1 /*
   2  * Copyright (c) 2012, 2013, 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_TRACE_TRACEEVENT_HPP
  26 #define SHARE_VM_TRACE_TRACEEVENT_HPP
  27 
  28 #include "utilities/macros.hpp"
  29 
  30 enum EventStartTime {
  31   UNTIMED,
  32   TIMED
  33 };
  34 
  35 #if INCLUDE_TRACE
  36 #include "trace/traceBackend.hpp"
  37 #include "trace/tracing.hpp"
  38 #include "tracefiles/traceEventIds.hpp"
  39 #include "tracefiles/traceTypes.hpp"
  40 #include "utilities/ticks.hpp"
  41 
  42 template<typename T>
  43 class TraceEvent : public StackObj {
  44  private:
  45   bool _started;
  46 #ifdef ASSERT
  47   bool _committed;
  48   bool _cancelled;
  49  protected:
  50   bool _ignore_check;
  51 #endif
  52 
  53  protected:
  54   jlong _startTime;
  55   jlong _endTime;
  56 
  57   void set_starttime(const TracingTime& time) {
  58     _startTime = time;
  59   }
  60 
  61   void set_endtime(const TracingTime& time) {
  62     _endTime = time;
  63   }
  64 
  65   TraceEvent(EventStartTime timing=TIMED) :
  66     _startTime(0),
  67     _endTime(0),
  68     _started(false)
  69 #ifdef ASSERT
  70     ,
  71     _committed(false),
  72     _cancelled(false),
  73     _ignore_check(false)
  74 #endif
  75   {
  76     if (T::is_enabled()) {
  77       _started = true;
  78       if (timing == TIMED && !T::isInstant) {
  79         static_cast<T*>(this)->set_starttime(Tracing::time());
  80       }
  81     }
  82   }
  83 
  84  public:
  85   static bool is_enabled() {
  86     return Tracing::is_event_enabled(T::eventId);
  87   }
  88 
  89   void set_starttime(const Ticks& time) {
  90     _startTime = time.value();
  91   }
  92 
  93   void set_endtime(const Ticks& time) {
  94     _endTime = time.value();
  95   }
  96 
  97   bool should_commit() {
  98     return _started;
  99   }
 100 
 101   void commit() {
 102     if (!should_commit()) {
 103       DEBUG_ONLY(cancel());
 104       return;
 105     }
 106     assert(!_cancelled, "Committing an event that has already been cancelled");
 107     if (_endTime == 0) {
 108       static_cast<T*>(this)->set_endtime(Tracing::time());
 109     }
 110     if (static_cast<T*>(this)->should_write()) {
 111       static_cast<T*>(this)->writeEvent();
 112     }
 113     DEBUG_ONLY(set_commited());
 114   }
 115 
 116   void cancel() {
 117     assert(!_committed && !_cancelled, "event was already committed/cancelled");
 118     DEBUG_ONLY(_cancelled = true);
 119   }
 120 
 121   static bool is_instant() {
 122     return T::isInstant;
 123   }
 124 
 125   static bool is_requestable() {
 126     return T::isRequestable;
 127   }
 128 
 129   static bool has_thread() {
 130     return T::hasThread;
 131   }
 132 
 133   static bool has_stacktrace() {
 134     return T::hasStackTrace;
 135   }
 136 
 137   ~TraceEvent() {
 138     if (_started) {
 139       assert(_ignore_check || _committed || _cancelled, "event was not committed/cancelled");
 140     }
 141   }
 142 
 143 #ifdef ASSERT
 144 
 145  protected:
 146   void ignoreCheck() {
 147     _ignore_check = true;
 148   }
 149 
 150  private:
 151   void set_commited() {
 152     assert(!_committed, "event has already been committed");
 153     _committed = true;
 154   }
 155 
 156 #endif // ASSERT
 157 };
 158 
 159 #endif // INCLUDE_TRACE
 160 #endif // SHARE_VM_TRACE_TRACEEVENT_HPP