/*

 * Copyright (c) 2014, 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 "jfr/leakprofiler/leakProfiler.hpp"

#include "jfr/leakprofiler/startOperation.hpp"

#include "jfr/leakprofiler/stopOperation.hpp"

#include "jfr/leakprofiler/checkpoint/eventEmitter.hpp"

#include "jfr/leakprofiler/sampling/objectSampler.hpp"

#include "jfr/recorder/service/jfrOptionSet.hpp"

#include "logging/log.hpp"

#include "memory/iterator.hpp"

#include "runtime/thread.inline.hpp"

#include "runtime/vmThread.hpp"

bool LeakProfiler::is_running() {

  return ObjectSampler::is_created();

}

bool LeakProfiler::start(int sample_count) {

  if (is_running()) {

    return true;

  }

  // Allows user to disable leak profiler on command line by setting queue size to zero.

  if (sample_count == 0) {

    return false;

  }

  if (UseZGC) {

    log_warning(jfr)("LeakProfiler is currently not supported in combination with ZGC");

    return false;

  }

  if (UseShenandoahGC) {

    log_warning(jfr)("LeakProfiler is currently not supported in combination with Shenandoah GC");

    return false;

  }

  assert(!is_running(), "invariant");

  assert(sample_count > 0, "invariant");

  // schedule the safepoint operation for installing the object sampler

  StartOperation op(sample_count);

  VMThread::execute(&op);

  if (!is_running()) {

    log_trace(jfr, system)("Object sampling could not be started because the sampler could not be allocated");

    return false;

  }

  assert(is_running(), "invariant");

  log_trace(jfr, system)("Object sampling started");

  return true;

}

bool LeakProfiler::stop() {

  if (!is_running()) {

    return false;

  }

  // schedule the safepoint operation for uninstalling and destroying the object sampler

  StopOperation op;

  VMThread::execute(&op);

  assert(!is_running(), "invariant");

  log_trace(jfr, system)("Object sampling stopped");

  return true;

}

void LeakProfiler::emit_events(int64_t cutoff_ticks, bool emit_all) {

  if (!is_running()) {

    return;

  }

  // exclusive access to object sampler instance

  ObjectSampler* const sampler = ObjectSampler::acquire();

  assert(sampler != NULL, "invariant");

  EventEmitter::emit(sampler, cutoff_ticks, emit_all);

  ObjectSampler::release();

}

void LeakProfiler::oops_do(BoolObjectClosure* is_alive, OopClosure* f) {

  assert(SafepointSynchronize::is_at_safepoint(),

    "Leak Profiler::oops_do(...) may only be called during safepoint");

  if (is_running()) {

    ObjectSampler::oops_do(is_alive, f);

  }

}

void LeakProfiler::sample(HeapWord* object, size_t size, JavaThread* thread) {

  assert(is_running(), "invariant");

  assert(thread != NULL, "invariant");

  assert(thread->thread_state() == _thread_in_vm, "invariant");

  // exclude compiler threads and code sweeper thread

  if (thread->is_hidden_from_external_view()) {

    return;

  }

  ObjectSampler::sample(object, size, thread);

}