libitm: Truncate undo log after rolling back.

	libitm/
	* local.cc (GTM::gtm_undolog::rollback): Truncate undo log after
	rolling back.
	* containers.h (GTM::vector::set_size): New.

From-SVN: r183173

libitm/ChangeLog

 2012-01-14  Torvald Riegel  <triegel@redhat.com>
 
+	* local.cc (GTM::gtm_undolog::rollback): Truncate undo log after
+	rolling back.
+	* containers.h (GTM::vector::set_size): New.
+
+2012-01-14  Torvald Riegel  <triegel@redhat.com>
+
 	PR libitm/51855
 	* config/generic/tls.h (GTM::mask_stack_top): New.
 	(GTM::mask_stack_bottom): Declare.

libitm/containers.h

@@ -92,6 +92,7 @@ class vector
   size_t size() const { return m_size; }
   size_t capacity() const { return this->capacity; }
 
+  void set_size (size_t size) { m_size = size; }
   void clear() { m_size = 0; }
 
   iterator push() {

libitm/local.cc

@@ -61,6 +61,7 @@ gtm_undolog::rollback (gtm_thread* tx, size_t until_size)
           if (likely(ptr > top || (uint8_t*)ptr + len <= bot))
             __builtin_memcpy (ptr, &undolog[i], len);
 	}
+      undolog.set_size(until_size);
     }
 }