From 1f3a37b19ccc481197ffd6a5cf014dfb07c6dd4e Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Tue, 26 May 2015 15:30:47 -0700 Subject: NaCl: Add NaCl-specific __lll_timedlock_wait. --- sysdeps/nacl/lll_timedlock_wait.c | 52 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 sysdeps/nacl/lll_timedlock_wait.c (limited to 'sysdeps/nacl') diff --git a/sysdeps/nacl/lll_timedlock_wait.c b/sysdeps/nacl/lll_timedlock_wait.c new file mode 100644 index 0000000000..df951ee8cb --- /dev/null +++ b/sysdeps/nacl/lll_timedlock_wait.c @@ -0,0 +1,52 @@ +/* Timed low level locking for pthread library. NaCl version. + Copyright (C) 2015 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include + + +/* This behaves the same as the generic version in nptl/. It's simpler + because it doesn't need to convert an absolute timeout to a relative + one (and back again in the lll_futex_timed_wait macro). */ + +int +__lll_timedlock_wait (int *futex, const struct timespec *abstime, int private) +{ + /* Reject invalid timeouts. */ + if (__glibc_unlikely (abstime->tv_nsec < 0) + || __glibc_unlikely (abstime->tv_nsec >= 1000000000)) + return EINVAL; + + /* Try locking. */ + int result = 0; + while (atomic_exchange_acq (futex, 2) != 0) + { + /* If *futex == 2, wait until woken or timeout. */ + result = __nacl_irt_futex.futex_wait_abs ((volatile int *) futex, 2, + abstime); + if (__glibc_likely (result == 0) + || __glibc_likely (result == ETIMEDOUT)) + break; + assert (result == EAGAIN); + } + + return result; +} -- cgit 1.4.1