/*

 * Copyright (c) 1999, 2018, 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.

 *

 */

#ifndef SHARE_VM_PRIMS_JVMTIIMPL_HPP

#define SHARE_VM_PRIMS_JVMTIIMPL_HPP

#include "classfile/systemDictionary.hpp"

#include "jvmtifiles/jvmti.h"

#include "oops/objArrayOop.hpp"

#include "prims/jvmtiEnvThreadState.hpp"

#include "prims/jvmtiEventController.hpp"

#include "prims/jvmtiTrace.hpp"

#include "prims/jvmtiUtil.hpp"

#include "runtime/stackValueCollection.hpp"

#include "runtime/vm_operations.hpp"

#include "utilities/ostream.hpp"

//

// Forward Declarations

//

class JvmtiBreakpoint;

class JvmtiBreakpoints;

///////////////////////////////////////////////////////////////

//

// class GrowableCache, GrowableElement

// Used by              : JvmtiBreakpointCache

// Used by JVMTI methods: none directly.

//

// GrowableCache is a permanent CHeap growable array of <GrowableElement *>

//

// In addition, the GrowableCache maintains a NULL terminated cache array of type address

// that's created from the element array using the function:

//     address GrowableElement::getCacheValue().

//

// Whenever the GrowableArray changes size, the cache array gets recomputed into a new C_HEAP allocated

// block of memory. Additionally, every time the cache changes its position in memory, the

//    void (*_listener_fun)(void *this_obj, address* cache)

// gets called with the cache's new address. This gives the user of the GrowableCache a callback

// to update its pointer to the address cache.

//

class GrowableElement : public CHeapObj<mtInternal> {

public:

  virtual ~GrowableElement() {}

  virtual address getCacheValue()          =0;

  virtual bool equals(GrowableElement* e)  =0;

  virtual bool lessThan(GrowableElement *e)=0;

  virtual GrowableElement *clone()         =0;

  virtual void oops_do(OopClosure* f)      =0;

  virtual void metadata_do(void f(Metadata*)) =0;

};

class GrowableCache {

private:

  // Object pointer passed into cache & listener functions.

  void *_this_obj;

  // Array of elements in the collection

  GrowableArray<GrowableElement *> *_elements;

  // Parallel array of cached values

  address *_cache;

  // Listener for changes to the _cache field.

  // Called whenever the _cache field has it's value changed

  // (but NOT when cached elements are recomputed).

  void (*_listener_fun)(void *, address*);

  static bool equals(void *, GrowableElement *);

  // recache all elements after size change, notify listener

  void recache();

public:

   GrowableCache();

   ~GrowableCache();

  void initialize(void *this_obj, void listener_fun(void *, address*) );

  // number of elements in the collection

  int length();

  // get the value of the index element in the collection

  GrowableElement* at(int index);

  // find the index of the element, -1 if it doesn't exist

  int find(GrowableElement* e);

  // append a copy of the element to the end of the collection, notify listener

  void append(GrowableElement* e);

  // insert a copy of the element using lessthan(), notify listener

  void insert(GrowableElement* e);

  // remove the element at index, notify listener

  void remove (int index);

  // clear out all elements and release all heap space, notify listener

  void clear();

  // apply f to every element and update the cache

  void oops_do(OopClosure* f);

  // walk metadata to preserve for RedefineClasses

  void metadata_do(void f(Metadata*));

  // update the cache after a full gc

  void gc_epilogue();

};

///////////////////////////////////////////////////////////////

//

// class JvmtiBreakpointCache

// Used by              : JvmtiBreakpoints

// Used by JVMTI methods: none directly.

// Note   : typesafe wrapper for GrowableCache of JvmtiBreakpoint

//

class JvmtiBreakpointCache : public CHeapObj<mtInternal> {

private:

  GrowableCache _cache;

public:

  JvmtiBreakpointCache()  {}

  ~JvmtiBreakpointCache() {}

  void initialize(void *this_obj, void listener_fun(void *, address*) ) {

    _cache.initialize(this_obj,listener_fun);

  }

  int length()                          { return _cache.length(); }

  JvmtiBreakpoint& at(int index)        { return (JvmtiBreakpoint&) *(_cache.at(index)); }

  int find(JvmtiBreakpoint& e)          { return _cache.find((GrowableElement *) &e); }

  void append(JvmtiBreakpoint& e)       { _cache.append((GrowableElement *) &e); }

  void remove (int index)               { _cache.remove(index); }

  void clear()                          { _cache.clear(); }

  void oops_do(OopClosure* f)           { _cache.oops_do(f); }

  void metadata_do(void f(Metadata*))   { _cache.metadata_do(f); }

  void gc_epilogue()                    { _cache.gc_epilogue(); }

};

///////////////////////////////////////////////////////////////

//

// class JvmtiBreakpoint

// Used by              : JvmtiBreakpoints

// Used by JVMTI methods: SetBreakpoint, ClearBreakpoint, ClearAllBreakpoints

// Note: Extends GrowableElement for use in a GrowableCache

//

// A JvmtiBreakpoint describes a location (class, method, bci) to break at.

//

typedef void (Method::*method_action)(int _bci);

class JvmtiBreakpoint : public GrowableElement {

private:

  Method*               _method;

  int                   _bci;

  Bytecodes::Code       _orig_bytecode;

  oop                   _class_holder;  // keeps _method memory from being deallocated

public:

  JvmtiBreakpoint();

  JvmtiBreakpoint(Method* m_method, jlocation location);

  bool equals(JvmtiBreakpoint& bp);

  bool lessThan(JvmtiBreakpoint &bp);

  void copy(JvmtiBreakpoint& bp);

  bool is_valid();

  address getBcp() const;

  void each_method_version_do(method_action meth_act);

  void set();

  void clear();

  void print_on(outputStream* out) const;

  Method* method() { return _method; }

  // GrowableElement implementation

  address getCacheValue()         { return getBcp(); }

  bool lessThan(GrowableElement* e) { Unimplemented(); return false; }

  bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); }

  void oops_do(OopClosure* f)     {

    // Mark the method loader as live so the Method* class loader doesn't get

    // unloaded and Method* memory reclaimed.

    f->do_oop(&_class_holder);

  }

  void metadata_do(void f(Metadata*)) {

    // walk metadata to preserve for RedefineClasses

    f(_method);

  }

  GrowableElement *clone()        {

    JvmtiBreakpoint *bp = new JvmtiBreakpoint();

    bp->copy(*this);

    return bp;

  }

};

///////////////////////////////////////////////////////////////

//

// class JvmtiBreakpoints

// Used by              : JvmtiCurrentBreakpoints

// Used by JVMTI methods: none directly

// Note: A Helper class

//

// JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint.

// All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints.

//

// Because _bps is only modified at safepoints, its possible to always use the

// cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints).

//

// It would be possible to make JvmtiBreakpoints a static class, but I've made it

// CHeap allocated to emphasize its similarity to JvmtiFramePops.

//

class JvmtiBreakpoints : public CHeapObj<mtInternal> {

private:

  JvmtiBreakpointCache _bps;

  // These should only be used by VM_ChangeBreakpoints

  // to insure they only occur at safepoints.

  // Todo: add checks for safepoint

  friend class VM_ChangeBreakpoints;

  void set_at_safepoint(JvmtiBreakpoint& bp);

  void clear_at_safepoint(JvmtiBreakpoint& bp);

  static void do_element(GrowableElement *e);

public:

  JvmtiBreakpoints(void listener_fun(void *, address *));

  ~JvmtiBreakpoints();

  int length();

  void oops_do(OopClosure* f);

  void metadata_do(void f(Metadata*));

  void print();

  int  set(JvmtiBreakpoint& bp);

  int  clear(JvmtiBreakpoint& bp);

  void clearall_in_class_at_safepoint(Klass* klass);

  void gc_epilogue();

};

///////////////////////////////////////////////////////////////

//

// class JvmtiCurrentBreakpoints

//

// A static wrapper class for the JvmtiBreakpoints that provides:

// 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint).

// 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary,

//    but I'm copying the code from JvmtiThreadState which needs to lazily initialize

//    JvmtiFramePops).

// 3. An oops_do entry point for GC'ing the breakpoint array.

//

class JvmtiCurrentBreakpoints : public AllStatic {

private:

  // Current breakpoints, lazily initialized by get_jvmti_breakpoints();

  static JvmtiBreakpoints *_jvmti_breakpoints;

  // NULL terminated cache of byte-code pointers corresponding to current breakpoints.

  // Updated only at safepoints (with listener_fun) when the cache is moved.

  // It exists only to make is_breakpoint fast.

  static address          *_breakpoint_list;

  static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; }

  static inline address *get_breakpoint_list()                     { return _breakpoint_list; }

  // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list.

  static void listener_fun(void *this_obj, address *cache);

public:

  static void initialize();

  static void destroy();

  // lazily create _jvmti_breakpoints and _breakpoint_list

  static JvmtiBreakpoints& get_jvmti_breakpoints();

  // quickly test whether the bcp matches a cached breakpoint in the list

  static inline bool is_breakpoint(address bcp);

  static void oops_do(OopClosure* f);

  static void metadata_do(void f(Metadata*)) NOT_JVMTI_RETURN;

  static void gc_epilogue();

};

// quickly test whether the bcp matches a cached breakpoint in the list

bool JvmtiCurrentBreakpoints::is_breakpoint(address bcp) {

    address *bps = get_breakpoint_list();

    if (bps == NULL) return false;

    for ( ; (*bps) != NULL; bps++) {

      if ((*bps) == bcp) return true;

    }

    return false;

}

///////////////////////////////////////////////////////////////

//

// class VM_ChangeBreakpoints

// Used by              : JvmtiBreakpoints

// Used by JVMTI methods: none directly.

// Note: A Helper class.

//

// VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class.

//

class VM_ChangeBreakpoints : public VM_Operation {

private:

  JvmtiBreakpoints* _breakpoints;

  int               _operation;

  JvmtiBreakpoint*  _bp;

public:

  enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1 };

  VM_ChangeBreakpoints(int operation, JvmtiBreakpoint *bp) {

    JvmtiBreakpoints& current_bps = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();

    _breakpoints = &current_bps;

    _bp = bp;

    _operation = operation;

    assert(bp != NULL, "bp != NULL");

  }

  VMOp_Type type() const { return VMOp_ChangeBreakpoints; }

  void doit();

  void oops_do(OopClosure* f);

  void metadata_do(void f(Metadata*));

};

///////////////////////////////////////////////////////////////

// The get/set local operations must only be done by the VM thread

// because the interpreter version needs to access oop maps, which can

// only safely be done by the VM thread

//

// I'm told that in 1.5 oop maps are now protected by a lock and

// we could get rid of the VM op

// However if the VM op is removed then the target thread must

// be suspended AND a lock will be needed to prevent concurrent

// setting of locals to the same java thread. This lock is needed

// to prevent compiledVFrames from trying to add deferred updates

// to the thread simultaneously.

//

class VM_GetOrSetLocal : public VM_Operation {

 protected:

  JavaThread* _thread;

  JavaThread* _calling_thread;

  jint        _depth;

  jint        _index;

  BasicType   _type;

  jvalue      _value;

  javaVFrame* _jvf;

  bool        _set;

  // It is possible to get the receiver out of a non-static native wrapper

  // frame.  Use VM_GetReceiver to do this.

  virtual bool getting_receiver() const { return false; }

  jvmtiError  _result;

  vframe* get_vframe();

  javaVFrame* get_java_vframe();

  bool check_slot_type(javaVFrame* vf);

public:

  // Constructor for non-object getter

  VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type);

  // Constructor for object or non-object setter

  VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value);

  // Constructor for object getter

  VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth,

                   int index);

  VMOp_Type type() const { return VMOp_GetOrSetLocal; }

  jvalue value()         { return _value; }

  jvmtiError result()    { return _result; }

  bool doit_prologue();

  void doit();

  bool allow_nested_vm_operations() const;

  const char* name() const                       { return "get/set locals"; }

  // Check that the klass is assignable to a type with the given signature.

  static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread);

};

class VM_GetReceiver : public VM_GetOrSetLocal {

 protected:

  virtual bool getting_receiver() const { return true; }

 public:

  VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth);

  const char* name() const                       { return "get receiver"; }

};

///////////////////////////////////////////////////////////////

//

// class JvmtiSuspendControl

//

// Convenience routines for suspending and resuming threads.

//

// All attempts by JVMTI to suspend and resume threads must go through the

// JvmtiSuspendControl interface.

//

// methods return true if successful

//

class JvmtiSuspendControl : public AllStatic {

public:

  // suspend the thread, taking it to a safepoint

  static bool suspend(JavaThread *java_thread);

  // resume the thread

  static bool resume(JavaThread *java_thread);

  static void print();

};

/**

 * When a thread (such as the compiler thread or VM thread) cannot post a

 * JVMTI event itself because the event needs to be posted from a Java

 * thread, then it can defer the event to the Service thread for posting.

 * The information needed to post the event is encapsulated into this class

 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service

 * thread will pick it up and post it.

 *

 * This is currently only used for posting compiled-method-load and unload

 * events, which we don't want posted from the compiler thread.

 */

class JvmtiDeferredEvent {

  friend class JvmtiDeferredEventQueue;

 private:

  typedef enum {

    TYPE_NONE,

    TYPE_COMPILED_METHOD_LOAD,

    TYPE_COMPILED_METHOD_UNLOAD,

    TYPE_DYNAMIC_CODE_GENERATED

  } Type;

  Type _type;

  union {

    nmethod* compiled_method_load;

    struct {

      nmethod* nm;

      jmethodID method_id;

      const void* code_begin;

    } compiled_method_unload;

    struct {

      const char* name;

      const void* code_begin;

      const void* code_end;

    } dynamic_code_generated;

  } _event_data;

  JvmtiDeferredEvent(Type t) : _type(t) {}

 public:

  JvmtiDeferredEvent() : _type(TYPE_NONE) {}

  // Factory methods

  static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm)

    NOT_JVMTI_RETURN_(JvmtiDeferredEvent());

  static JvmtiDeferredEvent compiled_method_unload_event(nmethod* nm,

      jmethodID id, const void* code) NOT_JVMTI_RETURN_(JvmtiDeferredEvent());

  static JvmtiDeferredEvent dynamic_code_generated_event(

      const char* name, const void* begin, const void* end)

          NOT_JVMTI_RETURN_(JvmtiDeferredEvent());

  // Actually posts the event.

  void post() NOT_JVMTI_RETURN;

};

/**

 * Events enqueued on this queue wake up the Service thread which dequeues

 * and posts the events.  The Service_lock is required to be held

 * when operating on the queue.

 */

class JvmtiDeferredEventQueue : AllStatic {

  friend class JvmtiDeferredEvent;

 private:

  class QueueNode : public CHeapObj<mtInternal> {

   private:

    JvmtiDeferredEvent _event;

    QueueNode* _next;

   public: