/*

 * Copyright (c) 2001, 2019, 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 "ci/ciMetadata.hpp"

#include "ci/ciMethodData.hpp"

#include "ci/ciReplay.hpp"

#include "ci/ciUtilities.inline.hpp"

#include "memory/allocation.inline.hpp"

#include "memory/resourceArea.hpp"

#include "runtime/deoptimization.hpp"

#include "utilities/copy.hpp"

// ciMethodData

// ------------------------------------------------------------------

// ciMethodData::ciMethodData

//

ciMethodData::ciMethodData(MethodData* md) : ciMetadata(md) {

  assert(md != NULL, "no null method data");

  Copy::zero_to_words((HeapWord*) &_orig, sizeof(_orig) / sizeof(HeapWord));

  _data = NULL;

  _data_size = 0;

  _extra_data_size = 0;

  _current_mileage = 0;

  _invocation_counter = 0;

  _backedge_counter = 0;

  _state = empty_state;

  _saw_free_extra_data = false;

  // Set an initial hint. Don't use set_hint_di() because

  // first_di() may be out of bounds if data_size is 0.

  _hint_di = first_di();

  // Initialize the escape information (to "don't know.");

  _eflags = _arg_local = _arg_stack = _arg_returned = 0;

  _parameters = NULL;

}

// ------------------------------------------------------------------

// ciMethodData::ciMethodData

//

// No MethodData*.

ciMethodData::ciMethodData() : ciMetadata(NULL) {

  Copy::zero_to_words((HeapWord*) &_orig, sizeof(_orig) / sizeof(HeapWord));

  _data = NULL;

  _data_size = 0;

  _extra_data_size = 0;

  _current_mileage = 0;

  _invocation_counter = 0;

  _backedge_counter = 0;

  _state = empty_state;

  _saw_free_extra_data = false;

  // Set an initial hint. Don't use set_hint_di() because

  // first_di() may be out of bounds if data_size is 0.

  _hint_di = first_di();

  // Initialize the escape information (to "don't know.");

  _eflags = _arg_local = _arg_stack = _arg_returned = 0;

  _parameters = NULL;

}

// Check for entries that reference an unloaded method

class PrepareExtraDataClosure : public CleanExtraDataClosure {

  MethodData*            _mdo;

  GrowableArray<Method*> _uncached_methods;

public:

  PrepareExtraDataClosure(MethodData* mdo)

    : _mdo(mdo),

      _uncached_methods()

  { }

  bool is_live(Method* m) {

    if (!m->method_holder()->is_loader_alive()) {

      return false;

    }

    if (CURRENT_ENV->cached_metadata(m) == NULL) {

      // Uncached entries need to be pre-populated.

      _uncached_methods.append(m);

    }

    return true;

  }

  bool has_safepointed() {

  }

  bool finish() {

    if (_uncached_methods.length() == 0) {

      // Preparation finished iff all Methods* were already cached.

      return true;

    }

    // Holding locks through safepoints is bad practice.

    MutexUnlocker mu(_mdo->extra_data_lock());

    for (int i = 0; i < _uncached_methods.length(); ++i) {

      if (has_safepointed()) {

        // The metadata in the growable array might contain stale

        // entries after a safepoint.

        return false;

      }

      Method* method = _uncached_methods.at(i);

      // Populating ciEnv caches may cause safepoints due

      // to taking the Compile_lock with safepoint checks.

      (void)CURRENT_ENV->get_method(method);

    }

    return false;

  }

};

void ciMethodData::prepare_metadata() {

  MethodData* mdo = get_MethodData();

  for (;;) {

    ResourceMark rm;

    PrepareExtraDataClosure cl(mdo);

    mdo->clean_extra_data(&cl);

    if (cl.finish()) {

      // When encountering uncached metadata, the Compile_lock might be

      // acquired when creating ciMetadata handles, causing safepoints

      // which requires a new round of preparation to clean out potentially

      // new unloading metadata.

      return;

    }

  }

}

void ciMethodData::load_extra_data() {

  MethodData* mdo = get_MethodData();

  MutexLocker ml(mdo->extra_data_lock());

  // Deferred metadata cleaning due to concurrent class unloading.

  prepare_metadata();

  // After metadata preparation, there is no stale metadata,

  // and no safepoints can introduce more stale metadata.

  NoSafepointVerifier no_safepoint;

  // speculative trap entries also hold a pointer to a Method so need to be translated

  DataLayout* dp_src  = mdo->extra_data_base();

  DataLayout* end_src = mdo->args_data_limit();

  DataLayout* dp_dst  = extra_data_base();

  for (;; dp_src = MethodData::next_extra(dp_src), dp_dst = MethodData::next_extra(dp_dst)) {

    assert(dp_src < end_src, "moved past end of extra data");

    assert(((intptr_t)dp_dst) - ((intptr_t)extra_data_base()) == ((intptr_t)dp_src) - ((intptr_t)mdo->extra_data_base()), "source and destination don't match");

    // New traps in the MDO may have been added since we copied the

    // data (concurrent deoptimizations before we acquired

    // extra_data_lock above) or can be removed (a safepoint may occur

    // in the prepare_metadata call above) as we translate the copy:

    // update the copy as we go.

    int tag = dp_src->tag();

    size_t entry_size = DataLayout::header_size_in_bytes();

    if (tag != DataLayout::no_tag) {

      ProfileData* src_data = dp_src->data_in();

      entry_size = src_data->size_in_bytes();

    }

    memcpy(dp_dst, dp_src, entry_size);

    switch(tag) {

    case DataLayout::speculative_trap_data_tag: {

      ciSpeculativeTrapData data_dst(dp_dst);

      SpeculativeTrapData   data_src(dp_src);

      data_dst.translate_from(&data_src);

      break;

    }

    case DataLayout::bit_data_tag:

      break;

    case DataLayout::no_tag:

    case DataLayout::arg_info_data_tag:

      // An empty slot or ArgInfoData entry marks the end of the trap data

      {

        return; // Need a block to avoid SS compiler bug

      }

    default:

      fatal("bad tag = %d", tag);

    }

  }

}

void ciMethodData::load_data() {

  MethodData* mdo = get_MethodData();

  if (mdo == NULL) {

    return;

  }

  // To do: don't copy the data if it is not "ripe" -- require a minimum #

  // of invocations.

  // Snapshot the data -- actually, take an approximate snapshot of

  // the data.  Any concurrently executing threads may be changing the

  // data as we copy it.

  Copy::disjoint_words_atomic((HeapWord*) mdo,

                              (HeapWord*) &_orig,

                              sizeof(_orig) / HeapWordSize);

  Arena* arena = CURRENT_ENV->arena();

  _data_size = mdo->data_size();

  _extra_data_size = mdo->extra_data_size();

  int total_size = _data_size + _extra_data_size;

  _data = (intptr_t *) arena->Amalloc(total_size);

  Copy::disjoint_words_atomic((HeapWord*) mdo->data_base(),

                              (HeapWord*) _data,

                              total_size / HeapWordSize);

  // Traverse the profile data, translating any oops into their

  // ci equivalents.

  ResourceMark rm;

  ciProfileData* ci_data = first_data();

  ProfileData* data = mdo->first_data();

  while (is_valid(ci_data)) {

    ci_data->translate_from(data);

    ci_data = next_data(ci_data);

    data = mdo->next_data(data);

  }

  if (mdo->parameters_type_data() != NULL) {

    _parameters = data_layout_at(mdo->parameters_type_data_di());

    ciParametersTypeData* parameters = new ciParametersTypeData(_parameters);

    parameters->translate_from(mdo->parameters_type_data());

  }

  load_extra_data();

  // Note:  Extra data are all BitData, and do not need translation.

  _current_mileage = MethodData::mileage_of(mdo->method());

  _invocation_counter = mdo->invocation_count();

  _backedge_counter = mdo->backedge_count();

  _state = mdo->is_mature()? mature_state: immature_state;

  _eflags = mdo->eflags();

  _arg_local = mdo->arg_local();

  _arg_stack = mdo->arg_stack();

  _arg_returned  = mdo->arg_returned();

#ifndef PRODUCT

  if (ReplayCompiles) {

    ciReplay::initialize(this);

  }

#endif

}

void ciReceiverTypeData::translate_receiver_data_from(const ProfileData* data) {

  for (uint row = 0; row < row_limit(); row++) {

    Klass* k = data->as_ReceiverTypeData()->receiver(row);

    if (k != NULL) {

      if (k->is_loader_alive()) {

        ciKlass* klass = CURRENT_ENV->get_klass(k);

        set_receiver(row, klass);

      } else {

        // With concurrent class unloading, the MDO could have stale metadata; override it

        clear_row(row);

      }

    }

  }

}

void ciTypeStackSlotEntries::translate_type_data_from(const TypeStackSlotEntries* entries) {

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

    intptr_t k = entries->type(i);

    Klass* klass = (Klass*)klass_part(k);

    if (klass != NULL && !klass->is_loader_alive()) {

      // With concurrent class unloading, the MDO could have stale metadata; override it

      TypeStackSlotEntries::set_type(i, TypeStackSlotEntries::with_status((Klass*)NULL, k));

    } else {

      TypeStackSlotEntries::set_type(i, translate_klass(k));

    }

  }

}

void ciReturnTypeEntry::translate_type_data_from(const ReturnTypeEntry* ret) {

  intptr_t k = ret->type();

  Klass* klass = (Klass*)klass_part(k);

  if (klass != NULL && !klass->is_loader_alive()) {

    // With concurrent class unloading, the MDO could have stale metadata; override it

    set_type(ReturnTypeEntry::with_status((Klass*)NULL, k));

  } else {

    set_type(translate_klass(k));

  }

}

void ciSpeculativeTrapData::translate_from(const ProfileData* data) {

  Method* m = data->as_SpeculativeTrapData()->method();

  ciMethod* ci_m = CURRENT_ENV->get_method(m);

  set_method(ci_m);

}

// Get the data at an arbitrary (sort of) data index.

ciProfileData* ciMethodData::data_at(int data_index) {

  if (out_of_bounds(data_index)) {

    return NULL;

  }

  DataLayout* data_layout = data_layout_at(data_index);

  switch (data_layout->tag()) {

  case DataLayout::no_tag:

  default:

    ShouldNotReachHere();

    return NULL;

  case DataLayout::bit_data_tag:

    return new ciBitData(data_layout);

  case DataLayout::counter_data_tag:

    return new ciCounterData(data_layout);

  case DataLayout::jump_data_tag:

    return new ciJumpData(data_layout);

  case DataLayout::receiver_type_data_tag:

    return new ciReceiverTypeData(data_layout);

  case DataLayout::virtual_call_data_tag:

    return new ciVirtualCallData(data_layout);

  case DataLayout::ret_data_tag:

    return new ciRetData(data_layout);

  case DataLayout::branch_data_tag:

    return new ciBranchData(data_layout);

  case DataLayout::multi_branch_data_tag:

    return new ciMultiBranchData(data_layout);

  case DataLayout::arg_info_data_tag:

    return new ciArgInfoData(data_layout);

  case DataLayout::call_type_data_tag:

    return new ciCallTypeData(data_layout);

  case DataLayout::virtual_call_type_data_tag:

    return new ciVirtualCallTypeData(data_layout);

  case DataLayout::parameters_type_data_tag:

    return new ciParametersTypeData(data_layout);

  };

}

// Iteration over data.

ciProfileData* ciMethodData::next_data(ciProfileData* current) {

  int current_index = dp_to_di(current->dp());

  int next_index = current_index + current->size_in_bytes();

  ciProfileData* next = data_at(next_index);

  return next;

}

ciProfileData* ciMethodData::bci_to_extra_data(int bci, ciMethod* m, bool& two_free_slots) {

  DataLayout* dp  = extra_data_base();

  DataLayout* end = args_data_limit();

  two_free_slots = false;

  for (;dp < end; dp = MethodData::next_extra(dp)) {

    switch(dp->tag()) {

    case DataLayout::no_tag:

      _saw_free_extra_data = true;  // observed an empty slot (common case)

      two_free_slots = (MethodData::next_extra(dp)->tag() == DataLayout::no_tag);

      return NULL;

    case DataLayout::arg_info_data_tag:

      return NULL; // ArgInfoData is at the end of extra data section.

    case DataLayout::bit_data_tag:

      if (m == NULL && dp->bci() == bci) {

        return new ciBitData(dp);

      }

      break;

    case DataLayout::speculative_trap_data_tag: {

      ciSpeculativeTrapData* data = new ciSpeculativeTrapData(dp);

      // data->method() might be null if the MDO is snapshotted

      // concurrently with a trap

      if (m != NULL && data->method() == m && dp->bci() == bci) {

        return data;

      }

      break;

    }

    default:

      fatal("bad tag = %d", dp->tag());

    }

  }

  return NULL;

}

// Translate a bci to its corresponding data, or NULL.

ciProfileData* ciMethodData::bci_to_data(int bci, ciMethod* m) {

  // If m is not NULL we look for a SpeculativeTrapData entry

  if (m == NULL) {

    ciProfileData* data = data_before(bci);

    for ( ; is_valid(data); data = next_data(data)) {

      if (data->bci() == bci) {

        set_hint_di(dp_to_di(data->dp()));

        return data;

      } else if (data->bci() > bci) {

        break;

      }

    }

  }

  bool two_free_slots = false;

  ciProfileData* result = bci_to_extra_data(bci, m, two_free_slots);

  if (result != NULL) {

    return result;

  }

  if (m != NULL && !two_free_slots) {

    // We were looking for a SpeculativeTrapData entry we didn't

    // find. Room is not available for more SpeculativeTrapData

    // entries, look in the non SpeculativeTrapData entries.

    return bci_to_data(bci, NULL);

  }

  return NULL;

}

// Conservatively decode the trap_state of a ciProfileData.

int ciMethodData::has_trap_at(ciProfileData* data, int reason) {

  typedef Deoptimization::DeoptReason DR_t;

  int per_bc_reason

    = Deoptimization::reason_recorded_per_bytecode_if_any((DR_t) reason);

  if (trap_count(reason) == 0) {

    // Impossible for this trap to have occurred, regardless of trap_state.

    // Note:  This happens if the MDO is empty.

    return 0;

  } else if (per_bc_reason == Deoptimization::Reason_none) {

    // We cannot conclude anything; a trap happened somewhere, maybe here.

    return -1;

  } else if (data == NULL) {

    // No profile here, not even an extra_data record allocated on the fly.

    // If there are empty extra_data records, and there had been a trap,

    // there would have been a non-null data pointer.  If there are no

    // free extra_data records, we must return a conservative -1.

    if (_saw_free_extra_data)

      return 0;                 // Q.E.D.

    else

      return -1;                // bail with a conservative answer

  } else {

    return Deoptimization::trap_state_has_reason(data->trap_state(), per_bc_reason);

  }

}

int ciMethodData::trap_recompiled_at(ciProfileData* data) {

  if (data == NULL) {

    return (_saw_free_extra_data? 0: -1);  // (see previous method)

  } else {

    return Deoptimization::trap_state_is_recompiled(data->trap_state())? 1: 0;

  }

}

void ciMethodData::clear_escape_info() {

  VM_ENTRY_MARK;

  MethodData* mdo = get_MethodData();

  if (mdo != NULL) {

    mdo->clear_escape_info();

    ArgInfoData *aid = arg_info();

    int arg_count = (aid == NULL) ? 0 : aid->number_of_args();

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

      set_arg_modified(i, 0);

    }

  }

  _eflags = _arg_local = _arg_stack = _arg_returned = 0;

}

// copy our escape info to the MethodData* if it exists

void ciMethodData::update_escape_info() {

  VM_ENTRY_MARK;

  MethodData* mdo = get_MethodData();

  if ( mdo != NULL) {

    mdo->set_eflags(_eflags);

    mdo->set_arg_local(_arg_local);

    mdo->set_arg_stack(_arg_stack);

    mdo->set_arg_returned(_arg_returned);

    int arg_count = mdo->method()->size_of_parameters();

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

      mdo->set_arg_modified(i, arg_modified(i));

    }

  }

}

void ciMethodData::set_compilation_stats(short loops, short blocks) {

  VM_ENTRY_MARK;

  MethodData* mdo = get_MethodData();

  if (mdo != NULL) {

    mdo->set_num_loops(loops);

    mdo->set_num_blocks(blocks);

  }

}

void ciMethodData::set_would_profile(bool p) {

  VM_ENTRY_MARK;

  MethodData* mdo = get_MethodData();

  if (mdo != NULL) {

    mdo->set_would_profile(p);

  }

}

void ciMethodData::set_argument_type(int bci, int i, ciKlass* k) {

  VM_ENTRY_MARK;

  MethodData* mdo = get_MethodData();

  if (mdo != NULL) {

    ProfileData* data = mdo->bci_to_data(bci);

    if (data != NULL) {

      if (data->is_CallTypeData()) {

        data->as_CallTypeData()->set_argument_type(i, k->get_Klass());

      } else {