1 /*
   2  * Copyright (c) 1997, 2014, 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 #ifndef SHARE_VM_RUNTIME_DTRACEJSDT_HPP
  26 #define SHARE_VM_RUNTIME_DTRACEJSDT_HPP
  27 
  28 #include "code/nmethod.hpp"
  29 
  30 class RegisteredProbes;
  31 typedef jlong OpaqueProbes;
  32 
  33 class DTraceJSDT : AllStatic {
  34  private:
  35 
  36   static int pd_activate(void* moduleBaseAddress, jstring module,
  37       jint providers_count, JVM_DTraceProvider* providers);
  38   static void pd_dispose(int handle);
  39   static jboolean pd_is_supported();
  40 
  41  public:
  42 
  43   static OpaqueProbes activate(
  44       jint version, jstring module_name, jint providers_count,
  45       JVM_DTraceProvider* providers, TRAPS);
  46   static jboolean is_probe_enabled(jmethodID method);
  47   static void dispose(OpaqueProbes handle);
  48   static jboolean is_supported();
  49 };
  50 
  51 class RegisteredProbes : public CHeapObj<mtInternal> {
  52  private:
  53   nmethod** _nmethods;      // all the probe methods
  54   size_t    _count;         // number of probe methods
  55   int       _helper_handle; // DTrace-assigned identifier
  56 
  57  public:
  58   RegisteredProbes(size_t count) {
  59     _count = count;
  60     _nmethods = NEW_C_HEAP_ARRAY(nmethod*, count, mtInternal);
  61   }
  62 
  63   ~RegisteredProbes() {
  64     for (size_t i = 0; i < _count; ++i) {
  65       // Let the sweeper reclaim it
  66       _nmethods[i]->make_not_entrant();
  67       _nmethods[i]->method()->clear_code();
  68     }
  69     FREE_C_HEAP_ARRAY(nmethod*, _nmethods);
  70     _nmethods = NULL;
  71     _count = 0;
  72   }
  73 
  74   static RegisteredProbes* toRegisteredProbes(OpaqueProbes p) {
  75     return (RegisteredProbes*)(intptr_t)p;
  76   }
  77 
  78   static OpaqueProbes toOpaqueProbes(RegisteredProbes* p) {
  79     return (OpaqueProbes)(intptr_t)p;
  80   }
  81 
  82   void set_helper_handle(int handle) { _helper_handle = handle; }
  83   int helper_handle() const { return _helper_handle; }
  84 
  85   nmethod* nmethod_at(size_t i) {
  86     assert(i >= 0 && i < _count, "bad nmethod index");
  87     return _nmethods[i];
  88   }
  89 
  90   void nmethod_at_put(size_t i, nmethod* nm) {
  91     assert(i >= 0 && i < _count, "bad nmethod index");
  92     _nmethods[i] = nm;
  93   }
  94 };
  95 
  96 #endif // SHARE_VM_RUNTIME_DTRACEJSDT_HPP