src/hotspot/share/gc/shared/concurrentGCThread.cpp
changeset 47216 71c04702a3d5
parent 39984 8ecc78131588
child 49449 ef5d5d343e2a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/shared/concurrentGCThread.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2001, 2016, 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/systemDictionary.hpp"
+#include "gc/shared/concurrentGCThread.hpp"
+#include "oops/instanceRefKlass.hpp"
+#include "oops/oop.inline.hpp"
+#include "runtime/init.hpp"
+#include "runtime/interfaceSupport.hpp"
+#include "runtime/java.hpp"
+#include "runtime/javaCalls.hpp"
+#include "runtime/os.hpp"
+
+ConcurrentGCThread::ConcurrentGCThread() :
+  _should_terminate(false), _has_terminated(false) {
+};
+
+void ConcurrentGCThread::create_and_start(ThreadPriority prio) {
+  if (os::create_thread(this, os::cgc_thread)) {
+    // XXX: need to set this to low priority
+    // unless "aggressive mode" set; priority
+    // should be just less than that of VMThread.
+    os::set_priority(this, prio);
+    if (!_should_terminate) {
+      os::start_thread(this);
+    }
+  }
+}
+
+void ConcurrentGCThread::initialize_in_thread() {
+  this->record_stack_base_and_size();
+  this->initialize_named_thread();
+  this->set_active_handles(JNIHandleBlock::allocate_block());
+  // From this time Thread::current() should be working.
+  assert(this == Thread::current(), "just checking");
+}
+
+void ConcurrentGCThread::wait_for_universe_init() {
+  MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag);
+  while (!is_init_completed() && !_should_terminate) {
+    CGC_lock->wait(Mutex::_no_safepoint_check_flag, 1);
+  }
+}
+
+void ConcurrentGCThread::terminate() {
+  assert(_should_terminate, "Should only be called on terminate request.");
+  // Signal that it is terminated
+  {
+    MutexLockerEx mu(Terminator_lock,
+                     Mutex::_no_safepoint_check_flag);
+    _has_terminated = true;
+    Terminator_lock->notify();
+  }
+}
+
+void ConcurrentGCThread::run() {
+  initialize_in_thread();
+  wait_for_universe_init();
+
+  run_service();
+
+  terminate();
+}
+
+void ConcurrentGCThread::stop() {
+  // it is ok to take late safepoints here, if needed
+  {
+    MutexLockerEx mu(Terminator_lock);
+    assert(!_has_terminated,   "stop should only be called once");
+    assert(!_should_terminate, "stop should only be called once");
+    _should_terminate = true;
+  }
+
+  stop_service();
+
+  {
+    MutexLockerEx mu(Terminator_lock);
+    while (!_has_terminated) {
+      Terminator_lock->wait();
+    }
+  }
+}