/*

 * Copyright (c) 2003, 2017, 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/systemDictionary.hpp"

#include "interpreter/interpreter.hpp"

#include "interpreter/oopMapCache.hpp"

#include "jvmtifiles/jvmtiEnv.hpp"

#include "logging/log.hpp"

#include "logging/logStream.hpp"

#include "memory/resourceArea.hpp"

#include "oops/instanceKlass.hpp"

#include "oops/oop.inline.hpp"

#include "prims/jvmtiAgentThread.hpp"

#include "prims/jvmtiEventController.inline.hpp"

#include "prims/jvmtiImpl.hpp"

#include "prims/jvmtiRedefineClasses.hpp"

#include "runtime/atomic.hpp"

#include "runtime/deoptimization.hpp"

#include "runtime/handles.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/interfaceSupport.hpp"

#include "runtime/javaCalls.hpp"

#include "runtime/os.hpp"

#include "runtime/serviceThread.hpp"

#include "runtime/signature.hpp"

#include "runtime/thread.inline.hpp"

#include "runtime/vframe.hpp"

#include "runtime/vframe_hp.hpp"

#include "runtime/vm_operations.hpp"

#include "utilities/exceptions.hpp"

//

// class JvmtiAgentThread

//

// JavaThread used to wrap a thread started by an agent

// using the JVMTI method RunAgentThread.

//

JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)

    : JavaThread(start_function_wrapper) {

    _env = env;

    _start_fn = start_fn;

    _start_arg = start_arg;

}

void

JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {

    // It is expected that any Agent threads will be created as

    // Java Threads.  If this is the case, notification of the creation

    // of the thread is given in JavaThread::thread_main().

    assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");

    assert(thread == JavaThread::current(), "sanity check");

    JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;

    dthread->call_start_function();

}

void

JvmtiAgentThread::call_start_function() {

    ThreadToNativeFromVM transition(this);

    _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);

}

//

// class GrowableCache - private methods

//

void GrowableCache::recache() {

  int len = _elements->length();

  FREE_C_HEAP_ARRAY(address, _cache);

  _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal);

  for (int i=0; i<len; i++) {

    _cache[i] = _elements->at(i)->getCacheValue();

    //

    // The cache entry has gone bad. Without a valid frame pointer

    // value, the entry is useless so we simply delete it in product

    // mode. The call to remove() will rebuild the cache again

    // without the bad entry.

    //

    if (_cache[i] == NULL) {

      assert(false, "cannot recache NULL elements");

      remove(i);

      return;

    }

  }

  _cache[len] = NULL;

  _listener_fun(_this_obj,_cache);

}

bool GrowableCache::equals(void* v, GrowableElement *e2) {

  GrowableElement *e1 = (GrowableElement *) v;

  assert(e1 != NULL, "e1 != NULL");

  assert(e2 != NULL, "e2 != NULL");

  return e1->equals(e2);

}

//

// class GrowableCache - public methods

//

GrowableCache::GrowableCache() {

  _this_obj       = NULL;

  _listener_fun   = NULL;

  _elements       = NULL;

  _cache          = NULL;

}

GrowableCache::~GrowableCache() {

  clear();

  delete _elements;

  FREE_C_HEAP_ARRAY(address, _cache);

}

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

  _this_obj       = this_obj;

  _listener_fun   = listener_fun;

  _elements       = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true);

  recache();

}

// number of elements in the collection

int GrowableCache::length() {

  return _elements->length();

}

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

GrowableElement* GrowableCache::at(int index) {

  GrowableElement *e = (GrowableElement *) _elements->at(index);

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

  return e;

}

int GrowableCache::find(GrowableElement* e) {

  return _elements->find(e, GrowableCache::equals);

}

// append a copy of the element to the end of the collection

void GrowableCache::append(GrowableElement* e) {

  GrowableElement *new_e = e->clone();

  _elements->append(new_e);

  recache();

}

// insert a copy of the element using lessthan()

void GrowableCache::insert(GrowableElement* e) {

  GrowableElement *new_e = e->clone();

  _elements->append(new_e);

  int n = length()-2;

  for (int i=n; i>=0; i--) {

    GrowableElement *e1 = _elements->at(i);

    GrowableElement *e2 = _elements->at(i+1);

    if (e2->lessThan(e1)) {

      _elements->at_put(i+1, e1);

      _elements->at_put(i,   e2);

    }

  }

  recache();

}

// remove the element at index

void GrowableCache::remove (int index) {

  GrowableElement *e = _elements->at(index);

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

  _elements->remove(e);

  delete e;

  recache();

}

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

// let our listener know that things have changed.

void GrowableCache::clear() {

  int len = _elements->length();

  for (int i=0; i<len; i++) {

    delete _elements->at(i);

  }

  _elements->clear();

  recache();

}

void GrowableCache::oops_do(OopClosure* f) {

  int len = _elements->length();

  for (int i=0; i<len; i++) {

    GrowableElement *e = _elements->at(i);

    e->oops_do(f);

  }

}

void GrowableCache::metadata_do(void f(Metadata*)) {

  int len = _elements->length();

  for (int i=0; i<len; i++) {

    GrowableElement *e = _elements->at(i);

    e->metadata_do(f);

  }

}

void GrowableCache::gc_epilogue() {

  int len = _elements->length();

  for (int i=0; i<len; i++) {

    _cache[i] = _elements->at(i)->getCacheValue();

  }

}

//

// class JvmtiBreakpoint

//

JvmtiBreakpoint::JvmtiBreakpoint() {

  _method = NULL;

  _bci    = 0;

  _class_holder = NULL;

}

JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) {

  _method        = m_method;

  _class_holder  = _method->method_holder()->klass_holder();

#ifdef CHECK_UNHANDLED_OOPS

  // _class_holder can't be wrapped in a Handle, because JvmtiBreakpoints are

  // sometimes allocated on the heap.

  //

  // The code handling JvmtiBreakpoints allocated on the stack can't be

  // interrupted by a GC until _class_holder is reachable by the GC via the

  // oops_do method.

  Thread::current()->allow_unhandled_oop(&_class_holder);

#endif // CHECK_UNHANDLED_OOPS

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

  _bci           = (int) location;

  assert(_bci >= 0, "_bci >= 0");

}

void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {

  _method   = bp._method;

  _bci      = bp._bci;

  _class_holder = bp._class_holder;

}

bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) {

  Unimplemented();

  return false;

}

bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {

  return _method   == bp._method

    &&   _bci      == bp._bci;

}

bool JvmtiBreakpoint::is_valid() {

  // class loader can be NULL

  return _method != NULL &&

         _bci >= 0;

}

address JvmtiBreakpoint::getBcp() const {

  return _method->bcp_from(_bci);

}

void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {

  ((Method*)_method->*meth_act)(_bci);

  // add/remove breakpoint to/from versions of the method that are EMCP.

  Thread *thread = Thread::current();

  InstanceKlass* ik = _method->method_holder();

  Symbol* m_name = _method->name();

  Symbol* m_signature = _method->signature();

  // search previous versions if they exist

  for (InstanceKlass* pv_node = ik->previous_versions();

       pv_node != NULL;

       pv_node = pv_node->previous_versions()) {

    Array<Method*>* methods = pv_node->methods();

    for (int i = methods->length() - 1; i >= 0; i--) {

      Method* method = methods->at(i);

      // Only set breakpoints in running EMCP methods.

      if (method->is_running_emcp() &&

          method->name() == m_name &&

          method->signature() == m_signature) {

        ResourceMark rm;

        log_debug(redefine, class, breakpoint)

          ("%sing breakpoint in %s(%s)", meth_act == &Method::set_breakpoint ? "sett" : "clear",

           method->name()->as_C_string(), method->signature()->as_C_string());

        (method->*meth_act)(_bci);

        break;

      }

    }

  }

}

void JvmtiBreakpoint::set() {

  each_method_version_do(&Method::set_breakpoint);

}

void JvmtiBreakpoint::clear() {

  each_method_version_do(&Method::clear_breakpoint);

}

void JvmtiBreakpoint::print_on(outputStream* out) const {

#ifndef PRODUCT

  ResourceMark rm;

  const char *class_name  = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();

  const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();

  out->print("Breakpoint(%s,%s,%d,%p)", class_name, method_name, _bci, getBcp());

#endif

}

//

// class VM_ChangeBreakpoints

//

// Modify the Breakpoints data structure at a safepoint

//

void VM_ChangeBreakpoints::doit() {

  switch (_operation) {

  case SET_BREAKPOINT:

    _breakpoints->set_at_safepoint(*_bp);

    break;

  case CLEAR_BREAKPOINT:

    _breakpoints->clear_at_safepoint(*_bp);

    break;

  default:

    assert(false, "Unknown operation");

  }

}

void VM_ChangeBreakpoints::oops_do(OopClosure* f) {

  // The JvmtiBreakpoints in _breakpoints will be visited via

  // JvmtiExport::oops_do.

  if (_bp != NULL) {

    _bp->oops_do(f);

  }

}

void VM_ChangeBreakpoints::metadata_do(void f(Metadata*)) {

  // Walk metadata in breakpoints to keep from being deallocated with RedefineClasses

  if (_bp != NULL) {

    _bp->metadata_do(f);

  }

}

//

// class JvmtiBreakpoints

//

// a JVMTI internal collection of JvmtiBreakpoint

//

JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {

  _bps.initialize(this,listener_fun);

}

JvmtiBreakpoints:: ~JvmtiBreakpoints() {}

void  JvmtiBreakpoints::oops_do(OopClosure* f) {

  _bps.oops_do(f);

}

void  JvmtiBreakpoints::metadata_do(void f(Metadata*)) {

  _bps.metadata_do(f);

}

void JvmtiBreakpoints::gc_epilogue() {

  _bps.gc_epilogue();

}

void JvmtiBreakpoints::print() {

#ifndef PRODUCT

  LogTarget(Trace, jvmti) log;

  LogStreamCHeap log_stream(log);

  int n = _bps.length();

  for (int i=0; i<n; i++) {

    JvmtiBreakpoint& bp = _bps.at(i);

    log_stream.print("%d: ", i);

    bp.print_on(&log_stream);

    log_stream.cr();

  }

#endif

}

void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {

  assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");

  int i = _bps.find(bp);

  if (i == -1) {

    _bps.append(bp);

    bp.set();

  }

}

void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {

  assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");

  int i = _bps.find(bp);

  if (i != -1) {

    _bps.remove(i);

    bp.clear();

  }

}

int JvmtiBreakpoints::length() { return _bps.length(); }

int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {

  if ( _bps.find(bp) != -1) {

     return JVMTI_ERROR_DUPLICATE;

  }

  VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);

  VMThread::execute(&set_breakpoint);

  return JVMTI_ERROR_NONE;

}

int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {

  if ( _bps.find(bp) == -1) {

     return JVMTI_ERROR_NOT_FOUND;

  }

  VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);

  VMThread::execute(&clear_breakpoint);

  return JVMTI_ERROR_NONE;

}

void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) {

  bool changed = true;

  // We are going to run thru the list of bkpts

  // and delete some.  This deletion probably alters

  // the list in some implementation defined way such

  // that when we delete entry i, the next entry might

  // no longer be at i+1.  To be safe, each time we delete

  // an entry, we'll just start again from the beginning.

  // We'll stop when we make a pass thru the whole list without

  // deleting anything.

  while (changed) {

    int len = _bps.length();

    changed = false;

    for (int i = 0; i < len; i++) {

      JvmtiBreakpoint& bp = _bps.at(i);

      if (bp.method()->method_holder() == klass) {

        bp.clear();

        _bps.remove(i);

        // This changed 'i' so we have to start over.

        changed = true;

        break;

      }

    }

  }

}

//

// class JvmtiCurrentBreakpoints

//

JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints  = NULL;

address *         JvmtiCurrentBreakpoints::_breakpoint_list    = NULL;

JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {

  if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);

  _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);

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

  return (*_jvmti_breakpoints);

}

void  JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {

  JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;

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

  debug_only(int n = this_jvmti->length(););

  assert(cache[n] == NULL, "cache must be NULL terminated");

  set_breakpoint_list(cache);

}

void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {

  if (_jvmti_breakpoints != NULL) {

    _jvmti_breakpoints->oops_do(f);

  }

}

void JvmtiCurrentBreakpoints::metadata_do(void f(Metadata*)) {

  if (_jvmti_breakpoints != NULL) {

    _jvmti_breakpoints->metadata_do(f);

  }

}