/*
 * Copyright (c) 2014, 2015, Dynatrace and/or its affiliates. All rights reserved.
 *
 * This file is part of the Lock Contention Tracing Subsystem for the HotSpot
 * Virtual Machine, which is developed at Christian Doppler Laboratory on
 * Monitoring and Evolution of Very-Large-Scale Software Systems. Please
 * contact us at <http://mevss.jku.at/> if you need additional information
 * or have any questions.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 *
 */

#include "evtrace/traceMetadata.hpp"

TraceMetadata::TraceMetadata() {
  _stack_cache = new TraceStackCache(this);
  _last_stack_id = 0;
  _last_global_seq = 0;
}

TraceMetadata::~TraceMetadata() {
  delete _stack_cache;
}

class TraceMetadata::MarkKlassUnknownClosure: public KlassClosure {
  static void mark_unknown(Method *m) {
    m->reset_tracing_known();
  }

public:
  virtual void do_klass(Klass *k) {
    k->reset_tracing_known();
    if (k->oop_is_instance()) {
      InstanceKlass::cast(k)->methods_do(mark_unknown);
    }
  }
};

class TraceMetadata::ClearInvalidatedMementoStacksClosure: public ThreadClosure {
  virtual void do_thread(Thread *t) {
    assert(t != NULL, "null thread");
    if (t->memento_stack_trace() != NULL && !t->memento_stack_trace()->is_valid()) {
      t->set_memento_stack_trace(NULL);
    }
  }
};

void TraceMetadata::purge_all() {
  assert(SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread(), "must be done in VM thread at safepoint");

  MarkKlassUnknownClosure mark_unknown;
  ClassLoaderDataGraph::classes_do(&mark_unknown);

  _stack_cache->purge_all();
}

void TraceMetadata::do_maintenance() {
  assert(SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread(), "must be done in VM thread at safepoint");

  if (_stack_cache->has_invalid_stacks()) {
    ClearInvalidatedMementoStacksClosure clear_invalid;
    Threads::threads_do(&clear_invalid);
  }

  _stack_cache->do_maintenance();
  assert(!_stack_cache->has_invalid_stacks(), "sanity");
}