--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/os_cpu/linux_zero/vm/thread_linux_zero.hpp	Tue Oct 13 12:04:21 2009 -0700
@@ -0,0 +1,104 @@
+/*
+ * Copyright 2000-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2007, 2008, 2009 Red Hat, Inc.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+ private:
+  ZeroStack  _zero_stack;
+  ZeroFrame* _top_zero_frame;
+
+  void pd_initialize() {
+    _top_zero_frame = NULL;
+  }
+
+ public:
+  ZeroStack *zero_stack() {
+    return &_zero_stack;
+  }
+
+ public:
+  ZeroFrame *top_zero_frame() {
+    return _top_zero_frame;
+  }
+  void push_zero_frame(ZeroFrame *frame) {
+    *(ZeroFrame **) frame = _top_zero_frame;
+    _top_zero_frame = frame;
+  }
+  void pop_zero_frame() {
+    zero_stack()->set_sp((intptr_t *) _top_zero_frame + 1);
+    _top_zero_frame = *(ZeroFrame **) _top_zero_frame;
+  }
+
+ public:
+  static ByteSize zero_stack_offset() {
+    return byte_offset_of(JavaThread, _zero_stack);
+  }
+  static ByteSize top_zero_frame_offset() {
+    return byte_offset_of(JavaThread, _top_zero_frame);
+  }
+
+ public:
+  void record_base_of_stack_pointer() {
+    assert(top_zero_frame() == NULL, "junk on stack prior to Java call");
+  }
+  void set_base_of_stack_pointer(intptr_t* base_sp) {
+    assert(base_sp == NULL, "should be");
+    assert(top_zero_frame() == NULL, "junk on stack after Java call");
+  }
+
+ public:
+  void set_last_Java_frame() {
+    JavaFrameAnchor *jfa = frame_anchor();
+    jfa->set_last_Java_sp((intptr_t *) top_zero_frame());
+  }
+  void reset_last_Java_frame() {
+    JavaFrameAnchor *jfa = frame_anchor();
+    jfa->set_last_Java_sp(NULL);
+  }
+
+ private:
+  frame pd_last_frame() {
+    assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
+    return frame(last_Java_sp(), zero_stack()->sp());
+  }
+
+ public:
+  // Check for pending suspend requests and pending asynchronous
+  // exceptions.  There are separate accessors for these, but
+  // _suspend_flags is volatile so using them would be unsafe.
+  bool has_special_condition_for_native_trans() {
+    return _suspend_flags != 0;
+  }
+
+ public:
+  bool pd_get_top_frame_for_signal_handler(frame* fr_addr,
+                                           void* ucontext,
+                                           bool isInJava) {
+    ShouldNotCallThis();
+  }
+
+  // These routines are only used on cpu architectures that
+  // have separate register stacks (Itanium).
+  static bool register_stack_overflow() { return false; }
+  static void enable_register_stack_guard() {}
+  static void disable_register_stack_guard() {}