1 /*
   2  * Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 
  26 #ifndef SHARE_PRIMS_STACKWALK_HPP
  27 #define SHARE_PRIMS_STACKWALK_HPP
  28 
  29 #include "oops/oop.hpp"
  30 #include "runtime/vframe.hpp"
  31 
  32 // BaseFrameStream is an abstract base class for encapsulating the VM-side
  33 // implementation of the StackWalker API.  There are two concrete subclasses:
  34 // - JavaFrameStream:
  35 //     -based on vframeStream; used in most instances
  36 // - LiveFrameStream:
  37 //     -based on javaVFrame; used for retrieving locals/monitors/operands for
  38 //      LiveStackFrame
  39 class BaseFrameStream : public StackObj {
  40 private:
  41   enum {
  42     magic_pos = 0
  43   };
  44 
  45   JavaThread*           _thread;
  46   jlong                 _anchor;
  47 protected:
  48   void fill_stackframe(Handle stackFrame, const methodHandle& method, TRAPS);
  49 public:
  50   BaseFrameStream(JavaThread* thread) : _thread(thread), _anchor(0L) {}
  51 
  52   virtual void    next()=0;
  53   virtual bool    at_end()=0;
  54 
  55   virtual Method* method()=0;
  56   virtual int     bci()=0;
  57 
  58   virtual void    fill_frame(int index, objArrayHandle  frames_array,
  59                              const methodHandle& method, TRAPS)=0;
  60 
  61   void setup_magic_on_entry(objArrayHandle frames_array);
  62   bool check_magic(objArrayHandle frames_array);
  63   bool cleanup_magic_on_exit(objArrayHandle frames_array);
  64 
  65   bool is_valid_in(Thread* thread, objArrayHandle frames_array) {
  66     return (_thread == thread && check_magic(frames_array));
  67   }
  68 
  69   jlong address_value() {
  70     return (jlong) castable_address(this);
  71   }
  72 
  73   static BaseFrameStream* from_current(JavaThread* thread, jlong magic, objArrayHandle frames_array);
  74 };
  75 
  76 class JavaFrameStream : public BaseFrameStream {
  77 private:
  78   vframeStream          _vfst;
  79   bool                  _need_method_info;
  80 public:
  81   JavaFrameStream(JavaThread* thread, int mode);
  82 
  83   void next();
  84   bool at_end()    { return _vfst.at_end(); }
  85 
  86   Method* method() { return _vfst.method(); }
  87   int bci()        { return _vfst.bci(); }
  88 
  89   void fill_frame(int index, objArrayHandle  frames_array,
  90                   const methodHandle& method, TRAPS);
  91 };
  92 
  93 class LiveFrameStream : public BaseFrameStream {
  94 private:
  95   enum {
  96     MODE_INTERPRETED = 0x01,
  97     MODE_COMPILED    = 0x02
  98   };
  99 
 100   javaVFrame*           _jvf;
 101 
 102   void fill_live_stackframe(Handle stackFrame, const methodHandle& method, TRAPS);
 103   static oop create_primitive_slot_instance(StackValueCollection* values,
 104                                             int i, BasicType type, TRAPS);
 105   static objArrayHandle monitors_to_object_array(GrowableArray<MonitorInfo*>* monitors,
 106                                                  TRAPS);
 107   static objArrayHandle values_to_object_array(StackValueCollection* values, TRAPS);
 108 public:
 109   LiveFrameStream(JavaThread* thread, RegisterMap* rm) : BaseFrameStream(thread) {
 110     _jvf = thread->last_java_vframe(rm);
 111   }
 112 
 113   void next()      { _jvf = _jvf->java_sender(); }
 114   bool at_end()    { return _jvf == NULL; }
 115 
 116   Method* method() { return _jvf->method(); }
 117   int bci()        { return _jvf->bci(); }
 118 
 119   void fill_frame(int index, objArrayHandle  frames_array,
 120                   const methodHandle& method, TRAPS);
 121 };
 122 
 123 class StackWalk : public AllStatic {
 124 private:
 125   static int fill_in_frames(jlong mode, BaseFrameStream& stream,
 126                             int max_nframes, int start_index,
 127                             objArrayHandle frames_array,
 128                             int& end_index, TRAPS);
 129 
 130   static inline bool get_caller_class(int mode) {
 131     return (mode & JVM_STACKWALK_GET_CALLER_CLASS) != 0;
 132   }
 133   static inline bool skip_hidden_frames(int mode) {
 134     return (mode & JVM_STACKWALK_SHOW_HIDDEN_FRAMES) == 0;
 135   }
 136   static inline bool live_frame_info(int mode) {
 137     return (mode & JVM_STACKWALK_FILL_LIVE_STACK_FRAMES) != 0;
 138   }
 139 
 140 public:
 141   static inline bool need_method_info(int mode) {
 142     return (mode & JVM_STACKWALK_FILL_CLASS_REFS_ONLY) == 0;
 143   }
 144   static inline bool use_frames_array(int mode) {
 145     return (mode & JVM_STACKWALK_FILL_CLASS_REFS_ONLY) == 0;
 146   }
 147   static oop walk(Handle stackStream, jlong mode,
 148                   int skip_frames, int frame_count, int start_index,
 149                   objArrayHandle frames_array,
 150                   TRAPS);
 151 
 152   static oop fetchFirstBatch(BaseFrameStream& stream, Handle stackStream,
 153                              jlong mode, int skip_frames, int frame_count,
 154                              int start_index, objArrayHandle frames_array, TRAPS);
 155 
 156   static jint fetchNextBatch(Handle stackStream, jlong mode, jlong magic,
 157                              int frame_count, int start_index,
 158                              objArrayHandle frames_array, TRAPS);
 159 };
 160 #endif // SHARE_PRIMS_STACKWALK_HPP