aoqi@0: /*
aoqi@0:  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #ifndef SHARE_VM_UTILITIES_EVENTS_HPP
aoqi@0: #define SHARE_VM_UTILITIES_EVENTS_HPP
aoqi@0: 
aoqi@0: #include "memory/allocation.hpp"
aoqi@0: #include "runtime/mutexLocker.hpp"
aoqi@0: #include "runtime/thread.hpp"
aoqi@0: #include "utilities/top.hpp"
aoqi@0: #include "utilities/vmError.hpp"
aoqi@0: 
aoqi@0: // Events and EventMark provide interfaces to log events taking place in the vm.
aoqi@0: // This facility is extremly useful for post-mortem debugging. The eventlog
aoqi@0: // often provides crucial information about events leading up to the crash.
aoqi@0: //
aoqi@0: // Abstractly the logs can record whatever they way but normally they
aoqi@0: // would record at least a timestamp and the current Thread, along
aoqi@0: // with whatever data they need in a ring buffer.  Commonly fixed
aoqi@0: // length text messages are recorded for simplicity but other
aoqi@0: // strategies could be used.  Several logs are provided by default but
aoqi@0: // new instances can be created as needed.
aoqi@0: 
aoqi@0: // The base event log dumping class that is registered for dumping at
aoqi@0: // crash time.  This is a very generic interface that is mainly here
aoqi@0: // for completeness.  Normally the templated EventLogBase would be
aoqi@0: // subclassed to provide different log types.
aoqi@0: class EventLog : public CHeapObj<mtInternal> {
aoqi@0:   friend class Events;
aoqi@0: 
aoqi@0:  private:
aoqi@0:   EventLog* _next;
aoqi@0: 
aoqi@0:   EventLog* next() const { return _next; }
aoqi@0: 
aoqi@0:  public:
aoqi@0:   // Automatically registers the log so that it will be printed during
aoqi@0:   // crashes.
aoqi@0:   EventLog();
aoqi@0: 
aoqi@0:   virtual void print_log_on(outputStream* out) = 0;
aoqi@0: };
aoqi@0: 
aoqi@0: 
aoqi@0: // A templated subclass of EventLog that provides basic ring buffer
aoqi@0: // functionality.  Most event loggers should subclass this, possibly
aoqi@0: // providing a more featureful log function if the existing copy
aoqi@0: // semantics aren't appropriate.  The name is used as the label of the
aoqi@0: // log when it is dumped during a crash.
aoqi@0: template <class T> class EventLogBase : public EventLog {
aoqi@0:   template <class X> class EventRecord : public CHeapObj<mtInternal> {
aoqi@0:    public:
aoqi@0:     double  timestamp;
aoqi@0:     Thread* thread;
aoqi@0:     X       data;
aoqi@0:   };
aoqi@0: 
aoqi@0:  protected:
aoqi@0:   Mutex           _mutex;
aoqi@0:   const char*     _name;
aoqi@0:   int             _length;
aoqi@0:   int             _index;
aoqi@0:   int             _count;
aoqi@0:   EventRecord<T>* _records;
aoqi@0: 
aoqi@0:  public:
aoqi@0:   EventLogBase<T>(const char* name, int length = LogEventsBufferEntries):
aoqi@0:     _name(name),
aoqi@0:     _length(length),
aoqi@0:     _count(0),
aoqi@0:     _index(0),
aoqi@0:     _mutex(Mutex::event, name) {
aoqi@0:     _records = new EventRecord<T>[length];
aoqi@0:   }
aoqi@0: 
aoqi@0:   double fetch_timestamp() {
aoqi@0:     return os::elapsedTime();
aoqi@0:   }
aoqi@0: 
aoqi@0:   // move the ring buffer to next open slot and return the index of
aoqi@0:   // the slot to use for the current message.  Should only be called
aoqi@0:   // while mutex is held.
aoqi@0:   int compute_log_index() {
aoqi@0:     int index = _index;
aoqi@0:     if (_count < _length) _count++;
aoqi@0:     _index++;
aoqi@0:     if (_index >= _length) _index = 0;
aoqi@0:     return index;
aoqi@0:   }
aoqi@0: 
aoqi@0:   bool should_log() {
aoqi@0:     // Don't bother adding new entries when we're crashing.  This also
aoqi@0:     // avoids mutating the ring buffer when printing the log.
aoqi@0:     return !VMError::fatal_error_in_progress();
aoqi@0:   }
aoqi@0: 
aoqi@0:   // Print the contents of the log
aoqi@0:   void print_log_on(outputStream* out);
aoqi@0: 
aoqi@0:  private:
aoqi@0:   void print_log_impl(outputStream* out);
aoqi@0: 
aoqi@0:   // Print a single element.  A templated implementation might need to
aoqi@0:   // be declared by subclasses.
aoqi@0:   void print(outputStream* out, T& e);
aoqi@0: 
aoqi@0:   void print(outputStream* out, EventRecord<T>& e) {
aoqi@0:     out->print("Event: %.3f ", e.timestamp);
aoqi@0:     if (e.thread != NULL) {
aoqi@0:       out->print("Thread " INTPTR_FORMAT " ", p2i(e.thread));
aoqi@0:     }
aoqi@0:     print(out, e.data);
aoqi@0:   }
aoqi@0: };
aoqi@0: 
aoqi@0: // A simple wrapper class for fixed size text messages.
aoqi@0: class StringLogMessage : public FormatBuffer<256> {
aoqi@0:  public:
aoqi@0:   // Wrap this buffer in a stringStream.
aoqi@0:   stringStream stream() {
aoqi@0:     return stringStream(_buf, size());
aoqi@0:   }
aoqi@0: };
aoqi@0: 
aoqi@0: // A simple ring buffer of fixed size text messages.
aoqi@0: class StringEventLog : public EventLogBase<StringLogMessage> {
aoqi@0:  public:
aoqi@0:   StringEventLog(const char* name, int count = LogEventsBufferEntries) : EventLogBase<StringLogMessage>(name, count) {}
aoqi@0: 
aoqi@0:   void logv(Thread* thread, const char* format, va_list ap) ATTRIBUTE_PRINTF(3, 0) {
aoqi@0:     if (!should_log()) return;
aoqi@0: 
aoqi@0:     double timestamp = fetch_timestamp();
aoqi@0:     MutexLockerEx ml(&_mutex, Mutex::_no_safepoint_check_flag);
aoqi@0:     int index = compute_log_index();
aoqi@0:     _records[index].thread = thread;
aoqi@0:     _records[index].timestamp = timestamp;
aoqi@0:     _records[index].data.printv(format, ap);
aoqi@0:   }
aoqi@0: 
aoqi@0:   void log(Thread* thread, const char* format, ...) ATTRIBUTE_PRINTF(3, 4) {
aoqi@0:     va_list ap;
aoqi@0:     va_start(ap, format);
aoqi@0:     logv(thread, format, ap);
aoqi@0:     va_end(ap);
aoqi@0:   }
aoqi@0: 
aoqi@0: };
aoqi@0: 
aoqi@0: 
aoqi@0: 
aoqi@0: class Events : AllStatic {
aoqi@0:   friend class EventLog;
aoqi@0: 
aoqi@0:  private:
aoqi@0:   static EventLog* _logs;
aoqi@0: 
aoqi@0:   // A log for generic messages that aren't well categorized.
aoqi@0:   static StringEventLog* _messages;
aoqi@0: 
aoqi@0:   // A log for internal exception related messages, like internal
aoqi@0:   // throws and implicit exceptions.
aoqi@0:   static StringEventLog* _exceptions;
aoqi@0: 
aoqi@0:   // Deoptization related messages
aoqi@0:   static StringEventLog* _deopt_messages;
aoqi@0: 
aoqi@0:  public:
aoqi@0:   static void print_all(outputStream* out);
aoqi@0: 
aoqi@0:   // Dump all events to the tty
aoqi@0:   static void print();
aoqi@0: 
aoqi@0:   // Logs a generic message with timestamp and format as printf.
aoqi@0:   static void log(Thread* thread, const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
aoqi@0: 
aoqi@0:   // Log exception related message
aoqi@0:   static void log_exception(Thread* thread, const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
aoqi@0: 
aoqi@0:   static void log_deopt_message(Thread* thread, const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
aoqi@0: 
aoqi@0:   // Register default loggers
aoqi@0:   static void init();
aoqi@0: };
aoqi@0: 
aoqi@0: inline void Events::log(Thread* thread, const char* format, ...) {
aoqi@0:   if (LogEvents) {
aoqi@0:     va_list ap;
aoqi@0:     va_start(ap, format);
aoqi@0:     _messages->logv(thread, format, ap);
aoqi@0:     va_end(ap);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: inline void Events::log_exception(Thread* thread, const char* format, ...) {
aoqi@0:   if (LogEvents) {
aoqi@0:     va_list ap;
aoqi@0:     va_start(ap, format);
aoqi@0:     _exceptions->logv(thread, format, ap);
aoqi@0:     va_end(ap);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: inline void Events::log_deopt_message(Thread* thread, const char* format, ...) {
aoqi@0:   if (LogEvents) {
aoqi@0:     va_list ap;
aoqi@0:     va_start(ap, format);
aoqi@0:     _deopt_messages->logv(thread, format, ap);
aoqi@0:     va_end(ap);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: template <class T>
aoqi@0: inline void EventLogBase<T>::print_log_on(outputStream* out) {
aoqi@0:   if (ThreadLocalStorage::get_thread_slow() == NULL) {
aoqi@0:     // Not a regular Java thread so don't bother locking
aoqi@0:     print_log_impl(out);
aoqi@0:   } else {
aoqi@0:     MutexLockerEx ml(&_mutex, Mutex::_no_safepoint_check_flag);
aoqi@0:     print_log_impl(out);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: // Dump the ring buffer entries that current have entries.
aoqi@0: template <class T>
aoqi@0: inline void EventLogBase<T>::print_log_impl(outputStream* out) {
aoqi@0:   out->print_cr("%s (%d events):", _name, _count);
aoqi@0:   if (_count == 0) {
aoqi@0:     out->print_cr("No events");
aoqi@0:     out->cr();
aoqi@0:     return;
aoqi@0:   }
aoqi@0: 
aoqi@0:   if (_count < _length) {
aoqi@0:     for (int i = 0; i < _count; i++) {
aoqi@0:       print(out, _records[i]);
aoqi@0:     }
aoqi@0:   } else {
aoqi@0:     for (int i = _index; i < _length; i++) {
aoqi@0:       print(out, _records[i]);
aoqi@0:     }
aoqi@0:     for (int i = 0; i < _index; i++) {
aoqi@0:       print(out, _records[i]);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   out->cr();
aoqi@0: }
aoqi@0: 
aoqi@0: // Implement a printing routine for the StringLogMessage
aoqi@0: template <>
aoqi@0: inline void EventLogBase<StringLogMessage>::print(outputStream* out, StringLogMessage& lm) {
aoqi@0:   out->print_raw(lm);
aoqi@0:   out->cr();
aoqi@0: }
aoqi@0: 
aoqi@0: // Place markers for the beginning and end up of a set of events.
aoqi@0: // These end up in the default log.
aoqi@0: class EventMark : public StackObj {
aoqi@0:   StringLogMessage _buffer;
aoqi@0: 
aoqi@0:  public:
aoqi@0:   // log a begin event, format as printf
aoqi@0:   EventMark(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
aoqi@0:   // log an end event
aoqi@0:   ~EventMark();
aoqi@0: };
aoqi@0: 
aoqi@0: #endif // SHARE_VM_UTILITIES_EVENTS_HPP