1 /*
   2  * Copyright (c) 2012, 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_RECORDER_SERVICE_JFREVENT_HPP
  26 #define SHARE_VM_JFR_RECORDER_SERVICE_JFREVENT_HPP
  27 
  28 #include "jfr/recorder/jfrEventSetting.inline.hpp"
  29 #include "jfr/recorder/stacktrace/jfrStackTraceRepository.hpp"
  30 #include "jfr/utilities/jfrTraceTime.hpp"
  31 #include "jfr/writers/jfrNativeEventWriter.hpp"
  32 #include "runtime/thread.hpp"
  33 #include "trace/traceEvent.hpp"
  34 #include "utilities/ticks.hpp"
  35 #ifdef ASSERT
  36 #include "utilities/bitMap.hpp"
  37 #endif
  38 
  39 #ifdef ASSERT
  40 class JfrTraceEventVerifier {
  41   template <typename>
  42   friend class JfrTraceEvent;
  43  private:
  44   // verification of event fields
  45   BitMap::bm_word_t _verification_storage[1];
  46   BitMapView _verification_bit_map;
  47 
  48   JfrTraceEventVerifier();
  49   void check(BitMap::idx_t field_idx) const;
  50   void set_field_bit(size_t field_idx);
  51   bool verify_field_bit(size_t field_idx) const;
  52 };
  53 
  54 #endif // ASSERT
  55 
  56 template <typename T>
  57 class JfrTraceEvent : public TraceEvent<T> {
  58  protected:
  59   JfrTraceEvent(EventStartTime timing=TIMED) : TraceEvent<T>(timing)
  60 #ifdef ASSERT
  61    , _verifier()
  62 #endif
  63    { }
  64 
  65  public:
  66   void set_starttime(const JfrTraceTime& time) {
  67     this->_startTime = time.value();
  68   }
  69 
  70   void set_endtime(const JfrTraceTime& time) {
  71     this->_endTime = time.value();
  72   }
  73 
  74   void set_starttime(const Ticks& time) {
  75     this->_startTime = JfrTraceTime::is_ft_enabled() ? time.ft_value() : time.value();
  76   }
  77 
  78   void set_endtime(const Ticks& time) {
  79     this->_endTime = JfrTraceTime::is_ft_enabled() ? time.ft_value() : time.value();
  80   }
  81 
  82  private:
  83   bool should_write() {
  84     if (T::isInstant || T::isRequestable || T::hasCutoff) {
  85       return true;
  86     }
  87     return (this->_endTime - this->_startTime) >= JfrEventSetting::threshold(T::eventId);
  88   }
  89 
  90   void writeEvent() {
  91     DEBUG_ONLY(assert_precondition();)
  92     Thread* const event_thread = Thread::current();
  93     JfrThreadData* const trace_data = event_thread->trace_data();
  94     JfrBuffer* const buffer = trace_data->native_buffer();
  95     if (buffer == NULL) {
  96       // most likely a pending OOM
  97       return;
  98     }
  99     JfrNativeEventWriter writer(buffer, event_thread);
 100     writer.write<u8>(T::eventId);
 101     assert(this->_startTime != 0, "invariant");
 102     writer.write(this->_startTime);
 103     if (!(T::isInstant || T::isRequestable) || T::hasCutoff) {
 104       assert(this->_endTime != 0, "invariant");
 105       writer.write(this->_endTime - this->_startTime);
 106     }
 107     if (T::hasThread) {
 108       writer.write(trace_data->thread_id());
 109     }
 110     if (T::hasStackTrace) {
 111       if (JfrEventSetting::has_stacktrace(T::eventId)) {
 112         if (trace_data->has_cached_stack_trace()) {
 113           writer.write(trace_data->cached_stack_trace_id());
 114         } else {
 115           writer.write(JfrStackTraceRepository::record(event_thread));
 116         }
 117       } else {
 118         writer.write<traceid>(0);
 119       }
 120     }
 121     // payload
 122     static_cast<T*>(this)->writeData(writer);
 123   }
 124 
 125 #ifdef ASSERT
 126  private:
 127   // verification of event fields
 128   JfrTraceEventVerifier _verifier;
 129 
 130   void assert_precondition() {
 131     assert(T::eventId >= (TraceEventId)NUM_RESERVED_EVENTS, "event id underflow invariant");
 132     assert(T::eventId < MaxTraceEventId, "event id overflow invariant");
 133     DEBUG_ONLY(static_cast<T*>(this)->verify());
 134   }
 135 
 136  protected:
 137   void set_field_bit(size_t field_idx) {
 138     _verifier.set_field_bit(field_idx);
 139     // it is ok to reuse an already committed event
 140     // granted you provide new informational content
 141     this->_committed = false;
 142   }
 143   bool verify_field_bit(size_t field_idx) const {
 144     return _verifier.verify_field_bit(field_idx);
 145   }
 146 #endif // ASSERT
 147 
 148   template <typename>
 149   friend class TraceEvent;
 150 };
 151 
 152 #endif // SHARE_VM_JFR_RECORDER_SERVICE_JFREVENT_HPP