NaCl: Make thread exit wake pthread_join.

1 files changed, 61 insertions, 0 deletions

diff --git a/sysdeps/nacl/lll_timedwait_tid.c b/sysdeps/nacl/lll_timedwait_tid.c
new file mode 100644
index 0000000000..ecaf0b113a
--- /dev/null
+++ b/sysdeps/nacl/lll_timedwait_tid.c
@@ -0,0 +1,61 @@
+/* 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;
+}