text: /*
   * Copyright (c) 1998, 2013, 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_JVMTIEXPORT_HPP
  #define SHARE_VM_PRIMS_JVMTIEXPORT_HPP
  
  #include "jvmtifiles/jvmti.h"
  #include "memory/allocation.hpp"
  #include "memory/iterator.hpp"
  #include "oops/oop.hpp"
  #include "oops/oopsHierarchy.hpp"
  #include "runtime/frame.hpp"
  #include "runtime/handles.hpp"
  #include "utilities/globalDefinitions.hpp"
  #include "utilities/growableArray.hpp"
  #include "utilities/macros.hpp"
  
  // Must be included after jvmti.h.
  #include "code/jvmticmlr.h"
  
  // Forward declarations
  
  class JvmtiEventControllerPrivate;
  class JvmtiManageCapabilities;
  class JvmtiEnv;
  class JvmtiThreadState;
  class AttachOperation;
  
  #define JVMTI_SUPPORT_FLAG(key)                                           \
    private:                                                                \
    static bool  _##key;                                                    \
    public:                                                                 \
    inline static void set_##key(bool on) {                                 \
      JVMTI_ONLY(_##key = (on != 0));                                       \
      NOT_JVMTI(report_unsupported(on));                                    \
    }                                                                       \
    inline static bool key() {                                              \
      JVMTI_ONLY(return _##key);                                            \
      NOT_JVMTI(return false);                                              \
    }
  
  
  // This class contains the JVMTI interface for the rest of hotspot.
  //
  class JvmtiExport : public AllStatic {
    friend class VMStructs;
    friend class CompileReplay;
  
   private:
  
  #if INCLUDE_JVMTI
    static int         _field_access_count;
    static int         _field_modification_count;
  
    static bool        _can_access_local_variables;
    static bool        _can_hotswap_or_post_breakpoint;
    static bool        _can_modify_any_class;
    static bool        _can_walk_any_space;
  #endif // INCLUDE_JVMTI
  
    JVMTI_SUPPORT_FLAG(can_get_source_debug_extension)
    JVMTI_SUPPORT_FLAG(can_maintain_original_method_order)
    JVMTI_SUPPORT_FLAG(can_post_interpreter_events)
    JVMTI_SUPPORT_FLAG(can_post_on_exceptions)
    JVMTI_SUPPORT_FLAG(can_post_breakpoint)
    JVMTI_SUPPORT_FLAG(can_post_field_access)
    JVMTI_SUPPORT_FLAG(can_post_field_modification)
    JVMTI_SUPPORT_FLAG(can_post_method_entry)
    JVMTI_SUPPORT_FLAG(can_post_method_exit)
    JVMTI_SUPPORT_FLAG(can_pop_frame)
    JVMTI_SUPPORT_FLAG(can_force_early_return)
  
    friend class JvmtiEventControllerPrivate;  // should only modify these flags
    JVMTI_SUPPORT_FLAG(should_post_single_step)
    JVMTI_SUPPORT_FLAG(should_post_field_access)
    JVMTI_SUPPORT_FLAG(should_post_field_modification)
    JVMTI_SUPPORT_FLAG(should_post_class_load)
    JVMTI_SUPPORT_FLAG(should_post_class_prepare)
    JVMTI_SUPPORT_FLAG(should_post_class_unload)
    JVMTI_SUPPORT_FLAG(should_post_native_method_bind)
    JVMTI_SUPPORT_FLAG(should_post_compiled_method_load)
    JVMTI_SUPPORT_FLAG(should_post_compiled_method_unload)
    JVMTI_SUPPORT_FLAG(should_post_dynamic_code_generated)
    JVMTI_SUPPORT_FLAG(should_post_monitor_contended_enter)
    JVMTI_SUPPORT_FLAG(should_post_monitor_contended_entered)
    JVMTI_SUPPORT_FLAG(should_post_monitor_wait)
    JVMTI_SUPPORT_FLAG(should_post_monitor_waited)
    JVMTI_SUPPORT_FLAG(should_post_data_dump)
    JVMTI_SUPPORT_FLAG(should_post_garbage_collection_start)
    JVMTI_SUPPORT_FLAG(should_post_garbage_collection_finish)
    JVMTI_SUPPORT_FLAG(should_post_on_exceptions)
  
    // ------ the below maybe don't have to be (but are for now)
    // fixed conditions here ------------
    // any events can be enabled
    JVMTI_SUPPORT_FLAG(should_post_thread_life)
    JVMTI_SUPPORT_FLAG(should_post_object_free)
    JVMTI_SUPPORT_FLAG(should_post_resource_exhausted)
  
    // we are holding objects on the heap - need to talk to GC - e.g.
    // breakpoint info
    JVMTI_SUPPORT_FLAG(should_clean_up_heap_objects)
    JVMTI_SUPPORT_FLAG(should_post_vm_object_alloc)
  
    // If flag cannot be implemented, give an error if on=true
    static void report_unsupported(bool on);
  
    // these should only be called by the friend class
    friend class JvmtiManageCapabilities;
    inline static void set_can_modify_any_class(bool on) {
      JVMTI_ONLY(_can_modify_any_class = (on != 0);)
    }
    inline static void set_can_access_local_variables(bool on) {
      JVMTI_ONLY(_can_access_local_variables = (on != 0);)
    }
    inline static void set_can_hotswap_or_post_breakpoint(bool on) {
      JVMTI_ONLY(_can_hotswap_or_post_breakpoint = (on != 0);)
    }
    inline static void set_can_walk_any_space(bool on) {
      JVMTI_ONLY(_can_walk_any_space = (on != 0);)
    }
  
    enum {
      JVMTI_VERSION_MASK   = 0x70000000,
      JVMTI_VERSION_VALUE  = 0x30000000,
      JVMDI_VERSION_VALUE  = 0x20000000
    };
  
    static void post_field_modification(JavaThread *thread, Method* method, address location,
                                        KlassHandle field_klass, Handle object, jfieldID field,
                                        char sig_type, jvalue *value);
  
  
    // posts a DynamicCodeGenerated event (internal/private implementation).
    // The public post_dynamic_code_generated* functions make use of the
    // internal implementation.  Also called from JvmtiDeferredEvent::post()
    static void post_dynamic_code_generated_internal(const char *name, const void *code_begin, const void *code_end) NOT_JVMTI_RETURN;
  
   private:
  
    // GenerateEvents support to allow posting of CompiledMethodLoad and
    // DynamicCodeGenerated events for a given environment.
    friend class JvmtiCodeBlobEvents;
  
    static void post_compiled_method_load(JvmtiEnv* env, const jmethodID method, const jint length,
                                          const void *code_begin, const jint map_length,
                                          const jvmtiAddrLocationMap* map) NOT_JVMTI_RETURN;
    static void post_dynamic_code_generated(JvmtiEnv* env, const char *name, const void *code_begin,
                                            const void *code_end) NOT_JVMTI_RETURN;
  
    // The RedefineClasses() API breaks some invariants in the "regular"
    // system. For example, there are sanity checks when GC'ing nmethods
    // that require the containing class to be unloading. However, when a
    // method is redefined, the old method and nmethod can become GC'able
    // without the containing class unloading. The state of becoming
    // GC'able can be asynchronous to the RedefineClasses() call since
    // the old method may still be running and cannot be GC'ed until
    // after all old invocations have finished. Additionally, a method
    // that has not been redefined may have an nmethod that depends on
    // the redefined method. The dependent nmethod will get deopted in
    // this case and may also be GC'able without the containing class
    // being unloaded.
    //
    // This flag indicates whether RedefineClasses() has ever redefined
    // one or more classes during the lifetime of the VM. The flag should
    // only be set by the friend class and can be queried by other sub
    // systems as needed to relax invariant checks.
    static bool _has_redefined_a_class;
    friend class VM_RedefineClasses;
    inline static void set_has_redefined_a_class() {
      JVMTI_ONLY(_has_redefined_a_class = true;)
    }
    // Flag to indicate if the compiler has recorded all dependencies. When the
    // can_redefine_classes capability is enabled in the OnLoad phase then the compiler
    // records all dependencies from startup. However if the capability is first
    // enabled some time later then the dependencies recorded by the compiler
    // are incomplete. This flag is used by RedefineClasses to know if the
    // dependency information is complete or not.
    static bool _all_dependencies_are_recorded;
  
   public:
    inline static bool has_redefined_a_class() {
      JVMTI_ONLY(return _has_redefined_a_class);
      NOT_JVMTI(return false);
    }
  
    inline static bool all_dependencies_are_recorded() {
      return _all_dependencies_are_recorded;
    }
  
    inline static void set_all_dependencies_are_recorded(bool on) {
      _all_dependencies_are_recorded = (on != 0);
    }
  
  
    // let JVMTI know that the JVM_OnLoad code is running
    static void enter_onload_phase() NOT_JVMTI_RETURN;
  
    // let JVMTI know that the VM isn't up yet (and JVM_OnLoad code isn't running)
    static void enter_primordial_phase() NOT_JVMTI_RETURN;
  
    // let JVMTI know that the VM isn't up yet but JNI is live
    static void enter_start_phase() NOT_JVMTI_RETURN;
  
    // let JVMTI know that the VM is fully up and running now
    static void enter_live_phase() NOT_JVMTI_RETURN;
  
    // ------ can_* conditions (below) are set at OnLoad and never changed ------------
    inline static bool can_modify_any_class()                       {
      JVMTI_ONLY(return _can_modify_any_class);
      NOT_JVMTI(return false);
    }
    inline static bool can_access_local_variables()                 {
      JVMTI_ONLY(return _can_access_local_variables);
      NOT_JVMTI(return false);
    }
    inline static bool can_hotswap_or_post_breakpoint()             {
      JVMTI_ONLY(return _can_hotswap_or_post_breakpoint);
      NOT_JVMTI(return false);
    }
    inline static bool can_walk_any_space()                         {
      JVMTI_ONLY(return _can_walk_any_space);
      NOT_JVMTI(return false);
    }
  
    // field access management
    static address  get_field_access_count_addr() NOT_JVMTI_RETURN_(0);
  
    // field modification management
    static address  get_field_modification_count_addr() NOT_JVMTI_RETURN_(0);
  
    // -----------------
  
    static bool is_jvmti_version(jint version)                      {
      JVMTI_ONLY(return (version & JVMTI_VERSION_MASK) == JVMTI_VERSION_VALUE);
      NOT_JVMTI(return false);
    }
    static bool is_jvmdi_version(jint version)                      {
      JVMTI_ONLY(return (version & JVMTI_VERSION_MASK) == JVMDI_VERSION_VALUE);
      NOT_JVMTI(return false);
    }
    static jint get_jvmti_interface(JavaVM *jvm, void **penv, jint version) NOT_JVMTI_RETURN_(0);
    static void decode_version_values(jint version, int * major, int * minor,
                                      int * micro) NOT_JVMTI_RETURN;
  
    // single stepping management methods
    static void at_single_stepping_point(JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
    static void expose_single_stepping(JavaThread *thread) NOT_JVMTI_RETURN;
    static bool hide_single_stepping(JavaThread *thread) NOT_JVMTI_RETURN_(false);
  
    // Methods that notify the debugger that something interesting has happened in the VM.
    static void post_vm_start              () NOT_JVMTI_RETURN;
    static void post_vm_initialized        () NOT_JVMTI_RETURN;
    static void post_vm_death              () NOT_JVMTI_RETURN;
  
    static void post_single_step           (JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
    static void post_raw_breakpoint        (JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
  
    static void post_exception_throw       (JavaThread *thread, Method* method, address location, oop exception) NOT_JVMTI_RETURN;
    static void notice_unwind_due_to_exception (JavaThread *thread, Method* method, address location, oop exception, bool in_handler_frame) NOT_JVMTI_RETURN;
  
    static oop jni_GetField_probe          (JavaThread *thread, jobject jobj,
      oop obj, Klass* klass, jfieldID fieldID, bool is_static)
      NOT_JVMTI_RETURN_(NULL);
    static oop jni_GetField_probe_nh       (JavaThread *thread, jobject jobj,
      oop obj, Klass* klass, jfieldID fieldID, bool is_static)
      NOT_JVMTI_RETURN_(NULL);
    static void post_field_access_by_jni   (JavaThread *thread, oop obj,
      Klass* klass, jfieldID fieldID, bool is_static) NOT_JVMTI_RETURN;
    static void post_field_access          (JavaThread *thread, Method* method,
      address location, KlassHandle field_klass, Handle object, jfieldID field) NOT_JVMTI_RETURN;
    static oop jni_SetField_probe          (JavaThread *thread, jobject jobj,
      oop obj, Klass* klass, jfieldID fieldID, bool is_static, char sig_type,
      jvalue *value) NOT_JVMTI_RETURN_(NULL);
    static oop jni_SetField_probe_nh       (JavaThread *thread, jobject jobj,
      oop obj, Klass* klass, jfieldID fieldID, bool is_static, char sig_type,
      jvalue *value) NOT_JVMTI_RETURN_(NULL);
    static void post_field_modification_by_jni(JavaThread *thread, oop obj,
      Klass* klass, jfieldID fieldID, bool is_static, char sig_type,
      jvalue *value);
    static void post_raw_field_modification(JavaThread *thread, Method* method,
      address location, KlassHandle field_klass, Handle object, jfieldID field,
      char sig_type, jvalue *value) NOT_JVMTI_RETURN;
  
    static void post_method_entry          (JavaThread *thread, Method* method, frame current_frame) NOT_JVMTI_RETURN;
    static void post_method_exit           (JavaThread *thread, Method* method, frame current_frame) NOT_JVMTI_RETURN;
  
    static void post_class_load            (JavaThread *thread, Klass* klass) NOT_JVMTI_RETURN;
    static void post_class_unload          (Klass* klass) NOT_JVMTI_RETURN;
    static void post_class_prepare         (JavaThread *thread, Klass* klass) NOT_JVMTI_RETURN;
  
    static void post_thread_start          (JavaThread *thread) NOT_JVMTI_RETURN;
    static void post_thread_end            (JavaThread *thread) NOT_JVMTI_RETURN;
  
    // Support for java.lang.instrument agent loading.
    static bool _should_post_class_file_load_hook;
    inline static void set_should_post_class_file_load_hook(bool on)     { _should_post_class_file_load_hook = on;  }
    inline static bool should_post_class_file_load_hook()           {
      JVMTI_ONLY(return _should_post_class_file_load_hook);
      NOT_JVMTI(return false;)
    }
    static void post_class_file_load_hook(Symbol* h_name, Handle class_loader,
                                          Handle h_protection_domain,
                                          unsigned char **data_ptr, unsigned char **end_ptr,
                                          JvmtiCachedClassFileData **cache_ptr) NOT_JVMTI_RETURN;
    static void post_native_method_bind(Method* method, address* function_ptr) NOT_JVMTI_RETURN;
    static void post_compiled_method_load(nmethod *nm) NOT_JVMTI_RETURN;
    static void post_dynamic_code_generated(const char *name, const void *code_begin, const void *code_end) NOT_JVMTI_RETURN;
  
    // used to post a CompiledMethodUnload event
    static void post_compiled_method_unload(jmethodID mid, const void *code_begin) NOT_JVMTI_RETURN;
  
    // similiar to post_dynamic_code_generated except that it can be used to
    // post a DynamicCodeGenerated event while holding locks in the VM. Any event
    // posted using this function is recorded by the enclosing event collector
    // -- JvmtiDynamicCodeEventCollector.
    static void post_dynamic_code_generated_while_holding_locks(const char* name, address code_begin, address code_end) NOT_JVMTI_RETURN;
  
    static void post_garbage_collection_finish() NOT_JVMTI_RETURN;
    static void post_garbage_collection_start() NOT_JVMTI_RETURN;
    static void post_data_dump() NOT_JVMTI_RETURN;
    static void post_monitor_contended_enter(JavaThread *thread, ObjectMonitor *obj_mntr) NOT_JVMTI_RETURN;
    static void post_monitor_contended_entered(JavaThread *thread, ObjectMonitor *obj_mntr) NOT_JVMTI_RETURN;
    static void post_monitor_wait(JavaThread *thread, oop obj, jlong timeout) NOT_JVMTI_RETURN;
    static void post_monitor_waited(JavaThread *thread, ObjectMonitor *obj_mntr, jboolean timed_out) NOT_JVMTI_RETURN;
    static void post_object_free(JvmtiEnv* env, jlong tag) NOT_JVMTI_RETURN;
    static void post_resource_exhausted(jint resource_exhausted_flags, const char* detail) NOT_JVMTI_RETURN;
    static void record_vm_internal_object_allocation(oop object) NOT_JVMTI_RETURN;
    // Post objects collected by vm_object_alloc_event_collector.
    static void post_vm_object_alloc(JavaThread *thread, oop object) NOT_JVMTI_RETURN;
    // Collects vm internal objects for later event posting.
    inline static void vm_object_alloc_event_collector(oop object) {
      if (should_post_vm_object_alloc()) {
        record_vm_internal_object_allocation(object);
      }
    }
    inline static void post_array_size_exhausted() {
      if (should_post_resource_exhausted()) {
        post_resource_exhausted(JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
                                "Requested array size exceeds VM limit");
      }
    }
  
    static void cleanup_thread             (JavaThread* thread) NOT_JVMTI_RETURN;
  
    static void oops_do(OopClosure* f) NOT_JVMTI_RETURN;
    static void weak_oops_do(BoolObjectClosure* b, OopClosure* f) NOT_JVMTI_RETURN;
    static void gc_epilogue() NOT_JVMTI_RETURN;
  
    static void transition_pending_onload_raw_monitors() NOT_JVMTI_RETURN;
  
    // attach support
    static jint load_agent_library(AttachOperation* op, outputStream* out) NOT_JVMTI_RETURN_(JNI_ERR);
  
    // SetNativeMethodPrefix support
    static char** get_all_native_method_prefixes(int* count_ptr) NOT_JVMTI_RETURN_(NULL);
  };
  
  // Support class used by JvmtiDynamicCodeEventCollector and others. It
  // describes a single code blob by name and address range.
  class JvmtiCodeBlobDesc : public CHeapObj<mtInternal> {
   private:
    char _name[64];
    address _code_begin;
    address _code_end;
  
   public:
    JvmtiCodeBlobDesc(const char *name, address code_begin, address code_end) {
      assert(name != NULL, "all code blobs must be named");
      strncpy(_name, name, sizeof(_name));
      _name[sizeof(_name)-1] = '\0';
      _code_begin = code_begin;
      _code_end = code_end;
    }
    char* name()                  { return _name; }
    address code_begin()          { return _code_begin; }
    address code_end()            { return _code_end; }
  };
  
  // JvmtiEventCollector is a helper class to setup thread for
  // event collection.
  class JvmtiEventCollector : public StackObj {
   private:
    JvmtiEventCollector* _prev;  // Save previous one to support nested event collector.
  
   public:
    void setup_jvmti_thread_state(); // Set this collector in current thread.
    void unset_jvmti_thread_state(); // Reset previous collector in current thread.
    virtual bool is_dynamic_code_event()   { return false; }
    virtual bool is_vm_object_alloc_event(){ return false; }
    JvmtiEventCollector *get_prev()        { return _prev; }
  };
  
  // A JvmtiDynamicCodeEventCollector is a helper class for the JvmtiExport
  // interface. It collects "dynamic code generated" events that are posted
  // while holding locks. When the event collector goes out of scope the
  // events will be posted.
  //
  // Usage :-
  //
  // {
  //   JvmtiDynamicCodeEventCollector event_collector;
  //   :
  //   { MutexLocker ml(...)
  //     :
  //     JvmtiExport::post_dynamic_code_generated_while_holding_locks(...)
  //   }
  //   // event collector goes out of scope => post events to profiler.
  // }
  
  class JvmtiDynamicCodeEventCollector : public JvmtiEventCollector {
   private:
    GrowableArray<JvmtiCodeBlobDesc*>* _code_blobs;           // collected code blob events
  
    friend class JvmtiExport;
    void register_stub(const char* name, address start, address end);
  
   public:
    JvmtiDynamicCodeEventCollector()  NOT_JVMTI_RETURN;
    ~JvmtiDynamicCodeEventCollector() NOT_JVMTI_RETURN;
    bool is_dynamic_code_event()   { return true; }
  
  };
  
  // Used to record vm internally allocated object oops and post
  // vm object alloc event for objects visible to java world.
  // Constructor enables JvmtiThreadState flag and all vm allocated
  // objects are recorded in a growable array. When destructor is
  // called the vm object alloc event is posted for each objects
  // visible to java world.
  // See jvm.cpp file for its usage.
  //
  class JvmtiVMObjectAllocEventCollector : public JvmtiEventCollector {
   private:
    GrowableArray<oop>* _allocated; // field to record vm internally allocated object oop.
    bool _enable;                   // This flag is enabled in constructor and disabled
                                    // in destructor before posting event. To avoid
                                    // collection of objects allocated while running java code inside
                                    // agent post_vm_object_alloc() event handler.
  
    //GC support
    void oops_do(OopClosure* f);
  
    friend class JvmtiExport;
    // Record vm allocated object oop.
    inline void record_allocation(oop obj);
  
    //GC support
    static void oops_do_for_all_threads(OopClosure* f);
  
   public:
    JvmtiVMObjectAllocEventCollector()  NOT_JVMTI_RETURN;
    ~JvmtiVMObjectAllocEventCollector() NOT_JVMTI_RETURN;
    bool is_vm_object_alloc_event()   { return true; }
  
    bool is_enabled()                 { return _enable; }
    void set_enabled(bool on)         { _enable = on; }
  };
  
  
  
  // Marker class to disable the posting of VMObjectAlloc events
  // within its scope.
  //
  // Usage :-
  //
  // {
  //   NoJvmtiVMObjectAllocMark njm;
  //   :
  //   // VMObjAlloc event will not be posted
  //   JvmtiExport::vm_object_alloc_event_collector(obj);
  //   :
  // }
  
  class NoJvmtiVMObjectAllocMark : public StackObj {
   private:
    // enclosing collector if enabled, NULL otherwise
    JvmtiVMObjectAllocEventCollector *_collector;
  
    bool was_enabled()    { return _collector != NULL; }
  
   public:
    NoJvmtiVMObjectAllocMark() NOT_JVMTI_RETURN;
    ~NoJvmtiVMObjectAllocMark() NOT_JVMTI_RETURN;
  };
  
  
  // Base class for reporting GC events to JVMTI.
  class JvmtiGCMarker : public StackObj {
   public:
    JvmtiGCMarker() NOT_JVMTI_RETURN;
    ~JvmtiGCMarker() NOT_JVMTI_RETURN;
  };
  
  // JvmtiHideSingleStepping is a helper class for hiding
  // internal single step events.
  class JvmtiHideSingleStepping : public StackObj {
   private:
    bool         _single_step_hidden;
    JavaThread * _thread;
  
   public:
    JvmtiHideSingleStepping(JavaThread * thread) {
      assert(thread != NULL, "sanity check");
  
      _single_step_hidden = false;
      _thread = thread;
      if (JvmtiExport::should_post_single_step()) {
        _single_step_hidden = JvmtiExport::hide_single_stepping(_thread);
      }
    }
  
    ~JvmtiHideSingleStepping() {
      if (_single_step_hidden) {
        JvmtiExport::expose_single_stepping(_thread);
      }
    }
  };
  
  #endif // SHARE_VM_PRIMS_JVMTIEXPORT_HPP
  