view src/share/vm/runtime/dtraceJSDT.hpp @ 3917:eca1193ca245

4965777: GC changes to support use of discovered field for pending references Summary: If and when the reference handler thread is able to use the discovered field to link reference objects in its pending list, so will GC. In that case, GC will scan through this field once a reference object has been placed on the pending list, but not scan that field before that stage, as the field is used by the concurrent GC thread to link discovered objects. When ReferenceHandleR thread does not use the discovered field for the purpose of linking the elements in the pending list, as would be the case in older JDKs, the JVM will fall back to the old behaviour of using the next field for that purpose. Reviewed-by: jcoomes, mchung, stefank
author ysr
date Wed, 07 Sep 2011 13:55:42 -0700
parents 1d1603768966
children d2a62e0f25eb
line wrap: on
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/*
 * Copyright (c) 1997, 2011, 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 SHARE_VM_RUNTIME_DTRACEJSDT_HPP
#define SHARE_VM_RUNTIME_DTRACEJSDT_HPP

#include "code/nmethod.hpp"
#ifdef TARGET_ARCH_x86
# include "nativeInst_x86.hpp"
#endif
#ifdef TARGET_ARCH_sparc
# include "nativeInst_sparc.hpp"
#endif
#ifdef TARGET_ARCH_zero
# include "nativeInst_zero.hpp"
#endif
#ifdef TARGET_ARCH_arm
# include "nativeInst_arm.hpp"
#endif
#ifdef TARGET_ARCH_ppc
# include "nativeInst_ppc.hpp"
#endif

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;
  }
};

#endif // SHARE_VM_RUNTIME_DTRACEJSDT_HPP