addons/LoggingConsumer/LoggingConsumer.cpp

/*
 * Copyright 1991-1999, Be Incorporated.
 * Copyright (c) 1999-2000, Eric Moon.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions, and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


// LoggingConsumer.cpp

#include "LoggingConsumer.h"
#include "LogWriter.h"
#include <media/MediaRoster.h>
#include <media/TimeSource.h>
#include <media/ParameterWeb.h>
#include <media/Buffer.h>
#include <kernel/OS.h>
#include <stdio.h>
#include <string.h>

// e.moon [11jun99]
#include <Catalog.h>
#include <Debug.h>

#undef B_TRANSLATION_CONTEXT
#define B_TRANSLATION_CONTEXT "CortexAddOnsLoggingConsumer"

// id's of the node's BParameters
const int32 INPUT_NULL_PARAM = 1;
const int32 LATENCY_PARAM = 2;
const int32 OUTPUT_NULL_PARAM = 3;
const int32 CPU_NULL_PARAM = 11;
const int32 CPU_SPIN_PARAM = 12;
const int32 PRIO_NULL_PARAM = 21;
const int32 PRIORITY_PARAM = 22;

// build the LoggingConsumer's BParameterWeb
static BParameterWeb* build_parameter_web()
{
	BParameterWeb* web = new BParameterWeb;

	BParameterGroup* mainGroup = web->MakeGroup(
		B_TRANSLATE("LoggingConsumer parameters"));
	BParameterGroup* group = mainGroup->MakeGroup(
		B_TRANSLATE("Latency control"));
	BParameter* nullParam = group->MakeNullParameter(INPUT_NULL_PARAM,
		B_MEDIA_NO_TYPE, B_TRANSLATE("Latency"), B_GENERIC);
	BParameter* latencyParam = group->MakeContinuousParameter(LATENCY_PARAM,
		B_MEDIA_NO_TYPE, "", B_GAIN, "ms", 5, 100, 5);
	nullParam->AddOutput(latencyParam);
	latencyParam->AddInput(nullParam);

	group = mainGroup->MakeGroup(B_TRANSLATE("CPU percentage"));
	nullParam = group->MakeNullParameter(CPU_NULL_PARAM, B_MEDIA_NO_TYPE,
		B_TRANSLATE("CPU spin percentage"), B_GENERIC);
	BContinuousParameter* cpuParam = group->MakeContinuousParameter(
		CPU_SPIN_PARAM, B_MEDIA_NO_TYPE, "",
		B_GAIN, B_TRANSLATE("percent"), 5, 80, 5);
	nullParam->AddOutput(cpuParam);
	cpuParam->AddInput(nullParam);

	group = mainGroup->MakeGroup(B_TRANSLATE("Priority"));
	nullParam = group->MakeNullParameter(PRIO_NULL_PARAM, B_MEDIA_NO_TYPE,
		B_TRANSLATE("Thread priority"), B_GENERIC);
	BDiscreteParameter* prioParam = group->MakeDiscreteParameter(PRIORITY_PARAM,
		B_MEDIA_NO_TYPE, "", B_GENERIC);
	prioParam->AddItem(5, "B_LOW_PRIORITY");
	prioParam->AddItem(10, "B_NORMAL_PRIORITY");
	prioParam->AddItem(15, "B_DISPLAY_PRIORITY");
	prioParam->AddItem(20, "B_URGENT_DISPLAY_PRIORITY");
	prioParam->AddItem(100, "B_REAL_TIME_DISPLAY_PRIORITY");
	prioParam->AddItem(110, "B_URGENT_PRIORITY");
	prioParam->AddItem(120, "B_REAL_TIME_PRIORITY");

	return web;
}

// --------------------
// LoggingConsumer class implementation
LoggingConsumer::LoggingConsumer(
	const entry_ref& logFile,
	BMediaAddOn* pAddOn)

	:	BMediaNode("LoggingConsumer"),
		BBufferConsumer(B_MEDIA_UNKNOWN_TYPE),
		BControllable(),
		BMediaEventLooper(),
		mLogRef(logFile),
		mWeb(NULL),
		mLateBuffers(0),
		mLatency(50 * 1000),		// default to 50 milliseconds
		mSpinPercentage(0.10),		// default to spinning 10% of total latency
		mPriority(B_URGENT_DISPLAY_PRIORITY),		// !!! testing; will be B_REAL_TIME_PRIORITY for release
		mLastLatencyChange(0),
		mLastSpinChange(0),
		mLastPrioChange(0),
		m_pAddOn(pAddOn)
{
	// spin off the logging thread
	mLogger = new LogWriter(logFile);

	// parameter-web init moved to NodeRegistered()
	// e.moon [11jun99]
}

LoggingConsumer::~LoggingConsumer()
{
	PRINT(("~LoggingConsumer()\n"));
	BMediaEventLooper::Quit();
// ahem:
// "Once you've called BControllable::SetParameterWeb(), the node takes
//  responsibility for the parameter web object and you shouldn't delete it. "
//	SetParameterWeb(NULL);
//	delete mWeb;

	// delete the logging thread only after the looper thread has quit, otherwise there's
	// a potential race condition with the looper thread trying to write to the now-
	// deleted log
	delete mLogger;
}

//
// Log message filtering control
//

void
LoggingConsumer::SetEnabled(log_what what, bool enable)
{
	mLogger->SetEnabled(what, enable);
}

void
LoggingConsumer::EnableAllMessages()
{
	mLogger->EnableAllMessages();
}

void
LoggingConsumer::DisableAllMessages()
{
	mLogger->DisableAllMessages();
}

//
// BMediaNode methods
//


BMediaAddOn*
LoggingConsumer::AddOn(int32 *internal_id) const
{
	PRINT(("~LoggingConsumer::AddOn()\n"));
	// e.moon [11jun99]
	if(m_pAddOn) {
		*internal_id = 0;
		return m_pAddOn;
	} else
		return NULL;
}

void
LoggingConsumer::SetRunMode(run_mode mode)
{
	// !!! Need to handle offline mode etc. properly!
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_SET_RUN_MODE, logMsg);

	BMediaEventLooper::SetRunMode(mode);
}

void
LoggingConsumer::Preroll()
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_PREROLL, logMsg);

	BMediaEventLooper::Preroll();
}

void
LoggingConsumer::SetTimeSource(BTimeSource* time_source)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_SET_TIME_SOURCE, logMsg);

	BMediaNode::SetTimeSource(time_source);
}

status_t
LoggingConsumer::RequestCompleted(const media_request_info &info)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_REQUEST_COMPLETED, logMsg);

	return BMediaNode::RequestCompleted(info);
}

// e.moon [11jun99; testing add-on]
status_t
LoggingConsumer::DeleteHook(BMediaNode* pNode) {
	PRINT(("LoggingConsumer::DeleteHook(%p)\n", pNode));
	return BBufferConsumer::DeleteHook(pNode);
//	ASSERT(pNode == this);
//	delete this;
//	return B_OK;
}

//
// BControllable methods
//

status_t
LoggingConsumer::GetParameterValue(int32 id, bigtime_t* last_change, void* value, size_t* ioSize)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	logMsg.param.id = id;
	mLogger->Log(LOG_GET_PARAM_VALUE, logMsg);

	// return an error if the caller hasn't reserved enough space for the parameter data.
	// we know that all of our parameters fit in a float or int32 (4 bytes), so we can just
	// check for it once here, instead of on a per-parameter basis
	if (*ioSize < sizeof(float)) return B_ERROR;

	// write out the designated parameter data
	switch (id)
	{
	case LATENCY_PARAM:
		*last_change = mLastLatencyChange;
		*((float*) value) = mLatency / 1000;		// the BParameter reads milliseconds, not microseconds
		*ioSize = sizeof(float);
		break;

	case CPU_SPIN_PARAM:
		*last_change = mLastSpinChange;
		*((float*) value) = mSpinPercentage;
		*ioSize = sizeof(float);
		break;

	case PRIORITY_PARAM:
		*last_change = mLastPrioChange;
		*((int32*) value) = mPriority;
		*ioSize = sizeof(int32);
		break;

	default:
		return B_ERROR;
	}

	return B_OK;
}

void
LoggingConsumer::SetParameterValue(int32 id, bigtime_t performance_time, const void* value, size_t size)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	logMsg.param.id = id;
	mLogger->Log(LOG_SET_PARAM_VALUE, logMsg);

	// if it's one of our parameters, enqueue a "set parameter" event for handling at the appropriate time
	switch (id)
	{
	case LATENCY_PARAM:
	case CPU_SPIN_PARAM:
	case PRIORITY_PARAM:
		{
			// !!! Change from B_USER_EVENT to B_SET_PARAMETER once it's defined
			media_timed_event event(performance_time, BTimedEventQueue::B_USER_EVENT,
				(void*) value, BTimedEventQueue::B_NO_CLEANUP, size, id, NULL);
			EventQueue()->AddEvent(event);
		}
		break;

	default:		// do nothing for other parameter IDs
		break;
	}
	return;
}

//
// BBufferConsumer methods
//

status_t
LoggingConsumer::HandleMessage(int32 message, const void *data, size_t size)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_HANDLE_MESSAGE, logMsg);

	// try each of our superclasses to handle the message
	status_t err;
	err = BControllable::HandleMessage(message, data, size);
	if (err) err = BBufferConsumer::HandleMessage(message, data, size);
	if (err) err = BMediaNode::HandleMessage(message, data, size);
	return err;
}

// all of these next methods are pure virtual in BBufferConsumer

status_t
LoggingConsumer::AcceptFormat(const media_destination& dest, media_format* format)
{
	char formatStr[256];
	string_for_format(*format, formatStr, 255);
	PRINT(("LoggingConsumer::AcceptFormat:\n\tformat %s\n", formatStr));

	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_ACCEPT_FORMAT, logMsg);

	// return an error if this isn't really our one input's destination
	if (dest != mInput.destination) return B_MEDIA_BAD_DESTINATION;

	// the destination given really is our input, and we accept any kind of media data,
	// so now we just confirm that we can handle whatever the producer asked for.
	return B_OK;
}

status_t
LoggingConsumer::GetNextInput(int32* cookie, media_input* out_input)
{
	// we have a single hardcoded input that can accept any kind of media data
	if (0 == *cookie)
	{
		mInput.format.type = B_MEDIA_UNKNOWN_TYPE;		// accept any format

		*out_input = mInput;
		*cookie = 1;
		return B_OK;
	}
	else return B_BAD_INDEX;
}

void
LoggingConsumer::DisposeInputCookie(int32 /*cookie*/ )
{
	// we don't use any kind of state or extra storage for iterating over our
	// inputs, so we don't have to do any special disposal of input cookies.
}

void
LoggingConsumer::BufferReceived(BBuffer* buffer)
{
	bigtime_t bufferStart = buffer->Header()->start_time;
	bigtime_t now = TimeSource()->Now();
	bigtime_t how_early = bufferStart - EventLatency() - SchedulingLatency() - now;

	log_message logMsg;
	logMsg.now = now;
	logMsg.buffer_data.start_time = bufferStart;
	logMsg.buffer_data.offset = how_early;
	mLogger->Log(LOG_BUFFER_RECEIVED, logMsg);

	// There's a special case here with handling B_MEDIA_PARAMETERS buffers.
	// These contain sets of parameter value changes, with their own performance
	// times embedded in the buffers.  So, we want to dispatch those parameter
	// changes as their own events rather than pushing this buffer on the queue to
	// be handled later.
	if (B_MEDIA_PARAMETERS == buffer->Header()->type)
	{
		ApplyParameterData(buffer->Data(), buffer->SizeUsed());
		buffer->Recycle();
	}
	else		// ahh, it's a regular media buffer, so push it on the event queue
	{
		status_t err;
		media_timed_event event(buffer->Header()->start_time, BTimedEventQueue::B_HANDLE_BUFFER,
			buffer, BTimedEventQueue::B_RECYCLE_BUFFER);
		err = EventQueue()->AddEvent(event);

		// HandleEvent() will recycle the buffer.  However, if we incurred an error trying to
		// put the event into the queue, we have to recycle it ourselves, since HandleEvent()
		// will never see the buffer in that case.
		if (err) buffer->Recycle();
	}
}

void
LoggingConsumer::ProducerDataStatus(const media_destination& for_whom, int32 status, bigtime_t at_performance_time)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	logMsg.data_status.status = status;
	mLogger->Log(LOG_PRODUCER_DATA_STATUS, logMsg);

	if (for_whom == mInput.destination)
	{
		media_timed_event event(at_performance_time, BTimedEventQueue::B_DATA_STATUS,
			&mInput, BTimedEventQueue::B_NO_CLEANUP, status, 0, NULL);
		EventQueue()->AddEvent(event);
	}
}

status_t
LoggingConsumer::GetLatencyFor(const media_destination& for_whom, bigtime_t* out_latency, media_node_id* out_timesource)
{
	// make sure this is one of my valid inputs
	if (for_whom != mInput.destination) return B_MEDIA_BAD_DESTINATION;

	// report internal latency + downstream latency here, NOT including scheduling latency.
	// we're a final consumer (no outputs), so we have no downstream latency.
	*out_latency = mLatency;
	*out_timesource = TimeSource()->ID();
	return B_OK;
}

status_t
LoggingConsumer::Connected(
	const media_source& producer,
	const media_destination& where,
	const media_format& with_format,
	media_input* out_input)
{

	char formatStr[256];
	string_for_format(with_format, formatStr, 255);
	PRINT(("LoggingConsumer::Connected:\n\tformat %s\n", formatStr));
	string_for_format(mInput.format, formatStr, 255);
	PRINT(("\tinput format %s\n", formatStr));

	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_CONNECTED, logMsg);

	if (where != mInput.destination) return B_MEDIA_BAD_DESTINATION;

	// calculate my latency here, because it may depend on buffer sizes/durations, then
	// tell the BMediaEventLooper how early we need to get the buffers
	SetEventLatency(mLatency);

	// record useful information about the connection, and return success
	// * e.moon [14jun99]: stores format
	mInput.format = with_format;
	mInput.source = producer;
	*out_input = mInput;
	return B_OK;
}

void
LoggingConsumer::Disconnected(
	const media_source& producer,
	const media_destination& where)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_DISCONNECTED, logMsg);

	// wipe out our input record
	mInput = media_input();
}

status_t
LoggingConsumer::FormatChanged(
	const media_source& producer,
	const media_destination& consumer,
	int32 change_tag,
	const media_format& format)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_FORMAT_CHANGED, logMsg);

	return B_OK;
}

status_t
LoggingConsumer::SeekTagRequested(
	const media_destination& destination,
	bigtime_t in_target_time,
	uint32 in_flags,
	media_seek_tag* out_seek_tag,
	bigtime_t* out_tagged_time,
	uint32* out_flags)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_SEEK_TAG, logMsg);

	return B_OK;
}

//
// BMediaEventLooper virtual methods
//

void
LoggingConsumer::NodeRegistered()
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_REGISTERED, logMsg);

	// publish our parameter web
	mWeb = build_parameter_web();
	SetParameterWeb(mWeb);

	// Set our priority and start the BMediaEventLooper's thread
	SetPriority(mPriority);
	Run();

	// Initialize as much of our input as we can, now that the Media Kit really "knows" about us
	mInput.destination.port = ControlPort();
	mInput.destination.id = 0;
	mInput.node = Node();
	strcpy(mInput.name, B_TRANSLATE("Logged input"));
}

void
LoggingConsumer::Start(bigtime_t performance_time)
{
	PRINT(("LoggingConsumer::Start(%" B_PRIdBIGTIME "): now %" B_PRIdBIGTIME "\n",
		performance_time, TimeSource()->Now()));

	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_START, logMsg);

	BMediaEventLooper::Start(performance_time);
}

void
LoggingConsumer::Stop(bigtime_t performance_time, bool immediate)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_STOP, logMsg);

	BMediaEventLooper::Stop(performance_time, immediate);
}

void
LoggingConsumer::Seek(bigtime_t media_time, bigtime_t performance_time)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_SEEK, logMsg);

	BMediaEventLooper::Seek(media_time, performance_time);
}

void
LoggingConsumer::TimeWarp(bigtime_t at_real_time, bigtime_t to_performance_time)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_TIMEWARP, logMsg);

	BMediaEventLooper::TimeWarp(at_real_time, to_performance_time);
}

void
LoggingConsumer::HandleEvent(const media_timed_event *event, bigtime_t /* lateness */, bool /* realTimeEvent */)
{
	log_message logMsg;
	logMsg.now = TimeSource()->Now();
	mLogger->Log(LOG_HANDLE_EVENT, logMsg);

	switch (event->type)
	{
	case BTimedEventQueue::B_HANDLE_BUFFER:
		{
			BBuffer* buffer = const_cast<BBuffer*>((BBuffer*) event->pointer);
			if (buffer)
			{
				media_header* hdr = buffer->Header();
				if (hdr->destination == mInput.destination.id)
				{
					bigtime_t now = TimeSource()->Now();
					bigtime_t perf_time = hdr->start_time;

					// the how_early calculated here doesn't include scheduling latency because
					// we've already been scheduled to handle the buffer
					bigtime_t how_early = perf_time - mLatency - now;

					// logMsg.now is already set
					logMsg.buffer_data.start_time = perf_time;
					logMsg.buffer_data.offset = how_early;
					mLogger->Log(LOG_BUFFER_HANDLED, logMsg);

					// if the buffer is late, we ignore it and report the fact to the producer
					// who sent it to us
					if (how_early < 0)
					{
						mLateBuffers++;
						NotifyLateProducer(mInput.source, -how_early, perf_time);
					}
					else
					{
						// burn some percentage of our stated latency in CPU time (controlled by
						// a BParameter).  this simulates a user-configurable amount of CPU cost
						// associated with the consumer.
						bigtime_t spin_start = ::system_time();
						bigtime_t spin_now = spin_start;
						bigtime_t usecToSpin = bigtime_t(mSpinPercentage / 100.0 * mLatency);
						while (spin_now - spin_start < usecToSpin)
						{
							for (long k = 0; k < 1000000; k++) { /* intentionally blank */ }
							spin_now = ::system_time();
						}
					}

					// we're done "processing the buffer;" now we recycle it and return to the loop
					buffer->Recycle();
				}
				else
				{
					//fprintf(stderr, "* Woah!  Got a buffer for a different destination!\n");
				}
			}
		}
		break;

	// !!! change to B_PARAMETER as soon as it's available

	// +++++ e.moon [16jun99]
	// !!! this can't be right: the parameter value is accessed by the pointer
	//     originally passed to SetParameterValue().  there's no guarantee that
	//     value's still valid, is there?

	case BTimedEventQueue::B_USER_EVENT:
		{
			size_t dataSize = size_t(event->data);
			int32 param = int32(event->bigdata);
			logMsg.param.id = param;

			// handle the message if there's sufficient data provided.  we only check against
			// sizeof(float) because all of our parameters happen to be 4 bytes.  if various
			// parameters took different amounts of data, we'd check the size on a per-parameter
			// basis.
			if (dataSize >= sizeof(float)) switch (param)
			{
			case LATENCY_PARAM:
				{
					float value = *((float*) event->pointer);
					mLatency = bigtime_t(value* 1000);
					mLastLatencyChange = logMsg.now;

					// my latency just changed, so reconfigure the BMediaEventLooper
					// to give me my events at the proper time
					SetEventLatency(mLatency);

					// tell the producer that my latency changed, and broadcast a message
					// about the parameter change to any applications that may be looking
					// for it through the BMediaRoster::StartWatching() mechanism.
					//
					// if we had more than one input, we'd need to tell *all* producers about
					// the change in our latency.
					SendLatencyChange(mInput.source, mInput.destination, EventLatency() + SchedulingLatency());
					BroadcastNewParameterValue(logMsg.now, param, &value, sizeof(value));

					// log the new latency value, for recordkeeping
					logMsg.param.value = value;
					mLogger->Log(LOG_SET_PARAM_HANDLED, logMsg);
				}
				break;

			case CPU_SPIN_PARAM:
				{
					float value = *((float*) event->pointer);
					mSpinPercentage = value;
					mLastSpinChange = logMsg.now;
					BroadcastNewParameterValue(logMsg.now, param, &value, sizeof(value));
					logMsg.param.value = value;
					mLogger->Log(LOG_SET_PARAM_HANDLED, logMsg);
				}
				break;

			case PRIORITY_PARAM:
				{
					mPriority = *((int32*) event->pointer);
					// DO NOT use ::set_thead_priority() to directly alter the node's control
					// thread priority.  BMediaEventLooper tracks the priority itself and recalculates
					// the node's scheduling latency whenever SetPriority() is called.  This is VERY
					// important for correct functioning of a node chain.  You should *only* alter a
					// BMediaEventLooper's priority by calling its SetPriority() method.
					SetPriority(mPriority);

					mLastPrioChange = logMsg.now;
					BroadcastNewParameterValue(logMsg.now, param, &mPriority, sizeof(mPriority));
					logMsg.param.value = (float) mPriority;
					mLogger->Log(LOG_SET_PARAM_HANDLED, logMsg);
				}
				break;

			// log the fact that we "handled" a "set parameter" event for a
			// nonexistent parameter
			default:
				mLogger->Log(LOG_INVALID_PARAM_HANDLED, logMsg);
				break;
			}
		}
		break;

	case BTimedEventQueue::B_START:
		// okay, let's go!
		mLogger->Log(LOG_START_HANDLED, logMsg);
		break;

	case BTimedEventQueue::B_STOP:
		mLogger->Log(LOG_STOP_HANDLED, logMsg);
		// stopping implies not handling any more buffers.  So, we flush all pending
		// buffers out of the event queue before returning to the event loop.
		EventQueue()->FlushEvents(0, BTimedEventQueue::B_ALWAYS, true, BTimedEventQueue::B_HANDLE_BUFFER);
		break;

	case BTimedEventQueue::B_SEEK:
		// seeking the log doesn't make any sense, so we just log that we handled the seek
		// and return without doing anything else
		mLogger->Log(LOG_SEEK_HANDLED, logMsg);
		break;

	case BTimedEventQueue::B_WARP:
		// similarly, time warps aren't meaningful to the logger, so just record it and return
		mLogger->Log(LOG_WARP_HANDLED, logMsg);
		break;

	case BTimedEventQueue::B_DATA_STATUS:
		// we really don't care about the producer's data status, but this is where
		// we'd do something about it if we did.
		logMsg.data_status.status = event->data;
		mLogger->Log(LOG_DATA_STATUS_HANDLED, logMsg);
		break;

	default:
		// hmm, someone enqueued a message that we don't understand.  log and ignore it.
		logMsg.unknown.what = event->type;
		mLogger->Log(LOG_HANDLE_UNKNOWN, logMsg);
		break;
	}
}