1 files changed, 62 insertions, 0 deletions
diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c
new file mode 100644
index 0000000000..1fa20e087c
--- /dev/null
+++ b/nptl/pthread_cancel.c
@@ -0,0 +1,62 @@
+/* Copyright (C) 2002 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+   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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <signal.h>
+#include "pthreadP.h"
+#include "atomic.h"
+
+
+int
+pthread_cancel (th)
+     pthread_t th;
+{
+  volatile struct pthread *pd = (volatile struct pthread *) th;
+
+  while (1)
+    {
+      int oldval = pd->cancelhandling;
+      int newval = oldval | CANCELED_BITMASK;
+
+      /* Avoid doing unnecessary work.  The atomic operation can
+	 potentially be expensive if the bug has to be locked and
+	 remote cache lines have to be invalidated.  */
+      if (oldval == newval)
+	break;
+
+      /* If the cancellation is handled asynchronously just send a
+	 signal.  We avoid this if possible since it's more
+	 expensive.  */
+      if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
+	{
+	  /* The cancellation handler will take care of marking the
+	     thread as canceled.  */
+	  pthread_kill (th, SIGCANCEL);
+
+	  break;
+	}
+
+      /* Mark the thread as canceled.  This has to be done
+	 atomically since other bits could be modified as well.  */
+      if (atomic_compare_and_exchange_acq (&pd->cancelhandling, newval,
+					   oldval) == 0)
+	break;
+    }
+
+  return 0;
+}