fd-tracker: add epoll/poll management wrappers to fd-tracker

[lttng-tools.git] / src / common / fd-tracker / utils-epoll.c

diff --git a/src/common/fd-tracker/utils-epoll.c b/src/common/fd-tracker/utils-epoll.c
new file mode 100644 (file)
index 0000000..3b38778
--- /dev/null
+++ b/src/common/fd-tracker/utils-epoll.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2018 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License, version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <common/compat/poll.h>
+
+#include "utils.h"
+
+struct create_args {
+       struct lttng_poll_event *events;
+       int size;
+       int flags;
+};
+
+static
+int open_epoll(void *data, int *out_fd)
+{
+       int ret;
+       struct create_args *args = data;
+
+       ret = lttng_poll_create(args->events, args->size, args->flags);
+       if (ret < 0) {
+               goto end;
+       }
+
+       *out_fd = args->events->epfd;
+end:
+       return ret;
+}
+
+static
+int close_epoll(void *data, int *in_fd)
+{
+       /* Will close the epfd. */
+       lttng_poll_clean((struct lttng_poll_event *) data);
+       return 0;
+}
+
+/*
+ * The epoll variant of the poll compat layer creates an unsuspendable fd which
+ * must be tracked.
+ */
+int fd_tracker_util_poll_create(struct fd_tracker *tracker, const char *name,
+               struct lttng_poll_event *events, int size, int flags)
+{
+       int out_fd;
+       struct create_args create_args = {
+               .events = events,
+               .size = size,
+               .flags = flags,
+       };
+
+       return fd_tracker_open_unsuspendable_fd(tracker, &out_fd, &name, 1,
+                       open_epoll, &create_args);
+}
+
+int fd_tracker_util_poll_clean(struct fd_tracker *tracker,
+               struct lttng_poll_event *events)
+{
+       return fd_tracker_close_unsuspendable_fd(tracker, &events->epfd, 1,
+                       close_epoll, events);
+}