X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Ffutex.c;h=d0f95abc8b8175ebb4bf158bd7df364cad2f4bcd;hp=384e957a22d0406751c13dd03f02edd22bb0b768;hb=HEAD;hpb=e55c055d9742a9af996214af306ea68c51e168d8

diff --git a/src/common/futex.c b/src/common/futex.c
deleted file mode 100644
index 384e957a2..000000000
--- a/src/common/futex.c
+++ /dev/null
@@ -1,123 +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, 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.
- */
-
-#define _LGPL_SOURCE
-#include <limits.h>
-#include <unistd.h>
-#include <urcu.h>
-#include <urcu/futex.h>
-
-#include <common/common.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).
- */
-LTTNG_HIDDEN
-void futex_wait_update(int32_t *futex, int active)
-{
-	if (active) {
-		uatomic_set(futex, 1);
-		if (futex_async(futex, FUTEX_WAKE,
-				INT_MAX, NULL, NULL, 0) < 0) {
-			PERROR("futex_async");
-			abort();
-		}
-	} else {
-		uatomic_set(futex, 0);
-	}
-
-	DBG("Futex wait update active %d", active);
-}
-
-/*
- * Prepare futex.
- */
-LTTNG_HIDDEN
-void futex_nto1_prepare(int32_t *futex)
-{
-	uatomic_set(futex, -1);
-	cmm_smp_mb();
-
-	DBG("Futex n to 1 prepare done");
-}
-
-/*
- * Wait futex.
- */
-LTTNG_HIDDEN
-void futex_nto1_wait(int32_t *futex)
-{
-	cmm_smp_mb();
-
-	if (uatomic_read(futex) != -1)
-		goto end;
-	while (futex_async(futex, FUTEX_WAIT, -1, NULL, NULL, 0)) {
-		switch (errno) {
-		case EWOULDBLOCK:
-			/* Value already changed. */
-			goto end;
-		case EINTR:
-			/* Retry if interrupted by signal. */
-			break;	/* Get out of switch. */
-		default:
-			/* Unexpected error. */
-			PERROR("futex_async");
-			abort();
-		}
-	}
-end:
-	DBG("Futex n to 1 wait done");
-}
-
-/*
- * Wake 1 futex.
- */
-LTTNG_HIDDEN
-void futex_nto1_wake(int32_t *futex)
-{
-	if (caa_unlikely(uatomic_read(futex) != -1))
-		goto end;
-	uatomic_set(futex, 0);
-	if (futex_async(futex, FUTEX_WAKE, 1, NULL, NULL, 0) < 0) {
-		PERROR("futex_async");
-		abort();
-	}
-end:
-	DBG("Futex n to 1 wake done");
-}