Move all sources to 'src/'

[lttng-ust.git] / liblttng-ust / compat_futex.c

diff --git a/liblttng-ust/compat_futex.c b/liblttng-ust/compat_futex.c
deleted file mode 100644 (file)
index adf1f44..0000000
--- a/liblttng-ust/compat_futex.c
+++ /dev/null
@@ -1,140 +0,0 @@
-/*
- * SPDX-License-Identifier: LGPL-2.1-or-later
- *
- * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * Userspace RCU library - sys_futex compatibility code
- */
-
-#include <stdio.h>
-#include <pthread.h>
-#include <signal.h>
-#include <assert.h>
-#include <errno.h>
-#include <poll.h>
-#include <stdint.h>
-
-#include <urcu/arch.h>
-#include <urcu/system.h>
-#include "futex.h"
-
-/*
- * Using attribute "weak" for __lttng_ust_compat_futex_lock and
- * __lttng_ust_compat_futex_cond. Those are globally visible by the entire
- * program, even though many shared objects may have their own version.
- * The first version that gets loaded will be used by the entire program
- * (executable and all shared objects).
- */
-
-__attribute__((weak))
-pthread_mutex_t __lttng_ust_compat_futex_lock = PTHREAD_MUTEX_INITIALIZER;
-__attribute__((weak))
-pthread_cond_t __lttng_ust_compat_futex_cond = PTHREAD_COND_INITIALIZER;
-
-/*
- * _NOT SIGNAL-SAFE_. pthread_cond is not signal-safe anyway. Though.
- * For now, timeout, uaddr2 and val3 are unused.
- * Waiter will relinquish the CPU until woken up.
- */
-
-int lttng_ust_compat_futex_noasync(int32_t *uaddr, int op, int32_t val,
-       const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
-{
-       int ret = 0, lockret;
-
-       /*
-        * Check if NULL. Don't let users expect that they are taken into
-        * account.
-        */
-       assert(!timeout);
-       assert(!uaddr2);
-       assert(!val3);
-
-       /*
-        * memory barriers to serialize with the previous uaddr modification.
-        */
-       cmm_smp_mb();
-
-       lockret = pthread_mutex_lock(&__lttng_ust_compat_futex_lock);
-       if (lockret) {
-               errno = lockret;
-               ret = -1;
-               goto end;
-       }
-       switch (op) {
-       case FUTEX_WAIT:
-               /*
-                * Wait until *uaddr is changed to something else than "val".
-                * Comparing *uaddr content against val figures out which
-                * thread has been awakened.
-                */
-               while (CMM_LOAD_SHARED(*uaddr) == val)
-                       pthread_cond_wait(&__lttng_ust_compat_futex_cond,
-                               &__lttng_ust_compat_futex_lock);
-               break;
-       case FUTEX_WAKE:
-               /*
-                * Each wake is sending a broadcast, thus attempting wakeup of
-                * all awaiting threads, independently of their respective
-                * uaddr.
-                */
-               pthread_cond_broadcast(&__lttng_ust_compat_futex_cond);
-               break;
-       default:
-               errno = EINVAL;
-               ret = -1;
-       }
-       lockret = pthread_mutex_unlock(&__lttng_ust_compat_futex_lock);
-       if (lockret) {
-               errno = lockret;
-               ret = -1;
-       }
-end:
-       return ret;
-}
-
-/*
- * _ASYNC SIGNAL-SAFE_.
- * For now, timeout, uaddr2 and val3 are unused.
- * Waiter will busy-loop trying to read the condition.
- * It is OK to use compat_futex_async() on a futex address on which
- * futex() WAKE operations are also performed.
- */
-
-int lttng_ust_compat_futex_async(int32_t *uaddr, int op, int32_t val,
-       const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
-{
-       int ret = 0;
-
-       /*
-        * Check if NULL. Don't let users expect that they are taken into
-        * account.
-        */
-       assert(!timeout);
-       assert(!uaddr2);
-       assert(!val3);
-
-       /*
-        * Ensure previous memory operations on uaddr have completed.
-        */
-       cmm_smp_mb();
-
-       switch (op) {
-       case FUTEX_WAIT:
-               while (CMM_LOAD_SHARED(*uaddr) == val) {
-                       if (poll(NULL, 0, 10) < 0) {
-                               ret = -1;
-                               /* Keep poll errno. Caller handles EINTR. */
-                               goto end;
-                       }
-               }
-               break;
-       case FUTEX_WAKE:
-               break;
-       default:
-               errno = EINVAL;
-               ret = -1;
-       }
-end:
-       return ret;
-}