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-rw-r--r--REORG.TODO/sysdeps/unix/sysv/linux/powerpc/elision-lock.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/unix/sysv/linux/powerpc/elision-lock.c b/REORG.TODO/sysdeps/unix/sysv/linux/powerpc/elision-lock.c
new file mode 100644
index 0000000000..f7a5cbcd3a
--- /dev/null
+++ b/REORG.TODO/sysdeps/unix/sysv/linux/powerpc/elision-lock.c
@@ -0,0 +1,86 @@
+/* elision-lock.c: Elided pthread mutex lock.
+   Copyright (C) 2015-2017 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 <stdio.h>
+#include <pthread.h>
+#include <pthreadP.h>
+#include <lowlevellock.h>
+#include <elision-conf.h>
+#include "htm.h"
+
+#if !defined(LLL_LOCK) && !defined(EXTRAARG)
+/* Make sure the configuration code is always linked in for static
+   libraries.  */
+#include "elision-conf.c"
+#endif
+
+#ifndef EXTRAARG
+# define EXTRAARG
+#endif
+#ifndef LLL_LOCK
+# define LLL_LOCK(a,b) lll_lock(a,b), 0
+#endif
+
+#define aconf __elision_aconf
+
+/* Adaptive lock using transactions.
+   By default the lock region is run as a transaction, and when it
+   aborts or the lock is busy the lock adapts itself.  */
+
+int
+__lll_lock_elision (int *lock, short *adapt_count, EXTRAARG int pshared)
+{
+  /* adapt_count is accessed concurrently but is just a hint.  Thus,
+     use atomic accesses but relaxed MO is sufficient.  */
+  if (atomic_load_relaxed (adapt_count) > 0)
+    {
+      goto use_lock;
+    }
+
+  for (int i = aconf.try_tbegin; i > 0; i--)
+    {
+      if (__libc_tbegin (0))
+	{
+	  if (*lock == 0)
+	    return 0;
+	  /* Lock was busy.  Fall back to normal locking.  */
+	  __libc_tabort (_ABORT_LOCK_BUSY);
+	}
+      else
+	{
+	  /* A persistent failure indicates that a retry will probably
+	     result in another failure.  Use normal locking now and
+	     for the next couple of calls.  */
+	  if (_TEXASRU_FAILURE_PERSISTENT (__builtin_get_texasru ()))
+	    {
+	      if (aconf.skip_lock_internal_abort > 0)
+		atomic_store_relaxed (adapt_count,
+				      aconf.skip_lock_internal_abort);
+	      goto use_lock;
+	    }
+	}
+     }
+
+  /* Fall back to locks for a bit if retries have been exhausted */
+  if (aconf.try_tbegin > 0 && aconf.skip_lock_out_of_tbegin_retries > 0)
+    atomic_store_relaxed (adapt_count,
+			  aconf.skip_lock_out_of_tbegin_retries);
+
+use_lock:
+  return LLL_LOCK ((*lock), pshared);
+}