diff options
Diffstat (limited to 'REORG.TODO/nptl/lll_timedlock_wait.c')
-rw-r--r-- | REORG.TODO/nptl/lll_timedlock_wait.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/REORG.TODO/nptl/lll_timedlock_wait.c b/REORG.TODO/nptl/lll_timedlock_wait.c new file mode 100644 index 0000000000..604953c04c --- /dev/null +++ b/REORG.TODO/nptl/lll_timedlock_wait.c @@ -0,0 +1,59 @@ +/* Timed low level locking for pthread library. Generic futex-using version. + Copyright (C) 2003-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003. + + 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 + <http://www.gnu.org/licenses/>. */ + +#include <atomic.h> +#include <errno.h> +#include <lowlevellock.h> +#include <sys/time.h> + + +int +__lll_timedlock_wait (int *futex, const struct timespec *abstime, int private) +{ + /* Reject invalid timeouts. */ + if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) + return EINVAL; + + /* Try locking. */ + while (atomic_exchange_acq (futex, 2) != 0) + { + struct timeval tv; + + /* Get the current time. */ + (void) __gettimeofday (&tv, NULL); + + /* Compute relative timeout. */ + struct timespec rt; + rt.tv_sec = abstime->tv_sec - tv.tv_sec; + rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000; + if (rt.tv_nsec < 0) + { + rt.tv_nsec += 1000000000; + --rt.tv_sec; + } + + if (rt.tv_sec < 0) + return ETIMEDOUT; + + /* If *futex == 2, wait until woken or timeout. */ + lll_futex_timed_wait (futex, 2, &rt, private); + } + + return 0; +} |