view src/share/vm/prims/jvmtiManageCapabilities.hpp @ 1716:be3f9c242c9d

6948538: CMS: BOT walkers can fall into object allocation and initialization cracks Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode. Reviewed-by: chrisphi, johnc, poonam
author ysr
date Mon, 16 Aug 2010 15:58:42 -0700
parents c18cbe5936b8
children f95d63e2154a
line wrap: on
line source

/*
 * Copyright (c) 2003, 2005, 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.
 *
 */

#ifndef _JAVA_JVMTI_MANAGE_CAPABILITIES_H_
#define _JAVA_JVMTI_MANAGE_CAPABILITIES_H_



class JvmtiManageCapabilities : public AllStatic {

private:

  // these four capabilities sets represent all potentially
  // available capabilities.  They are disjoint, covering
  // the four cases: (OnLoad vs OnLoad+live phase) X
  // (one environment vs any environment).
  static jvmtiCapabilities always_capabilities;
  static jvmtiCapabilities onload_capabilities;
  static jvmtiCapabilities always_solo_capabilities;
  static jvmtiCapabilities onload_solo_capabilities;

  // solo capabilities that have not been grabbed
  static jvmtiCapabilities always_solo_remaining_capabilities;
  static jvmtiCapabilities onload_solo_remaining_capabilities;

  // all capabilities ever acquired
  static jvmtiCapabilities acquired_capabilities;

  // basic intenal operations
  static jvmtiCapabilities *either(const jvmtiCapabilities *a, const jvmtiCapabilities *b, jvmtiCapabilities *result);
  static jvmtiCapabilities *both(const jvmtiCapabilities *a, const jvmtiCapabilities *b, jvmtiCapabilities *result);
  static jvmtiCapabilities *exclude(const jvmtiCapabilities *a, const jvmtiCapabilities *b, jvmtiCapabilities *result);
  static bool has_some(const jvmtiCapabilities *a);
  static void update();

  // init functions
  static jvmtiCapabilities init_always_capabilities();
  static jvmtiCapabilities init_onload_capabilities();
  static jvmtiCapabilities init_always_solo_capabilities();
  static jvmtiCapabilities init_onload_solo_capabilities();

public:
  static void initialize();

  // may have to adjust always capabilities when VM initialization has completed
  static void recompute_always_capabilities();

  // queries and actions
  static void get_potential_capabilities(const jvmtiCapabilities *current,
                                         const jvmtiCapabilities *prohibited,
                                         jvmtiCapabilities *result);
  static jvmtiError add_capabilities(const jvmtiCapabilities *current,
                                     const jvmtiCapabilities *prohibited,
                                     const jvmtiCapabilities *desired,
                                     jvmtiCapabilities *result);
  static void relinquish_capabilities(const jvmtiCapabilities *current,
                                      const jvmtiCapabilities *unwanted,
                                      jvmtiCapabilities *result);
  static void copy_capabilities(const jvmtiCapabilities *from, jvmtiCapabilities *to);

#ifndef PRODUCT
  static void print(const jvmtiCapabilities* caps);
#endif
};

#endif   /* _JAVA_JVMTI_MANAGE_CAPABILITIES_H_ */