/*

 * Copyright (c) 2003, 2016, 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 "jvmtifiles/jvmtiEnv.hpp"

#include "prims/jvmtiExport.hpp"

#include "prims/jvmtiManageCapabilities.hpp"

static const jint CAPA_SIZE = (JVMTI_INTERNAL_CAPABILITY_COUNT + 7) / 8;

  // capabilities which are always potentially available

jvmtiCapabilities JvmtiManageCapabilities::always_capabilities;

  // capabilities which are potentially available during OnLoad

jvmtiCapabilities JvmtiManageCapabilities::onload_capabilities;

  // capabilities which are always potentially available

  // but to only one environment

jvmtiCapabilities JvmtiManageCapabilities::always_solo_capabilities;

  // capabilities which are potentially available during OnLoad

  // but to only one environment

jvmtiCapabilities JvmtiManageCapabilities::onload_solo_capabilities;

  // remaining capabilities which are always potentially available

  // but to only one environment

jvmtiCapabilities JvmtiManageCapabilities::always_solo_remaining_capabilities;

  // remaining capabilities which are potentially available during OnLoad

  // but to only one environment

jvmtiCapabilities JvmtiManageCapabilities::onload_solo_remaining_capabilities;

  // all capabilities ever acquired

jvmtiCapabilities JvmtiManageCapabilities::acquired_capabilities;

void JvmtiManageCapabilities::initialize() {

  always_capabilities = init_always_capabilities();

  if (JvmtiEnv::get_phase() != JVMTI_PHASE_ONLOAD) {

    recompute_always_capabilities();

  }

  onload_capabilities = init_onload_capabilities();

  always_solo_capabilities = init_always_solo_capabilities();

  onload_solo_capabilities = init_onload_solo_capabilities();

  always_solo_remaining_capabilities = init_always_solo_capabilities();

  onload_solo_remaining_capabilities = init_onload_solo_capabilities();

  memset(&acquired_capabilities, 0, sizeof(acquired_capabilities));

}

// if the capability sets are initialized in the onload phase then

// it happens before class data sharing (CDS) is initialized. If it

// turns out that CDS gets disabled then we must adjust the always

// capabilities. To ensure a consistent view of the capabililties

// anything we add here should already be in the onload set.

void JvmtiManageCapabilities::recompute_always_capabilities() {

  if (!UseSharedSpaces) {

    jvmtiCapabilities jc = always_capabilities;

    jc.can_generate_all_class_hook_events = 1;

    always_capabilities = jc;

  }

}

// corresponding init functions

jvmtiCapabilities JvmtiManageCapabilities::init_always_capabilities() {

  jvmtiCapabilities jc;

  memset(&jc, 0, sizeof(jc));

  jc.can_get_bytecodes = 1;

  jc.can_signal_thread = 1;

  jc.can_get_source_file_name = 1;

  jc.can_get_line_numbers = 1;

  jc.can_get_synthetic_attribute = 1;

  jc.can_get_monitor_info = 1;

  jc.can_get_constant_pool = 1;

  jc.can_generate_monitor_events = 1;

  jc.can_generate_garbage_collection_events = 1;

  jc.can_generate_compiled_method_load_events = 1;

  jc.can_generate_native_method_bind_events = 1;

  jc.can_generate_vm_object_alloc_events = 1;

  if (os::is_thread_cpu_time_supported()) {

    jc.can_get_current_thread_cpu_time = 1;

    jc.can_get_thread_cpu_time = 1;

  }

  jc.can_redefine_classes = 1;

  jc.can_redefine_any_class = 1;

  jc.can_retransform_classes = 1;

  jc.can_retransform_any_class = 1;

  jc.can_set_native_method_prefix = 1;

  jc.can_tag_objects = 1;

  jc.can_generate_object_free_events = 1;

  jc.can_generate_resource_exhaustion_heap_events = 1;

  jc.can_generate_resource_exhaustion_threads_events = 1;

  return jc;

}

jvmtiCapabilities JvmtiManageCapabilities::init_onload_capabilities() {

  jvmtiCapabilities jc;

  memset(&jc, 0, sizeof(jc));

#ifndef ZERO

  jc.can_pop_frame = 1;

  jc.can_force_early_return = 1;

#endif // !ZERO

  jc.can_get_source_debug_extension = 1;

  jc.can_access_local_variables = 1;

  jc.can_maintain_original_method_order = 1;

  jc.can_generate_all_class_hook_events = 1;

  jc.can_generate_single_step_events = 1;

  jc.can_generate_exception_events = 1;

  jc.can_generate_frame_pop_events = 1;

  jc.can_generate_method_entry_events = 1;

  jc.can_generate_method_exit_events = 1;

  jc.can_get_owned_monitor_info = 1;

  jc.can_get_owned_monitor_stack_depth_info = 1;

  jc.can_get_current_contended_monitor = 1;

  jc.can_generate_early_vmstart = 1;

  return jc;

}

jvmtiCapabilities JvmtiManageCapabilities::init_always_solo_capabilities() {

  jvmtiCapabilities jc;

  memset(&jc, 0, sizeof(jc));

  jc.can_suspend = 1;

  return jc;

}

jvmtiCapabilities JvmtiManageCapabilities::init_onload_solo_capabilities() {

  jvmtiCapabilities jc;

  memset(&jc, 0, sizeof(jc));

  jc.can_generate_field_modification_events = 1;

  jc.can_generate_field_access_events = 1;

  jc.can_generate_breakpoint_events = 1;

  return jc;

}

jvmtiCapabilities *JvmtiManageCapabilities::either(const jvmtiCapabilities *a, const jvmtiCapabilities *b,

                                                   jvmtiCapabilities *result) {

  char *ap = (char *)a;

  char *bp = (char *)b;

  char *resultp = (char *)result;

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

    *resultp++ = *ap++ | *bp++;

  }

  return result;

}

jvmtiCapabilities *JvmtiManageCapabilities::both(const jvmtiCapabilities *a, const jvmtiCapabilities *b,

                                                    jvmtiCapabilities *result) {

  char *ap = (char *)a;

  char *bp = (char *)b;

  char *resultp = (char *)result;

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

    *resultp++ = *ap++ & *bp++;

  }

  return result;

}

jvmtiCapabilities *JvmtiManageCapabilities::exclude(const jvmtiCapabilities *a, const jvmtiCapabilities *b,

                                                    jvmtiCapabilities *result) {

  char *ap = (char *)a;

  char *bp = (char *)b;

  char *resultp = (char *)result;

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

    *resultp++ = *ap++ & ~*bp++;

  }

  return result;

}

bool JvmtiManageCapabilities::has_some(const jvmtiCapabilities *a) {

  char *ap = (char *)a;

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

    if (*ap++ != 0) {

      return true;

    }

  }

  return false;

}

void JvmtiManageCapabilities::copy_capabilities(const jvmtiCapabilities *from, jvmtiCapabilities *to) {

  char *ap = (char *)from;

  char *resultp = (char *)to;

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

    *resultp++ = *ap++;

  }

}

void JvmtiManageCapabilities::get_potential_capabilities(const jvmtiCapabilities *current,

                                                         const jvmtiCapabilities *prohibited,

                                                         jvmtiCapabilities *result) {

  // exclude prohibited capabilities, must be before adding current

  exclude(&always_capabilities, prohibited, result);

  // must include current since it may possess solo capabilities and now prohibited

  either(result, current, result);

  // add other remaining

  either(result, &always_solo_remaining_capabilities, result);

  // if this is during OnLoad more capabilities are available

  if (JvmtiEnv::get_phase() == JVMTI_PHASE_ONLOAD) {

    either(result, &onload_capabilities, result);

    either(result, &onload_solo_remaining_capabilities, result);

  }

}

jvmtiError JvmtiManageCapabilities::add_capabilities(const jvmtiCapabilities *current,

                                                     const jvmtiCapabilities *prohibited,

                                                     const jvmtiCapabilities *desired,

                                                     jvmtiCapabilities *result) {

  // check that the capabilities being added are potential capabilities

  jvmtiCapabilities temp;

  get_potential_capabilities(current, prohibited, &temp);

  if (has_some(exclude(desired, &temp, &temp))) {

    return JVMTI_ERROR_NOT_AVAILABLE;

  }

  // add to the set of ever acquired capabilities

  either(&acquired_capabilities, desired, &acquired_capabilities);

  // onload capabilities that got added are now permanent - so, also remove from onload

  both(&onload_capabilities, desired, &temp);

  either(&always_capabilities, &temp, &always_capabilities);

  exclude(&onload_capabilities, &temp, &onload_capabilities);

  // same for solo capabilities (transferred capabilities in the remaining sets handled as part of standard grab - below)

  both(&onload_solo_capabilities, desired, &temp);

  either(&always_solo_capabilities, &temp, &always_solo_capabilities);

  exclude(&onload_solo_capabilities, &temp, &onload_solo_capabilities);

  // remove solo capabilities that are now taken

  exclude(&always_solo_remaining_capabilities, desired, &always_solo_remaining_capabilities);

  exclude(&onload_solo_remaining_capabilities, desired, &onload_solo_remaining_capabilities);

  // return the result

  either(current, desired, result);

  update();

  return JVMTI_ERROR_NONE;

}

void JvmtiManageCapabilities::relinquish_capabilities(const jvmtiCapabilities *current,

                                                      const jvmtiCapabilities *unwanted,

                                                      jvmtiCapabilities *result) {

  jvmtiCapabilities to_trash;

  jvmtiCapabilities temp;

  // can't give up what you don't have

  both(current, unwanted, &to_trash);

  // restore solo capabilities but only those that belong

  either(&always_solo_remaining_capabilities, both(&always_solo_capabilities, &to_trash, &temp),

         &always_solo_remaining_capabilities);

  either(&onload_solo_remaining_capabilities, both(&onload_solo_capabilities, &to_trash, &temp),

         &onload_solo_remaining_capabilities);

  update();

  // return the result

  exclude(current, unwanted, result);

}

void JvmtiManageCapabilities::update() {

  jvmtiCapabilities avail;

  // all capabilities

  either(&always_capabilities, &always_solo_capabilities, &avail);

  bool interp_events =

    avail.can_generate_field_access_events ||

    avail.can_generate_field_modification_events ||

    avail.can_generate_single_step_events ||

    avail.can_generate_frame_pop_events ||

    avail.can_generate_method_entry_events ||

    avail.can_generate_method_exit_events;

#ifdef ZERO

  bool enter_all_methods =

    interp_events ||

    avail.can_generate_breakpoint_events;

  if (enter_all_methods) {

    // Disable these when tracking the bytecodes

    UseFastEmptyMethods = false;

    UseFastAccessorMethods = false;

  }

#endif // ZERO

  if (avail.can_generate_breakpoint_events) {

    RewriteFrequentPairs = false;

  }

  // If can_redefine_classes is enabled in the onload phase then we know that the

  // dependency information recorded by the compiler is complete.

  if ((avail.can_redefine_classes || avail.can_retransform_classes) &&

      JvmtiEnv::get_phase() == JVMTI_PHASE_ONLOAD) {

    JvmtiExport::set_all_dependencies_are_recorded(true);

  }

  JvmtiExport::set_can_get_source_debug_extension(avail.can_get_source_debug_extension);

  JvmtiExport::set_can_maintain_original_method_order(avail.can_maintain_original_method_order);

  JvmtiExport::set_can_post_interpreter_events(interp_events);

  JvmtiExport::set_can_hotswap_or_post_breakpoint(

    avail.can_generate_breakpoint_events ||

    avail.can_redefine_classes ||

    avail.can_retransform_classes);

  JvmtiExport::set_can_modify_any_class(

    avail.can_generate_breakpoint_events ||

    avail.can_generate_all_class_hook_events);

  JvmtiExport::set_can_walk_any_space(

    avail.can_tag_objects);   // disable sharing in onload phase

  // This controls whether the compilers keep extra locals live to

  // improve the debugging experience so only set them if the selected

  // capabilities look like a debugger.

  JvmtiExport::set_can_access_local_variables(

    avail.can_access_local_variables ||

    avail.can_generate_breakpoint_events ||

    avail.can_generate_frame_pop_events);

  JvmtiExport::set_can_post_on_exceptions(

    avail.can_generate_exception_events ||

    avail.can_generate_frame_pop_events ||

    avail.can_generate_method_exit_events);

  JvmtiExport::set_can_post_breakpoint(avail.can_generate_breakpoint_events);

  JvmtiExport::set_can_post_field_access(avail.can_generate_field_access_events);

  JvmtiExport::set_can_post_field_modification(avail.can_generate_field_modification_events);

  JvmtiExport::set_can_post_method_entry(avail.can_generate_method_entry_events);

  JvmtiExport::set_can_post_method_exit(avail.can_generate_method_exit_events ||

                                        avail.can_generate_frame_pop_events);

  JvmtiExport::set_can_pop_frame(avail.can_pop_frame);

  JvmtiExport::set_can_force_early_return(avail.can_force_early_return);

  JvmtiExport::set_should_clean_up_heap_objects(avail.can_generate_breakpoint_events);

}

#ifndef PRODUCT

void JvmtiManageCapabilities:: print(const jvmtiCapabilities* cap) {

  if (cap->can_tag_objects)

  if (cap->can_generate_field_modification_events)

  if (cap->can_generate_field_access_events)

  if (cap->can_get_bytecodes)

  if (cap->can_get_synthetic_attribute)

  if (cap->can_get_owned_monitor_info)

  if (cap->can_get_current_contended_monitor)

  if (cap->can_get_monitor_info)

  if (cap->can_get_constant_pool)

  if (cap->can_pop_frame)

  if (cap->can_force_early_return)

  if (cap->can_redefine_classes)

  if (cap->can_retransform_classes)

  if (cap->can_signal_thread)

  if (cap->can_get_source_file_name)

  if (cap->can_get_line_numbers)

  if (cap->can_get_source_debug_extension)

  if (cap->can_access_local_variables)

  if (cap->can_maintain_original_method_order)

  if (cap->can_generate_single_step_events)

  if (cap->can_generate_exception_events)

  if (cap->can_generate_frame_pop_events)

  if (cap->can_generate_breakpoint_events)

  if (cap->can_suspend)

  if (cap->can_redefine_any_class )

  if (cap->can_retransform_any_class )

  if (cap->can_get_current_thread_cpu_time)

  if (cap->can_get_thread_cpu_time)

  if (cap->can_generate_method_entry_events)

  if (cap->can_generate_method_exit_events)

  if (cap->can_generate_all_class_hook_events)

  if (cap->can_generate_compiled_method_load_events)

  if (cap->can_generate_monitor_events)

  if (cap->can_generate_vm_object_alloc_events)

  if (cap->can_generate_native_method_bind_events)

  if (cap->can_generate_garbage_collection_events)

  if (cap->can_generate_object_free_events)

  if (cap->can_generate_resource_exhaustion_heap_events)

  if (cap->can_generate_resource_exhaustion_threads_events)

  if (cap->can_generate_early_vmstart)

}

#endif