Complete change of the source directory tree

[lttng-tools.git] / lttng-sessiond / futex.c

diff --git a/lttng-sessiond/futex.c b/lttng-sessiond/futex.c
deleted file mode 100644 (file)
index e01771e..0000000
--- a/lttng-sessiond/futex.c
+++ /dev/null
@@ -1,102 +0,0 @@
-/*
- * Copyright (C)  2011 - David Goulet <david.goulet@polymtl.ca>
- *                       Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; only version 2
- * of the License.
- *
- * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
- */
-
-#define _GNU_SOURCE
-#include <limits.h>
-#include <sys/syscall.h>
-#include <unistd.h>
-#include <urcu.h>
-#include <urcu/futex.h>
-
-#include <lttngerr.h>
-
-#include "futex.h"
-
-/*
- * This futex wait/wake scheme only works for N wakers / 1 waiters. Hence the
- * "nto1" added to all function signature.
- *
- * Please see wait_gp()/update_counter_and_wait() calls in urcu.c in the urcu
- * git tree for a detail example of this scheme being used. futex_async() is
- * the urcu wrapper over the futex() sycall.
- *
- * There is also a formal verification available in the git tree.
- *
- *   branch: formal-model
- *   commit id: 2a8044f3493046fcc8c67016902dc7beec6f026a
- *
- * Ref: git://git.lttng.org/userspace-rcu.git
- */
-
-/*
- * Update futex according to active or not. This scheme is used to wake every
- * libust waiting on the shared memory map futex hence the INT_MAX used in the
- * futex() call. If active, we set the value and wake everyone else we indicate
- * that we are gone (cleanup() case).
- */
-void futex_wait_update(int32_t *futex, int active)
-{
-       if (active) {
-               uatomic_set(futex, 1);
-               futex_async(futex, FUTEX_WAKE,
-                               INT_MAX, NULL, NULL, 0);
-       } else {
-               uatomic_set(futex, 0);
-       }
-
-       DBG("Futex wait update active %d", active);
-}
-
-/*
- * Prepare futex.
- */
-void futex_nto1_prepare(int32_t *futex)
-{
-       uatomic_set(futex, -1);
-       cmm_smp_mb();
-
-       DBG("Futex n to 1 prepare done");
-}
-
-/*
- * Wait futex.
- */
-void futex_nto1_wait(int32_t *futex)
-{
-       cmm_smp_mb();
-
-       if (uatomic_read(futex) == -1) {
-               futex_async(futex, FUTEX_WAIT, -1, NULL, NULL, 0);
-       }
-
-       DBG("Futex n to 1 wait done");
-}
-
-/*
- * Wake 1 futex.
- */
-void futex_nto1_wake(int32_t *futex)
-{
-       if (caa_unlikely(uatomic_read(futex) == -1)) {
-               uatomic_set(futex, 0);
-               futex_async(futex, FUTEX_WAKE, 1, NULL, NULL, 0);
-       }
-
-       DBG("Futex n to 1 wake done");
-}