system_wrappers/source/trace_impl.cc - src/webrtc - Git at Google

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */

 #include "webrtc/system_wrappers/source/trace_impl.h"

 #include <assert.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>

 #ifdef _WIN32
 #include "webrtc/system_wrappers/source/trace_win.h"
 #else
 #include "webrtc/system_wrappers/source/trace_posix.h"
 #endif  // _WIN32

 #include "webrtc/system_wrappers/interface/sleep.h"

 #define KEY_LEN_CHARS 31

 #ifdef _WIN32
 #pragma warning(disable:4355)
 #endif  // _WIN32

 namespace webrtc {

 const int Trace::kBoilerplateLength = 71;
 const int Trace::kTimestampPosition = 13;
 const int Trace::kTimestampLength = 12;
 uint32_t Trace::level_filter_ = kTraceDefault;

 // Construct On First Use idiom. Avoids "static initialization order fiasco".
 TraceImpl* TraceImpl::StaticInstance(CountOperation count_operation,
                                      const TraceLevel level) {
   // Sanities to avoid taking lock unless absolutely necessary (for
   // performance reasons). count_operation == kAddRefNoCreate implies that a
   // message will be written to file.
   if ((level != kTraceAll) && (count_operation == kAddRefNoCreate)) {
     if (!(level & level_filter())) {
       return NULL;
     }
   }
   TraceImpl* impl =
     GetStaticInstance<TraceImpl>(count_operation);
   return impl;
 }

 TraceImpl* TraceImpl::GetTrace(const TraceLevel level) {
   return StaticInstance(kAddRefNoCreate, level);
 }

 TraceImpl* TraceImpl::CreateInstance() {
 #if defined(_WIN32)
   return new TraceWindows();
 #else
   return new TracePosix();
 #endif
 }

 TraceImpl::TraceImpl()
     : critsect_interface_(CriticalSectionWrapper::CreateCriticalSection()),
       callback_(NULL),
       row_count_text_(0),
       file_count_text_(0),
       trace_file_(*FileWrapper::Create()),
       thread_(*ThreadWrapper::CreateThread(TraceImpl::Run, this,
                                            kHighestPriority, "Trace")),
       event_(*EventWrapper::Create()),
       critsect_array_(CriticalSectionWrapper::CreateCriticalSection()),
       next_free_idx_(),
       level_(),
       length_(),
       message_queue_(),
       active_queue_(0) {
   next_free_idx_[0] = 0;
   next_free_idx_[1] = 0;

   unsigned int tid = 0;
   thread_.Start(tid);

   for (int m = 0; m < WEBRTC_TRACE_NUM_ARRAY; ++m) {
     for (int n = 0; n < WEBRTC_TRACE_MAX_QUEUE; ++n) {
       message_queue_[m][n] = new
       char[WEBRTC_TRACE_MAX_MESSAGE_SIZE];
     }
   }
 }

 bool TraceImpl::StopThread() {
   // Release the worker thread so that it can flush any lingering messages.
   event_.Set();

   // Allow 10 ms for pending messages to be flushed out.
   // TODO(hellner): why not use condition variables to do this? Or let the
   //                worker thread die and let this thread flush remaining
   //                messages?
   SleepMs(10);

   thread_.SetNotAlive();
   // Make sure the thread finishes as quickly as possible (instead of having
   // to wait for the timeout).
   event_.Set();
   bool stopped = thread_.Stop();

   CriticalSectionScoped lock(critsect_interface_);
   trace_file_.Flush();
   trace_file_.CloseFile();
   return stopped;
 }

 TraceImpl::~TraceImpl() {
   StopThread();
   delete &event_;
   delete &trace_file_;
   delete &thread_;
   delete critsect_interface_;
   delete critsect_array_;

   for (int m = 0; m < WEBRTC_TRACE_NUM_ARRAY; ++m) {
     for (int n = 0; n < WEBRTC_TRACE_MAX_QUEUE; ++n) {
       delete [] message_queue_[m][n];
     }
   }
 }

 int32_t TraceImpl::AddThreadId(char* trace_message) const {
   uint32_t thread_id = ThreadWrapper::GetThreadId();
   // Messages is 12 characters.
   return sprintf(trace_message, "%10u; ", thread_id);
 }

 int32_t TraceImpl::AddLevel(char* sz_message, const TraceLevel level) const {
   const int kMessageLength = 12;
   switch (level) {
     case kTraceTerseInfo:
       // Add the appropriate amount of whitespace.
       memset(sz_message, ' ', kMessageLength);
       sz_message[kMessageLength] = '\0';
       break;
     case kTraceStateInfo:
       sprintf(sz_message, "STATEINFO ; ");
       break;
     case kTraceWarning:
       sprintf(sz_message, "WARNING   ; ");
       break;
     case kTraceError:
       sprintf(sz_message, "ERROR     ; ");
       break;
     case kTraceCritical:
       sprintf(sz_message, "CRITICAL  ; ");
       break;
     case kTraceInfo:
       sprintf(sz_message, "DEBUGINFO ; ");
       break;
     case kTraceModuleCall:
       sprintf(sz_message, "MODULECALL; ");
       break;
     case kTraceMemory:
       sprintf(sz_message, "MEMORY    ; ");
       break;
     case kTraceTimer:
       sprintf(sz_message, "TIMER     ; ");
       break;
     case kTraceStream:
       sprintf(sz_message, "STREAM    ; ");
       break;
     case kTraceApiCall:
       sprintf(sz_message, "APICALL   ; ");
       break;
     case kTraceDebug:
       sprintf(sz_message, "DEBUG     ; ");
       break;
     default:
       assert(false);
       return 0;
   }
   // All messages are 12 characters.
   return kMessageLength;
 }

 int32_t TraceImpl::AddModuleAndId(char* trace_message,
                                   const TraceModule module,
                                   const int32_t id) const {
   // Use long int to prevent problems with different definitions of
   // int32_t.
   // TODO(hellner): is this actually a problem? If so, it should be better to
   //                clean up int32_t
   const long int idl = id;
   const int kMessageLength = 25;
   if (idl != -1) {
     const unsigned long int id_engine = id >> 16;
     const unsigned long int id_channel = id & 0xffff;

     switch (module) {
       case kTraceUndefined:
         // Add the appropriate amount of whitespace.
         memset(trace_message, ' ', kMessageLength);
         trace_message[kMessageLength] = '\0';
         break;
       case kTraceVoice:
         sprintf(trace_message, "       VOICE:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceVideo:
         sprintf(trace_message, "       VIDEO:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceUtility:
         sprintf(trace_message, "     UTILITY:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceRtpRtcp:
         sprintf(trace_message, "    RTP/RTCP:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceTransport:
         sprintf(trace_message, "   TRANSPORT:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceAudioCoding:
         sprintf(trace_message, "AUDIO CODING:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceSrtp:
         sprintf(trace_message, "        SRTP:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceAudioMixerServer:
         sprintf(trace_message, " AUDIO MIX/S:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceAudioMixerClient:
         sprintf(trace_message, " AUDIO MIX/C:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceVideoCoding:
         sprintf(trace_message, "VIDEO CODING:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceVideoMixer:
         // Print sleep time and API call
         sprintf(trace_message, "   VIDEO MIX:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceFile:
         sprintf(trace_message, "        FILE:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceAudioProcessing:
         sprintf(trace_message, "  AUDIO PROC:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceAudioDevice:
         sprintf(trace_message, "AUDIO DEVICE:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceVideoRenderer:
         sprintf(trace_message, "VIDEO RENDER:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceVideoCapture:
         sprintf(trace_message, "VIDEO CAPTUR:%5ld %5ld;", id_engine,
                 id_channel);
         break;
       case kTraceRemoteBitrateEstimator:
         sprintf(trace_message, "     BWE RBE:%5ld %5ld;", id_engine,
                 id_channel);
         break;
     }
   } else {
     switch (module) {
       case kTraceUndefined:
         // Add the appropriate amount of whitespace.
         memset(trace_message, ' ', kMessageLength);
         trace_message[kMessageLength] = '\0';
         break;
       case kTraceVoice:
         sprintf(trace_message, "       VOICE:%11ld;", idl);
         break;
       case kTraceVideo:
         sprintf(trace_message, "       VIDEO:%11ld;", idl);
         break;
       case kTraceUtility:
         sprintf(trace_message, "     UTILITY:%11ld;", idl);
         break;
       case kTraceRtpRtcp:
         sprintf(trace_message, "    RTP/RTCP:%11ld;", idl);
         break;
       case kTraceTransport:
         sprintf(trace_message, "   TRANSPORT:%11ld;", idl);
         break;
       case kTraceAudioCoding:
         sprintf(trace_message, "AUDIO CODING:%11ld;", idl);
         break;
       case kTraceSrtp:
         sprintf(trace_message, "        SRTP:%11ld;", idl);
         break;
       case kTraceAudioMixerServer:
         sprintf(trace_message, " AUDIO MIX/S:%11ld;", idl);
         break;
       case kTraceAudioMixerClient:
         sprintf(trace_message, " AUDIO MIX/C:%11ld;", idl);
         break;
       case kTraceVideoCoding:
         sprintf(trace_message, "VIDEO CODING:%11ld;", idl);
         break;
       case kTraceVideoMixer:
         sprintf(trace_message, "   VIDEO MIX:%11ld;", idl);
         break;
       case kTraceFile:
         sprintf(trace_message, "        FILE:%11ld;", idl);
         break;
       case kTraceAudioProcessing:
         sprintf(trace_message, "  AUDIO PROC:%11ld;", idl);
         break;
       case kTraceAudioDevice:
         sprintf(trace_message, "AUDIO DEVICE:%11ld;", idl);
         break;
       case kTraceVideoRenderer:
         sprintf(trace_message, "VIDEO RENDER:%11ld;", idl);
         break;
       case kTraceVideoCapture:
         sprintf(trace_message, "VIDEO CAPTUR:%11ld;", idl);
         break;
       case kTraceRemoteBitrateEstimator:
         sprintf(trace_message, "     BWE RBE:%11ld;", idl);
         break;
     }
   }
   return kMessageLength;
 }

 int32_t TraceImpl::SetTraceFileImpl(const char* file_name_utf8,
                                     const bool add_file_counter) {
   CriticalSectionScoped lock(critsect_interface_);

   trace_file_.Flush();
   trace_file_.CloseFile();

   if (file_name_utf8) {
     if (add_file_counter) {
       file_count_text_ = 1;

       char file_name_with_counter_utf8[FileWrapper::kMaxFileNameSize];
       CreateFileName(file_name_utf8, file_name_with_counter_utf8,
                      file_count_text_);
       if (trace_file_.OpenFile(file_name_with_counter_utf8, false, false,
                                true) == -1) {
         return -1;
       }
     } else {
       file_count_text_ = 0;
       if (trace_file_.OpenFile(file_name_utf8, false, false, true) == -1) {
         return -1;
       }
     }
   }
   row_count_text_ = 0;
   return 0;
 }

 int32_t TraceImpl::TraceFileImpl(
     char file_name_utf8[FileWrapper::kMaxFileNameSize]) {
   CriticalSectionScoped lock(critsect_interface_);
   return trace_file_.FileName(file_name_utf8, FileWrapper::kMaxFileNameSize);
 }

 int32_t TraceImpl::SetTraceCallbackImpl(TraceCallback* callback) {
   CriticalSectionScoped lock(critsect_interface_);
   callback_ = callback;
   return 0;
 }

 int32_t TraceImpl::AddMessage(
     char* trace_message,
     const char msg[WEBRTC_TRACE_MAX_MESSAGE_SIZE],
     const uint16_t written_so_far) const {
   int length = 0;
   if (written_so_far >= WEBRTC_TRACE_MAX_MESSAGE_SIZE) {
     return -1;
   }
   // - 2 to leave room for newline and NULL termination.
 #ifdef _WIN32
   length = _snprintf(trace_message,
                      WEBRTC_TRACE_MAX_MESSAGE_SIZE - written_so_far - 2,
                      "%s", msg);
   if (length < 0) {
     length = WEBRTC_TRACE_MAX_MESSAGE_SIZE - written_so_far - 2;
     trace_message[length] = 0;
   }
 #else
   length = snprintf(trace_message,
                     WEBRTC_TRACE_MAX_MESSAGE_SIZE - written_so_far - 2,
                     "%s", msg);
   if (length < 0 ||
       length > WEBRTC_TRACE_MAX_MESSAGE_SIZE - written_so_far - 2) {
     length = WEBRTC_TRACE_MAX_MESSAGE_SIZE - written_so_far - 2;
     trace_message[length] = 0;
   }
 #endif
   // Length with NULL termination.
   return length + 1;
 }

 void TraceImpl::AddMessageToList(
     const char trace_message[WEBRTC_TRACE_MAX_MESSAGE_SIZE],
     const uint16_t length,
     const TraceLevel level) {
 // NOTE(andresp): Enabled externally.
 #ifdef WEBRTC_DIRECT_TRACE
   if (callback_) {
     callback_->Print(level, trace_message, length);
   }
   return;
 #endif

   CriticalSectionScoped lock(critsect_array_);

   if (next_free_idx_[active_queue_] >= WEBRTC_TRACE_MAX_QUEUE) {
     if (!trace_file_.Open() && !callback_) {
       // Keep at least the last 1/4 of old messages when not logging.
       // TODO(hellner): isn't this redundant. The user will make it known
       //                when to start logging. Why keep messages before
       //                that?
       for (int n = 0; n < WEBRTC_TRACE_MAX_QUEUE / 4; ++n) {
         const int last_quarter_offset = (3 * WEBRTC_TRACE_MAX_QUEUE / 4);
         memcpy(message_queue_[active_queue_][n],
                message_queue_[active_queue_][n + last_quarter_offset],
                WEBRTC_TRACE_MAX_MESSAGE_SIZE);
       }
       next_free_idx_[active_queue_] = WEBRTC_TRACE_MAX_QUEUE / 4;
     } else {
       // More messages are being written than there is room for in the
       // buffer. Drop any new messages.
       // TODO(hellner): its probably better to drop old messages instead
       //                of new ones. One step further: if this happens
       //                it's due to writing faster than what can be
       //                processed. Maybe modify the filter at this point.
       //                E.g. turn of STREAM.
       return;
     }
   }

   uint16_t idx = next_free_idx_[active_queue_];
   next_free_idx_[active_queue_]++;

   level_[active_queue_][idx] = level;
   length_[active_queue_][idx] = length;
   memcpy(message_queue_[active_queue_][idx], trace_message, length);

   if (next_free_idx_[active_queue_] == WEBRTC_TRACE_MAX_QUEUE - 1) {
     // Logging more messages than can be worked off. Log a warning.
     const char warning_msg[] = "WARNING MISSING TRACE MESSAGES\n";
     level_[active_queue_][next_free_idx_[active_queue_]] = kTraceWarning;
     length_[active_queue_][next_free_idx_[active_queue_]] = strlen(warning_msg);
     memcpy(message_queue_[active_queue_][next_free_idx_[active_queue_]],
            warning_msg, strlen(warning_msg));
     next_free_idx_[active_queue_]++;
   }
 }

 bool TraceImpl::Run(void* obj) {
   return static_cast<TraceImpl*>(obj)->Process();
 }

 bool TraceImpl::Process() {
   if (event_.Wait(1000) == kEventSignaled) {
     // This slightly odd construction is to avoid locking |critsect_interface_|
     // while calling WriteToFile() since it's locked inside the function.
     critsect_interface_->Enter();
     bool write_to_file = trace_file_.Open() || callback_;
     critsect_interface_->Leave();
     if (write_to_file) {
       WriteToFile();
     }
   } else {
     CriticalSectionScoped lock(critsect_interface_);
     trace_file_.Flush();
   }
   return true;
 }

 void TraceImpl::WriteToFile() {
   uint8_t local_queue_active = 0;
   uint16_t local_next_free_idx = 0;

   // There are two buffers. One for reading (for writing to file) and one for
   // writing (for storing new messages). Let new messages be posted to the
   // unused buffer so that the current buffer can be flushed safely.
   {
     CriticalSectionScoped lock(critsect_array_);
     local_next_free_idx = next_free_idx_[active_queue_];
     next_free_idx_[active_queue_] = 0;
     local_queue_active = active_queue_;
     if (active_queue_ == 0) {
       active_queue_ = 1;
     } else {
       active_queue_ = 0;
     }
   }
   if (local_next_free_idx == 0) {
     return;
   }

   CriticalSectionScoped lock(critsect_interface_);

   for (uint16_t idx = 0; idx < local_next_free_idx; ++idx) {
     TraceLevel local_level = level_[local_queue_active][idx];
     if (callback_) {
       callback_->Print(local_level, message_queue_[local_queue_active][idx],
                        length_[local_queue_active][idx]);
     }
     if (trace_file_.Open()) {
       if (row_count_text_ > WEBRTC_TRACE_MAX_FILE_SIZE) {
         // wrap file
         row_count_text_ = 0;
         trace_file_.Flush();

         if (file_count_text_ == 0) {
           trace_file_.Rewind();
         } else {
           char old_file_name[FileWrapper::kMaxFileNameSize];
           char new_file_name[FileWrapper::kMaxFileNameSize];

           // get current name
           trace_file_.FileName(old_file_name,
                                FileWrapper::kMaxFileNameSize);
           trace_file_.CloseFile();

           file_count_text_++;

           UpdateFileName(old_file_name, new_file_name, file_count_text_);

           if (trace_file_.OpenFile(new_file_name, false, false,
                                    true) == -1) {
             return;
           }
         }
       }
       if (row_count_text_ ==  0) {
         char message[WEBRTC_TRACE_MAX_MESSAGE_SIZE + 1];
         int32_t length = AddDateTimeInfo(message);
         if (length != -1) {
           message[length] = 0;
           message[length - 1] = '\n';
           trace_file_.Write(message, length);
           row_count_text_++;
         }
         length = AddBuildInfo(message);
         if (length != -1) {
           message[length + 1] = 0;
           message[length] = '\n';
           message[length - 1] = '\n';
           trace_file_.Write(message, length + 1);
           row_count_text_++;
           row_count_text_++;
         }
       }
       uint16_t length = length_[local_queue_active][idx];
       message_queue_[local_queue_active][idx][length] = 0;
       message_queue_[local_queue_active][idx][length - 1] = '\n';
       trace_file_.Write(message_queue_[local_queue_active][idx], length);
       row_count_text_++;
     }
   }
 }

 void TraceImpl::AddImpl(const TraceLevel level, const TraceModule module,
                         const int32_t id,
                         const char msg[WEBRTC_TRACE_MAX_MESSAGE_SIZE]) {
   if (TraceCheck(level)) {
     char trace_message[WEBRTC_TRACE_MAX_MESSAGE_SIZE];
     char* message_ptr = trace_message;

     int32_t len = 0;
     int32_t ack_len = 0;

     len = AddLevel(message_ptr, level);
     if (len == -1) {
       return;
     }
     message_ptr += len;
     ack_len += len;

     len = AddTime(message_ptr, level);
     if (len == -1) {
       return;
     }
     message_ptr += len;
     ack_len += len;

     len = AddModuleAndId(message_ptr, module, id);
     if (len == -1) {
       return;
     }
     message_ptr += len;
     ack_len += len;

     len = AddThreadId(message_ptr);
     if (len < 0) {
       return;
     }
     message_ptr += len;
     ack_len += len;

     len = AddMessage(message_ptr, msg, (uint16_t)ack_len);
     if (len == -1) {
       return;
     }
     ack_len += len;
     AddMessageToList(trace_message, (uint16_t)ack_len, level);

     // Make sure that messages are written as soon as possible.
     event_.Set();
   }
 }

 bool TraceImpl::TraceCheck(const TraceLevel level) const {
   return (level & level_filter()) ? true : false;
 }

 bool TraceImpl::UpdateFileName(
     const char file_name_utf8[FileWrapper::kMaxFileNameSize],
     char file_name_with_counter_utf8[FileWrapper::kMaxFileNameSize],
     const uint32_t new_count) const {
   int32_t length = (int32_t)strlen(file_name_utf8);
   if (length < 0) {
     return false;
   }

   int32_t length_without_file_ending = length - 1;
   while (length_without_file_ending > 0) {
     if (file_name_utf8[length_without_file_ending] == '.') {
       break;
     } else {
       length_without_file_ending--;
     }
   }
   if (length_without_file_ending == 0) {
     length_without_file_ending = length;
   }
   int32_t length_to_ = length_without_file_ending - 1;
   while (length_to_ > 0) {
     if (file_name_utf8[length_to_] == '_') {
       break;
     } else {
       length_to_--;
     }
   }

   memcpy(file_name_with_counter_utf8, file_name_utf8, length_to_);
   sprintf(file_name_with_counter_utf8 + length_to_, "_%lu%s",
           static_cast<long unsigned int>(new_count),
           file_name_utf8 + length_without_file_ending);
   return true;
 }

 bool TraceImpl::CreateFileName(
     const char file_name_utf8[FileWrapper::kMaxFileNameSize],
     char file_name_with_counter_utf8[FileWrapper::kMaxFileNameSize],
     const uint32_t new_count) const {
   int32_t length = (int32_t)strlen(file_name_utf8);
   if (length < 0) {
     return false;
   }

   int32_t length_without_file_ending = length - 1;
   while (length_without_file_ending > 0) {
     if (file_name_utf8[length_without_file_ending] == '.') {
       break;
     } else {
       length_without_file_ending--;
     }
   }
   if (length_without_file_ending == 0) {
     length_without_file_ending = length;
   }
   memcpy(file_name_with_counter_utf8, file_name_utf8,
          length_without_file_ending);
   sprintf(file_name_with_counter_utf8 + length_without_file_ending, "_%lu%s",
           static_cast<long unsigned int>(new_count),
           file_name_utf8 + length_without_file_ending);
   return true;
 }

 void Trace::CreateTrace() {
   TraceImpl::StaticInstance(kAddRef);
 }

 void Trace::ReturnTrace() {
   TraceImpl::StaticInstance(kRelease);
 }

 int32_t Trace::TraceFile(char file_name[FileWrapper::kMaxFileNameSize]) {
   TraceImpl* trace = TraceImpl::GetTrace();
   if (trace) {
     int ret_val = trace->TraceFileImpl(file_name);
     ReturnTrace();
     return ret_val;
   }
   return -1;
 }

 int32_t Trace::SetTraceFile(const char* file_name,
                             const bool add_file_counter) {
   TraceImpl* trace = TraceImpl::GetTrace();
   if (trace) {
     int ret_val = trace->SetTraceFileImpl(file_name, add_file_counter);
     ReturnTrace();
     return ret_val;
   }
   return -1;
 }

 int32_t Trace::SetTraceCallback(TraceCallback* callback) {
   TraceImpl* trace = TraceImpl::GetTrace();
   if (trace) {
     int ret_val = trace->SetTraceCallbackImpl(callback);
     ReturnTrace();
     return ret_val;
   }
   return -1;
 }

 void Trace::Add(const TraceLevel level, const TraceModule module,
                 const int32_t id, const char* msg, ...) {
   TraceImpl* trace = TraceImpl::GetTrace(level);
   if (trace) {
     if (trace->TraceCheck(level)) {
       char temp_buff[WEBRTC_TRACE_MAX_MESSAGE_SIZE];
       char* buff = 0;
       if (msg) {
         va_list args;
         va_start(args, msg);
 #ifdef _WIN32
         _vsnprintf(temp_buff, WEBRTC_TRACE_MAX_MESSAGE_SIZE - 1, msg, args);
 #else
         vsnprintf(temp_buff, WEBRTC_TRACE_MAX_MESSAGE_SIZE - 1, msg, args);
 #endif
         va_end(args);
         buff = temp_buff;
       }
       trace->AddImpl(level, module, id, buff);
     }
     ReturnTrace();
   }
 }

 }  // namespace webrtc
	/*
	* Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
	*
	* Use of this source code is governed by a BSD-style license
	* that can be found in the LICENSE file in the root of the source
	* tree. An additional intellectual property rights grant can be found
	* in the file PATENTS. All contributing project authors may
	* be found in the AUTHORS file in the root of the source tree.
	*/

	#include "webrtc/system_wrappers/source/trace_impl.h"

	#include <assert.h>
	#include <stdarg.h>
	#include <stdio.h>
	#include <string.h>

	#ifdef _WIN32
	#include "webrtc/system_wrappers/source/trace_win.h"
	#else
	#include "webrtc/system_wrappers/source/trace_posix.h"
	#endif // _WIN32

	#include "webrtc/system_wrappers/interface/sleep.h"

	#define KEY_LEN_CHARS 31

	#ifdef _WIN32
	#pragma warning(disable:4355)
	#endif // _WIN32

	namespace webrtc {

	const int Trace::kBoilerplateLength = 71;
	const int Trace::kTimestampPosition = 13;
	const int Trace::kTimestampLength = 12;
	uint32_t Trace::level_filter_ = kTraceDefault;

	// Construct On First Use idiom. Avoids "static initialization order fiasco".
	TraceImpl* TraceImpl::StaticInstance(CountOperation count_operation,
	const TraceLevel level) {
	// Sanities to avoid taking lock unless absolutely necessary (for
	// performance reasons). count_operation == kAddRefNoCreate implies that a
	// message will be written to file.
	if ((level != kTraceAll) && (count_operation == kAddRefNoCreate)) {
	if (!(level & level_filter())) {
	return NULL;
	}
	}
	TraceImpl* impl =
	GetStaticInstance<TraceImpl>(count_operation);
	return impl;
	}

	TraceImpl* TraceImpl::GetTrace(const TraceLevel level) {
	return StaticInstance(kAddRefNoCreate, level);
	}

	TraceImpl* TraceImpl::CreateInstance() {
	#if defined(_WIN32)
	return new TraceWindows();
	#else
	return new TracePosix();
	#endif
	}

	TraceImpl::TraceImpl()
	: critsect_interface_(CriticalSectionWrapper::CreateCriticalSection()),
	callback_(NULL),
	row_count_text_(0),
	file_count_text_(0),
	trace_file_(*FileWrapper::Create()),
	thread_(*ThreadWrapper::CreateThread(TraceImpl::Run, this,
	kHighestPriority, "Trace")),
	event_(*EventWrapper::Create()),
	critsect_array_(CriticalSectionWrapper::CreateCriticalSection()),
	next_free_idx_(),
	level_(),
	length_(),
	message_queue_(),
	active_queue_(0) {
	next_free_idx_[0] = 0;
	next_free_idx_[1] = 0;

	unsigned int tid = 0;
	thread_.Start(tid);

	for (int m = 0; m < WEBRTC_TRACE_NUM_ARRAY; ++m) {
	for (int n = 0; n < WEBRTC_TRACE_MAX_QUEUE; ++n) {
	message_queue_[m][n] = new
	char[WEBRTC_TRACE_MAX_MESSAGE_SIZE];
	}
	}
	}

	bool TraceImpl::StopThread() {
	// Release the worker thread so that it can flush any lingering messages.
	event_.Set();

	// Allow 10 ms for pending messages to be flushed out.
	// TODO(hellner): why not use condition variables to do this? Or let the
	// worker thread die and let this thread flush remaining
	// messages?
	SleepMs(10);

	thread_.SetNotAlive();
	// Make sure the thread finishes as quickly as possible (instead of having
	// to wait for the timeout).
	event_.Set();
	bool stopped = thread_.Stop();

	CriticalSectionScoped lock(critsect_interface_);
	trace_file_.Flush();
	trace_file_.CloseFile();
	return stopped;
	}

	TraceImpl::~TraceImpl() {
	StopThread();
	delete &event_;
	delete &trace_file_;
	delete &thread_;
	delete critsect_interface_;
	delete critsect_array_;

	for (int m = 0; m < WEBRTC_TRACE_NUM_ARRAY; ++m) {
	for (int n = 0; n < WEBRTC_TRACE_MAX_QUEUE; ++n) {
	delete [] message_queue_[m][n];
	}
	}
	}

	int32_t TraceImpl::AddThreadId(char* trace_message) const {
	uint32_t thread_id = ThreadWrapper::GetThreadId();
	// Messages is 12 characters.
	return sprintf(trace_message, "%10u; ", thread_id);
	}

	int32_t TraceImpl::AddLevel(char* sz_message, const TraceLevel level) const {
	const int kMessageLength = 12;
	switch (level) {
	case kTraceTerseInfo:
	// Add the appropriate amount of whitespace.
	memset(sz_message, ' ', kMessageLength);
	sz_message[kMessageLength] = '\0';
	break;
	case kTraceStateInfo:
	sprintf(sz_message, "STATEINFO ; ");
	break;
	case kTraceWarning:
	sprintf(sz_message, "WARNING ; ");
	break;
	case kTraceError:
	sprintf(sz_message, "ERROR ; ");
	break;
	case kTraceCritical:
	sprintf(sz_message, "CRITICAL ; ");
	break;
	case kTraceInfo:
	sprintf(sz_message, "DEBUGINFO ; ");
	break;
	case kTraceModuleCall:
	sprintf(sz_message, "MODULECALL; ");
	break;
	case kTraceMemory:
	sprintf(sz_message, "MEMORY ; ");
	break;
	case kTraceTimer:
	sprintf(sz_message, "TIMER ; ");
	break;
	case kTraceStream:
	sprintf(sz_message, "STREAM ; ");
	break;
	case kTraceApiCall:
	sprintf(sz_message, "APICALL ; ");
	break;
	case kTraceDebug:
	sprintf(sz_message, "DEBUG ; ");
	break;
	default:
	assert(false);
	return 0;
	}
	// All messages are 12 characters.
	return kMessageLength;
	}

	int32_t TraceImpl::AddModuleAndId(char* trace_message,
	const TraceModule module,
	const int32_t id) const {
	// Use long int to prevent problems with different definitions of
	// int32_t.
	// TODO(hellner): is this actually a problem? If so, it should be better to
	// clean up int32_t
	const long int idl = id;
	const int kMessageLength = 25;
	if (idl != -1) {
	const unsigned long int id_engine = id >> 16;
	const unsigned long int id_channel = id & 0xffff;

	switch (module) {
	case kTraceUndefined:
	// Add the appropriate amount of whitespace.
	memset(trace_message, ' ', kMessageLength);
	trace_message[kMessageLength] = '\0';
	break;
	case kTraceVoice:
	sprintf(trace_message, " VOICE:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceVideo:
	sprintf(trace_message, " VIDEO:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceUtility:
	sprintf(trace_message, " UTILITY:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceRtpRtcp:
	sprintf(trace_message, " RTP/RTCP:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceTransport:
	sprintf(trace_message, " TRANSPORT:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceAudioCoding:
	sprintf(trace_message, "AUDIO CODING:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceSrtp:
	sprintf(trace_message, " SRTP:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceAudioMixerServer:
	sprintf(trace_message, " AUDIO MIX/S:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceAudioMixerClient:
	sprintf(trace_message, " AUDIO MIX/C:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceVideoCoding:
	sprintf(trace_message, "VIDEO CODING:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceVideoMixer:
	// Print sleep time and API call
	sprintf(trace_message, " VIDEO MIX:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceFile:
	sprintf(trace_message, " FILE:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceAudioProcessing:
	sprintf(trace_message, " AUDIO PROC:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceAudioDevice:
	sprintf(trace_message, "AUDIO DEVICE:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceVideoRenderer:
	sprintf(trace_message, "VIDEO RENDER:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceVideoCapture:
	sprintf(trace_message, "VIDEO CAPTUR:%5ld %5ld;", id_engine,
	id_channel);
	break;
	case kTraceRemoteBitrateEstimator:
	sprintf(trace_message, " BWE RBE:%5ld %5ld;", id_engine,
	id_channel);
	break;
	}
	} else {
	switch (module) {
	case kTraceUndefined:
	// Add the appropriate amount of whitespace.
	memset(trace_message, ' ', kMessageLength);
	trace_message[kMessageLength] = '\0';
	break;
	case kTraceVoice:
	sprintf(trace_message, " VOICE:%11ld;", idl);
	break;
	case kTraceVideo:
	sprintf(trace_message, " VIDEO:%11ld;", idl);
	break;
	case kTraceUtility:
	sprintf(trace_message, " UTILITY:%11ld;", idl);
	break;
	case kTraceRtpRtcp:
	sprintf(trace_message, " RTP/RTCP:%11ld;", idl);
	break;
	case kTraceTransport:
	sprintf(trace_message, " TRANSPORT:%11ld;", idl);
	break;
	case kTraceAudioCoding:
	sprintf(trace_message, "AUDIO CODING:%11ld;", idl);
	break;
	case kTraceSrtp:
	sprintf(trace_message, " SRTP:%11ld;", idl);
	break;
	case kTraceAudioMixerServer:
	sprintf(trace_message, " AUDIO MIX/S:%11ld;", idl);
	break;
	case kTraceAudioMixerClient:
	sprintf(trace_message, " AUDIO MIX/C:%11ld;", idl);
	break;
	case kTraceVideoCoding:
	sprintf(trace_message, "VIDEO CODING:%11ld;", idl);
	break;
	case kTraceVideoMixer:
	sprintf(trace_message, " VIDEO MIX:%11ld;", idl);
	break;
	case kTraceFile:
	sprintf(trace_message, " FILE:%11ld;", idl);
	break;
	case kTraceAudioProcessing:
	sprintf(trace_message, " AUDIO PROC:%11ld;", idl);
	break;
	case kTraceAudioDevice:
	sprintf(trace_message, "AUDIO DEVICE:%11ld;", idl);
	break;
	case kTraceVideoRenderer:
	sprintf(trace_message, "VIDEO RENDER:%11ld;", idl);
	break;
	case kTraceVideoCapture:
	sprintf(trace_message, "VIDEO CAPTUR:%11ld;", idl);
	break;
	case kTraceRemoteBitrateEstimator:
	sprintf(trace_message, " BWE RBE:%11ld;", idl);
	break;
	}
	}
	return kMessageLength;
	}

	int32_t TraceImpl::SetTraceFileImpl(const char* file_name_utf8,
	const bool add_file_counter) {
	CriticalSectionScoped lock(critsect_interface_);

	trace_file_.Flush();
	trace_file_.CloseFile();

	if (file_name_utf8) {
	if (add_file_counter) {
	file_count_text_ = 1;

	char file_name_with_counter_utf8[FileWrapper::kMaxFileNameSize];
	CreateFileName(file_name_utf8, file_name_with_counter_utf8,
	file_count_text_);
	if (trace_file_.OpenFile(file_name_with_counter_utf8, false, false,
	true) == -1) {
	return -1;
	}
	} else {
	file_count_text_ = 0;
	if (trace_file_.OpenFile(file_name_utf8, false, false, true) == -1) {
	return -1;
	}
	}
	}
	row_count_text_ = 0;
	return 0;
	}

	int32_t TraceImpl::TraceFileImpl(
	char file_name_utf8[FileWrapper::kMaxFileNameSize]) {
	CriticalSectionScoped lock(critsect_interface_);
	return trace_file_.FileName(file_name_utf8, FileWrapper::kMaxFileNameSize);
	}

	int32_t TraceImpl::SetTraceCallbackImpl(TraceCallback* callback) {
	CriticalSectionScoped lock(critsect_interface_);
	callback_ = callback;
	return 0;
	}

	int32_t TraceImpl::AddMessage(
	char* trace_message,
	const char msg[WEBRTC_TRACE_MAX_MESSAGE_SIZE],
	const uint16_t written_so_far) const {
	int length = 0;
	if (written_so_far >= WEBRTC_TRACE_MAX_MESSAGE_SIZE) {
	return -1;
	}
	// - 2 to leave room for newline and NULL termination.
	#ifdef _WIN32
	length = _snprintf(trace_message,
	WEBRTC_TRACE_MAX_MESSAGE_SIZE - written_so_far - 2,
	"%s", msg);
	if (length < 0) {
	length = WEBRTC_TRACE_MAX_MESSAGE_SIZE - written_so_far - 2;
	trace_message[length] = 0;
	}
	#else
	length = snprintf(trace_message,
	WEBRTC_TRACE_MAX_MESSAGE_SIZE - written_so_far - 2,
	"%s", msg);
	if (length < 0 \|\|
	length > WEBRTC_TRACE_MAX_MESSAGE_SIZE - written_so_far - 2) {
	length = WEBRTC_TRACE_MAX_MESSAGE_SIZE - written_so_far - 2;
	trace_message[length] = 0;
	}
	#endif
	// Length with NULL termination.
	return length + 1;
	}

	void TraceImpl::AddMessageToList(
	const char trace_message[WEBRTC_TRACE_MAX_MESSAGE_SIZE],
	const uint16_t length,
	const TraceLevel level) {
	// NOTE(andresp): Enabled externally.
	#ifdef WEBRTC_DIRECT_TRACE
	if (callback_) {
	callback_->Print(level, trace_message, length);
	}
	return;
	#endif

	CriticalSectionScoped lock(critsect_array_);

	if (next_free_idx_[active_queue_] >= WEBRTC_TRACE_MAX_QUEUE) {
	if (!trace_file_.Open() && !callback_) {
	// Keep at least the last 1/4 of old messages when not logging.
	// TODO(hellner): isn't this redundant. The user will make it known
	// when to start logging. Why keep messages before
	// that?
	for (int n = 0; n < WEBRTC_TRACE_MAX_QUEUE / 4; ++n) {
	const int last_quarter_offset = (3 * WEBRTC_TRACE_MAX_QUEUE / 4);
	memcpy(message_queue_[active_queue_][n],
	message_queue_[active_queue_][n + last_quarter_offset],
	WEBRTC_TRACE_MAX_MESSAGE_SIZE);
	}
	next_free_idx_[active_queue_] = WEBRTC_TRACE_MAX_QUEUE / 4;
	} else {
	// More messages are being written than there is room for in the
	// buffer. Drop any new messages.
	// TODO(hellner): its probably better to drop old messages instead
	// of new ones. One step further: if this happens
	// it's due to writing faster than what can be
	// processed. Maybe modify the filter at this point.
	// E.g. turn of STREAM.
	return;
	}
	}

	uint16_t idx = next_free_idx_[active_queue_];
	next_free_idx_[active_queue_]++;

	level_[active_queue_][idx] = level;
	length_[active_queue_][idx] = length;
	memcpy(message_queue_[active_queue_][idx], trace_message, length);

	if (next_free_idx_[active_queue_] == WEBRTC_TRACE_MAX_QUEUE - 1) {
	// Logging more messages than can be worked off. Log a warning.
	const char warning_msg[] = "WARNING MISSING TRACE MESSAGES\n";
	level_[active_queue_][next_free_idx_[active_queue_]] = kTraceWarning;
	length_[active_queue_][next_free_idx_[active_queue_]] = strlen(warning_msg);
	memcpy(message_queue_[active_queue_][next_free_idx_[active_queue_]],
	warning_msg, strlen(warning_msg));
	next_free_idx_[active_queue_]++;
	}
	}

	bool TraceImpl::Run(void* obj) {
	return static_cast<TraceImpl*>(obj)->Process();
	}

	bool TraceImpl::Process() {
	if (event_.Wait(1000) == kEventSignaled) {
	// This slightly odd construction is to avoid locking \|critsect_interface_\|
	// while calling WriteToFile() since it's locked inside the function.
	critsect_interface_->Enter();
	bool write_to_file = trace_file_.Open() \|\| callback_;
	critsect_interface_->Leave();
	if (write_to_file) {
	WriteToFile();
	}
	} else {
	CriticalSectionScoped lock(critsect_interface_);
	trace_file_.Flush();
	}
	return true;
	}

	void TraceImpl::WriteToFile() {
	uint8_t local_queue_active = 0;
	uint16_t local_next_free_idx = 0;

	// There are two buffers. One for reading (for writing to file) and one for
	// writing (for storing new messages). Let new messages be posted to the
	// unused buffer so that the current buffer can be flushed safely.
	{
	CriticalSectionScoped lock(critsect_array_);
	local_next_free_idx = next_free_idx_[active_queue_];
	next_free_idx_[active_queue_] = 0;
	local_queue_active = active_queue_;
	if (active_queue_ == 0) {
	active_queue_ = 1;
	} else {
	active_queue_ = 0;
	}
	}
	if (local_next_free_idx == 0) {
	return;
	}

	CriticalSectionScoped lock(critsect_interface_);

	for (uint16_t idx = 0; idx < local_next_free_idx; ++idx) {
	TraceLevel local_level = level_[local_queue_active][idx];
	if (callback_) {
	callback_->Print(local_level, message_queue_[local_queue_active][idx],
	length_[local_queue_active][idx]);
	}
	if (trace_file_.Open()) {
	if (row_count_text_ > WEBRTC_TRACE_MAX_FILE_SIZE) {
	// wrap file
	row_count_text_ = 0;
	trace_file_.Flush();

	if (file_count_text_ == 0) {
	trace_file_.Rewind();
	} else {
	char old_file_name[FileWrapper::kMaxFileNameSize];
	char new_file_name[FileWrapper::kMaxFileNameSize];

	// get current name
	trace_file_.FileName(old_file_name,
	FileWrapper::kMaxFileNameSize);
	trace_file_.CloseFile();

	file_count_text_++;

	UpdateFileName(old_file_name, new_file_name, file_count_text_);

	if (trace_file_.OpenFile(new_file_name, false, false,
	true) == -1) {
	return;
	}
	}
	}
	if (row_count_text_ == 0) {
	char message[WEBRTC_TRACE_MAX_MESSAGE_SIZE + 1];
	int32_t length = AddDateTimeInfo(message);
	if (length != -1) {
	message[length] = 0;
	message[length - 1] = '\n';
	trace_file_.Write(message, length);
	row_count_text_++;
	}
	length = AddBuildInfo(message);
	if (length != -1) {
	message[length + 1] = 0;
	message[length] = '\n';
	message[length - 1] = '\n';
	trace_file_.Write(message, length + 1);
	row_count_text_++;
	row_count_text_++;
	}
	}
	uint16_t length = length_[local_queue_active][idx];
	message_queue_[local_queue_active][idx][length] = 0;
	message_queue_[local_queue_active][idx][length - 1] = '\n';
	trace_file_.Write(message_queue_[local_queue_active][idx], length);
	row_count_text_++;
	}
	}
	}

	void TraceImpl::AddImpl(const TraceLevel level, const TraceModule module,
	const int32_t id,
	const char msg[WEBRTC_TRACE_MAX_MESSAGE_SIZE]) {
	if (TraceCheck(level)) {
	char trace_message[WEBRTC_TRACE_MAX_MESSAGE_SIZE];
	char* message_ptr = trace_message;

	int32_t len = 0;
	int32_t ack_len = 0;

	len = AddLevel(message_ptr, level);
	if (len == -1) {
	return;
	}
	message_ptr += len;
	ack_len += len;

	len = AddTime(message_ptr, level);
	if (len == -1) {
	return;
	}
	message_ptr += len;
	ack_len += len;

	len = AddModuleAndId(message_ptr, module, id);
	if (len == -1) {
	return;
	}
	message_ptr += len;
	ack_len += len;

	len = AddThreadId(message_ptr);
	if (len < 0) {
	return;
	}
	message_ptr += len;
	ack_len += len;

	len = AddMessage(message_ptr, msg, (uint16_t)ack_len);
	if (len == -1) {
	return;
	}
	ack_len += len;
	AddMessageToList(trace_message, (uint16_t)ack_len, level);

	// Make sure that messages are written as soon as possible.
	event_.Set();
	}
	}

	bool TraceImpl::TraceCheck(const TraceLevel level) const {
	return (level & level_filter()) ? true : false;
	}

	bool TraceImpl::UpdateFileName(
	const char file_name_utf8[FileWrapper::kMaxFileNameSize],
	char file_name_with_counter_utf8[FileWrapper::kMaxFileNameSize],
	const uint32_t new_count) const {
	int32_t length = (int32_t)strlen(file_name_utf8);
	if (length < 0) {
	return false;
	}

	int32_t length_without_file_ending = length - 1;
	while (length_without_file_ending > 0) {
	if (file_name_utf8[length_without_file_ending] == '.') {
	break;
	} else {
	length_without_file_ending--;
	}
	}
	if (length_without_file_ending == 0) {
	length_without_file_ending = length;
	}
	int32_t length_to_ = length_without_file_ending - 1;
	while (length_to_ > 0) {
	if (file_name_utf8[length_to_] == '_') {
	break;
	} else {
	length_to_--;
	}
	}

	memcpy(file_name_with_counter_utf8, file_name_utf8, length_to_);
	sprintf(file_name_with_counter_utf8 + length_to_, "_%lu%s",
	static_cast<long unsigned int>(new_count),
	file_name_utf8 + length_without_file_ending);
	return true;
	}

	bool TraceImpl::CreateFileName(
	const char file_name_utf8[FileWrapper::kMaxFileNameSize],
	char file_name_with_counter_utf8[FileWrapper::kMaxFileNameSize],
	const uint32_t new_count) const {
	int32_t length = (int32_t)strlen(file_name_utf8);
	if (length < 0) {
	return false;
	}

	int32_t length_without_file_ending = length - 1;
	while (length_without_file_ending > 0) {
	if (file_name_utf8[length_without_file_ending] == '.') {
	break;
	} else {
	length_without_file_ending--;
	}
	}
	if (length_without_file_ending == 0) {
	length_without_file_ending = length;
	}
	memcpy(file_name_with_counter_utf8, file_name_utf8,
	length_without_file_ending);
	sprintf(file_name_with_counter_utf8 + length_without_file_ending, "_%lu%s",
	static_cast<long unsigned int>(new_count),
	file_name_utf8 + length_without_file_ending);
	return true;
	}

	void Trace::CreateTrace() {
	TraceImpl::StaticInstance(kAddRef);
	}

	void Trace::ReturnTrace() {
	TraceImpl::StaticInstance(kRelease);
	}

	int32_t Trace::TraceFile(char file_name[FileWrapper::kMaxFileNameSize]) {
	TraceImpl* trace = TraceImpl::GetTrace();
	if (trace) {
	int ret_val = trace->TraceFileImpl(file_name);
	ReturnTrace();
	return ret_val;
	}
	return -1;
	}

	int32_t Trace::SetTraceFile(const char* file_name,
	const bool add_file_counter) {
	TraceImpl* trace = TraceImpl::GetTrace();
	if (trace) {
	int ret_val = trace->SetTraceFileImpl(file_name, add_file_counter);
	ReturnTrace();
	return ret_val;
	}
	return -1;
	}

	int32_t Trace::SetTraceCallback(TraceCallback* callback) {
	TraceImpl* trace = TraceImpl::GetTrace();
	if (trace) {
	int ret_val = trace->SetTraceCallbackImpl(callback);
	ReturnTrace();
	return ret_val;
	}
	return -1;
	}

	void Trace::Add(const TraceLevel level, const TraceModule module,
	const int32_t id, const char* msg, ...) {
	TraceImpl* trace = TraceImpl::GetTrace(level);
	if (trace) {
	if (trace->TraceCheck(level)) {
	char temp_buff[WEBRTC_TRACE_MAX_MESSAGE_SIZE];
	char* buff = 0;
	if (msg) {
	va_list args;
	va_start(args, msg);
	#ifdef _WIN32
	_vsnprintf(temp_buff, WEBRTC_TRACE_MAX_MESSAGE_SIZE - 1, msg, args);
	#else
	vsnprintf(temp_buff, WEBRTC_TRACE_MAX_MESSAGE_SIZE - 1, msg, args);
	#endif
	va_end(args);
	buff = temp_buff;
	}
	trace->AddImpl(level, module, id, buff);
	}
	ReturnTrace();
	}
	}

	} // namespace webrtc