--- /dev/null	2015-11-20 14:00:31.000000000 -0800
+++ new/hotspot/src/share/vm/prims/stackwalk.cpp	2015-11-20 14:00:31.000000000 -0800
@@ -0,0 +1,470 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "classfile/javaClasses.hpp"
+#include "classfile/javaClasses.inline.hpp"
+#include "classfile/vmSymbols.hpp"
+#include "memory/oopFactory.hpp"
+#include "oops/oop.inline.hpp"
+#include "oops/objArrayOop.inline.hpp"
+#include "prims/stackwalk.hpp"
+#include "runtime/globals.hpp"
+#include "runtime/handles.inline.hpp"
+#include "runtime/javaCalls.hpp"
+#include "runtime/vframe.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+// setup and cleanup actions
+void StackWalkAnchor::setup_magic_on_entry(objArrayHandle classes_array) {
+  classes_array->obj_at_put(magic_pos, _thread->threadObj());
+  _anchor = address_value();
+  assert(check_magic(classes_array), "invalid magic");
+}
+
+bool StackWalkAnchor::check_magic(objArrayHandle classes_array) {
+  oop   m1 = classes_array->obj_at(magic_pos);
+  jlong m2 = _anchor;
+  if (m1 == _thread->threadObj() && m2 == address_value())  return true;
+  return false;
+}
+
+bool StackWalkAnchor::cleanup_magic_on_exit(objArrayHandle classes_array) {
+  bool ok = check_magic(classes_array);
+  classes_array->obj_at_put(magic_pos, NULL);
+  _anchor = 0L;
+  return ok;
+}
+
+// Returns StackWalkAnchor for the current stack being traversed.
+// 
+// Parameters:
+//  thread         Current Java thread.
+//  magic          Magic value used for each stack walking
+//  classes_array  User-supplied buffers.  The 0th element is reserved
+//                 to this StackWalkAnchor to use
+//
+StackWalkAnchor* StackWalkAnchor::from_current(JavaThread* thread, jlong magic,
+                                               objArrayHandle classes_array)
+{
+  assert(thread != NULL && thread->is_Java_thread(), "");
+  oop m1 = classes_array->obj_at(magic_pos);
+  if (m1 != thread->threadObj())      return NULL;
+  if (magic == 0L)                    return NULL;
+  StackWalkAnchor* anchor = (StackWalkAnchor*) (intptr_t) magic;
+  if (!anchor->is_valid_in(thread, classes_array))   return NULL;
+  return anchor;
+}
+
+// Unpacks one or more frames into user-supplied buffers.
+// Updates the end index, and returns the number of unpacked frames.
+// Always start with the existing vfst.method and bci.
+// Do not call vfst.next to advance over the last returned value.
+// In other words, do not leave any stale data in the vfst.
+//
+// Parameters:
+//   mode           Restrict which frames to be decoded.
+//   vfst           vFrameStream.
+//   max_nframes    Maximum number of frames to be filled.
+//   start_index    Start index to the user-supplied buffers.
+//   classes_array  Buffer to store classes in, starting at start_index.
+//   frames_array   Buffer to store StackFrame in, starting at start_index.
+//                  NULL if not used.
+//   end_index      End index to the user-supplied buffers with unpacked frames.
+//
+// Returns the number of frames whose information was transferred into the buffers.
+//
+int StackWalk::fill_in_frames(jlong mode, vframeStream& vfst,
+                              int max_nframes, int start_index,
+                              objArrayHandle  classes_array,
+                              objArrayHandle  frames_array,
+                              int& end_index, TRAPS) {
+  if (TraceStackWalk) {
+    tty->print_cr("fill_in_frames limit=%d start=%d frames length=%d",
+                  max_nframes, start_index, classes_array->length());
+  }
+  assert(max_nframes > 0, "invalid max_nframes");
+  assert(start_index + max_nframes <= classes_array->length(), "oob");
+  
+  int frames_decoded = 0;
+  for (; !vfst.at_end(); vfst.next()) {
+    Method* method = vfst.method();
+    int bci = vfst.bci();
+    
+    if (method == NULL) continue;
+    if (!ShowHiddenFrames && StackWalk::skip_hidden_frames(mode)) {
+      if (method->is_hidden()) {
+        if (TraceStackWalk) {
+          tty->print("  hidden method: "); method->print_short_name();
+          tty->print("\n");
+        }
+        continue;
+      }
+    }
+    
+    int index = end_index++;
+    if (TraceStackWalk) {
+      tty->print("  %d: frame method: ", index); method->print_short_name();
+      tty->print_cr(" bci=%d", bci);
+    }
+    
+    classes_array->obj_at_put(index, method->method_holder()->java_mirror());
+    // fill in StackFrameInfo and initialize MemberName
+    if (live_frame_info(mode)) {
+      Handle stackFrame(frames_array->obj_at(index));
+      fill_live_stackframe(stackFrame, method, bci, vfst.java_frame(), CHECK_0);
+    } else if (need_method_info(mode)) {
+      Handle stackFrame(frames_array->obj_at(index));
+      fill_stackframe(stackFrame, method, bci);
+    }
+    if (++frames_decoded >= max_nframes)  break;
+  }
+  return frames_decoded;
+}
+
+static oop create_primitive_value_instance(StackValueCollection* values, int i, TRAPS) {
+  Klass* k = SystemDictionary::resolve_or_null(vmSymbols::java_lang_LiveStackFrameInfo(), CHECK_NULL);
+  instanceKlassHandle ik (THREAD, k);
+
+  JavaValue result(T_OBJECT);
+  JavaCallArguments args;
+  Symbol* signature = NULL;
+
+  // ## TODO: type is only available in LocalVariable table, if present.
+  // ## StackValue type is T_INT or T_OBJECT.
+  switch (values->at(i)->type()) {
+    case T_INT:
+      args.push_int(values->int_at(i));
+      signature = vmSymbols::asPrimitive_int_signature();
+      break;
+
+    case T_LONG:
+      args.push_long(values->long_at(i));
+      signature = vmSymbols::asPrimitive_long_signature();
+      break;
+
+    case T_FLOAT:
+      args.push_float(values->float_at(i));
+      signature = vmSymbols::asPrimitive_float_signature();
+      break;
+
+    case T_DOUBLE:
+      args.push_double(values->double_at(i));
+      signature = vmSymbols::asPrimitive_double_signature();
+      break;
+
+    case T_BYTE:
+      args.push_int(values->int_at(i));
+      signature = vmSymbols::asPrimitive_byte_signature();
+      break;
+
+    case T_SHORT:
+      args.push_int(values->int_at(i));
+      signature = vmSymbols::asPrimitive_short_signature();
+      break;
+
+    case T_CHAR:
+      args.push_int(values->int_at(i));
+      signature = vmSymbols::asPrimitive_char_signature();
+      break;
+
+    case T_BOOLEAN:
+      args.push_int(values->int_at(i));
+      signature = vmSymbols::asPrimitive_boolean_signature();
+      break;
+
+    case T_OBJECT:
+      return values->obj_at(i)();
+
+    case T_CONFLICT:
+      // put a non-null slot
+      args.push_int(0);
+      signature = vmSymbols::asPrimitive_int_signature();
+      break;
+      
+    default: ShouldNotReachHere();
+  }
+  JavaCalls::call_static(&result,
+                         ik,
+                         vmSymbols::asPrimitive_name(),
+                         signature,
+                         &args,
+                         CHECK_NULL);
+  return (instanceOop) result.get_jobject();
+}
+
+static objArrayHandle values_to_object_array(StackValueCollection* values, TRAPS) {
+  objArrayHandle empty;
+  int length = values->size();
+  objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
+                                                   length, CHECK_(empty));
+  objArrayHandle array_h(THREAD, array_oop);
+  for (int i = 0; i < values->size(); i++) {
+    StackValue* st = values->at(i);
+    oop obj = create_primitive_value_instance(values, i, CHECK_(empty));
+    if (obj != NULL)
+      array_h->obj_at_put(i, obj);
+  }
+  return array_h;
+}
+
+static objArrayHandle monitors_to_object_array(GrowableArray<MonitorInfo*>* monitors, TRAPS) {
+  int length = monitors->length();
+  objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
+                                                   length, CHECK_(objArrayHandle()));
+  objArrayHandle array_h(THREAD, array_oop);
+  for (int i = 0; i < length; i++) {
+    MonitorInfo* monitor = monitors->at(i);
+    array_h->obj_at_put(i, monitor->owner());
+  }
+  return array_h;
+}
+
+// Fill StackFrameInfo with declaringClass and bci and initialize memberName
+void StackWalk::fill_stackframe(Handle stackFrame, const methodHandle& method, int bci) {
+  java_lang_StackFrameInfo::set_declaringClass(stackFrame(), method->method_holder()->java_mirror());
+  java_lang_StackFrameInfo::set_method_and_bci(stackFrame(), method, bci);
+}
+
+// Fill LiveStackFrameInfo with locals, monitors, and expressions
+void StackWalk::fill_live_stackframe(Handle stackFrame, const methodHandle& method,
+                                     int bci, javaVFrame* jvf, TRAPS) {
+  fill_stackframe(stackFrame, method, bci);
+  if (jvf != NULL) {
+    StackValueCollection* locals = jvf->locals();
+    StackValueCollection* expressions = jvf->expressions();
+    GrowableArray<MonitorInfo*>* monitors = jvf->monitors();
+
+    if (!locals->is_empty()) {
+      objArrayHandle locals_h = values_to_object_array(locals, CHECK);
+      java_lang_LiveStackFrameInfo::set_locals(stackFrame(), locals_h());
+    }
+    if (!expressions->is_empty()) {
+      objArrayHandle expressions_h = values_to_object_array(expressions, CHECK);
+      java_lang_LiveStackFrameInfo::set_operands(stackFrame(), expressions_h());
+    }
+    if (monitors->length() > 0) {
+      objArrayHandle monitors_h = monitors_to_object_array(monitors, CHECK);
+      java_lang_LiveStackFrameInfo::set_monitors(stackFrame(), monitors_h());
+    }
+  }
+}
+
+// Begins stack walking.
+//
+// Parameters:
+//   stackStream    StackStream object
+//   mode           Stack walking mode.
+//   skip_frames    Number of frames to be skipped.
+//   frame_count    Number of frames to be traversed.
+//   start_index    Start index to the user-supplied buffers.
+//   classes_array  Buffer to store classes in, starting at start_index.
+//   frames_array   Buffer to store StackFrame in, starting at start_index.
+//                  NULL if not used.
+//
+// Returns Object returned from AbstractStackWalker::doStackWalk call.
+//
+oop StackWalk::walk(Handle stackStream, jlong mode,
+                    int skip_frames, int frame_count, int start_index,
+                    objArrayHandle classes_array,
+                    objArrayHandle frames_array,
+                    TRAPS) {
+  JavaThread* jt = (JavaThread*)THREAD;
+  if (TraceStackWalk) {
+    tty->print_cr("Start walking: mode " JLONG_FORMAT " skip %d frames batch size %d",
+                  mode, skip_frames, frame_count);
+  }
+
+  if (need_method_info(mode)) {
+    if (frames_array.is_null()) {
+      THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL);
+    }
+  }
+
+  Klass* stackWalker_klass = SystemDictionary::StackWalker_klass();
+  Klass* abstractStackWalker_klass = SystemDictionary::AbstractStackWalker_klass();
+
+  methodHandle m_doStackWalk(THREAD, Universe::do_stack_walk_method());
+
+  // Open up a traversable stream onto my stack.
+  // This stream will be made available by *reference* to the inner Java call.
+  StackWalkAnchor anchor(jt);
+  vframeStream& vfst = anchor.vframe_stream();
+
+  {
+    // Skip all methods from AbstractStackWalker and StackWalk (enclosing method)
+    if (!fill_in_stacktrace(mode)) {
+      while (!vfst.at_end()) {
+        InstanceKlass* ik = vfst.method()->method_holder();
+        if (ik != stackWalker_klass &&
+              ik != abstractStackWalker_klass && ik->super() != abstractStackWalker_klass)  {
+          break;
+        }
+
+        if (TraceStackWalk) {
+          tty->print("  skip "); vfst.method()->print_short_name(); tty->print("\n");
+        }
+        vfst.next();
+      }
+    }
+
+    // For exceptions, skip Throwable::fillInStackTrace and <init> methods
+    // of the exception class and superclasses
+    if (fill_in_stacktrace(mode)) {
+      bool skip_to_fillInStackTrace = false;
+      bool skip_throwableInit_check = false;
+      while (!vfst.at_end() && !skip_throwableInit_check) {
+        InstanceKlass* ik = vfst.method()->method_holder();
+        Method* method = vfst.method();
+        if (!skip_to_fillInStackTrace) {
+          if (ik == SystemDictionary::Throwable_klass() &&
+              method->name() == vmSymbols::fillInStackTrace_name()) {
+              // this frame will be skipped
+              skip_to_fillInStackTrace = true;
+          }
+        } else if (!(ik->is_subclass_of(SystemDictionary::Throwable_klass()) &&
+                     method->name() == vmSymbols::object_initializer_name())) {
+            // there are none or we've seen them all - either way stop checking
+            skip_throwableInit_check = true;
+            break;
+        }
+
+        if (TraceStackWalk) {
+          tty->print("stack walk: skip "); vfst.method()->print_short_name(); tty->print("\n");
+        }
+        vfst.next();
+      }
+    }
+
+    // stack frame has been traversed individually and resume stack walk
+    // from the stack frame at depth == skip_frames.
+    for (int n=0; n < skip_frames && !vfst.at_end(); vfst.next(), n++) {
+      if (TraceStackWalk) {
+        tty->print("  skip "); vfst.method()->print_short_name();
+        tty->print_cr(" frame id: " PTR_FORMAT " pc: " PTR_FORMAT,
+                      p2i(vfst.frame_id()), p2i(vfst.frame_pc()));
+      }
+    }
+  }
+
+  // The Method* pointer in the vfst has a very short shelf life.  Grab it now.
+  int end_index = start_index;
+  int numFrames = 0;
+  if (!vfst.at_end()) {
+    numFrames = fill_in_frames(mode, vfst, frame_count, start_index, classes_array,
+                               frames_array, end_index, CHECK_NULL);
+    if (numFrames < 1) {
+      THROW_MSG_(vmSymbols::java_lang_InternalError(), "stack walk: decode failed", NULL);
+    }
+  }
+
+  // JVM_CallStackWalk walks the stack and fills in stack frames, then calls to
+  // Java method java.lang.StackStreamFactory.AbstractStackWalker::doStackWalk
+  // which calls the implementation to consume the stack frames.
+  // When JVM_CallStackWalk returns, it invalidates the stack stream.
+  JavaValue result(T_OBJECT);
+  JavaCallArguments args(stackStream);
+  args.push_long(anchor.address_value());
+  args.push_int(skip_frames);
+  args.push_int(frame_count);
+  args.push_int(start_index);
+  args.push_int(end_index);
+
+  // Link the thread and vframe stream into the callee-visible object
+  anchor.setup_magic_on_entry(classes_array);
+
+  JavaCalls::call(&result, m_doStackWalk, &args, THREAD);
+
+  // Do this before anything else happens, to disable any lingering stream objects
+  bool ok = anchor.cleanup_magic_on_exit(classes_array);
+
+  // Throw pending exception if we must
+  (void) (CHECK_NULL);
+
+  if (!ok) {
+    THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers on exit", NULL);
+  }
+
+  // Return normally
+  return (oop)result.get_jobject();
+
+}
+
+// Walk the next batch of stack frames
+//
+// Parameters:
+//   stackStream    StackStream object
+//   mode           Stack walking mode.
+//   magic          Must be valid value to continue the stack walk
+//   frame_count    Number of frames to be decoded.
+//   start_index    Start index to the user-supplied buffers.
+//   classes_array  Buffer to store classes in, starting at start_index.
+//   frames_array   Buffer to store StackFrame in, starting at start_index.
+//                  NULL if not used.
+//
+// Returns the end index of frame filled in the buffer.
+//
+jint StackWalk::moreFrames(Handle stackStream, jlong mode, jlong magic,
+                           int frame_count, int start_index,
+                           objArrayHandle classes_array,
+                           objArrayHandle frames_array,
+                           TRAPS)
+{
+  JavaThread* jt = (JavaThread*)THREAD;
+  StackWalkAnchor* existing_anchor = StackWalkAnchor::from_current(jt, magic, classes_array);
+  if (existing_anchor == NULL) {
+    THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers", 0L);
+  }
+
+  if ((need_method_info(mode) || live_frame_info(mode)) && frames_array.is_null()) {
+    THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", 0L);
+  }
+
+  if (TraceStackWalk) {
+    tty->print_cr("StackWalk::moreFrames frame_count %d existing_anchor " PTR_FORMAT " start %d frames %d",
+                  frame_count, p2i(existing_anchor), start_index, classes_array->length());
+  }
+  int end_index = start_index;
+  if (frame_count <= 0) {
+    return end_index;        // No operation.
+  }
+
+  int count = frame_count + start_index;
+  assert (classes_array->length() >= count, "not enough space in buffers");
+
+  StackWalkAnchor& anchor = (*existing_anchor);
+  vframeStream& vfst = anchor.vframe_stream();
+  if (!vfst.at_end()) {
+    vfst.next();  // this was the last frame decoded in the previous batch
+    if (!vfst.at_end()) {
+      int n = fill_in_frames(mode, vfst, frame_count, start_index, classes_array,
+                             frames_array, end_index, CHECK_0);
+      if (n < 1) {
+        THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: later decode failed", 0L);
+      }
+      return end_index;
+    }
+  }
+  return end_index;
+}