1 /*
   2  * Copyright (c) 1999, 2010, 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_PRIMS_JVMTIUTIL_HPP
  26 #define SHARE_VM_PRIMS_JVMTIUTIL_HPP
  27 
  28 #include "jvmtifiles/jvmti.h"
  29 #include "memory/resourceArea.hpp"
  30 #include "prims/jvmtiEventController.hpp"
  31 
  32 ///////////////////////////////////////////////////////////////
  33 //
  34 // class JvmtiUtil
  35 //
  36 // class for miscellaneous jvmti utility static methods
  37 //
  38 
  39 class JvmtiUtil : AllStatic {
  40 
  41   static ResourceArea* _single_threaded_resource_area;
  42 
  43   static const char* _error_names[];
  44   static const bool  _event_threaded[];
  45 
  46 public:
  47 
  48   static ResourceArea* single_threaded_resource_area();
  49 
  50   static const char* error_name(int num)    { return _error_names[num]; }    // To Do: add range checking
  51 
  52   static const bool has_event_capability(jvmtiEvent event_type, const jvmtiCapabilities* capabilities_ptr);
  53 
  54   static const bool  event_threaded(int num) {
  55     if (num >= JVMTI_MIN_EVENT_TYPE_VAL && num <= JVMTI_MAX_EVENT_TYPE_VAL) {
  56       return _event_threaded[num];
  57     }
  58     if (num >= EXT_MIN_EVENT_TYPE_VAL && num <= EXT_MAX_EVENT_TYPE_VAL) {
  59       return false;
  60     }
  61     ShouldNotReachHere();
  62     return false;
  63   }
  64 };
  65 
  66 
  67 ///////////////////////////////////////////////////////////////
  68 //
  69 // class SafeResourceMark
  70 //
  71 // ResourceMarks that work before threads exist
  72 //
  73 
  74 class SafeResourceMark : public ResourceMark {
  75 
  76   ResourceArea* safe_resource_area() {
  77     Thread* thread;
  78 
  79     if (Threads::number_of_threads() == 0) {
  80       return JvmtiUtil::single_threaded_resource_area();
  81     }
  82     thread = ThreadLocalStorage::thread();
  83     if (thread == NULL) {
  84       return JvmtiUtil::single_threaded_resource_area();
  85     }
  86     return thread->resource_area();
  87   }
  88 
  89  public:
  90 
  91   SafeResourceMark() : ResourceMark(safe_resource_area()) {}
  92 
  93 };
  94 
  95 #endif // SHARE_VM_PRIMS_JVMTIUTIL_HPP