1 /*
   2  * Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 class RegisteredProbes;
  26 typedef jlong OpaqueProbes;
  27 
  28 class DTraceJSDT : AllStatic {
  29  private:
  30 
  31   static int pd_activate(void* moduleBaseAddress, jstring module,
  32       jint providers_count, JVM_DTraceProvider* providers);
  33   static void pd_dispose(int handle);
  34   static jboolean pd_is_supported();
  35 
  36  public:
  37 
  38   static OpaqueProbes activate(
  39       jint version, jstring module_name, jint providers_count,
  40       JVM_DTraceProvider* providers, TRAPS);
  41   static jboolean is_probe_enabled(jmethodID method);
  42   static void dispose(OpaqueProbes handle);
  43   static jboolean is_supported();
  44 };
  45 
  46 class RegisteredProbes : public CHeapObj {
  47  private:
  48   nmethod** _nmethods;      // all the probe methods
  49   size_t    _count;         // number of probe methods
  50   int       _helper_handle; // DTrace-assigned identifier
  51 
  52  public:
  53   RegisteredProbes(size_t count) {
  54     _count = count;
  55     _nmethods = NEW_C_HEAP_ARRAY(nmethod*, count);
  56   }
  57 
  58   ~RegisteredProbes() {
  59     for (size_t i = 0; i < _count; ++i) {
  60       // Let the sweeper reclaim it
  61       _nmethods[i]->make_not_entrant();
  62       _nmethods[i]->method()->clear_code();
  63     }
  64     FREE_C_HEAP_ARRAY(nmethod*, _nmethods);
  65     _nmethods = NULL;
  66     _count = 0;
  67   }
  68 
  69   static RegisteredProbes* toRegisteredProbes(OpaqueProbes p) {
  70     return (RegisteredProbes*)(intptr_t)p;
  71   }
  72 
  73   static OpaqueProbes toOpaqueProbes(RegisteredProbes* p) {
  74     return (OpaqueProbes)(intptr_t)p;
  75   }
  76 
  77   void set_helper_handle(int handle) { _helper_handle = handle; }
  78   int helper_handle() const { return _helper_handle; }
  79 
  80   nmethod* nmethod_at(size_t i) {
  81     assert(i >= 0 && i < _count, "bad nmethod index");
  82     return _nmethods[i];
  83   }
  84 
  85   void nmethod_at_put(size_t i, nmethod* nm) {
  86     assert(i >= 0 && i < _count, "bad nmethod index");
  87     _nmethods[i] = nm;
  88   }
  89 };