/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* 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.
*
*/
#ifndef SERIALGC
#include "runtime/thread.hpp"
#endif
class VoidClosure;
// A SuspendibleThreadSet is (obviously) a set of threads that can be
// suspended. A thread can join and later leave the set, and periodically
// yield. If some thread (not in the set) requests, via suspend_all, that
// the threads be suspended, then the requesting thread is blocked until
// all the threads in the set have yielded or left the set. (Threads may
// not enter the set when an attempted suspension is in progress.) The
// suspending thread later calls resume_all, allowing the suspended threads
// to continue.
class SuspendibleThreadSet {
int _async;
bool _async_stop;
int _async_stopped;
bool _initialized;
double _suspend_all_start;
void initialize_work();
public:
// Add the current thread to the set. May block if a suspension
// is in progress.
void join();
// Removes the current thread from the set.
void leave();
// Returns "true" iff an suspension is in progress.
// Suspends the current thread if a suspension is in progress (for
// the duration of the suspension.)
// Return when all threads in the set are suspended.
void suspend_all();
// Allow suspended threads to resume.
void resume_all();
// Redundant initializations okay.
void initialize() {
// Double-check dirty read idiom.
if (!_initialized) initialize_work();
}
};
friend class VMStructs;
protected:
bool _should_terminate;
bool _has_terminated;
enum CGC_flag_type {
};
static int _CGC_flag;
// All instances share this one set.
// Create and start the thread (setting it's priority high.)
void create_and_start();
// Do initialization steps in the thread: record stack base and size,
// init thread local storage, set JNI handle block.
void initialize_in_thread();
// Wait until Universe::is_fully_initialized();
void wait_for_universe_init();
// Record that the current thread is terminating, and will do more
// concurrent work.
void terminate();
public:
// Constructor
~ConcurrentGCThread() {} // Exists to call NamedThread destructor.
// Tester
bool is_ConcurrentGC_thread() const { return true; }
static void safepoint_synchronize();
static void safepoint_desynchronize();
// All overridings should probably do _sts::yield, but we allow
// overriding for distinguished debugging messages. Default is to do
// nothing.
virtual void yield() {}
// they are prefixed by sts since there are already yield() and
// should_yield() (non-static) methods in this class and it was an
// easy way to differentiate them.
static bool stsShouldYield();
static void stsJoin();
static void stsLeave();
};
// The SurrogateLockerThread is used by concurrent GC threads for
// manipulating Java monitors, in particular, currently for
// manipulating the pending_list_lock. XXX
friend class VMStructs;
public:
enum SLT_msg_type {
};
private:
// the following are shared with the CMSThread
public:
bool is_hidden_from_external_view() const { return true; }
void loop(); // main method
};
#endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_CONCURRENTGCTHREAD_HPP