Cleanup: autoconf 'dirfd' detection

[lttng-tools.git] / src / common / compat / compat-epoll.c

diff --git a/src/common/compat/compat-epoll.c b/src/common/compat/compat-epoll.c
index 794041726ad51226e331c511526c4ff95de128d5..9055f51291475ae31b9508f7197d3eb581d2cc89 100644 (file)
--- a/src/common/compat/compat-epoll.c
+++ b/src/common/compat/compat-epoll.c
@@ -1,18 +1,8 @@
 /*
 /*

- * Copyright (C)  2011 - David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>

  *
  *

- * 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.
+ * SPDX-License-Identifier: GPL-2.0-only

  *
  *

- * 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.

  */
 
 #define _LGPL_SOURCE
  */
 
 #define _LGPL_SOURCE


@@ -32,7 +22,17 @@
 
 #include "poll.h"
 
 
 #include "poll.h"
 

-unsigned int poll_max_size;
+/*
+ * Maximum number of fd we can monitor.
+ *
+ * For epoll(7), /proc/sys/fs/epoll/max_user_watches (since Linux 2.6.28) will
+ * be used for the maximum size of the poll set. If this interface is not
+ * available, according to the manpage, the max_user_watches value is 1/25 (4%)
+ * of the available low memory divided by the registration cost in bytes which
+ * is 90 bytes on a 32-bit kernel and 160 bytes on a 64-bit kernel.
+ *
+ */
+static unsigned int poll_max_size;

 
 /*
  * Resize the epoll events structure of the new size.
 
 /*
  * Resize the epoll events structure of the new size.


@@ -68,6 +68,7 @@ error:
 /*
  * Create epoll set and allocate returned events structure.
  */
 /*
  * Create epoll set and allocate returned events structure.
  */

+LTTNG_HIDDEN

 int compat_epoll_create(struct lttng_poll_event *events, int size, int flags)
 {
        int ret;
 int compat_epoll_create(struct lttng_poll_event *events, int size, int flags)
 {
        int ret;


@@ -120,6 +121,7 @@ error:
 /*
  * Add a fd to the epoll set with requesting events.
  */
 /*
  * Add a fd to the epoll set with requesting events.
  */

+LTTNG_HIDDEN

 int compat_epoll_add(struct lttng_poll_event *events, int fd, uint32_t req_events)
 {
        int ret;
 int compat_epoll_add(struct lttng_poll_event *events, int fd, uint32_t req_events)
 {
        int ret;


@@ -167,6 +169,7 @@ error:
 /*
  * Remove a fd from the epoll set.
  */
 /*
  * Remove a fd from the epoll set.
  */

+LTTNG_HIDDEN

 int compat_epoll_del(struct lttng_poll_event *events, int fd)
 {
        int ret;
 int compat_epoll_del(struct lttng_poll_event *events, int fd)
 {
        int ret;


@@ -201,6 +204,7 @@ error:
 /*
  * Set an fd's events.
  */
 /*
  * Set an fd's events.
  */

+LTTNG_HIDDEN

 int compat_epoll_mod(struct lttng_poll_event *events, int fd, uint32_t req_events)
 {
        int ret;
 int compat_epoll_mod(struct lttng_poll_event *events, int fd, uint32_t req_events)
 {
        int ret;


@@ -242,6 +246,7 @@ error:
 /*
  * Wait on epoll set. This is a blocking call of timeout value.
  */
 /*
  * Wait on epoll set. This is a blocking call of timeout value.
  */

+LTTNG_HIDDEN

 int compat_epoll_wait(struct lttng_poll_event *events, int timeout,
                bool interruptible)
 {
 int compat_epoll_wait(struct lttng_poll_event *events, int timeout,
                bool interruptible)
 {


@@ -296,6 +301,7 @@ error:
 /*
  * Setup poll set maximum size.
  */
 /*
  * Setup poll set maximum size.
  */

+LTTNG_HIDDEN

 int compat_epoll_set_max_size(void)
 {
        int ret, fd, retval = 0;
 int compat_epoll_set_max_size(void)
 {
        int ret, fd, retval = 0;