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Java example source code file (method.cpp)

This example Java source code file (method.cpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

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Java - Java tags/keywords

assert, breakpointinfo, classloaderdata, instanceklass, intptr_format, jnimethodblock, method, methoddata, null, product, resourcemark, symbol, thread, traps

The method.cpp Java example source code

/*
 * Copyright (c) 1997, 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.
 *
 */

#include "precompiled.hpp"
#include "classfile/metadataOnStackMark.hpp"
#include "classfile/systemDictionary.hpp"
#include "code/debugInfoRec.hpp"
#include "gc_interface/collectedHeap.inline.hpp"
#include "interpreter/bytecodeStream.hpp"
#include "interpreter/bytecodeTracer.hpp"
#include "interpreter/bytecodes.hpp"
#include "interpreter/interpreter.hpp"
#include "interpreter/oopMapCache.hpp"
#include "memory/gcLocker.hpp"
#include "memory/generation.hpp"
#include "memory/heapInspection.hpp"
#include "memory/metadataFactory.hpp"
#include "memory/oopFactory.hpp"
#include "oops/constMethod.hpp"
#include "oops/methodData.hpp"
#include "oops/method.hpp"
#include "oops/oop.inline.hpp"
#include "oops/symbol.hpp"
#include "prims/jvmtiExport.hpp"
#include "prims/methodHandles.hpp"
#include "prims/nativeLookup.hpp"
#include "runtime/arguments.hpp"
#include "runtime/compilationPolicy.hpp"
#include "runtime/frame.inline.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/relocator.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/signature.hpp"
#include "utilities/quickSort.hpp"
#include "utilities/xmlstream.hpp"


// Implementation of Method

Method* Method::allocate(ClassLoaderData* loader_data,
                         int byte_code_size,
                         AccessFlags access_flags,
                         InlineTableSizes* sizes,
                         ConstMethod::MethodType method_type,
                         TRAPS) {
  assert(!access_flags.is_native() || byte_code_size == 0,
         "native methods should not contain byte codes");
  ConstMethod* cm = ConstMethod::allocate(loader_data,
                                          byte_code_size,
                                          sizes,
                                          method_type,
                                          CHECK_NULL);

  int size = Method::size(access_flags.is_native());

  return new (loader_data, size, false, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags, size);
}

Method::Method(ConstMethod* xconst, AccessFlags access_flags, int size) {
  No_Safepoint_Verifier no_safepoint;
  set_constMethod(xconst);
  set_access_flags(access_flags);
  set_method_size(size);
#ifdef CC_INTERP
  set_result_index(T_VOID);
#endif
  set_intrinsic_id(vmIntrinsics::_none);
  set_jfr_towrite(false);
  set_force_inline(false);
  set_hidden(false);
  set_dont_inline(false);
  set_method_data(NULL);
  set_method_counters(NULL);
  set_vtable_index(Method::garbage_vtable_index);

  // Fix and bury in Method*
  set_interpreter_entry(NULL); // sets i2i entry and from_int
  set_adapter_entry(NULL);
  clear_code(); // from_c/from_i get set to c2i/i2i

  if (access_flags.is_native()) {
    clear_native_function();
    set_signature_handler(NULL);
  }

  NOT_PRODUCT(set_compiled_invocation_count(0);)
}

// Release Method*.  The nmethod will be gone when we get here because
// we've walked the code cache.
void Method::deallocate_contents(ClassLoaderData* loader_data) {
  MetadataFactory::free_metadata(loader_data, constMethod());
  set_constMethod(NULL);
  MetadataFactory::free_metadata(loader_data, method_data());
  set_method_data(NULL);
  MetadataFactory::free_metadata(loader_data, method_counters());
  set_method_counters(NULL);
  // The nmethod will be gone when we get here.
  if (code() != NULL) _code = NULL;
}

address Method::get_i2c_entry() {
  assert(_adapter != NULL, "must have");
  return _adapter->get_i2c_entry();
}

address Method::get_c2i_entry() {
  assert(_adapter != NULL, "must have");
  return _adapter->get_c2i_entry();
}

address Method::get_c2i_unverified_entry() {
  assert(_adapter != NULL, "must have");
  return _adapter->get_c2i_unverified_entry();
}

char* Method::name_and_sig_as_C_string() const {
  return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
}

char* Method::name_and_sig_as_C_string(char* buf, int size) const {
  return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
}

char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
  const char* klass_name = klass->external_name();
  int klass_name_len  = (int)strlen(klass_name);
  int method_name_len = method_name->utf8_length();
  int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
  char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
  strcpy(dest, klass_name);
  dest[klass_name_len] = '.';
  strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
  strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
  dest[len] = 0;
  return dest;
}

char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
  Symbol* klass_name = klass->name();
  klass_name->as_klass_external_name(buf, size);
  int len = (int)strlen(buf);

  if (len < size - 1) {
    buf[len++] = '.';

    method_name->as_C_string(&(buf[len]), size - len);
    len = (int)strlen(buf);

    signature->as_C_string(&(buf[len]), size - len);
  }

  return buf;
}

int Method::fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS) {
  // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
  // access exception table
  ExceptionTable table(mh());
  int length = table.length();
  // iterate through all entries sequentially
  constantPoolHandle pool(THREAD, mh->constants());
  for (int i = 0; i < length; i ++) {
    //reacquire the table in case a GC happened
    ExceptionTable table(mh());
    int beg_bci = table.start_pc(i);
    int end_bci = table.end_pc(i);
    assert(beg_bci <= end_bci, "inconsistent exception table");
    if (beg_bci <= throw_bci && throw_bci < end_bci) {
      // exception handler bci range covers throw_bci => investigate further
      int handler_bci = table.handler_pc(i);
      int klass_index = table.catch_type_index(i);
      if (klass_index == 0) {
        return handler_bci;
      } else if (ex_klass.is_null()) {
        return handler_bci;
      } else {
        // we know the exception class => get the constraint class
        // this may require loading of the constraint class; if verification
        // fails or some other exception occurs, return handler_bci
        Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
        KlassHandle klass = KlassHandle(THREAD, k);
        assert(klass.not_null(), "klass not loaded");
        if (ex_klass->is_subtype_of(klass())) {
          return handler_bci;
        }
      }
    }
  }

  return -1;
}

void Method::mask_for(int bci, InterpreterOopMap* mask) {

  Thread* myThread    = Thread::current();
  methodHandle h_this(myThread, this);
#ifdef ASSERT
  bool has_capability = myThread->is_VM_thread() ||
                        myThread->is_ConcurrentGC_thread() ||
                        myThread->is_GC_task_thread();

  if (!has_capability) {
    if (!VerifyStack && !VerifyLastFrame) {
      // verify stack calls this outside VM thread
      warning("oopmap should only be accessed by the "
              "VM, GC task or CMS threads (or during debugging)");
      InterpreterOopMap local_mask;
      method_holder()->mask_for(h_this, bci, &local_mask);
      local_mask.print();
    }
  }
#endif
  method_holder()->mask_for(h_this, bci, mask);
  return;
}


int Method::bci_from(address bcp) const {
#ifdef ASSERT
  { ResourceMark rm;
  assert(is_native() && bcp == code_base() || contains(bcp) || is_error_reported(),
         err_msg("bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s", bcp, name_and_sig_as_C_string()));
  }
#endif
  return bcp - code_base();
}


// Return (int)bcx if it appears to be a valid BCI.
// Return bci_from((address)bcx) if it appears to be a valid BCP.
// Return -1 otherwise.
// Used by profiling code, when invalid data is a possibility.
// The caller is responsible for validating the Method* itself.
int Method::validate_bci_from_bcx(intptr_t bcx) const {
  // keep bci as -1 if not a valid bci
  int bci = -1;
  if (bcx == 0 || (address)bcx == code_base()) {
    // code_size() may return 0 and we allow 0 here
    // the method may be native
    bci = 0;
  } else if (frame::is_bci(bcx)) {
    if (bcx < code_size()) {
      bci = (int)bcx;
    }
  } else if (contains((address)bcx)) {
    bci = (address)bcx - code_base();
  }
  // Assert that if we have dodged any asserts, bci is negative.
  assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
  return bci;
}

address Method::bcp_from(int bci) const {
  assert((is_native() && bci == 0)  || (!is_native() && 0 <= bci && bci < code_size()), "illegal bci");
  address bcp = code_base() + bci;
  assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
  return bcp;
}


int Method::size(bool is_native) {
  // If native, then include pointers for native_function and signature_handler
  int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
  int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord;
  return align_object_size(header_size() + extra_words);
}


Symbol* Method::klass_name() const {
  Klass* k = method_holder();
  assert(k->is_klass(), "must be klass");
  InstanceKlass* ik = (InstanceKlass*) k;
  return ik->name();
}


// Attempt to return method oop to original state.  Clear any pointers
// (to objects outside the shared spaces).  We won't be able to predict
// where they should point in a new JVM.  Further initialize some
// entries now in order allow them to be write protected later.

void Method::remove_unshareable_info() {
  unlink_method();
}


bool Method::was_executed_more_than(int n) {
  // Invocation counter is reset when the Method* is compiled.
  // If the method has compiled code we therefore assume it has
  // be excuted more than n times.
  if (is_accessor() || is_empty_method() || (code() != NULL)) {
    // interpreter doesn't bump invocation counter of trivial methods
    // compiler does not bump invocation counter of compiled methods
    return true;
  }
  else if ((method_counters() != NULL &&
            method_counters()->invocation_counter()->carry()) ||
           (method_data() != NULL &&
            method_data()->invocation_counter()->carry())) {
    // The carry bit is set when the counter overflows and causes
    // a compilation to occur.  We don't know how many times
    // the counter has been reset, so we simply assume it has
    // been executed more than n times.
    return true;
  } else {
    return invocation_count() > n;
  }
}

#ifndef PRODUCT
void Method::print_invocation_count() {
  if (is_static()) tty->print("static ");
  if (is_final()) tty->print("final ");
  if (is_synchronized()) tty->print("synchronized ");
  if (is_native()) tty->print("native ");
  method_holder()->name()->print_symbol_on(tty);
  tty->print(".");
  name()->print_symbol_on(tty);
  signature()->print_symbol_on(tty);

  if (WizardMode) {
    // dump the size of the byte codes
    tty->print(" {%d}", code_size());
  }
  tty->cr();

  tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());
  tty->print_cr ("  invocation_counter:           %8d ", invocation_count());
  tty->print_cr ("  backedge_counter:             %8d ", backedge_count());
  if (CountCompiledCalls) {
    tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());
  }

}
#endif

// Build a MethodData* object to hold information about this method
// collected in the interpreter.
void Method::build_interpreter_method_data(methodHandle method, TRAPS) {
  // Do not profile method if current thread holds the pending list lock,
  // which avoids deadlock for acquiring the MethodData_lock.
  if (InstanceRefKlass::owns_pending_list_lock((JavaThread*)THREAD)) {
    return;
  }

  // Grab a lock here to prevent multiple
  // MethodData*s from being created.
  MutexLocker ml(MethodData_lock, THREAD);
  if (method->method_data() == NULL) {
    ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
    MethodData* method_data = MethodData::allocate(loader_data, method, CHECK);
    method->set_method_data(method_data);
    if (PrintMethodData && (Verbose || WizardMode)) {
      ResourceMark rm(THREAD);
      tty->print("build_interpreter_method_data for ");
      method->print_name(tty);
      tty->cr();
      // At the end of the run, the MDO, full of data, will be dumped.
    }
  }
}

MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
  methodHandle mh(m);
  ClassLoaderData* loader_data = mh->method_holder()->class_loader_data();
  MethodCounters* counters = MethodCounters::allocate(loader_data, CHECK_NULL);
  if (mh->method_counters() == NULL) {
    mh->set_method_counters(counters);
  } else {
    MetadataFactory::free_metadata(loader_data, counters);
  }
  return mh->method_counters();
}

void Method::cleanup_inline_caches() {
  // The current system doesn't use inline caches in the interpreter
  // => nothing to do (keep this method around for future use)
}


int Method::extra_stack_words() {
  // not an inline function, to avoid a header dependency on Interpreter
  return extra_stack_entries() * Interpreter::stackElementSize;
}


void Method::compute_size_of_parameters(Thread *thread) {
  ArgumentSizeComputer asc(signature());
  set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
}

#ifdef CC_INTERP
void Method::set_result_index(BasicType type)          {
  _result_index = Interpreter::BasicType_as_index(type);
}
#endif

BasicType Method::result_type() const {
  ResultTypeFinder rtf(signature());
  return rtf.type();
}


bool Method::is_empty_method() const {
  return  code_size() == 1
      && *code_base() == Bytecodes::_return;
}


bool Method::is_vanilla_constructor() const {
  // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
  // which only calls the superclass vanilla constructor and possibly does stores of
  // zero constants to local fields:
  //
  //   aload_0
  //   invokespecial
  //   indexbyte1
  //   indexbyte2
  //
  // followed by an (optional) sequence of:
  //
  //   aload_0
  //   aconst_null / iconst_0 / fconst_0 / dconst_0
  //   putfield
  //   indexbyte1
  //   indexbyte2
  //
  // followed by:
  //
  //   return

  assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
  assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
  int size = code_size();
  // Check if size match
  if (size == 0 || size % 5 != 0) return false;
  address cb = code_base();
  int last = size - 1;
  if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
    // Does not call superclass default constructor
    return false;
  }
  // Check optional sequence
  for (int i = 4; i < last; i += 5) {
    if (cb[i] != Bytecodes::_aload_0) return false;
    if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
    if (cb[i+2] != Bytecodes::_putfield) return false;
  }
  return true;
}


bool Method::compute_has_loops_flag() {
  BytecodeStream bcs(this);
  Bytecodes::Code bc;

  while ((bc = bcs.next()) >= 0) {
    switch( bc ) {
      case Bytecodes::_ifeq:
      case Bytecodes::_ifnull:
      case Bytecodes::_iflt:
      case Bytecodes::_ifle:
      case Bytecodes::_ifne:
      case Bytecodes::_ifnonnull:
      case Bytecodes::_ifgt:
      case Bytecodes::_ifge:
      case Bytecodes::_if_icmpeq:
      case Bytecodes::_if_icmpne:
      case Bytecodes::_if_icmplt:
      case Bytecodes::_if_icmpgt:
      case Bytecodes::_if_icmple:
      case Bytecodes::_if_icmpge:
      case Bytecodes::_if_acmpeq:
      case Bytecodes::_if_acmpne:
      case Bytecodes::_goto:
      case Bytecodes::_jsr:
        if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
        break;

      case Bytecodes::_goto_w:
      case Bytecodes::_jsr_w:
        if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
        break;
    }
  }
  _access_flags.set_loops_flag_init();
  return _access_flags.has_loops();
}

bool Method::is_final_method(AccessFlags class_access_flags) const {
  // or "does_not_require_vtable_entry"
  // default method or overpass can occur, is not final (reuses vtable entry)
  // private methods get vtable entries for backward class compatibility.
  if (is_overpass() || is_default_method())  return false;
  return is_final() || class_access_flags.is_final();
}

bool Method::is_final_method() const {
  return is_final_method(method_holder()->access_flags());
}

bool Method::is_default_method() const {
  if (method_holder() != NULL &&
      method_holder()->is_interface() &&
      !is_abstract()) {
    return true;
  } else {
    return false;
  }
}

bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
  if (is_final_method(class_access_flags))  return true;
#ifdef ASSERT
  ResourceMark rm;
  bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
  if (class_access_flags.is_interface()) {
      assert(is_nonv == is_static(), err_msg("is_nonv=%s", name_and_sig_as_C_string()));
  }
#endif
  assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
  return vtable_index() == nonvirtual_vtable_index;
}

bool Method::can_be_statically_bound() const {
  return can_be_statically_bound(method_holder()->access_flags());
}

bool Method::is_accessor() const {
  if (code_size() != 5) return false;
  if (size_of_parameters() != 1) return false;
  if (java_code_at(0) != Bytecodes::_aload_0 ) return false;
  if (java_code_at(1) != Bytecodes::_getfield) return false;
  if (java_code_at(4) != Bytecodes::_areturn &&
      java_code_at(4) != Bytecodes::_ireturn ) return false;
  return true;
}


bool Method::is_initializer() const {
  return name() == vmSymbols::object_initializer_name() || is_static_initializer();
}

bool Method::has_valid_initializer_flags() const {
  return (is_static() ||
          method_holder()->major_version() < 51);
}

bool Method::is_static_initializer() const {
  // For classfiles version 51 or greater, ensure that the clinit method is
  // static.  Non-static methods with the name "<clinit>" are not static
  // initializers. (older classfiles exempted for backward compatibility)
  return name() == vmSymbols::class_initializer_name() &&
         has_valid_initializer_flags();
}


objArrayHandle Method::resolved_checked_exceptions_impl(Method* this_oop, TRAPS) {
  int length = this_oop->checked_exceptions_length();
  if (length == 0) {  // common case
    return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
  } else {
    methodHandle h_this(THREAD, this_oop);
    objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
    objArrayHandle mirrors (THREAD, m_oop);
    for (int i = 0; i < length; i++) {
      CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
      Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
      assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
      mirrors->obj_at_put(i, k->java_mirror());
    }
    return mirrors;
  }
};


int Method::line_number_from_bci(int bci) const {
  if (bci == SynchronizationEntryBCI) bci = 0;
  assert(bci == 0 || 0 <= bci && bci < code_size(), "illegal bci");
  int best_bci  =  0;
  int best_line = -1;

  if (has_linenumber_table()) {
    // The line numbers are a short array of 2-tuples [start_pc, line_number].
    // Not necessarily sorted and not necessarily one-to-one.
    CompressedLineNumberReadStream stream(compressed_linenumber_table());
    while (stream.read_pair()) {
      if (stream.bci() == bci) {
        // perfect match
        return stream.line();
      } else {
        // update best_bci/line
        if (stream.bci() < bci && stream.bci() >= best_bci) {
          best_bci  = stream.bci();
          best_line = stream.line();
        }
      }
    }
  }
  return best_line;
}


bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
  if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
    Thread *thread = Thread::current();
    Symbol* klass_name = constants()->klass_name_at(klass_index);
    Handle loader(thread, method_holder()->class_loader());
    Handle prot  (thread, method_holder()->protection_domain());
    return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
  } else {
    return true;
  }
}


bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
  int klass_index = constants()->klass_ref_index_at(refinfo_index);
  if (must_be_resolved) {
    // Make sure klass is resolved in constantpool.
    if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
  }
  return is_klass_loaded_by_klass_index(klass_index);
}


void Method::set_native_function(address function, bool post_event_flag) {
  assert(function != NULL, "use clear_native_function to unregister natives");
  assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
  address* native_function = native_function_addr();

  // We can see racers trying to place the same native function into place. Once
  // is plenty.
  address current = *native_function;
  if (current == function) return;
  if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
      function != NULL) {
    // native_method_throw_unsatisfied_link_error_entry() should only
    // be passed when post_event_flag is false.
    assert(function !=
      SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
      "post_event_flag mis-match");

    // post the bind event, and possible change the bind function
    JvmtiExport::post_native_method_bind(this, &function);
  }
  *native_function = function;
  // This function can be called more than once. We must make sure that we always
  // use the latest registered method -> check if a stub already has been generated.
  // If so, we have to make it not_entrant.
  nmethod* nm = code(); // Put it into local variable to guard against concurrent updates
  if (nm != NULL) {
    nm->make_not_entrant();
  }
}


bool Method::has_native_function() const {
  if (is_method_handle_intrinsic())
    return false;  // special-cased in SharedRuntime::generate_native_wrapper
  address func = native_function();
  return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
}


void Method::clear_native_function() {
  // Note: is_method_handle_intrinsic() is allowed here.
  set_native_function(
    SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
    !native_bind_event_is_interesting);
  clear_code();
}

address Method::critical_native_function() {
  methodHandle mh(this);
  return NativeLookup::lookup_critical_entry(mh);
}


void Method::set_signature_handler(address handler) {
  address* signature_handler =  signature_handler_addr();
  *signature_handler = handler;
}


void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
  if (PrintCompilation && report) {
    ttyLocker ttyl;
    tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
    if (comp_level == CompLevel_all) {
      tty->print("all levels ");
    } else {
      tty->print("levels ");
      for (int i = (int)CompLevel_none; i <= comp_level; i++) {
        tty->print("%d ", i);
      }
    }
    this->print_short_name(tty);
    int size = this->code_size();
    if (size > 0) {
      tty->print(" (%d bytes)", size);
    }
    if (reason != NULL) {
      tty->print("   %s", reason);
    }
    tty->cr();
  }
  if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
    ttyLocker ttyl;
    xtty->begin_elem("make_not_%scompilable thread='" UINTX_FORMAT "'",
                     is_osr ? "osr_" : "", os::current_thread_id());
    if (reason != NULL) {
      xtty->print(" reason=\'%s\'", reason);
    }
    xtty->method(this);
    xtty->stamp();
    xtty->end_elem();
  }
}

bool Method::is_always_compilable() const {
  // Generated adapters must be compiled
  if (is_method_handle_intrinsic() && is_synthetic()) {
    assert(!is_not_c1_compilable(), "sanity check");
    assert(!is_not_c2_compilable(), "sanity check");
    return true;
  }

  return false;
}

bool Method::is_not_compilable(int comp_level) const {
  if (number_of_breakpoints() > 0)
    return true;
  if (is_always_compilable())
    return false;
  if (comp_level == CompLevel_any)
    return is_not_c1_compilable() || is_not_c2_compilable();
  if (is_c1_compile(comp_level))
    return is_not_c1_compilable();
  if (is_c2_compile(comp_level))
    return is_not_c2_compilable();
  return false;
}

// call this when compiler finds that this method is not compilable
void Method::set_not_compilable(int comp_level, bool report, const char* reason) {
  if (is_always_compilable()) {
    // Don't mark a method which should be always compilable
    return;
  }
  print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
  if (comp_level == CompLevel_all) {
    set_not_c1_compilable();
    set_not_c2_compilable();
  } else {
    if (is_c1_compile(comp_level))
      set_not_c1_compilable();
    if (is_c2_compile(comp_level))
      set_not_c2_compilable();
  }
  CompilationPolicy::policy()->disable_compilation(this);
  assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
}

bool Method::is_not_osr_compilable(int comp_level) const {
  if (is_not_compilable(comp_level))
    return true;
  if (comp_level == CompLevel_any)
    return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
  if (is_c1_compile(comp_level))
    return is_not_c1_osr_compilable();
  if (is_c2_compile(comp_level))
    return is_not_c2_osr_compilable();
  return false;
}

void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) {
  print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
  if (comp_level == CompLevel_all) {
    set_not_c1_osr_compilable();
    set_not_c2_osr_compilable();
  } else {
    if (is_c1_compile(comp_level))
      set_not_c1_osr_compilable();
    if (is_c2_compile(comp_level))
      set_not_c2_osr_compilable();
  }
  CompilationPolicy::policy()->disable_compilation(this);
  assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
}

// Revert to using the interpreter and clear out the nmethod
void Method::clear_code() {

  // this may be NULL if c2i adapters have not been made yet
  // Only should happen at allocate time.
  if (_adapter == NULL) {
    _from_compiled_entry    = NULL;
  } else {
    _from_compiled_entry    = _adapter->get_c2i_entry();
  }
  OrderAccess::storestore();
  _from_interpreted_entry = _i2i_entry;
  OrderAccess::storestore();
  _code = NULL;
}

// Called by class data sharing to remove any entry points (which are not shared)
void Method::unlink_method() {
  _code = NULL;
  _i2i_entry = NULL;
  _from_interpreted_entry = NULL;
  if (is_native()) {
    *native_function_addr() = NULL;
    set_signature_handler(NULL);
  }
  NOT_PRODUCT(set_compiled_invocation_count(0);)
  _adapter = NULL;
  _from_compiled_entry = NULL;

  // In case of DumpSharedSpaces, _method_data should always be NULL.
  //
  // During runtime (!DumpSharedSpaces), when we are cleaning a
  // shared class that failed to load, this->link_method() may
  // have already been called (before an exception happened), so
  // this->_method_data may not be NULL.
  assert(!DumpSharedSpaces || _method_data == NULL, "unexpected method data?");

  set_method_data(NULL);
  set_method_counters(NULL);
}

// Called when the method_holder is getting linked. Setup entrypoints so the method
// is ready to be called from interpreter, compiler, and vtables.
void Method::link_method(methodHandle h_method, TRAPS) {
  // If the code cache is full, we may reenter this function for the
  // leftover methods that weren't linked.
  if (_i2i_entry != NULL) return;

  assert(_adapter == NULL, "init'd to NULL" );
  assert( _code == NULL, "nothing compiled yet" );

  // Setup interpreter entrypoint
  assert(this == h_method(), "wrong h_method()" );
  address entry = Interpreter::entry_for_method(h_method);
  assert(entry != NULL, "interpreter entry must be non-null");
  // Sets both _i2i_entry and _from_interpreted_entry
  set_interpreter_entry(entry);

  // Don't overwrite already registered native entries.
  if (is_native() && !has_native_function()) {
    set_native_function(
      SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
      !native_bind_event_is_interesting);
  }

  // Setup compiler entrypoint.  This is made eagerly, so we do not need
  // special handling of vtables.  An alternative is to make adapters more
  // lazily by calling make_adapter() from from_compiled_entry() for the
  // normal calls.  For vtable calls life gets more complicated.  When a
  // call-site goes mega-morphic we need adapters in all methods which can be
  // called from the vtable.  We need adapters on such methods that get loaded
  // later.  Ditto for mega-morphic itable calls.  If this proves to be a
  // problem we'll make these lazily later.
  (void) make_adapters(h_method, CHECK);

  // ONLY USE the h_method now as make_adapter may have blocked

}

address Method::make_adapters(methodHandle mh, TRAPS) {
  // Adapters for compiled code are made eagerly here.  They are fairly
  // small (generally < 100 bytes) and quick to make (and cached and shared)
  // so making them eagerly shouldn't be too expensive.
  AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
  if (adapter == NULL ) {
    THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "out of space in CodeCache for adapters");
  }

  mh->set_adapter_entry(adapter);
  mh->_from_compiled_entry = adapter->get_c2i_entry();
  return adapter->get_c2i_entry();
}

// The verified_code_entry() must be called when a invoke is resolved
// on this method.

// It returns the compiled code entry point, after asserting not null.
// This function is called after potential safepoints so that nmethod
// or adapter that it points to is still live and valid.
// This function must not hit a safepoint!
address Method::verified_code_entry() {
  debug_only(No_Safepoint_Verifier nsv;)
  assert(_from_compiled_entry != NULL, "must be set");
  return _from_compiled_entry;
}

// Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
// (could be racing a deopt).
// Not inline to avoid circular ref.
bool Method::check_code() const {
  // cached in a register or local.  There's a race on the value of the field.
  nmethod *code = (nmethod *)OrderAccess::load_ptr_acquire(&_code);
  return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
}

// Install compiled code.  Instantly it can execute.
void Method::set_code(methodHandle mh, nmethod *code) {
  assert( code, "use clear_code to remove code" );
  assert( mh->check_code(), "" );

  guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");

  // These writes must happen in this order, because the interpreter will
  // directly jump to from_interpreted_entry which jumps to an i2c adapter
  // which jumps to _from_compiled_entry.
  mh->_code = code;             // Assign before allowing compiled code to exec

  int comp_level = code->comp_level();
  // In theory there could be a race here. In practice it is unlikely
  // and not worth worrying about.
  if (comp_level > mh->highest_comp_level()) {
    mh->set_highest_comp_level(comp_level);
  }

  OrderAccess::storestore();
#ifdef SHARK
  mh->_from_interpreted_entry = code->insts_begin();
#else //!SHARK
  mh->_from_compiled_entry = code->verified_entry_point();
  OrderAccess::storestore();
  // Instantly compiled code can execute.
  if (!mh->is_method_handle_intrinsic())
    mh->_from_interpreted_entry = mh->get_i2c_entry();
#endif //!SHARK
}


bool Method::is_overridden_in(Klass* k) const {
  InstanceKlass* ik = InstanceKlass::cast(k);

  if (ik->is_interface()) return false;

  // If method is an interface, we skip it - except if it
  // is a miranda method
  if (method_holder()->is_interface()) {
    // Check that method is not a miranda method
    if (ik->lookup_method(name(), signature()) == NULL) {
      // No implementation exist - so miranda method
      return false;
    }
    return true;
  }

  assert(ik->is_subclass_of(method_holder()), "should be subklass");
  assert(ik->vtable() != NULL, "vtable should exist");
  if (!has_vtable_index()) {
    return false;
  } else {
    Method* vt_m = ik->method_at_vtable(vtable_index());
    return vt_m != this;
  }
}


// give advice about whether this Method* should be cached or not
bool Method::should_not_be_cached() const {
  if (is_old()) {
    // This method has been redefined. It is either EMCP or obsolete
    // and we don't want to cache it because that would pin the method
    // down and prevent it from being collectible if and when it
    // finishes executing.
    return true;
  }

  // caching this method should be just fine
  return false;
}


/**
 *  Returns true if this is one of the specially treated methods for
 *  security related stack walks (like Reflection.getCallerClass).
 */
bool Method::is_ignored_by_security_stack_walk() const {
  const bool use_new_reflection = JDK_Version::is_gte_jdk14x_version() && UseNewReflection;

  if (intrinsic_id() == vmIntrinsics::_invoke) {
    // This is Method.invoke() -- ignore it
    return true;
  }
  if (use_new_reflection &&
      method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
    // This is an auxilary frame -- ignore it
    return true;
  }
  if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
    // This is an internal adapter frame for method handles -- ignore it
    return true;
  }
  return false;
}


// Constant pool structure for invoke methods:
enum {
  _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
  _imcp_invoke_signature,       // utf8: (variable Symbol*)
  _imcp_limit
};

// Test if this method is an MH adapter frame generated by Java code.
// Cf. java/lang/invoke/InvokerBytecodeGenerator
bool Method::is_compiled_lambda_form() const {
  return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
}

// Test if this method is an internal MH primitive method.
bool Method::is_method_handle_intrinsic() const {
  vmIntrinsics::ID iid = intrinsic_id();
  return (MethodHandles::is_signature_polymorphic(iid) &&
          MethodHandles::is_signature_polymorphic_intrinsic(iid));
}

bool Method::has_member_arg() const {
  vmIntrinsics::ID iid = intrinsic_id();
  return (MethodHandles::is_signature_polymorphic(iid) &&
          MethodHandles::has_member_arg(iid));
}

// Make an instance of a signature-polymorphic internal MH primitive.
methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
                                                         Symbol* signature,
                                                         TRAPS) {
  ResourceMark rm;
  methodHandle empty;

  KlassHandle holder = SystemDictionary::MethodHandle_klass();
  Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
  assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
  if (TraceMethodHandles) {
    tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
  }

  // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
  name->increment_refcount();
  signature->increment_refcount();

  int cp_length = _imcp_limit;
  ClassLoaderData* loader_data = holder->class_loader_data();
  constantPoolHandle cp;
  {
    ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
    cp = constantPoolHandle(THREAD, cp_oop);
  }
  cp->set_pool_holder(InstanceKlass::cast(holder()));
  cp->symbol_at_put(_imcp_invoke_name,       name);
  cp->symbol_at_put(_imcp_invoke_signature,  signature);
  cp->set_has_preresolution();

  // decide on access bits:  public or not?
  int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
  bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
  if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
  assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");

  methodHandle m;
  {
    InlineTableSizes sizes;
    Method* m_oop = Method::allocate(loader_data, 0,
                                     accessFlags_from(flags_bits), &sizes,
                                     ConstMethod::NORMAL, CHECK_(empty));
    m = methodHandle(THREAD, m_oop);
  }
  m->set_constants(cp());
  m->set_name_index(_imcp_invoke_name);
  m->set_signature_index(_imcp_invoke_signature);
  assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
  assert(m->signature() == signature, "");
#ifdef CC_INTERP
  ResultTypeFinder rtf(signature);
  m->set_result_index(rtf.type());
#endif
  m->compute_size_of_parameters(THREAD);
  m->init_intrinsic_id();
  assert(m->is_method_handle_intrinsic(), "");
#ifdef ASSERT
  if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
  assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
  assert(m->intrinsic_id() == iid, "correctly predicted iid");
#endif //ASSERT

  // Finally, set up its entry points.
  assert(m->can_be_statically_bound(), "");
  m->set_vtable_index(Method::nonvirtual_vtable_index);
  m->link_method(m, CHECK_(empty));

  if (TraceMethodHandles && (Verbose || WizardMode))
    m->print_on(tty);

  return m;
}

Klass* Method::check_non_bcp_klass(Klass* klass) {
  if (klass != NULL && klass->class_loader() != NULL) {
    if (klass->oop_is_objArray())
      klass = ObjArrayKlass::cast(klass)->bottom_klass();
    return klass;
  }
  return NULL;
}


methodHandle Method::clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
                                                u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
  // Code below does not work for native methods - they should never get rewritten anyway
  assert(!m->is_native(), "cannot rewrite native methods");
  // Allocate new Method*
  AccessFlags flags = m->access_flags();

  ConstMethod* cm = m->constMethod();
  int checked_exceptions_len = cm->checked_exceptions_length();
  int localvariable_len = cm->localvariable_table_length();
  int exception_table_len = cm->exception_table_length();
  int method_parameters_len = cm->method_parameters_length();
  int method_annotations_len = cm->method_annotations_length();
  int parameter_annotations_len = cm->parameter_annotations_length();
  int type_annotations_len = cm->type_annotations_length();
  int default_annotations_len = cm->default_annotations_length();

  InlineTableSizes sizes(
      localvariable_len,
      new_compressed_linenumber_size,
      exception_table_len,
      checked_exceptions_len,
      method_parameters_len,
      cm->generic_signature_index(),
      method_annotations_len,
      parameter_annotations_len,
      type_annotations_len,
      default_annotations_len,
      0);

  ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
  Method* newm_oop = Method::allocate(loader_data,
                                      new_code_length,
                                      flags,
                                      &sizes,
                                      m->method_type(),
                                      CHECK_(methodHandle()));
  methodHandle newm (THREAD, newm_oop);
  int new_method_size = newm->method_size();

  // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
  ConstMethod* newcm = newm->constMethod();
  int new_const_method_size = newm->constMethod()->size();

  memcpy(newm(), m(), sizeof(Method));

  // Create shallow copy of ConstMethod.
  memcpy(newcm, m->constMethod(), sizeof(ConstMethod));

  // Reset correct method/const method, method size, and parameter info
  newm->set_constMethod(newcm);
  newm->constMethod()->set_code_size(new_code_length);
  newm->constMethod()->set_constMethod_size(new_const_method_size);
  newm->set_method_size(new_method_size);
  assert(newm->code_size() == new_code_length, "check");
  assert(newm->method_parameters_length() == method_parameters_len, "check");
  assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
  assert(newm->exception_table_length() == exception_table_len, "check");
  assert(newm->localvariable_table_length() == localvariable_len, "check");
  // Copy new byte codes
  memcpy(newm->code_base(), new_code, new_code_length);
  // Copy line number table
  if (new_compressed_linenumber_size > 0) {
    memcpy(newm->compressed_linenumber_table(),
           new_compressed_linenumber_table,
           new_compressed_linenumber_size);
  }
  // Copy method_parameters
  if (method_parameters_len > 0) {
    memcpy(newm->method_parameters_start(),
           m->method_parameters_start(),
           method_parameters_len * sizeof(MethodParametersElement));
  }
  // Copy checked_exceptions
  if (checked_exceptions_len > 0) {
    memcpy(newm->checked_exceptions_start(),
           m->checked_exceptions_start(),
           checked_exceptions_len * sizeof(CheckedExceptionElement));
  }
  // Copy exception table
  if (exception_table_len > 0) {
    memcpy(newm->exception_table_start(),
           m->exception_table_start(),
           exception_table_len * sizeof(ExceptionTableElement));
  }
  // Copy local variable number table
  if (localvariable_len > 0) {
    memcpy(newm->localvariable_table_start(),
           m->localvariable_table_start(),
           localvariable_len * sizeof(LocalVariableTableElement));
  }
  // Copy stackmap table
  if (m->has_stackmap_table()) {
    int code_attribute_length = m->stackmap_data()->length();
    Array<u1>* stackmap_data =
      MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
    memcpy((void*)stackmap_data->adr_at(0),
           (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
    newm->set_stackmap_data(stackmap_data);
  }

  // copy annotations over to new method
  newcm->copy_annotations_from(cm);
  return newm;
}

vmSymbols::SID Method::klass_id_for_intrinsics(Klass* holder) {
  // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
  // because we are not loading from core libraries
  // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
  // which does not use the class default class loader so we check for its loader here
  InstanceKlass* ik = InstanceKlass::cast(holder);
  if ((ik->class_loader() != NULL) && !SystemDictionary::is_ext_class_loader(ik->class_loader())) {
    return vmSymbols::NO_SID;   // regardless of name, no intrinsics here
  }

  // see if the klass name is well-known:
  Symbol* klass_name = ik->name();
  return vmSymbols::find_sid(klass_name);
}

void Method::init_intrinsic_id() {
  assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
  const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
  assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
  assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");

  // the klass name is well-known:
  vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
  assert(klass_id != vmSymbols::NO_SID, "caller responsibility");

  // ditto for method and signature:
  vmSymbols::SID  name_id = vmSymbols::find_sid(name());
  if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
      && name_id == vmSymbols::NO_SID)
    return;
  vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());
  if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
      && sig_id == vmSymbols::NO_SID)  return;
  jshort flags = access_flags().as_short();

  vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
  if (id != vmIntrinsics::_none) {
    set_intrinsic_id(id);
    return;
  }

  // A few slightly irregular cases:
  switch (klass_id) {
  case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
    // Second chance: check in regular Math.
    switch (name_id) {
    case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
    case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
    case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
      // pretend it is the corresponding method in the non-strict class:
      klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
      id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
      break;
    }
    break;

  // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*.
  case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
    if (!is_native())  break;
    id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
    if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
      id = vmIntrinsics::_none;
    break;
  }

  if (id != vmIntrinsics::_none) {
    // Set up its iid.  It is an alias method.
    set_intrinsic_id(id);
    return;
  }
}

// These two methods are static since a GC may move the Method
bool Method::load_signature_classes(methodHandle m, TRAPS) {
  if (THREAD->is_Compiler_thread()) {
    // There is nothing useful this routine can do from within the Compile thread.
    // Hopefully, the signature contains only well-known classes.
    // We could scan for this and return true/false, but the caller won't care.
    return false;
  }
  bool sig_is_loaded = true;
  Handle class_loader(THREAD, m->method_holder()->class_loader());
  Handle protection_domain(THREAD, m->method_holder()->protection_domain());
  ResourceMark rm(THREAD);
  Symbol*  signature = m->signature();
  for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
    if (ss.is_object()) {
      Symbol* sym = ss.as_symbol(CHECK_(false));
      Symbol*  name  = sym;
      Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
                                             protection_domain, THREAD);
      // We are loading classes eagerly. If a ClassNotFoundException or
      // a LinkageError was generated, be sure to ignore it.
      if (HAS_PENDING_EXCEPTION) {
        if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
            PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
          CLEAR_PENDING_EXCEPTION;
        } else {
          return false;
        }
      }
      if( klass == NULL) { sig_is_loaded = false; }
    }
  }
  return sig_is_loaded;
}

bool Method::has_unloaded_classes_in_signature(methodHandle m, TRAPS) {
  Handle class_loader(THREAD, m->method_holder()->class_loader());
  Handle protection_domain(THREAD, m->method_holder()->protection_domain());
  ResourceMark rm(THREAD);
  Symbol*  signature = m->signature();
  for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
    if (ss.type() == T_OBJECT) {
      Symbol* name = ss.as_symbol_or_null();
      if (name == NULL) return true;
      Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
      if (klass == NULL) return true;
    }
  }
  return false;
}

// Exposed so field engineers can debug VM
void Method::print_short_name(outputStream* st) {
  ResourceMark rm;
#ifdef PRODUCT
  st->print(" %s::", method_holder()->external_name());
#else
  st->print(" %s::", method_holder()->internal_name());
#endif
  name()->print_symbol_on(st);
  if (WizardMode) signature()->print_symbol_on(st);
  else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
    MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
}

// Comparer for sorting an object array containing
// Method*s.
static int method_comparator(Method* a, Method* b) {
  return a->name()->fast_compare(b->name());
}

// This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
// default_methods also uses this without the ordering for fast find_method
void Method::sort_methods(Array<Method*>* methods, bool idempotent, bool set_idnums) {
  int length = methods->length();
  if (length > 1) {
    {
      No_Safepoint_Verifier nsv;
      QuickSort::sort<Method*>(methods->data(), length, method_comparator, idempotent);
    }
    // Reset method ordering
    if (set_idnums) {
      for (int i = 0; i < length; i++) {
        Method* m = methods->at(i);
        m->set_method_idnum(i);
      }
    }
  }
}

//-----------------------------------------------------------------------------------
// Non-product code unless JVM/TI needs it

#if !defined(PRODUCT) || INCLUDE_JVMTI
class SignatureTypePrinter : public SignatureTypeNames {
 private:
  outputStream* _st;
  bool _use_separator;

  void type_name(const char* name) {
    if (_use_separator) _st->print(", ");
    _st->print(name);
    _use_separator = true;
  }

 public:
  SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
    _st = st;
    _use_separator = false;
  }

  void print_parameters()              { _use_separator = false; iterate_parameters(); }
  void print_returntype()              { _use_separator = false; iterate_returntype(); }
};


void Method::print_name(outputStream* st) {
  Thread *thread = Thread::current();
  ResourceMark rm(thread);
  SignatureTypePrinter sig(signature(), st);
  st->print("%s ", is_static() ? "static" : "virtual");
  sig.print_returntype();
  st->print(" %s.", method_holder()->internal_name());
  name()->print_symbol_on(st);
  st->print("(");
  sig.print_parameters();
  st->print(")");
}
#endif // !PRODUCT || INCLUDE_JVMTI


//-----------------------------------------------------------------------------------
// Non-product code

#ifndef PRODUCT
void Method::print_codes_on(outputStream* st) const {
  print_codes_on(0, code_size(), st);
}

void Method::print_codes_on(int from, int to, outputStream* st) const {
  Thread *thread = Thread::current();
  ResourceMark rm(thread);
  methodHandle mh (thread, (Method*)this);
  BytecodeStream s(mh);
  s.set_interval(from, to);
  BytecodeTracer::set_closure(BytecodeTracer::std_closure());
  while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
}
#endif // not PRODUCT


// Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas
// between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
// we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used
// as end-of-stream terminator.

void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) {
  // bci and line number does not compress into single byte.
  // Write out escape character and use regular compression for bci and line number.
  write_byte((jubyte)0xFF);
  write_signed_int(bci_delta);
  write_signed_int(line_delta);
}

// See comment in method.hpp which explains why this exists.
#if defined(_M_AMD64) && _MSC_VER >= 1400
#pragma optimize("", off)
void CompressedLineNumberWriteStream::write_pair(int bci, int line) {
  write_pair_inline(bci, line);
}
#pragma optimize("", on)
#endif

CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
  _bci = 0;
  _line = 0;
};


bool CompressedLineNumberReadStream::read_pair() {
  jubyte next = read_byte();
  // Check for terminator
  if (next == 0) return false;
  if (next == 0xFF) {
    // Escape character, regular compression used
    _bci  += read_signed_int();
    _line += read_signed_int();
  } else {
    // Single byte compression used
    _bci  += next >> 3;
    _line += next & 0x7;
  }
  return true;
}


Bytecodes::Code Method::orig_bytecode_at(int bci) const {
  BreakpointInfo* bp = method_holder()->breakpoints();
  for (; bp != NULL; bp = bp->next()) {
    if (bp->match(this, bci)) {
      return bp->orig_bytecode();
    }
  }
  {
    ResourceMark rm;
    fatal(err_msg("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci));
  }
  return Bytecodes::_shouldnotreachhere;
}

void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
  assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
  BreakpointInfo* bp = method_holder()->breakpoints();
  for (; bp != NULL; bp = bp->next()) {
    if (bp->match(this, bci)) {
      bp->set_orig_bytecode(code);
      // and continue, in case there is more than one
    }
  }
}

void Method::set_breakpoint(int bci) {
  InstanceKlass* ik = method_holder();
  BreakpointInfo *bp = new BreakpointInfo(this, bci);
  bp->set_next(ik->breakpoints());
  ik->set_breakpoints(bp);
  // do this last:
  bp->set(this);
}

static void clear_matches(Method* m, int bci) {
  InstanceKlass* ik = m->method_holder();
  BreakpointInfo* prev_bp = NULL;
  BreakpointInfo* next_bp;
  for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
    next_bp = bp->next();
    // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
    if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
      // do this first:
      bp->clear(m);
      // unhook it
      if (prev_bp != NULL)
        prev_bp->set_next(next_bp);
      else
        ik->set_breakpoints(next_bp);
      delete bp;
      // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
      // at same location. So we have multiple matching (method_index and bci)
      // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
      // breakpoint for clear_breakpoint request and keep all other method versions
      // BreakpointInfo for future clear_breakpoint request.
      // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
      // which is being called when class is unloaded. We delete all the Breakpoint
      // information for all versions of method. We may not correctly restore the original
      // bytecode in all method versions, but that is ok. Because the class is being unloaded
      // so these methods won't be used anymore.
      if (bci >= 0) {
        break;
      }
    } else {
      // This one is a keeper.
      prev_bp = bp;
    }
  }
}

void Method::clear_breakpoint(int bci) {
  assert(bci >= 0, "");
  clear_matches(this, bci);
}

void Method::clear_all_breakpoints() {
  clear_matches(this, -1);
}


int Method::invocation_count() {
  MethodCounters *mcs = method_counters();
  if (TieredCompilation) {
    MethodData* const mdo = method_data();
    if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
        ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
      return InvocationCounter::count_limit;
    } else {
      return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
             ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
    }
  } else {
    return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
  }
}

int Method::backedge_count() {
  MethodCounters *mcs = method_counters();
  if (TieredCompilation) {
    MethodData* const mdo = method_data();
    if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
        ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
      return InvocationCounter::count_limit;
    } else {
      return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
             ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
    }
  } else {
    return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
  }
}

int Method::highest_comp_level() const {
  const MethodData* mdo = method_data();
  if (mdo != NULL) {
    return mdo->highest_comp_level();
  } else {
    return CompLevel_none;
  }
}

int Method::highest_osr_comp_level() const {
  const MethodData* mdo = method_data();
  if (mdo != NULL) {
    return mdo->highest_osr_comp_level();
  } else {
    return CompLevel_none;
  }
}

void Method::set_highest_comp_level(int level) {
  MethodData* mdo = method_data();
  if (mdo != NULL) {
    mdo->set_highest_comp_level(level);
  }
}

void Method::set_highest_osr_comp_level(int level) {
  MethodData* mdo = method_data();
  if (mdo != NULL) {
    mdo->set_highest_osr_comp_level(level);
  }
}

BreakpointInfo::BreakpointInfo(Method* m, int bci) {
  _bci = bci;
  _name_index = m->name_index();
  _signature_index = m->signature_index();
  _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
  if (_orig_bytecode == Bytecodes::_breakpoint)
    _orig_bytecode = m->orig_bytecode_at(_bci);
  _next = NULL;
}

void BreakpointInfo::set(Method* method) {
#ifdef ASSERT
  {
    Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
    if (code == Bytecodes::_breakpoint)
      code = method->orig_bytecode_at(_bci);
    assert(orig_bytecode() == code, "original bytecode must be the same");
  }
#endif
  Thread *thread = Thread::current();
  *method->bcp_from(_bci) = Bytecodes::_breakpoint;
  method->incr_number_of_breakpoints(thread);
  SystemDictionary::notice_modification();
  {
    // Deoptimize all dependents on this method
    HandleMark hm(thread);
    methodHandle mh(thread, method);
    Universe::flush_dependents_on_method(mh);
  }
}

void BreakpointInfo::clear(Method* method) {
  *method->bcp_from(_bci) = orig_bytecode();
  assert(method->number_of_breakpoints() > 0, "must not go negative");
  method->decr_number_of_breakpoints(Thread::current());
}

// jmethodID handling

// This is a block allocating object, sort of like JNIHandleBlock, only a
// lot simpler.  There aren't many of these, they aren't long, they are rarely
// deleted and so we can do some suboptimal things.
// It's allocated on the CHeap because once we allocate a jmethodID, we can
// never get rid of it.
// It would be nice to be able to parameterize the number of methods for
// the null_class_loader but then we'd have to turn this and ClassLoaderData
// into templates.

// I feel like this brain dead class should exist somewhere in the STL

class JNIMethodBlock : public CHeapObj<mtClass> {
  enum { number_of_methods = 8 };

  Method*         _methods[number_of_methods];
  int             _top;
  JNIMethodBlock* _next;
 public:
  static Method* const _free_method;

  JNIMethodBlock() : _next(NULL), _top(0) {
    for (int i = 0; i< number_of_methods; i++) _methods[i] = _free_method;
  }

  Method** add_method(Method* m) {
    if (_top < number_of_methods) {
      // top points to the next free entry.
      int i = _top;
      _methods[i] = m;
      _top++;
      return &_methods[i];
    } else if (_top == number_of_methods) {
      // if the next free entry ran off the block see if there's a free entry
      for (int i = 0; i< number_of_methods; i++) {
        if (_methods[i] == _free_method) {
          _methods[i] = m;
          return &_methods[i];
        }
      }
      // Only check each block once for frees.  They're very unlikely.
      // Increment top past the end of the block.
      _top++;
    }
    // need to allocate a next block.
    if (_next == NULL) {
      _next = new JNIMethodBlock();
    }
    return _next->add_method(m);
  }

  bool contains(Method** m) {
    for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {
      for (int i = 0; i< number_of_methods; i++) {
        if (&(b->_methods[i]) == m) {
          return true;
        }
      }
    }
    return false;  // not found
  }

  // Doesn't really destroy it, just marks it as free so it can be reused.
  void destroy_method(Method** m) {
#ifdef ASSERT
    assert(contains(m), "should be a methodID");
#endif // ASSERT
    *m = _free_method;
  }

  // During class unloading the methods are cleared, which is different
  // than freed.
  void clear_all_methods() {
    for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {
      for (int i = 0; i< number_of_methods; i++) {
        _methods[i] = NULL;
      }
    }
  }
#ifndef PRODUCT
  int count_methods() {
    // count all allocated methods
    int count = 0;
    for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {
      for (int i = 0; i< number_of_methods; i++) {
        if (_methods[i] != _free_method) count++;
      }
    }
    return count;
  }
#endif // PRODUCT
};

// Something that can't be mistaken for an address or a markOop
Method* const JNIMethodBlock::_free_method = (Method*)55;

// Add a method id to the jmethod_ids
jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
  ClassLoaderData* cld = loader_data;

  if (!SafepointSynchronize::is_at_safepoint()) {
    // Have to add jmethod_ids() to class loader data thread-safely.
    // Also have to add the method to the list safely, which the cld lock
    // protects as well.
    MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
    if (cld->jmethod_ids() == NULL) {
      cld->set_jmethod_ids(new JNIMethodBlock());
    }
    // jmethodID is a pointer to Method*
    return (jmethodID)cld->jmethod_ids()->add_method(m);
  } else {
    // At safepoint, we are single threaded and can set this.
    if (cld->jmethod_ids() == NULL) {
      cld->set_jmethod_ids(new JNIMethodBlock());
    }
    // jmethodID is a pointer to Method*
    return (jmethodID)cld->jmethod_ids()->add_method(m);
  }
}

// Mark a jmethodID as free.  This is called when there is a data race in
// InstanceKlass while creating the jmethodID cache.
void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
  ClassLoaderData* cld = loader_data;
  Method** ptr = (Method**)m;
  assert(cld->jmethod_ids() != NULL, "should have method handles");
  cld->jmethod_ids()->destroy_method(ptr);
}

void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
  // Can't assert the method_holder is the same because the new method has the
  // scratch method holder.
  assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
           == new_method->method_holder()->class_loader(),
         "changing to a different class loader");
  // Just change the method in place, jmethodID pointer doesn't change.
  *((Method**)jmid) = new_method;
}

bool Method::is_method_id(jmethodID mid) {
  Method* m = resolve_jmethod_id(mid);
  assert(m != NULL, "should be called with non-null method");
  InstanceKlass* ik = m->method_holder();
  ClassLoaderData* cld = ik->class_loader_data();
  if (cld->jmethod_ids() == NULL) return false;
  return (cld->jmethod_ids()->contains((Method**)mid));
}

Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
  if (mid == NULL) return NULL;
  Method* o = resolve_jmethod_id(mid);
  if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
    return NULL;
  }
  return o;
};

void Method::set_on_stack(const bool value) {
  // Set both the method itself and its constant pool.  The constant pool
  // on stack means some method referring to it is also on the stack.
  _access_flags.set_on_stack(value);
  constants()->set_on_stack(value);
  if (value) MetadataOnStackMark::record(this);
}

// Called when the class loader is unloaded to make all methods weak.
void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
  loader_data->jmethod_ids()->clear_all_methods();
}


// Check that this pointer is valid by checking that the vtbl pointer matches
bool Method::is_valid_method() const {
  if (this == NULL) {
    return false;
  } else if (!is_metaspace_object()) {
    return false;
  } else {
    Method m;
    // This assumes that the vtbl pointer is the first word of a C++ object.
    // This assumption is also in universe.cpp patch_klass_vtble
    void* vtbl2 = dereference_vptr((void*)&m);
    void* this_vtbl = dereference_vptr((void*)this);
    return vtbl2 == this_vtbl;
  }
}

#ifndef PRODUCT
void Method::print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) {
  out->print_cr("jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
}
#endif // PRODUCT


// Printing

#ifndef PRODUCT

void Method::print_on(outputStream* st) const {
  ResourceMark rm;
  assert(is_method(), "must be method");
  st->print_cr(internal_name());
  // get the effect of PrintOopAddress, always, for methods:
  st->print_cr(" - this oop:          "INTPTR_FORMAT, (intptr_t)this);
  st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
  st->print   (" - constants:         "INTPTR_FORMAT" ", (address)constants());
  constants()->print_value_on(st); st->cr();
  st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
  st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
  st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
  st->print_cr(" - max stack:         %d",   max_stack());
  st->print_cr(" - max locals:        %d",   max_locals());
  st->print_cr(" - size of params:    %d",   size_of_parameters());
  st->print_cr(" - method size:       %d",   method_size());
  if (intrinsic_id() != vmIntrinsics::_none)
    st->print_cr(" - intrinsic id:      %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
  if (highest_comp_level() != CompLevel_none)
    st->print_cr(" - highest level:     %d", highest_comp_level());
  st->print_cr(" - vtable index:      %d",   _vtable_index);
  st->print_cr(" - i2i entry:         " INTPTR_FORMAT, interpreter_entry());
  st->print(   " - adapters:          ");
  AdapterHandlerEntry* a = ((Method*)this)->adapter();
  if (a == NULL)
    st->print_cr(INTPTR_FORMAT, a);
  else
    a->print_adapter_on(st);
  st->print_cr(" - compiled entry     " INTPTR_FORMAT, from_compiled_entry());
  st->print_cr(" - code size:         %d",   code_size());
  if (code_size() != 0) {
    st->print_cr(" - code start:        " INTPTR_FORMAT, code_base());
    st->print_cr(" - code end (excl):   " INTPTR_FORMAT, code_base() + code_size());
  }
  if (method_data() != NULL) {
    st->print_cr(" - method data:       " INTPTR_FORMAT, (address)method_data());
  }
  st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
  if (checked_exceptions_length() > 0) {
    CheckedExceptionElement* table = checked_exceptions_start();
    st->print_cr(" - checked ex start:  " INTPTR_FORMAT, table);
    if (Verbose) {
      for (int i = 0; i < checked_exceptions_length(); i++) {
        st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
      }
    }
  }
  if (has_linenumber_table()) {
    u_char* table = compressed_linenumber_table();
    st->print_cr(" - linenumber start:  " INTPTR_FORMAT, table);
    if (Verbose) {
      CompressedLineNumberReadStream stream(table);
      while (stream.read_pair()) {
        st->print_cr("   - line %d: %d", stream.line(), stream.bci());
      }
    }
  }
  st->print_cr(" - localvar length:   %d",   localvariable_table_length());
  if (localvariable_table_length() > 0) {
    LocalVariableTableElement* table = localvariable_table_start();
    st->print_cr(" - localvar start:    " INTPTR_FORMAT, table);
    if (Verbose) {
      for (int i = 0; i < localvariable_table_length(); i++) {
        int bci = table[i].start_bci;
        int len = table[i].length;
        const char* name = constants()->printable_name_at(table[i].name_cp_index);
        const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
        int slot = table[i].slot;
        st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
      }
    }
  }
  if (code() != NULL) {
    st->print   (" - compiled code: ");
    code()->print_value_on(st);
  }
  if (is_native()) {
    st->print_cr(" - native function:   " INTPTR_FORMAT, native_function());
    st->print_cr(" - signature handler: " INTPTR_FORMAT, signature_handler());
  }
}

#endif //PRODUCT

void Method::print_value_on(outputStream* st) const {
  assert(is_method(), "must be method");
  st->print(internal_name());
  print_address_on(st);
  st->print(" ");
  name()->print_value_on(st);
  st->print(" ");
  signature()->print_value_on(st);
  st->print(" in ");
  method_holder()->print_value_on(st);
  if (WizardMode) st->print("#%d", _vtable_index);
  if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
  if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
}

#if INCLUDE_SERVICES
// Size Statistics
void Method::collect_statistics(KlassSizeStats *sz) const {
  int mysize = sz->count(this);
  sz->_method_bytes += mysize;
  sz->_method_all_bytes += mysize;
  sz->_rw_bytes += mysize;

  if (constMethod()) {
    constMethod()->collect_statistics(sz);
  }
  if (method_data()) {
    method_data()->collect_statistics(sz);
  }
}
#endif // INCLUDE_SERVICES

// Verification

void Method::verify_on(outputStream* st) {
  guarantee(is_method(), "object must be method");
  guarantee(constants()->is_constantPool(), "should be constant pool");
  guarantee(constMethod()->is_constMethod(), "should be ConstMethod*");
  MethodData* md = method_data();
  guarantee(md == NULL ||
      md->is_methodData(), "should be method data");
}

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