/*
 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */

#include "gc/shared/gc_globals.hpp"
#include "memory/allocation.inline.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/symbol.hpp"
#include "runtime/atomic.hpp"
#include "runtime/javaThread.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/osThread.hpp"
#include "runtime/timer.hpp"
#include "utilities/events.hpp"

EventLog* Events::_logs = nullptr;
StringEventLog* Events::_messages = nullptr;
StringEventLog* Events::_memprotect_messages = nullptr;
StringEventLog* Events::_nmethod_flush_messages = nullptr;
StringEventLog* Events::_vm_operations = nullptr;
StringEventLog* Events::_zgc_phase_switch = nullptr;
ExceptionsEventLog* Events::_exceptions = nullptr;
StringEventLog* Events::_redefinitions = nullptr;
UnloadingEventLog* Events::_class_unloading = nullptr;
StringEventLog* Events::_class_loading = nullptr;
StringEventLog* Events::_deopt_messages = nullptr;
StringEventLog* Events::_dll_messages = nullptr;

EventLog::EventLog() {
  // This is normally done during bootstrap when we're only single threaded,
  // but use lock free add because there are some events that are created later.
  EventLog* old_head;
  do {
    old_head = Atomic::load(&Events::_logs);
    _next = old_head;
  } while (Atomic::cmpxchg(&Events::_logs, old_head, this) != old_head);
}

// For each registered event logger, print out the current contents of
// the buffer.
void Events::print_all(outputStream* out, int max) {
  EventLog* log = Atomic::load(&Events::_logs);
  while (log != nullptr) {
    log->print_log_on(out, max);
    log = log->next();
  }
}

// Print a single event log specified by name.
void Events::print_one(outputStream* out, const char* log_name, int max) {
  EventLog* log = Atomic::load(&Events::_logs);
  int num_printed = 0;
  while (log != nullptr) {
    if (log->matches_name_or_handle(log_name)) {
      log->print_log_on(out, max);
      num_printed ++;
    }
    log = log->next();
  }
  // Write a short error note if no name matched.
  if (num_printed == 0) {
    out->print_cr("The name \"%s\" did not match any known event log. "
                  "Valid event log names are:", log_name);
    EventLog* log = Atomic::load(&Events::_logs);
    while (log != nullptr) {
      log->print_names(out);
      out->cr();
      log = log->next();
    }
  }
}


void Events::print() {
  print_all(tty);
}

void Events::init() {
  if (LogEvents) {
    _messages = new StringEventLog("Events", "events");
    _nmethod_flush_messages = new StringEventLog("Nmethod flushes", "nmethodflushes");
    _memprotect_messages = new StringEventLog("Memory protections", "memprotects");
    _vm_operations = new StringEventLog("VM Operations", "vmops");
    if (UseZGC) {
      _zgc_phase_switch = new StringEventLog("ZGC Phase Switch", "zgcps");
    }
    _exceptions = new ExceptionsEventLog("Internal exceptions", "exc");
    _redefinitions = new StringEventLog("Classes redefined", "redef");
    _class_unloading = new UnloadingEventLog("Classes unloaded", "unload");
    _class_loading = new StringEventLog("Classes loaded", "load");
    _deopt_messages = new StringEventLog("Deoptimization events", "deopt");
    _dll_messages = new StringEventLog("Dll operation events", "dll");
  }
}

void eventlog_init() {
  Events::init();
}

///////////////////////////////////////////////////////////////////////////
// EventMark

EventMarkBase::EventMarkBase(EventLogFunction log_function) :
    _log_function(log_function),
    _buffer() {}

void EventMarkBase::log_start(const char* format, va_list argp) {
  // Save a copy of begin message and log it.
  _buffer.printv(format, argp);
  _log_function(nullptr, "%s", _buffer.buffer());
}

void EventMarkBase::log_end() {
  // Append " done" to the begin message and log it
  _buffer.append(" done");
  _log_function(nullptr, "%s", _buffer.buffer());
}

void UnloadingEventLog::log(Thread* thread, InstanceKlass* ik) {
  if (!should_log()) return;

  double timestamp = fetch_timestamp();
  // Unloading events are single threaded.
  int index = compute_log_index();
  _records[index].thread = thread;
  _records[index].timestamp = timestamp;
  stringStream st(_records[index].data.buffer(),
                  _records[index].data.size());
  st.print("Unloading class " PTR_FORMAT " ", p2i(ik));
  ik->name()->print_value_on(&st);
}

void ExceptionsEventLog::log(Thread* thread, Handle h_exception,
                             const char* message, const char* file, int line,
                             int message_length_limit) {
  if (!should_log()) return;

  double timestamp = fetch_timestamp();
  MutexLocker ml(&_mutex, Mutex::_no_safepoint_check_flag);
  int index = compute_log_index();
  _records[index].thread = thread;
  _records[index].timestamp = timestamp;
  stringStream st(_records[index].data.buffer(),
                  _records[index].data.size());
  st.print("Exception <");
  h_exception->print_value_on(&st);
  if (message != nullptr) {
    int len = message_length_limit > 0 ? message_length_limit : (int)strlen(message);
    st.print(": %.*s", len, message);
  }
  st.print("> (" PTR_FORMAT ") \n"
           "thrown [%s, line %d]",
           p2i(h_exception()), file, line);
}