/*

 * Copyright (c) 2016, 2017, 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 "aot/aotCodeHeap.hpp"

#include "aot/aotLoader.hpp"

#include "aot/compiledIC_aot.hpp"

#include "code/codeCache.hpp"

#include "code/compiledIC.hpp"

#include "code/nativeInst.hpp"

#include "compiler/compilerOracle.hpp"

#include "gc/shared/cardTableModRefBS.hpp"

#include "gc/shared/collectedHeap.hpp"

#include "gc/shared/gcLocker.hpp"

#include "jvmci/compilerRuntime.hpp"

#include "jvmci/jvmciRuntime.hpp"

#include "oops/method.hpp"

#include "runtime/java.hpp"

#include "runtime/os.hpp"

#include "runtime/sharedRuntime.hpp"

#include "utilities/xmlstream.hpp"

#include <stdio.h>

#if 0

static void metadata_oops_do(Metadata** metadata_begin, Metadata **metadata_end, OopClosure* f) {

  // Visit the metadata/oops section

  for (Metadata** p = metadata_begin; p < metadata_end; p++) {

    Metadata* m = *p;

    intptr_t meta = (intptr_t)m;

    if ((meta & 1) == 1) {

      // already resolved

      m = (Metadata*)(meta & ~1);

    } else {

      continue;

    }

    assert(Metaspace::contains(m), "");

    if (m->is_method()) {

      m = ((Method*)m)->method_holder();

    }

    assert(m->is_klass(), "must be");

    oop o = ((Klass*)m)->klass_holder();

    if (o != NULL) {

      f->do_oop(&o);

    }

  }

}

#endif

bool AOTCompiledMethod::do_unloading_oops(address low_boundary, BoolObjectClosure* is_alive, bool unloading_occurred) {

  return false;

}

oop AOTCompiledMethod::oop_at(int index) const {

  if (index == 0) { // 0 is reserved

    return NULL;

  }

  Metadata** entry = _metadata_got + (index - 1);

  intptr_t meta = (intptr_t)*entry;

  if ((meta & 1) == 1) {

    // already resolved

    Klass* k = (Klass*)(meta & ~1);

    return k->java_mirror();

  }

  // The entry is string which we need to resolve.

  const char* meta_name = _heap->get_name_at((int)meta);

  int klass_len = build_u2_from((address)meta_name);

  const char* klass_name = meta_name + 2;

  // Quick check the current method's holder.

  Klass* k = _method->method_holder();

  ResourceMark rm; // for signature_name()

  if (strncmp(k->signature_name(), klass_name, klass_len) != 0) { // Does not match?

    // Search klass in got cells in DSO which have this compiled method.

    k = _heap->get_klass_from_got(klass_name, klass_len, _method);

  }

  int method_name_len = build_u2_from((address)klass_name + klass_len);

  guarantee(method_name_len == 0, "only klass is expected here");

  meta = ((intptr_t)k) | 1;

  *entry = (Metadata*)meta; // Should be atomic on x64

  return k->java_mirror();

}

Metadata* AOTCompiledMethod::metadata_at(int index) const {

  if (index == 0) { // 0 is reserved

    return NULL;

  }

  assert(index - 1 < _metadata_size, "");

  {

    Metadata** entry = _metadata_got + (index - 1);

    intptr_t meta = (intptr_t)*entry;

    if ((meta & 1) == 1) {

      // already resolved

      Metadata *m = (Metadata*)(meta & ~1);

      return m;

    }

    // The entry is string which we need to resolve.

    const char* meta_name = _heap->get_name_at((int)meta);

    int klass_len = build_u2_from((address)meta_name);

    const char* klass_name = meta_name + 2;

    // Quick check the current method's holder.

    Klass* k = _method->method_holder();

    bool klass_matched = true;

    ResourceMark rm; // for signature_name() and find_method()

    if (strncmp(k->signature_name(), klass_name, klass_len) != 0) { // Does not match?

      // Search klass in got cells in DSO which have this compiled method.

      k = _heap->get_klass_from_got(klass_name, klass_len, _method);

      klass_matched = false;

    }

    int method_name_len = build_u2_from((address)klass_name + klass_len);

    if (method_name_len == 0) { // Array or Klass name only?

      meta = ((intptr_t)k) | 1;

      *entry = (Metadata*)meta; // Should be atomic on x64

      return (Metadata*)k;

    } else { // Method

      // Quick check the current method's name.

      Method* m = _method;

      int signature_len = build_u2_from((address)klass_name + klass_len + 2 + method_name_len);

      int full_len = 2 + klass_len + 2 + method_name_len + 2 + signature_len;

      if (!klass_matched || memcmp(_name, meta_name, full_len) != 0) { // Does not match?

        Thread* thread = Thread::current();

        const char* method_name = klass_name + klass_len;

        m = AOTCodeHeap::find_method(k, thread, method_name);

      }

      meta = ((intptr_t)m) | 1;

      *entry = (Metadata*)meta; // Should be atomic on x64

      return (Metadata*)m;

    }

  }

  ShouldNotReachHere(); return NULL;

}

bool AOTCompiledMethod::make_not_entrant_helper(int new_state) {

  // Make sure the method is not flushed in case of a safepoint in code below.

  methodHandle the_method(method());

  NoSafepointVerifier nsv;

  {

    // Enter critical section.  Does not block for safepoint.

    MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);

    if (*_state_adr == new_state) {

      // another thread already performed this transition so nothing

      // to do, but return false to indicate this.

      return false;

    }

    // Change state

    OrderAccess::storestore();

    *_state_adr = new_state;

    // Log the transition once

    log_state_change();

#ifdef TIERED

    // Remain non-entrant forever

    if (new_state == not_entrant && method() != NULL) {

        method()->set_aot_code(NULL);

    }

#endif

    // Remove AOTCompiledMethod from method.

    if (method() != NULL && (method()->code() == this ||

                             method()->from_compiled_entry() == verified_entry_point())) {

      HandleMark hm;

      method()->clear_code(false /* already owns Patching_lock */);

    }

  } // leave critical region under Patching_lock

  if (TraceCreateZombies) {

    ResourceMark m;

    const char *new_state_str = (new_state == not_entrant) ? "not entrant" : "not used";

    tty->print_cr("aot method <" INTPTR_FORMAT "> %s code made %s", p2i(this), this->method() ? this->method()->name_and_sig_as_C_string() : "null", new_state_str);

  }

  return true;

}

bool AOTCompiledMethod::make_entrant() {

  assert(!method()->is_old(), "reviving evolved method!");

  assert(*_state_adr != not_entrant, "%s", method()->has_aot_code() ? "has_aot_code() not cleared" : "caller didn't check has_aot_code()");

  // Make sure the method is not flushed in case of a safepoint in code below.

  methodHandle the_method(method());

  NoSafepointVerifier nsv;

  {

    // Enter critical section.  Does not block for safepoint.

    MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);

    if (*_state_adr == in_use) {

      // another thread already performed this transition so nothing

      // to do, but return false to indicate this.

      return false;

    }

    // Change state

    OrderAccess::storestore();

    *_state_adr = in_use;

    // Log the transition once

    log_state_change();

  } // leave critical region under Patching_lock

  if (TraceCreateZombies) {

    ResourceMark m;

    tty->print_cr("aot method <" INTPTR_FORMAT "> %s code made entrant", p2i(this), this->method() ? this->method()->name_and_sig_as_C_string() : "null");

  }

  return true;

}

// We don't have full dependencies for AOT methods, so flushing is

// more conservative than for nmethods.

void AOTCompiledMethod::flush_evol_dependents_on(InstanceKlass* dependee) {

  if (is_java_method()) {

    cleanup_inline_caches();

    mark_for_deoptimization();

    make_not_entrant();

  }

}

// Iterate over metadata calling this function.   Used by RedefineClasses

// Copied from nmethod::metadata_do

void AOTCompiledMethod::metadata_do(void f(Metadata*)) {

  address low_boundary = verified_entry_point();

  {

    // Visit all immediate references that are embedded in the instruction stream.

    RelocIterator iter(this, low_boundary);

    while (iter.next()) {

      if (iter.type() == relocInfo::metadata_type ) {

        metadata_Relocation* r = iter.metadata_reloc();

        // In this metadata, we must only follow those metadatas directly embedded in

        // the code.  Other metadatas (oop_index>0) are seen as part of

        // the metadata section below.

        assert(1 == (r->metadata_is_immediate()) +

               (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),

               "metadata must be found in exactly one place");

        if (r->metadata_is_immediate() && r->metadata_value() != NULL) {

          Metadata* md = r->metadata_value();

          if (md != _method) f(md);

        }

      } else if (iter.type() == relocInfo::virtual_call_type) {

        // Check compiledIC holders associated with this nmethod

        CompiledIC *ic = CompiledIC_at(&iter);

        if (ic->is_icholder_call()) {

          CompiledICHolder* cichk = ic->cached_icholder();

          f(cichk->holder_method());

          f(cichk->holder_klass());

        } else {

          // Get Klass* or NULL (if value is -1) from GOT cell of virtual call PLT stub.

          Metadata* ic_oop = ic->cached_metadata();

          if (ic_oop != NULL) {

            f(ic_oop);

          }

        }

      } else if (iter.type() == relocInfo::static_call_type ||

                 iter.type() == relocInfo::opt_virtual_call_type){

        // Check Method* in AOT c2i stub for other calls.

        Metadata* meta = (Metadata*)nativeLoadGot_at(nativePltCall_at(iter.addr())->plt_c2i_stub())->data();

        if (meta != NULL) {

          f(meta);

        }

      }

    }

  }

  // Visit the metadata section

  for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {

    Metadata* m = *p;

    intptr_t meta = (intptr_t)m;

    if ((meta & 1) == 1) {

      // already resolved

      m = (Metadata*)(meta & ~1);

    } else {

      continue;

    }

    assert(Metaspace::contains(m), "");

    f(m);

  }

  // Visit metadata not embedded in the other places.

  if (_method != NULL) f(_method);

}

void AOTCompiledMethod::print() const {

  print_on(tty, "AOTCompiledMethod");

}

void AOTCompiledMethod::print_on(outputStream* st) const {

  print_on(st, "AOTCompiledMethod");

}

// Print out more verbose output usually for a newly created aot method.

void AOTCompiledMethod::print_on(outputStream* st, const char* msg) const {

  if (st != NULL) {

    ttyLocker ttyl;

    st->print("%7d ", (int) st->time_stamp().milliseconds());

    st->print("%4d ", _aot_id);    // print compilation number

    st->print("    aot[%2d]", _heap->dso_id());

    // Stubs have _method == NULL

    if (_method == NULL) {

      st->print("   %s", _name);

    } else {

      ResourceMark m;

      st->print("   %s", _method->name_and_sig_as_C_string());

    }

    if (Verbose) {

      st->print(" entry at " INTPTR_FORMAT, p2i(_code));

    }

    if (msg != NULL) {

      st->print("   %s", msg);

    }

    st->cr();

  }

}

void AOTCompiledMethod::print_value_on(outputStream* st) const {

  st->print("AOTCompiledMethod ");

  print_on(st, NULL);

}

// Print a short set of xml attributes to identify this aot method.  The

// output should be embedded in some other element.

void AOTCompiledMethod::log_identity(xmlStream* log) const {

  log->print(" aot_id='%d'", _aot_id);

  log->print(" aot='%2d'", _heap->dso_id());

}

void AOTCompiledMethod::log_state_change() const {

  if (LogCompilation) {

    ResourceMark m;

    if (xtty != NULL) {

      ttyLocker ttyl;  // keep the following output all in one block

      if (*_state_adr == not_entrant) {

        xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'",

                         os::current_thread_id());

      } else if (*_state_adr == not_used) {

        xtty->begin_elem("make_not_used thread='" UINTX_FORMAT "'",

                         os::current_thread_id());

      } else if (*_state_adr == in_use) {

        xtty->begin_elem("make_entrant thread='" UINTX_FORMAT "'",

                         os::current_thread_id());

      }

      log_identity(xtty);

      xtty->stamp();

      xtty->end_elem();

    }

  }

  if (PrintCompilation) {

    ResourceMark m;

    if (*_state_adr == not_entrant) {

      print_on(tty, "made not entrant");

    } else if (*_state_adr == not_used) {

      print_on(tty, "made not used");

    } else if (*_state_adr == in_use) {

      print_on(tty, "made entrant");

    }

  }

}

NativeInstruction* PltNativeCallWrapper::get_load_instruction(virtual_call_Relocation* r) const {

  return nativeLoadGot_at(_call->plt_load_got());

}

void PltNativeCallWrapper::verify_resolve_call(address dest) const {

  CodeBlob* db = CodeCache::find_blob_unsafe(dest);

  if (db == NULL) {

    assert(dest == _call->plt_resolve_call(), "sanity");

  }

}

void PltNativeCallWrapper::set_to_interpreted(const methodHandle& method, CompiledICInfo& info) {

  assert(!info.to_aot(), "only for nmethod");

  CompiledPltStaticCall* csc = CompiledPltStaticCall::at(instruction_address());

  csc->set_to_interpreted(method, info.entry());

}

NativeCallWrapper* AOTCompiledMethod::call_wrapper_at(address call) const {

  return new PltNativeCallWrapper((NativePltCall*) call);

}

NativeCallWrapper* AOTCompiledMethod::call_wrapper_before(address return_pc) const {

  return new PltNativeCallWrapper(nativePltCall_before(return_pc));

}

CompiledStaticCall* AOTCompiledMethod::compiledStaticCall_at(Relocation* call_site) const {

  return CompiledPltStaticCall::at(call_site);

}

CompiledStaticCall* AOTCompiledMethod::compiledStaticCall_at(address call_site) const {

  return CompiledPltStaticCall::at(call_site);

}

CompiledStaticCall* AOTCompiledMethod::compiledStaticCall_before(address return_addr) const {

  return CompiledPltStaticCall::before(return_addr);

}

address AOTCompiledMethod::call_instruction_address(address pc) const {

  NativePltCall* pltcall = nativePltCall_before(pc);

  return pltcall->instruction_address();

}

bool AOTCompiledMethod::is_evol_dependent_on(Klass* dependee) {

  return !is_aot_runtime_stub() && _heap->is_dependent_method(dependee, this);

}

void AOTCompiledMethod::clear_inline_caches() {

  assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");

  if (is_zombie()) {

    return;

  }

  RelocIterator iter(this);

  while (iter.next()) {

    iter.reloc()->clear_inline_cache();

    if (iter.type() == relocInfo::opt_virtual_call_type) {

      CompiledIC* cic = CompiledIC_at(&iter);

      assert(cic->is_clean(), "!");

      nativePltCall_at(iter.addr())->set_stub_to_clean();

    }

  }

}