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 <common/compat/poll.hpp>
   9
  10 #include "utils.hpp"
  11
  12 #ifdef HAVE_EPOLL
  13
  14 namespace {
  15 struct create_args {
  16         struct lttng_poll_event *events;
  17         int size;
  18         int flags;
  19 };
  20 } /* namespace */
  21
  22 static int open_epoll(void *data, int *out_fd)
  23 {
  24         int ret;
  25         struct create_args *args = (create_args *) data;
  26
  27         ret = lttng_poll_create(args->events, args->size, args->flags);
  28         if (ret < 0) {
  29                 goto end;
  30         }
  31
  32         *out_fd = args->events->epfd;
  33 end:
  34         return ret;
  35 }
  36
  37 static int close_epoll(void *data, int *in_fd __attribute__((unused)))
  38 {
  39         /* Will close the epfd. */
  40         lttng_poll_clean((struct lttng_poll_event *) data);
  41         return 0;
  42 }
  43
  44 /*
  45  * The epoll variant of the poll compat layer creates an unsuspendable fd which
  46  * must be tracked.
  47  */
  48 int fd_tracker_util_poll_create(struct fd_tracker *tracker,
  49                 const char *name,
  50                 struct lttng_poll_event *events,
  51                 int size,
  52                 int flags)
  53 {
  54         int out_fd;
  55         struct create_args create_args = {
  56                 .events = events,
  57                 .size = size,
  58                 .flags = flags,
  59         };
  60
  61         return fd_tracker_open_unsuspendable_fd(
  62                         tracker, &out_fd, &name, 1, open_epoll, &create_args);
  63 }
  64
  65 int fd_tracker_util_poll_clean(
  66                 struct fd_tracker *tracker, struct lttng_poll_event *events)
  67 {
  68         return fd_tracker_close_unsuspendable_fd(
  69                         tracker, &events->epfd, 1, close_epoll, events);
  70 }
  71
  72 #else /* HAVE_EPOLL */
  73
  74 /*
  75  * The epoll variant of the poll compat layer creates an unsuspendable fd which
  76  * must be tracked.
  77  */
  78 int fd_tracker_util_poll_create(
  79                 struct fd_tracker *tracker __attribute__((unused)),
  80                 const char *name __attribute__((unused)),
  81                 struct lttng_poll_event *events,
  82                 int size,
  83                 int flags __attribute__((unused)))
  84 {
  85         return lttng_poll_create(events, size, flags);
  86 }
  87
  88 int fd_tracker_util_poll_clean(
  89                 struct fd_tracker *tracker __attribute__((unused)),
  90                 struct lttng_poll_event *events)
  91 {
  92         lttng_poll_clean(events);
  93         return 0;
  94 }
  95
  96 #endif /* !HAVE_EPOLL */