1 /*
   2  * Copyright (c) 2016, 2018, 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_JFR_SUPPORT_JFRFLUSH_HPP
  26 #define SHARE_VM_JFR_SUPPORT_JFRFLUSH_HPP
  27 
  28 #include "jfr/recorder/storage/jfrBuffer.hpp"
  29 #include "jfr/utilities/jfrTypes.hpp"
  30 #include "memory/allocation.hpp"
  31 
  32 class Thread;
  33 
  34 class JfrFlush : public StackObj {
  35  public:
  36   typedef JfrBuffer Type;
  37   JfrFlush(Type* old, size_t used, size_t requested, Thread* t);
  38   Type* result() const { return _result; }
  39  private:
  40   Type* _result;
  41 };
  42 
  43 void jfr_conditional_flush(JfrEventId id, size_t size, Thread* t);
  44 bool jfr_is_event_enabled(JfrEventId id);
  45 bool jfr_has_stacktrace_enabled(JfrEventId id);
  46 bool jfr_save_stacktrace(Thread* t);
  47 void jfr_clear_stacktrace(Thread* t);
  48 
  49 template <typename Event>
  50 class JfrConditionalFlush {
  51  protected:
  52   bool _enabled;
  53  public:
  54   typedef JfrBuffer Type;
  55   JfrConditionalFlush(Thread* t) : _enabled(jfr_is_event_enabled(Event::eventId)) {
  56     if (_enabled) {
  57       jfr_conditional_flush(Event::eventId, sizeof(Event), t);
  58     }
  59   }
  60 };
  61 
  62 template <typename Event>
  63 class JfrConditionalFlushWithStacktrace : public JfrConditionalFlush<Event> {
  64   Thread* _t;
  65   bool _owner;
  66  public:
  67   JfrConditionalFlushWithStacktrace(Thread* t) : JfrConditionalFlush<Event>(t), _t(t), _owner(false) {
  68     if (this->_enabled && Event::has_stacktrace() && jfr_has_stacktrace_enabled(Event::eventId)) {
  69       _owner = jfr_save_stacktrace(t);
  70     }
  71   }
  72   ~JfrConditionalFlushWithStacktrace() {
  73     if (_owner) {
  74       jfr_clear_stacktrace(_t);
  75     }
  76   }
  77 };
  78 
  79 #endif // SHARE_VM_JFR_SUPPORT_JFRFLUSH_HPP