                                 int flags __attribute__((unused)))
  79 {
  80         return lttng_poll_create(events, size, flags);
  81 }
  82
  83 int fd_tracker_util_poll_clean(struct fd_tracker *tracker __attribute__((unused)),
  84                                struct lttng_poll_event *events)
  85 {
  86         lttng_poll_clean(events);
  87         return 0;
  88 }
  89
  90 #endif /* !HAVE_EPOLL */