1 /*
   2  * Copyright (c) 2012, 2016, 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 (TIMED == timing && !T::isInstant) {
  79         static_cast<T*>(this)->set_starttime(Tracing::time());
  80       }
  81     }
  82   }
  83 
  84  public:
  85   void set_starttime(const Ticks& time) {
  86     _startTime = time.value();
  87   }
  88 
  89   void set_endtime(const Ticks& time) {
  90     _endTime = time.value();
  91   }
  92 
  93   static bool is_enabled() {
  94     return Tracing::is_event_enabled(T::eventId);
  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 (_startTime == 0) {
 108       static_cast<T*>(this)->set_starttime(Tracing::time());
 109     } else if (_endTime == 0) {
 110       static_cast<T*>(this)->set_endtime(Tracing::time());
 111     }
 112     if (static_cast<T*>(this)->should_write()) {
 113       static_cast<T*>(this)->writeEvent();
 114     }
 115     DEBUG_ONLY(set_commited());
 116   }
 117 
 118   static TraceEventId id() {
 119     return T::eventId;
 120   }
 121 
 122   static bool is_instant() {
 123     return T::isInstant;
 124   }
 125 
 126   static bool is_requestable() {
 127     return T::isRequestable;
 128   }
 129 
 130   static bool has_thread() {
 131     return T::hasThread;
 132   }
 133 
 134   static bool has_stacktrace() {
 135     return T::hasStackTrace;
 136   }
 137 
 138   void cancel() {
 139     assert(!_committed && !_cancelled,
 140       "event was already committed/cancelled");
 141     DEBUG_ONLY(_cancelled = true);
 142   }
 143 
 144   ~TraceEvent() {
 145     if (_started) {
 146       assert(_ignore_check || _committed || _cancelled,
 147         "event was not committed/cancelled");
 148     }
 149   }
 150 
 151 #ifdef ASSERT
 152  protected:
 153   void ignoreCheck() {
 154     _ignore_check = true;
 155   }
 156 
 157  private:
 158   void set_commited() {
 159     assert(!_committed, "event has already been committed");
 160     _committed = true;
 161   }
 162 #endif // ASSERT
 163 };
 164 
 165 #endif // INCLUDE_TRACE
 166 #endif // SHARE_VM_TRACE_TRACEEVENT_HPP