/*

 * Copyright (c) 2015, 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/classLoaderDataGraph.hpp"

#include "classfile/stringTable.hpp"

#include "classfile/systemDictionary.hpp"

#include "code/codeCache.hpp"

#include "compiler/oopMap.hpp"

#include "gc/shared/barrierSet.hpp"

#include "gc/shared/barrierSetNMethod.hpp"

#include "gc/shared/oopStorageParState.inline.hpp"

#include "gc/shared/suspendibleThreadSet.hpp"

#include "gc/z/zBarrierSetNMethod.hpp"

#include "gc/z/zGlobals.hpp"

#include "gc/z/zNMethod.hpp"

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

#include "gc/z/zRootsIterator.hpp"

#include "gc/z/zStat.hpp"

#include "gc/z/zThreadLocalData.hpp"

#include "memory/resourceArea.hpp"

#include "memory/universe.hpp"

#include "prims/jvmtiExport.hpp"

#include "prims/resolvedMethodTable.hpp"

#include "runtime/atomic.hpp"

#include "runtime/jniHandles.hpp"

#include "runtime/thread.hpp"

#include "runtime/safepoint.hpp"

#include "runtime/synchronizer.hpp"

#include "services/management.hpp"

#include "utilities/debug.hpp"

#if INCLUDE_JFR

#include "jfr/jfr.hpp"

#endif

static const ZStatSubPhase ZSubPhasePauseRootsSetup("Pause Roots Setup");

static const ZStatSubPhase ZSubPhasePauseRoots("Pause Roots");

static const ZStatSubPhase ZSubPhasePauseRootsTeardown("Pause Roots Teardown");

static const ZStatSubPhase ZSubPhasePauseRootsUniverse("Pause Roots Universe");

static const ZStatSubPhase ZSubPhasePauseRootsObjectSynchronizer("Pause Roots ObjectSynchronizer");

static const ZStatSubPhase ZSubPhasePauseRootsManagement("Pause Roots Management");

static const ZStatSubPhase ZSubPhasePauseRootsJVMTIExport("Pause Roots JVMTIExport");

static const ZStatSubPhase ZSubPhasePauseRootsJVMTIWeakExport("Pause Roots JVMTIWeakExport");

static const ZStatSubPhase ZSubPhasePauseRootsSystemDictionary("Pause Roots SystemDictionary");

static const ZStatSubPhase ZSubPhasePauseRootsThreads("Pause Roots Threads");

static const ZStatSubPhase ZSubPhasePauseRootsCodeCache("Pause Roots CodeCache");

static const ZStatSubPhase ZSubPhaseConcurrentRootsSetup("Concurrent Roots Setup");

static const ZStatSubPhase ZSubPhaseConcurrentRoots("Concurrent Roots");

static const ZStatSubPhase ZSubPhaseConcurrentRootsTeardown("Concurrent Roots Teardown");

static const ZStatSubPhase ZSubPhaseConcurrentRootsJNIHandles("Concurrent Roots JNIHandles");

static const ZStatSubPhase ZSubPhaseConcurrentRootsClassLoaderDataGraph("Concurrent Roots ClassLoaderDataGraph");

static const ZStatSubPhase ZSubPhasePauseWeakRootsSetup("Pause Weak Roots Setup");

static const ZStatSubPhase ZSubPhasePauseWeakRoots("Pause Weak Roots");

static const ZStatSubPhase ZSubPhasePauseWeakRootsTeardown("Pause Weak Roots Teardown");

static const ZStatSubPhase ZSubPhasePauseWeakRootsJVMTIWeakExport("Pause Weak Roots JVMTIWeakExport");

static const ZStatSubPhase ZSubPhasePauseWeakRootsJFRWeak("Pause Weak Roots JFRWeak");

static const ZStatSubPhase ZSubPhaseConcurrentWeakRoots("Concurrent Weak Roots");

static const ZStatSubPhase ZSubPhaseConcurrentWeakRootsVMWeakHandles("Concurrent Weak Roots VMWeakHandles");

static const ZStatSubPhase ZSubPhaseConcurrentWeakRootsJNIWeakHandles("Concurrent Weak Roots JNIWeakHandles");

static const ZStatSubPhase ZSubPhaseConcurrentWeakRootsStringTable("Concurrent Weak Roots StringTable");

static const ZStatSubPhase ZSubPhaseConcurrentWeakRootsResolvedMethodTable("Concurrent Weak Roots ResolvedMethodTable");

template <typename T, void (T::*F)(ZRootsIteratorClosure*)>

ZSerialOopsDo<T, F>::ZSerialOopsDo(T* iter) :

    _iter(iter),

    _claimed(false) {}

template <typename T, void (T::*F)(ZRootsIteratorClosure*)>

void ZSerialOopsDo<T, F>::oops_do(ZRootsIteratorClosure* cl) {

  if (!_claimed && Atomic::cmpxchg(true, &_claimed, false) == false) {

    (_iter->*F)(cl);

  }

}

template <typename T, void (T::*F)(ZRootsIteratorClosure*)>

ZParallelOopsDo<T, F>::ZParallelOopsDo(T* iter) :

    _iter(iter),

    _completed(false) {}

template <typename T, void (T::*F)(ZRootsIteratorClosure*)>

void ZParallelOopsDo<T, F>::oops_do(ZRootsIteratorClosure* cl) {

  if (!_completed) {

    (_iter->*F)(cl);

    if (!_completed) {

      _completed = true;

    }

  }

}

template <typename T, void (T::*F)(BoolObjectClosure*, ZRootsIteratorClosure*)>

ZSerialWeakOopsDo<T, F>::ZSerialWeakOopsDo(T* iter) :

    _iter(iter),

    _claimed(false) {}

template <typename T, void (T::*F)(BoolObjectClosure*, ZRootsIteratorClosure*)>

void ZSerialWeakOopsDo<T, F>::weak_oops_do(BoolObjectClosure* is_alive, ZRootsIteratorClosure* cl) {

  if (!_claimed && Atomic::cmpxchg(true, &_claimed, false) == false) {

    (_iter->*F)(is_alive, cl);

  }

}

template <typename T, void (T::*F)(BoolObjectClosure*, ZRootsIteratorClosure*)>

ZParallelWeakOopsDo<T, F>::ZParallelWeakOopsDo(T* iter) :

    _iter(iter),

    _completed(false) {}

template <typename T, void (T::*F)(BoolObjectClosure*, ZRootsIteratorClosure*)>

void ZParallelWeakOopsDo<T, F>::weak_oops_do(BoolObjectClosure* is_alive, ZRootsIteratorClosure* cl) {

  if (!_completed) {

    (_iter->*F)(is_alive, cl);

    if (!_completed) {

      _completed = true;

    }

  }

}

class ZRootsIteratorCodeBlobClosure : public CodeBlobToOopClosure {

private:

  BarrierSetNMethod* _bs;

public:

  ZRootsIteratorCodeBlobClosure(OopClosure* cl) :

    CodeBlobToOopClosure(cl, true /* fix_relocations */),

    _bs(BarrierSet::barrier_set()->barrier_set_nmethod()) {}

  virtual void do_code_blob(CodeBlob* cb) {

    nmethod* const nm = cb->as_nmethod_or_null();

    if (nm != NULL && !nm->test_set_oops_do_mark()) {

      CodeBlobToOopClosure::do_code_blob(cb);

      _bs->disarm(nm);

    }

  }

};

class ZRootsIteratorThreadClosure : public ThreadClosure {

private:

  ZRootsIteratorClosure* _cl;

public:

  ZRootsIteratorThreadClosure(ZRootsIteratorClosure* cl) :

      _cl(cl) {}

  virtual void do_thread(Thread* thread) {

    ZRootsIteratorCodeBlobClosure code_cl(_cl);

    thread->oops_do(_cl, ClassUnloading ? &code_cl : NULL);

    _cl->do_thread(thread);

  }

};

ZRootsIterator::ZRootsIterator() :

    _universe(this),

    _object_synchronizer(this),

    _management(this),

    _jvmti_export(this),

    _jvmti_weak_export(this),

    _system_dictionary(this),

    _threads(this),

    _code_cache(this) {

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

  ZStatTimer timer(ZSubPhasePauseRootsSetup);

  Threads::change_thread_claim_token();

  COMPILER2_PRESENT(DerivedPointerTable::clear());

  if (ClassUnloading) {

    nmethod::oops_do_marking_prologue();

  } else {

    ZNMethod::oops_do_begin();

  }

}

ZRootsIterator::~ZRootsIterator() {

  ZStatTimer timer(ZSubPhasePauseRootsTeardown);

  ResourceMark rm;

  if (ClassUnloading) {

    nmethod::oops_do_marking_epilogue();

  } else {

    ZNMethod::oops_do_end();

  }

  COMPILER2_PRESENT(DerivedPointerTable::update_pointers());

  Threads::assert_all_threads_claimed();

}

void ZRootsIterator::do_universe(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseRootsUniverse);

  Universe::oops_do(cl);

}

void ZRootsIterator::do_object_synchronizer(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseRootsObjectSynchronizer);

  ObjectSynchronizer::oops_do(cl);

}

void ZRootsIterator::do_management(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseRootsManagement);

  Management::oops_do(cl);

}

void ZRootsIterator::do_jvmti_export(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseRootsJVMTIExport);

  JvmtiExport::oops_do(cl);

}

void ZRootsIterator::do_jvmti_weak_export(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseRootsJVMTIWeakExport);

  AlwaysTrueClosure always_alive;

  JvmtiExport::weak_oops_do(&always_alive, cl);

}

void ZRootsIterator::do_system_dictionary(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseRootsSystemDictionary);

  SystemDictionary::oops_do(cl);

}

void ZRootsIterator::do_threads(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseRootsThreads);

  ResourceMark rm;

  ZRootsIteratorThreadClosure thread_cl(cl);

  Threads::possibly_parallel_threads_do(true, &thread_cl);

}

void ZRootsIterator::do_code_cache(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseRootsCodeCache);

  ZNMethod::oops_do(cl);

}

void ZRootsIterator::oops_do(ZRootsIteratorClosure* cl, bool visit_jvmti_weak_export) {

  ZStatTimer timer(ZSubPhasePauseRoots);

  _universe.oops_do(cl);

  _object_synchronizer.oops_do(cl);

  _management.oops_do(cl);

  _jvmti_export.oops_do(cl);

  _system_dictionary.oops_do(cl);

  _threads.oops_do(cl);

  if (!ClassUnloading) {

    _code_cache.oops_do(cl);

  }

  if (visit_jvmti_weak_export) {

    _jvmti_weak_export.oops_do(cl);

  }

}

ZConcurrentRootsIterator::ZConcurrentRootsIterator(bool marking) :

    _marking(marking),

    _sts_joiner(marking /* active */),

    _jni_handles_iter(JNIHandles::global_handles()),

    _jni_handles(this),

    _class_loader_data_graph(this) {

  ZStatTimer timer(ZSubPhaseConcurrentRootsSetup);

  if (_marking) {

    ClassLoaderDataGraph_lock->lock();

    ClassLoaderDataGraph::clear_claimed_marks();

  }

}

ZConcurrentRootsIterator::~ZConcurrentRootsIterator() {

  ZStatTimer timer(ZSubPhaseConcurrentRootsTeardown);

  if (_marking) {

    ClassLoaderDataGraph_lock->unlock();

  }

}

void ZConcurrentRootsIterator::do_jni_handles(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhaseConcurrentRootsJNIHandles);

  _jni_handles_iter.oops_do(cl);

}

void ZConcurrentRootsIterator::do_class_loader_data_graph(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhaseConcurrentRootsClassLoaderDataGraph);

  if (_marking) {

    CLDToOopClosure cld_cl(cl, ClassLoaderData::_claim_strong);

    ClassLoaderDataGraph::always_strong_cld_do(&cld_cl);

  } else {

    CLDToOopClosure cld_cl(cl, ClassLoaderData::_claim_none);

    ClassLoaderDataGraph::cld_do(&cld_cl);

  }

}

void ZConcurrentRootsIterator::oops_do(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhaseConcurrentRoots);

  _jni_handles.oops_do(cl);

  _class_loader_data_graph.oops_do(cl);

}

ZWeakRootsIterator::ZWeakRootsIterator() :

    _jvmti_weak_export(this),

    _jfr_weak(this) {

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

  ZStatTimer timer(ZSubPhasePauseWeakRootsSetup);

}

ZWeakRootsIterator::~ZWeakRootsIterator() {

  ZStatTimer timer(ZSubPhasePauseWeakRootsTeardown);

}

void ZWeakRootsIterator::do_jvmti_weak_export(BoolObjectClosure* is_alive, ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseWeakRootsJVMTIWeakExport);

  JvmtiExport::weak_oops_do(is_alive, cl);

}

void ZWeakRootsIterator::do_jfr_weak(BoolObjectClosure* is_alive, ZRootsIteratorClosure* cl) {

#if INCLUDE_JFR

  ZStatTimer timer(ZSubPhasePauseWeakRootsJFRWeak);

  Jfr::weak_oops_do(is_alive, cl);

#endif

}

void ZWeakRootsIterator::weak_oops_do(BoolObjectClosure* is_alive, ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseWeakRoots);

  _jvmti_weak_export.weak_oops_do(is_alive, cl);

  _jfr_weak.weak_oops_do(is_alive, cl);

}

void ZWeakRootsIterator::oops_do(ZRootsIteratorClosure* cl) {

  AlwaysTrueClosure always_alive;

  weak_oops_do(&always_alive, cl);

}

ZConcurrentWeakRootsIterator::ZConcurrentWeakRootsIterator() :

    _vm_weak_handles_iter(SystemDictionary::vm_weak_oop_storage()),

    _jni_weak_handles_iter(JNIHandles::weak_global_handles()),

    _string_table_iter(StringTable::weak_storage()),

    _resolved_method_table_iter(ResolvedMethodTable::weak_storage()),

    _vm_weak_handles(this),

    _jni_weak_handles(this),

    _string_table(this),

    _resolved_method_table(this) {

  StringTable::reset_dead_counter();

  ResolvedMethodTable::reset_dead_counter();

}

ZConcurrentWeakRootsIterator::~ZConcurrentWeakRootsIterator() {

  StringTable::finish_dead_counter();

  ResolvedMethodTable::finish_dead_counter();

}

void ZConcurrentWeakRootsIterator::do_vm_weak_handles(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhaseConcurrentWeakRootsVMWeakHandles);

  _vm_weak_handles_iter.oops_do(cl);

}

void ZConcurrentWeakRootsIterator::do_jni_weak_handles(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhaseConcurrentWeakRootsJNIWeakHandles);

  _jni_weak_handles_iter.oops_do(cl);

}

template <class Container>

class ZDeadCounterClosure : public ZRootsIteratorClosure  {

private:

  ZRootsIteratorClosure* const _cl;

  size_t                       _ndead;

public:

  ZDeadCounterClosure(ZRootsIteratorClosure* cl) :

      _cl(cl),

      _ndead(0) {}

  ~ZDeadCounterClosure() {

    Container::inc_dead_counter(_ndead);

  }

  virtual void do_oop(oop* p) {

    _cl->do_oop(p);

    if (*p == NULL) {

      _ndead++;

    }

  }

  virtual void do_oop(narrowOop* p) {

    ShouldNotReachHere();

  }

};

void ZConcurrentWeakRootsIterator::do_string_table(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhaseConcurrentWeakRootsStringTable);

  ZDeadCounterClosure<StringTable> counter_cl(cl);

  _string_table_iter.oops_do(&counter_cl);

}

void ZConcurrentWeakRootsIterator::do_resolved_method_table(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhaseConcurrentWeakRootsResolvedMethodTable);

  ZDeadCounterClosure<ResolvedMethodTable> counter_cl(cl);

  _resolved_method_table_iter.oops_do(&counter_cl);

}

void ZConcurrentWeakRootsIterator::oops_do(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhaseConcurrentWeakRoots);

  _vm_weak_handles.oops_do(cl);

  _jni_weak_handles.oops_do(cl);

  _string_table.oops_do(cl);

  _resolved_method_table.oops_do(cl);

}

ZThreadRootsIterator::ZThreadRootsIterator() :

    _threads(this) {

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

  ZStatTimer timer(ZSubPhasePauseRootsSetup);

  Threads::change_thread_claim_token();

}

ZThreadRootsIterator::~ZThreadRootsIterator() {

  ZStatTimer timer(ZSubPhasePauseRootsTeardown);

  Threads::assert_all_threads_claimed();

}

void ZThreadRootsIterator::do_threads(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseRootsThreads);

  ResourceMark rm;

  Threads::possibly_parallel_oops_do(true, cl, NULL);

}

void ZThreadRootsIterator::oops_do(ZRootsIteratorClosure* cl) {

  ZStatTimer timer(ZSubPhasePauseRoots);

  _threads.oops_do(cl);

}