diff options
Diffstat (limited to 'REORG.TODO/nptl/lll_timedwait_tid.c')
-rw-r--r-- | REORG.TODO/nptl/lll_timedwait_tid.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/REORG.TODO/nptl/lll_timedwait_tid.c b/REORG.TODO/nptl/lll_timedwait_tid.c new file mode 100644 index 0000000000..e4c8de0f99 --- /dev/null +++ b/REORG.TODO/nptl/lll_timedwait_tid.c @@ -0,0 +1,70 @@ +/* Timed waiting for thread death. 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> + + +/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex + wake-up when the clone terminates. The memory location contains the + thread ID while the clone is running and is reset to zero by the kernel + afterwards. The kernel up to version 3.16.3 does not use the private futex + operations for futex wake-up when the clone terminates. */ +int +__lll_timedwait_tid (int *tidp, const struct timespec *abstime) +{ + int tid; + + if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) + return EINVAL; + + /* Repeat until thread terminated. */ + while ((tid = *tidp) != 0) + { + struct timeval tv; + struct timespec rt; + + /* Get the current time. */ + (void) __gettimeofday (&tv, NULL); + + /* Compute relative timeout. */ + 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; + } + + /* Already timed out? */ + if (rt.tv_sec < 0) + return ETIMEDOUT; + + /* If *tidp == tid, wait until thread terminates or the wait times out. + The kernel up to version 3.16.3 does not use the private futex + operations for futex wake-up when the clone terminates. + */ + if (lll_futex_timed_wait (tidp, tid, &rt, LLL_SHARED) == -ETIMEDOUT) + return ETIMEDOUT; + } + + return 0; +} |