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-rw-r--r--sysdeps/nacl/lll_timedwait_tid.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/sysdeps/nacl/lll_timedwait_tid.c b/sysdeps/nacl/lll_timedwait_tid.c
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index 0000000..ecaf0b1
--- /dev/null
+++ b/sysdeps/nacl/lll_timedwait_tid.c
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+/* Timed waiting for thread death. 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <assert.h>
+#include <atomic.h>
+#include <errno.h>
+#include <lowlevellock.h>
+#include <sys/time.h>
+
+int
+__lll_timedwait_tid (int *tidp, const struct timespec *abstime)
+{
+ /* Reject invalid timeouts. */
+ if (__glibc_unlikely (abstime->tv_nsec < 0)
+ || __glibc_unlikely (abstime->tv_nsec >= 1000000000))
+ return EINVAL;
+
+ /* Repeat until thread terminated. */
+ int tid;
+ while ((tid = atomic_load_relaxed (tidp)) != 0)
+ {
+ /* See exit-thread.h for details. */
+ if (tid == NACL_EXITING_TID)
+ /* The thread should now be in the process of exiting, so it will
+ finish quick enough that the timeout doesn't matter. If any
+ thread ever stays in this state for long, there is something
+ catastrophically wrong. */
+ BUSY_WAIT_NOP;
+ else
+ {
+ assert (tid > 0);
+
+ /* If *FUTEX == TID, wait until woken or timeout. */
+ int err = __nacl_irt_futex.futex_wait_abs ((volatile int *) tidp,
+ tid, abstime);
+ if (err != 0)
+ {
+ if (__glibc_likely (err == ETIMEDOUT))
+ return err;
+ assert (err == EAGAIN);
+ }
+ }
+ }
+
+ return 0;
+}