view src/share/vm/runtime/dtraceJSDT.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 d1605aabd0a1
children c18cbe5936b8
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/*
 * Copyright 1997-2008 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 RegisteredProbes;
typedef jlong OpaqueProbes;

class DTraceJSDT : AllStatic {
 private:

  static int pd_activate(void* moduleBaseAddress, jstring module,
      jint providers_count, JVM_DTraceProvider* providers);
  static void pd_dispose(int handle);
  static jboolean pd_is_supported();

 public:

  static OpaqueProbes activate(
      jint version, jstring module_name, jint providers_count,
      JVM_DTraceProvider* providers, TRAPS);
  static jboolean is_probe_enabled(jmethodID method);
  static void dispose(OpaqueProbes handle);
  static jboolean is_supported();
};

class RegisteredProbes : public CHeapObj {
 private:
  nmethod** _nmethods;      // all the probe methods
  size_t    _count;         // number of probe methods
  int       _helper_handle; // DTrace-assigned identifier

 public:
  RegisteredProbes(size_t count) {
    _count = count;
    _nmethods = NEW_C_HEAP_ARRAY(nmethod*, count);
  }

  ~RegisteredProbes() {
    for (size_t i = 0; i < _count; ++i) {
      // Let the sweeper reclaim it
      _nmethods[i]->make_not_entrant();
      _nmethods[i]->method()->clear_code();
    }
    FREE_C_HEAP_ARRAY(nmethod*, _nmethods);
    _nmethods = NULL;
    _count = 0;
  }

  static RegisteredProbes* toRegisteredProbes(OpaqueProbes p) {
    return (RegisteredProbes*)(intptr_t)p;
  }

  static OpaqueProbes toOpaqueProbes(RegisteredProbes* p) {
    return (OpaqueProbes)(intptr_t)p;
  }

  void set_helper_handle(int handle) { _helper_handle = handle; }
  int helper_handle() const { return _helper_handle; }

  nmethod* nmethod_at(size_t i) {
    assert(i >= 0 && i < _count, "bad nmethod index");
    return _nmethods[i];
  }

  void nmethod_at_put(size_t i, nmethod* nm) {
    assert(i >= 0 && i < _count, "bad nmethod index");
    _nmethods[i] = nm;
  }
};