runtime/debugger.h

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * Dalvik-specific side of debugger support.  (The JDWP code is intended to
 * be relatively generic.)
 */
#ifndef ART_RUNTIME_DEBUGGER_H_
#define ART_RUNTIME_DEBUGGER_H_

#include <pthread.h>

#include <map>
#include <set>
#include <string>
#include <vector>

#include "gc_root.h"
#include "jdwp/jdwp.h"
#include "jni.h"
#include "jvalue.h"
#include "object_callbacks.h"
#include "thread_state.h"

namespace art {
namespace mirror {
class ArtField;
class ArtMethod;
class Class;
class Object;
class Throwable;
}  // namespace mirror
class AllocRecord;
class ObjectRegistry;
class ScopedObjectAccessUnchecked;
class StackVisitor;
class Thread;
class ThrowLocation;

/*
 * Invoke-during-breakpoint support.
 */
struct DebugInvokeReq {
  DebugInvokeReq()
      : ready(false), invoke_needed(false),
        receiver(NULL), thread(NULL), klass(NULL), method(NULL),
        arg_count(0), arg_values(NULL), options(0), error(JDWP::ERR_NONE),
        result_tag(JDWP::JT_VOID), exception(0),
        lock("a DebugInvokeReq lock", kBreakpointInvokeLock),
        cond("a DebugInvokeReq condition variable", lock) {
  }

  /* boolean; only set when we're in the tail end of an event handler */
  bool ready;

  /* boolean; set if the JDWP thread wants this thread to do work */
  bool invoke_needed;

  /* request */
  mirror::Object* receiver;      /* not used for ClassType.InvokeMethod */
  mirror::Object* thread;
  mirror::Class* klass;
  mirror::ArtMethod* method;
  uint32_t arg_count;
  uint64_t* arg_values;   /* will be NULL if arg_count_ == 0 */
  uint32_t options;

  /* result */
  JDWP::JdwpError error;
  JDWP::JdwpTag result_tag;
  JValue result_value;
  JDWP::ObjectId exception;

  /* condition variable to wait on while the method executes */
  Mutex lock DEFAULT_MUTEX_ACQUIRED_AFTER;
  ConditionVariable cond GUARDED_BY(lock);

  void VisitRoots(RootCallback* callback, void* arg, const RootInfo& root_info)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  void Clear();

 private:
  DISALLOW_COPY_AND_ASSIGN(DebugInvokeReq);
};

// Thread local data-structure that holds fields for controlling single-stepping.
struct SingleStepControl {
  SingleStepControl()
      : is_active(false), step_size(JDWP::SS_MIN), step_depth(JDWP::SD_INTO),
        method(nullptr), stack_depth(0) {
  }

  // Are we single-stepping right now?
  bool is_active;

  // See JdwpStepSize and JdwpStepDepth for details.
  JDWP::JdwpStepSize step_size;
  JDWP::JdwpStepDepth step_depth;

  // The location this single-step was initiated from.
  // A single-step is initiated in a suspended thread. We save here the current method and the
  // set of DEX pcs associated to the source line number where the suspension occurred.
  // This is used to support SD_INTO and SD_OVER single-step depths so we detect when a single-step
  // causes the execution of an instruction in a different method or at a different line number.
  mirror::ArtMethod* method;
  std::set<uint32_t> dex_pcs;

  // The stack depth when this single-step was initiated. This is used to support SD_OVER and SD_OUT
  // single-step depth.
  int stack_depth;

  void VisitRoots(RootCallback* callback, void* arg, const RootInfo& root_info)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  bool ContainsDexPc(uint32_t dex_pc) const;

  void Clear();

 private:
  DISALLOW_COPY_AND_ASSIGN(SingleStepControl);
};

// TODO rename to InstrumentationRequest.
class DeoptimizationRequest {
 public:
  enum Kind {
    kNothing,                   // no action.
    kRegisterForEvent,          // start listening for instrumentation event.
    kUnregisterForEvent,        // stop listening for instrumentation event.
    kFullDeoptimization,        // deoptimize everything.
    kFullUndeoptimization,      // undeoptimize everything.
    kSelectiveDeoptimization,   // deoptimize one method.
    kSelectiveUndeoptimization  // undeoptimize one method.
  };

  DeoptimizationRequest() : kind_(kNothing), instrumentation_event_(0), method_(nullptr) {}

  DeoptimizationRequest(const DeoptimizationRequest& other)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
      : kind_(other.kind_), instrumentation_event_(other.instrumentation_event_) {
    // Create a new JNI global reference for the method.
    SetMethod(other.Method());
  }

  mirror::ArtMethod* Method() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  void SetMethod(mirror::ArtMethod* m) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Name 'Kind()' would collide with the above enum name.
  Kind GetKind() const {
    return kind_;
  }

  void SetKind(Kind kind) {
    kind_ = kind;
  }

  uint32_t InstrumentationEvent() const {
    return instrumentation_event_;
  }

  void SetInstrumentationEvent(uint32_t instrumentation_event) {
    instrumentation_event_ = instrumentation_event;
  }

 private:
  Kind kind_;

  // TODO we could use a union to hold the instrumentation_event and the method since they
  // respectively have sense only for kRegisterForEvent/kUnregisterForEvent and
  // kSelectiveDeoptimization/kSelectiveUndeoptimization.

  // Event to start or stop listening to. Only for kRegisterForEvent and kUnregisterForEvent.
  uint32_t instrumentation_event_;

  // Method for selective deoptimization.
  jmethodID method_;
};
std::ostream& operator<<(std::ostream& os, const DeoptimizationRequest::Kind& rhs);

class Dbg {
 public:
  class TypeCache {
   public:
    // Returns a weak global for the input type. Deduplicates.
    jobject Add(mirror::Class* t) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_,
                                                        Locks::alloc_tracker_lock_);
    // Clears the type cache and deletes all the weak global refs.
    void Clear() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_,
                                       Locks::alloc_tracker_lock_);

   private:
    std::multimap<int32_t, jobject> objects_;
  };

  static bool ParseJdwpOptions(const std::string& options);
  static void SetJdwpAllowed(bool allowed);

  static void StartJdwp();
  static void StopJdwp();

  // Invoked by the GC in case we need to keep DDMS informed.
  static void GcDidFinish() LOCKS_EXCLUDED(Locks::mutator_lock_);

  // Return the DebugInvokeReq for the current thread.
  static DebugInvokeReq* GetInvokeReq();

  static Thread* GetDebugThread();
  static void ClearWaitForEventThread();

  /*
   * Enable/disable breakpoints and step modes.  Used to provide a heads-up
   * when the debugger attaches.
   */
  static void Connected();
  static void GoActive()
      LOCKS_EXCLUDED(Locks::breakpoint_lock_, Locks::deoptimization_lock_, Locks::mutator_lock_);
  static void Disconnected() LOCKS_EXCLUDED(Locks::deoptimization_lock_, Locks::mutator_lock_);
  static void Disposed();

  // Returns true if we're actually debugging with a real debugger, false if it's
  // just DDMS (or nothing at all).
  static bool IsDebuggerActive();

  // Returns true if we had -Xrunjdwp or -agentlib:jdwp= on the command line.
  static bool IsJdwpConfigured();

  static bool IsDisposed();

  /*
   * Time, in milliseconds, since the last debugger activity.  Does not
   * include DDMS activity.  Returns -1 if there has been no activity.
   * Returns 0 if we're in the middle of handling a debugger request.
   */
  static int64_t LastDebuggerActivity();

  static void UndoDebuggerSuspensions()
    LOCKS_EXCLUDED(Locks::thread_list_lock_,
                   Locks::thread_suspend_count_lock_);

  /*
   * Class, Object, Array
   */
  static std::string GetClassName(JDWP::RefTypeId id)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static std::string GetClassName(mirror::Class* klass)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetClassObject(JDWP::RefTypeId id, JDWP::ObjectId* class_object_id)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetSuperclass(JDWP::RefTypeId id, JDWP::RefTypeId* superclass_id)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetClassLoader(JDWP::RefTypeId id, JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetModifiers(JDWP::RefTypeId id, JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetReflectedType(JDWP::RefTypeId class_id, JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void GetClassList(std::vector<JDWP::RefTypeId>* classes)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetClassInfo(JDWP::RefTypeId class_id, JDWP::JdwpTypeTag* pTypeTag,
                                      uint32_t* pStatus, std::string* pDescriptor)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void FindLoadedClassBySignature(const char* descriptor, std::vector<JDWP::RefTypeId>* ids)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetReferenceType(JDWP::ObjectId object_id, JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetSignature(JDWP::RefTypeId ref_type_id, std::string* signature)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetSourceFile(JDWP::RefTypeId ref_type_id, std::string* source_file)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetObjectTag(JDWP::ObjectId object_id, uint8_t* tag)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static size_t GetTagWidth(JDWP::JdwpTag tag);

  static JDWP::JdwpError GetArrayLength(JDWP::ObjectId array_id, int32_t* length)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError OutputArray(JDWP::ObjectId array_id, int offset, int count,
                                     JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError SetArrayElements(JDWP::ObjectId array_id, int offset, int count,
                                          JDWP::Request* request)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static JDWP::ObjectId CreateString(const std::string& str)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError CreateObject(JDWP::RefTypeId class_id, JDWP::ObjectId* new_object)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError CreateArrayObject(JDWP::RefTypeId array_class_id, uint32_t length,
                                           JDWP::ObjectId* new_array)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  //
  // Event filtering.
  //
  static bool MatchThread(JDWP::ObjectId expected_thread_id, Thread* event_thread)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static bool MatchLocation(const JDWP::JdwpLocation& expected_location,
                            const JDWP::EventLocation& event_location)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static bool MatchType(mirror::Class* event_class, JDWP::RefTypeId class_id)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static bool MatchField(JDWP::RefTypeId expected_type_id, JDWP::FieldId expected_field_id,
                         mirror::ArtField* event_field)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static bool MatchInstance(JDWP::ObjectId expected_instance_id, mirror::Object* event_instance)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  //
  // Monitors.
  //
  static JDWP::JdwpError GetMonitorInfo(JDWP::ObjectId object_id, JDWP::ExpandBuf* reply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetOwnedMonitors(JDWP::ObjectId thread_id,
                                          std::vector<JDWP::ObjectId>* monitors,
                                          std::vector<uint32_t>* stack_depths)
      LOCKS_EXCLUDED(Locks::thread_list_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetContendedMonitor(JDWP::ObjectId thread_id,
                                             JDWP::ObjectId* contended_monitor)
      LOCKS_EXCLUDED(Locks::thread_list_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  //
  // Heap.
  //
  static JDWP::JdwpError GetInstanceCounts(const std::vector<JDWP::RefTypeId>& class_ids,
                                           std::vector<uint64_t>* counts)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetInstances(JDWP::RefTypeId class_id, int32_t max_count,
                                      std::vector<JDWP::ObjectId>* instances)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetReferringObjects(JDWP::ObjectId object_id, int32_t max_count,
                                             std::vector<JDWP::ObjectId>* referring_objects)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError DisableCollection(JDWP::ObjectId object_id)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError EnableCollection(JDWP::ObjectId object_id)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError IsCollected(JDWP::ObjectId object_id, bool* is_collected)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void DisposeObject(JDWP::ObjectId object_id, uint32_t reference_count)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  //
  // Methods and fields.
  //
  static std::string GetMethodName(JDWP::MethodId method_id)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError OutputDeclaredFields(JDWP::RefTypeId ref_type_id, bool with_generic,
                                              JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError OutputDeclaredMethods(JDWP::RefTypeId ref_type_id, bool with_generic,
                                               JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError OutputDeclaredInterfaces(JDWP::RefTypeId ref_type_id,
                                                  JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void OutputLineTable(JDWP::RefTypeId ref_type_id, JDWP::MethodId method_id,
                              JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void OutputVariableTable(JDWP::RefTypeId ref_type_id, JDWP::MethodId id, bool with_generic,
                                  JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void OutputMethodReturnValue(JDWP::MethodId method_id, const JValue* return_value,
                                      JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void OutputFieldValue(JDWP::FieldId field_id, const JValue* field_value,
                               JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetBytecodes(JDWP::RefTypeId class_id, JDWP::MethodId method_id,
                                      std::vector<uint8_t>* bytecodes)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static std::string GetFieldName(JDWP::FieldId field_id)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpTag GetFieldBasicTag(JDWP::FieldId field_id)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpTag GetStaticFieldBasicTag(JDWP::FieldId field_id)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetFieldValue(JDWP::ObjectId object_id, JDWP::FieldId field_id,
                                       JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError SetFieldValue(JDWP::ObjectId object_id, JDWP::FieldId field_id,
                                       uint64_t value, int width)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetStaticFieldValue(JDWP::RefTypeId ref_type_id, JDWP::FieldId field_id,
                                             JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError SetStaticFieldValue(JDWP::FieldId field_id, uint64_t value, int width)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static JDWP::JdwpError StringToUtf8(JDWP::ObjectId string_id, std::string* str)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void OutputJValue(JDWP::JdwpTag tag, const JValue* return_value, JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  /*
   * Thread, ThreadGroup, Frame
   */
  static JDWP::JdwpError GetThreadName(JDWP::ObjectId thread_id, std::string* name)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
      LOCKS_EXCLUDED(Locks::thread_list_lock_);
  static JDWP::JdwpError GetThreadGroup(JDWP::ObjectId thread_id, JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
      LOCKS_EXCLUDED(Locks::thread_list_lock_);
  static JDWP::JdwpError GetThreadGroupName(JDWP::ObjectId thread_group_id,
                                            JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetThreadGroupParent(JDWP::ObjectId thread_group_id,
                                              JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetThreadGroupChildren(JDWP::ObjectId thread_group_id,
                                                JDWP::ExpandBuf* pReply)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::ObjectId GetSystemThreadGroupId()
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static JDWP::JdwpThreadStatus ToJdwpThreadStatus(ThreadState state);
  static JDWP::JdwpError GetThreadStatus(JDWP::ObjectId thread_id,
                                         JDWP::JdwpThreadStatus* pThreadStatus,
                                         JDWP::JdwpSuspendStatus* pSuspendStatus)
      LOCKS_EXCLUDED(Locks::thread_list_lock_);
  static JDWP::JdwpError GetThreadDebugSuspendCount(JDWP::ObjectId thread_id,
                                                    JDWP::ExpandBuf* pReply)
      LOCKS_EXCLUDED(Locks::thread_list_lock_,
                     Locks::thread_suspend_count_lock_);
  // static void WaitForSuspend(JDWP::ObjectId thread_id);

  // Fills 'thread_ids' with the threads in the given thread group. If thread_group_id == 0,
  // returns all threads.
  static void GetThreads(mirror::Object* thread_group, std::vector<JDWP::ObjectId>* thread_ids)
      LOCKS_EXCLUDED(Locks::thread_list_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static JDWP::JdwpError GetThreadFrameCount(JDWP::ObjectId thread_id, size_t* result)
      LOCKS_EXCLUDED(Locks::thread_list_lock_);
  static JDWP::JdwpError GetThreadFrames(JDWP::ObjectId thread_id, size_t start_frame,
                                         size_t frame_count, JDWP::ExpandBuf* buf)
      LOCKS_EXCLUDED(Locks::thread_list_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static JDWP::ObjectId GetThreadSelfId() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::ObjectId GetThreadId(Thread* thread) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static void SuspendVM()
      LOCKS_EXCLUDED(Locks::thread_list_lock_,
                     Locks::thread_suspend_count_lock_);
  static void ResumeVM()
      LOCKS_EXCLUDED(Locks::thread_list_lock_,
                     Locks::thread_suspend_count_lock_);
  static JDWP::JdwpError SuspendThread(JDWP::ObjectId thread_id, bool request_suspension = true)
      LOCKS_EXCLUDED(Locks::mutator_lock_,
                     Locks::thread_list_lock_,
                     Locks::thread_suspend_count_lock_);

  static void ResumeThread(JDWP::ObjectId thread_id)
      LOCKS_EXCLUDED(Locks::thread_list_lock_,
                     Locks::thread_suspend_count_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void SuspendSelf();

  static JDWP::JdwpError GetThisObject(JDWP::ObjectId thread_id, JDWP::FrameId frame_id,
                                       JDWP::ObjectId* result)
      LOCKS_EXCLUDED(Locks::thread_list_lock_,
                     Locks::thread_suspend_count_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError GetLocalValues(JDWP::Request* request, JDWP::ExpandBuf* pReply)
      LOCKS_EXCLUDED(Locks::thread_list_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError SetLocalValues(JDWP::Request* request)
      LOCKS_EXCLUDED(Locks::thread_list_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static JDWP::JdwpError Interrupt(JDWP::ObjectId thread_id)
      LOCKS_EXCLUDED(Locks::thread_list_lock_);

  /*
   * Debugger notification
   */
  enum EventFlag {
    kBreakpoint     = 0x01,
    kSingleStep     = 0x02,
    kMethodEntry    = 0x04,
    kMethodExit     = 0x08,
  };
  static void PostFieldAccessEvent(mirror::ArtMethod* m, int dex_pc, mirror::Object* this_object,
                                   mirror::ArtField* f)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void PostFieldModificationEvent(mirror::ArtMethod* m, int dex_pc,
                                         mirror::Object* this_object, mirror::ArtField* f,
                                         const JValue* field_value)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void PostException(const ThrowLocation& throw_location, mirror::ArtMethod* catch_method,
                            uint32_t catch_dex_pc, mirror::Throwable* exception)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void PostThreadStart(Thread* t)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void PostThreadDeath(Thread* t)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void PostClassPrepare(mirror::Class* c)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static void UpdateDebugger(Thread* thread, mirror::Object* this_object,
                             mirror::ArtMethod* method, uint32_t new_dex_pc,
                             int event_flags, const JValue* return_value)
      LOCKS_EXCLUDED(Locks::breakpoint_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Indicates whether we need deoptimization for debugging.
  static bool RequiresDeoptimization();

  // Records deoptimization request in the queue.
  static void RequestDeoptimization(const DeoptimizationRequest& req)
      LOCKS_EXCLUDED(Locks::deoptimization_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Support delayed full undeoptimization requests. This is currently only used for single-step
  // events.
  static void DelayFullUndeoptimization() LOCKS_EXCLUDED(Locks::deoptimization_lock_);
  static void ProcessDelayedFullUndeoptimizations()
      LOCKS_EXCLUDED(Locks::deoptimization_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Manage deoptimization after updating JDWP events list. Suspends all threads, processes each
  // request and finally resumes all threads.
  static void ManageDeoptimization()
      LOCKS_EXCLUDED(Locks::deoptimization_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Breakpoints.
  static void WatchLocation(const JDWP::JdwpLocation* pLoc, DeoptimizationRequest* req)
      LOCKS_EXCLUDED(Locks::breakpoint_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void UnwatchLocation(const JDWP::JdwpLocation* pLoc, DeoptimizationRequest* req)
      LOCKS_EXCLUDED(Locks::breakpoint_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Single-stepping.
  static JDWP::JdwpError ConfigureStep(JDWP::ObjectId thread_id, JDWP::JdwpStepSize size,
                                       JDWP::JdwpStepDepth depth)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void UnconfigureStep(JDWP::ObjectId thread_id)
      LOCKS_EXCLUDED(Locks::thread_list_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static JDWP::JdwpError InvokeMethod(JDWP::ObjectId thread_id, JDWP::ObjectId object_id,
                                      JDWP::RefTypeId class_id, JDWP::MethodId method_id,
                                      uint32_t arg_count, uint64_t* arg_values,
                                      JDWP::JdwpTag* arg_types, uint32_t options,
                                      JDWP::JdwpTag* pResultTag, uint64_t* pResultValue,
                                      JDWP::ObjectId* pExceptObj)
      LOCKS_EXCLUDED(Locks::thread_list_lock_,
                     Locks::thread_suspend_count_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void ExecuteMethod(DebugInvokeReq* pReq);

  /*
   * DDM support.
   */
  static void DdmSendThreadNotification(Thread* t, uint32_t type)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void DdmSetThreadNotification(bool enable)
      LOCKS_EXCLUDED(Locks::thread_list_lock_);
  static bool DdmHandlePacket(JDWP::Request* request, uint8_t** pReplyBuf, int* pReplyLen);
  static void DdmConnected() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void DdmDisconnected() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void DdmSendChunk(uint32_t type, const std::vector<uint8_t>& bytes)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void DdmSendChunk(uint32_t type, size_t len, const uint8_t* buf)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void DdmSendChunkV(uint32_t type, const iovec* iov, int iov_count)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static void VisitRoots(RootCallback* callback, void* arg)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  /*
   * Recent allocation tracking support.
   */
  static void RecordAllocation(Thread* self, mirror::Class* type, size_t byte_count)
      LOCKS_EXCLUDED(Locks::alloc_tracker_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void SetAllocTrackingEnabled(bool enabled) LOCKS_EXCLUDED(Locks::alloc_tracker_lock_);
  static bool IsAllocTrackingEnabled() {
    return recent_allocation_records_ != nullptr;
  }
  static jbyteArray GetRecentAllocations()
      LOCKS_EXCLUDED(Locks::alloc_tracker_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static size_t HeadIndex() EXCLUSIVE_LOCKS_REQUIRED(Locks::alloc_tracker_lock_);
  static void DumpRecentAllocations() LOCKS_EXCLUDED(Locks::alloc_tracker_lock_);

  enum HpifWhen {
    HPIF_WHEN_NEVER = 0,
    HPIF_WHEN_NOW = 1,
    HPIF_WHEN_NEXT_GC = 2,
    HPIF_WHEN_EVERY_GC = 3
  };
  static int DdmHandleHpifChunk(HpifWhen when)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  enum HpsgWhen {
    HPSG_WHEN_NEVER = 0,
    HPSG_WHEN_EVERY_GC = 1,
  };
  enum HpsgWhat {
    HPSG_WHAT_MERGED_OBJECTS = 0,
    HPSG_WHAT_DISTINCT_OBJECTS = 1,
  };
  static bool DdmHandleHpsgNhsgChunk(HpsgWhen when, HpsgWhat what, bool native);

  static void DdmSendHeapInfo(HpifWhen reason)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void DdmSendHeapSegments(bool native)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static ObjectRegistry* GetObjectRegistry() {
    return gRegistry;
  }

  static JDWP::JdwpTag TagFromObject(const ScopedObjectAccessUnchecked& soa, mirror::Object* o)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static JDWP::JdwpTypeTag GetTypeTag(mirror::Class* klass)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static JDWP::FieldId ToFieldId(const mirror::ArtField* f)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static void SetJdwpLocation(JDWP::JdwpLocation* location, mirror::ArtMethod* m, uint32_t dex_pc)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static JDWP::JdwpState* GetJdwpState();

 private:
  static JDWP::JdwpError GetLocalValue(const StackVisitor& visitor,
                                       ScopedObjectAccessUnchecked& soa, int slot,
                                       JDWP::JdwpTag tag, uint8_t* buf, size_t width)
      LOCKS_EXCLUDED(Locks::thread_list_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static JDWP::JdwpError SetLocalValue(StackVisitor& visitor, int slot, JDWP::JdwpTag tag,
                                       uint64_t value, size_t width)
      LOCKS_EXCLUDED(Locks::thread_list_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static void DdmBroadcast(bool connect) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  static void PostThreadStartOrStop(Thread*, uint32_t)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static void PostLocationEvent(mirror::ArtMethod* method, int pcOffset,
                                mirror::Object* thisPtr, int eventFlags,
                                const JValue* return_value)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static void ProcessDeoptimizationRequest(const DeoptimizationRequest& request)
      EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_);

  static void RequestDeoptimizationLocked(const DeoptimizationRequest& req)
      EXCLUSIVE_LOCKS_REQUIRED(Locks::deoptimization_lock_)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  static AllocRecord* recent_allocation_records_ PT_GUARDED_BY(Locks::alloc_tracker_lock_);
  static size_t alloc_record_max_ GUARDED_BY(Locks::alloc_tracker_lock_);
  static size_t alloc_record_head_ GUARDED_BY(Locks::alloc_tracker_lock_);
  static size_t alloc_record_count_ GUARDED_BY(Locks::alloc_tracker_lock_);

  static ObjectRegistry* gRegistry;

  // Deoptimization requests to be processed each time the event list is updated. This is used when
  // registering and unregistering events so we do not deoptimize while holding the event list
  // lock.
  // TODO rename to instrumentation_requests.
  static std::vector<DeoptimizationRequest> deoptimization_requests_ GUARDED_BY(Locks::deoptimization_lock_);

  // Count the number of events requiring full deoptimization. When the counter is > 0, everything
  // is deoptimized, otherwise everything is undeoptimized.
  // Note: we fully deoptimize on the first event only (when the counter is set to 1). We fully
  // undeoptimize when the last event is unregistered (when the counter is set to 0).
  static size_t full_deoptimization_event_count_ GUARDED_BY(Locks::deoptimization_lock_);

  // Count the number of full undeoptimization requests delayed to next resume or end of debug
  // session.
  static size_t delayed_full_undeoptimization_count_ GUARDED_BY(Locks::deoptimization_lock_);

  static size_t* GetReferenceCounterForEvent(uint32_t instrumentation_event);

  // Weak global type cache, TODO improve this.
  static TypeCache type_cache_ GUARDED_BY(Locks::alloc_tracker_lock_);

  // Instrumentation event reference counters.
  // TODO we could use an array instead of having all these dedicated counters. Instrumentation
  // events are bits of a mask so we could convert them to array index.
  static size_t dex_pc_change_event_ref_count_ GUARDED_BY(Locks::deoptimization_lock_);
  static size_t method_enter_event_ref_count_ GUARDED_BY(Locks::deoptimization_lock_);
  static size_t method_exit_event_ref_count_ GUARDED_BY(Locks::deoptimization_lock_);
  static size_t field_read_event_ref_count_ GUARDED_BY(Locks::deoptimization_lock_);
  static size_t field_write_event_ref_count_ GUARDED_BY(Locks::deoptimization_lock_);
  static size_t exception_catch_event_ref_count_ GUARDED_BY(Locks::deoptimization_lock_);
  static uint32_t instrumentation_events_ GUARDED_BY(Locks::mutator_lock_);

  friend class AllocRecord;  // For type_cache_ with proper annotalysis.
  DISALLOW_COPY_AND_ASSIGN(Dbg);
};

#define CHUNK_TYPE(_name) \
    static_cast<uint32_t>((_name)[0] << 24 | (_name)[1] << 16 | (_name)[2] << 8 | (_name)[3])

}  // namespace art

#endif  // ART_RUNTIME_DEBUGGER_H_