view src/share/vm/runtime/jniPeriodicChecker.hpp @ 1145:e018e6884bd8

6631166: CMS: better heuristics when combatting fragmentation Summary: Autonomic per-worker free block cache sizing, tunable coalition policies, fixes to per-size block statistics, retuned gain and bandwidth of some feedback loop filters to allow quicker reactivity to abrupt changes in ambient demand, and other heuristics to reduce fragmentation of the CMS old gen. Also tightened some assertions, including those related to locking. Reviewed-by: jmasa
author ysr
date Wed, 23 Dec 2009 09:23:54 -0800
parents a61af66fc99e
children c18cbe5936b8
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/*
 * Copyright 2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

class JniPeriodicCheckerTask;

/*
 * This gets activated under Xcheck:jni (CheckJNICalls), and is typically
 * to detect any errors caused by JNI applications, such as signal handler,
 * hijacking, va 0x0 hijacking either by mmap or an OS error.
 */


class JniPeriodicChecker : AllStatic {

  friend class JniPeriodicCheckerTask;

  private:
    static JniPeriodicCheckerTask* _task;

  public:
    // Start/stop task
    static void engage();
    static void disengage();

    static bool is_active() { return _task != NULL; }

    static void initialize();
    static void destroy();
};

void jniPeriodicChecker_exit();