/*

 * Copyright (c) 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 "classfile/classLoaderData.hpp"

#include "gc/z/zAddress.hpp"

#include "gc/z/zHeap.inline.hpp"

#include "gc/z/zOop.hpp"

#include "gc/z/zResurrection.hpp"

#include "gc/z/zRootsIterator.hpp"

#include "gc/z/zStat.hpp"

#include "gc/z/zVerify.hpp"

#include "memory/iterator.inline.hpp"

#include "oops/oop.hpp"

#define BAD_OOP_ARG(o, p)   "Bad oop " PTR_FORMAT " found at " PTR_FORMAT, p2i(o), p2i(p)

static void verify_oop(oop* p) {

  const oop o = RawAccess<>::oop_load(p);

  if (o != NULL) {

    const uintptr_t addr = ZOop::to_address(o);

    guarantee(ZAddress::is_good(addr), BAD_OOP_ARG(o, p));

    guarantee(oopDesc::is_oop(ZOop::from_address(addr)), BAD_OOP_ARG(o, p));

  }

}

static void verify_possibly_weak_oop(oop* p) {

  const oop o = RawAccess<>::oop_load(p);

  if (o != NULL) {

    const uintptr_t addr = ZOop::to_address(o);

    guarantee(ZAddress::is_good(addr) || ZAddress::is_finalizable_good(addr), BAD_OOP_ARG(o, p));

    guarantee(oopDesc::is_oop(ZOop::from_address(ZAddress::good(addr))), BAD_OOP_ARG(o, p));

  }

}

class ZVerifyRootClosure : public ZRootsIteratorClosure {

public:

  virtual void do_oop(oop* p) {

    verify_oop(p);

  }

  virtual void do_oop(narrowOop*) {

    ShouldNotReachHere();

  }

};

class ZVerifyOopClosure : public ClaimMetadataVisitingOopIterateClosure, public ZRootsIteratorClosure  {

private:

  const bool _verify_weaks;

public:

  ZVerifyOopClosure(bool verify_weaks) :

      ClaimMetadataVisitingOopIterateClosure(ClassLoaderData::_claim_other),

      _verify_weaks(verify_weaks) {}

  virtual void do_oop(oop* p) {

    if (_verify_weaks) {

      verify_possibly_weak_oop(p);

    } else {

      // We should never encounter finalizable oops through strong

      // paths. This assumes we have only visited strong roots.

      verify_oop(p);

    }

  }

  virtual void do_oop(narrowOop* p) {

    ShouldNotReachHere();

  }

  virtual ReferenceIterationMode reference_iteration_mode() {

    return _verify_weaks ? DO_FIELDS : DO_FIELDS_EXCEPT_REFERENT;

  }

#ifdef ASSERT

  // Verification handled by the closure itself

  virtual bool should_verify_oops() {

    return false;

  }

#endif

};

template <typename RootsIterator>

void ZVerify::roots() {

  assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint");

  assert(!ZResurrection::is_blocked(), "Invalid phase");

  if (ZVerifyRoots) {

    ZVerifyRootClosure cl;

    RootsIterator iter;

    iter.oops_do(&cl);

  }

}

void ZVerify::roots_strong() {

  roots<ZRootsIterator>();

}

void ZVerify::roots_weak() {

  roots<ZWeakRootsIterator>();

}

void ZVerify::roots_concurrent_strong() {

  roots<ZConcurrentRootsIteratorClaimNone>();

}

void ZVerify::roots_concurrent_weak() {

  roots<ZConcurrentWeakRootsIterator>();

}

void ZVerify::roots(bool verify_weaks) {

  roots_strong();

  roots_concurrent_strong();

  if (verify_weaks) {

    roots_weak();

    roots_concurrent_weak();

  }

}

void ZVerify::objects(bool verify_weaks) {

  assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint");

  assert(ZGlobalPhase == ZPhaseMarkCompleted, "Invalid phase");

  assert(!ZResurrection::is_blocked(), "Invalid phase");

  if (ZVerifyObjects) {

    ZVerifyOopClosure cl(verify_weaks);

    ObjectToOopClosure object_cl(&cl);

    ZHeap::heap()->object_iterate(&object_cl, verify_weaks);

  }

}

void ZVerify::roots_and_objects(bool verify_weaks) {

  roots(verify_weaks);

  objects(verify_weaks);

}

void ZVerify::before_zoperation() {

  // Verify strong roots

  ZStatTimerDisable disable;

  roots_strong();

}

void ZVerify::after_mark() {

  // Verify all strong roots and strong references

  ZStatTimerDisable disable;

  roots_and_objects(false /* verify_weaks */);

}

void ZVerify::after_weak_processing() {

  // Verify all roots and all references

  ZStatTimerDisable disable;

  roots_and_objects(true /* verify_weaks */);

}