Implement log merging. (40a4498b) · Commits · e / os / android_frameworks_av

include/media/nbaio/NBLog.h

+138 −7

Original line number	Diff line number	Diff line
		@@ -23,6 +23,8 @@
		#include <utils/Mutex.h>
		#include <audio_utils/fifo.h>

		#include <vector>

		namespace android {

		class String8;
		@@ -40,9 +42,10 @@ enum Event {
		EVENT_RESERVED,
		EVENT_STRING, // ASCII string, not NUL-terminated
		EVENT_TIMESTAMP, // clock_gettime(CLOCK_MONOTONIC)
		EVENT_INTEGER,
		EVENT_FLOAT,
		EVENT_PID,
		EVENT_INTEGER, // integer value entry
		EVENT_FLOAT, // floating point value entry
		EVENT_PID, // process ID and process name
		EVENT_AUTHOR, // author index (present in merged logs) tracks entry's original log
		EVENT_START_FMT, // logFormat start event: entry includes format string, following
		// entries contain format arguments
		EVENT_END_FMT, // end of logFormat argument list
		@@ -68,6 +71,49 @@ public:
		static const size_t kOverhead = 3; // mEvent, mLength, mData[...], duplicate mLength
		};

		// ---------------------------------------------------------------------------
		// API for handling format entry operations

		// a formatted entry has the following structure:
		// * START_FMT entry, containing the format string
		// * author entry of the thread that generated it (optional, present in merged log)
		// * TIMESTAMP entry
		// * format arg1
		// * format arg2
		// * ...
		// * END_FMT entry

		class FormatEntry {
		public:
		// build a Format Entry starting in the given pointer
		explicit FormatEntry(const uint8_t *entry);

		// Entry's format string
		const char* formatString() const;

		// Enrty's format string length
		size_t formatStringLength() const;

		// Format arguments (excluding format string, timestamp and author)
		const uint8_t *args() const;

		// get format entry timestamp
		timespec timestamp() const;

		// entry's author index (-1 if none present)
		int author() const;

		// copy entry, adding author before timestamp, returns size of original entry
		// (intended for merger)
		size_t copyTo(std::unique_ptr<audio_utils_fifo_writer> &dst, int author) const;
		private:
		// copies ordinary entry from src to dst, and returns length of entry
		size_t copyEntry(std::unique_ptr<audio_utils_fifo_writer> &dst, const uint8_t *src)
		const;

		const uint8_t *mEntry;
		};

		// representation of a single log entry in shared memory
		// byte[0] mEvent
		// byte[1] mLength
		@@ -82,9 +128,8 @@ public:
		static void appendInt(String8 body, const void data);
		static void appendFloat(String8 body, const void data);
		static void appendPID(String8 body, const void data, size_t length);
		static int handleFormat(const char fmt, size_t length, const uint8_t data,
		String8 timestamp, String8 body);
		static void appendTimestamp(String8 body, const void data);
		static size_t fmtEntryLength(const uint8_t *data);

		public:

		@@ -215,6 +260,31 @@ private:
		class Reader : public RefBase {
		public:

		// A snapshot of a readers buffer
		class Snapshot {
		public:
		Snapshot() : mData(NULL), mAvail(0), mLost(0) {}

		Snapshot(size_t bufferSize) : mData(new uint8_t[bufferSize]) {}

		~Snapshot() { delete[] mData; }

		// copy of the buffer
		const uint8_t *data() const { return mData; }

		// amount of data available (given by audio_utils_fifo_reader)
		size_t available() const { return mAvail; }

		// amount of data lost (given by audio_utils_fifo_reader)
		size_t lost() const { return mLost; }

		private:
		friend class Reader;
		const uint8_t *mData;
		size_t mAvail;
		size_t mLost;
		};

		// Input parameter 'size' is the desired size of the timeline in byte units.
		// The size of the shared memory must be at least Timeline::sharedSize(size).
		Reader(const void *shared, size_t size);
		@@ -222,6 +292,11 @@ public:

		virtual ~Reader();

		// get snapshot of readers fifo buffer, effectively consuming the buffer
		std::unique_ptr<Snapshot> getSnapshot();
		// dump a particular snapshot of the reader
		void dump(int fd, size_t indent, Snapshot & snap);
		// dump the current content of the reader's buffer
		void dump(int fd, size_t indent = 0);
		bool isIMemory(const sp<IMemory>& iMemory) const;

		@@ -237,10 +312,66 @@ private:
		// non-NULL unless constructor fails

		void dumpLine(const String8& timestamp, String8& body);
		int handleFormat(const FormatEntry &fmtEntry,
		String8 *timestamp,
		String8 *body);
		// dummy method for handling absent author entry
		virtual size_t handleAuthor(const FormatEntry &fmtEntry, String8 *body) { return 0; }

		static const size_t kSquashTimestamp = 5; // squash this many or more adjacent timestamps
		};

		// Wrapper for a reader with a name. Contains a pointer to the reader and a pointer to the name
		class NamedReader {
		public:
		NamedReader() { mName[0] = '\0'; } // for Vector
		NamedReader(const sp<NBLog::Reader>& reader, const char *name) :
		mReader(reader)
		{ strlcpy(mName, name, sizeof(mName)); }
		~NamedReader() { }
		const sp<NBLog::Reader>& reader() const { return mReader; }
		const char* name() const { return mName; }

		private:
		sp<NBLog::Reader> mReader;
		static const size_t kMaxName = 32;
		char mName[kMaxName];
		};

		// ---------------------------------------------------------------------------

		class Merger : public RefBase {
		public:
		Merger(const void *shared, size_t size);

		virtual ~Merger() {}

		void addReader(const NamedReader &reader);
		// TODO add removeReader
		void merge();
		const std::vector<NamedReader> *getNamedReaders() const;
		private:
		// vector of the readers the merger is supposed to merge from.
		// every reader reads from a writer's buffer
		std::vector<NamedReader> mNamedReaders;
		uint8_t *mBuffer;
		Shared * const mShared;
		std::unique_ptr<audio_utils_fifo> mFifo;
		std::unique_ptr<audio_utils_fifo_writer> mFifoWriter;

		static struct timespec getTimestamp(const uint8_t *data);
		};

		class MergeReader : public Reader {
		public:
		MergeReader(const void *shared, size_t size, Merger &merger);
		private:
		const std::vector<NamedReader> *mNamedReaders;
		// handle author entry by looking up the author's name and appending it to the body
		// returns number of bytes read from fmtEntry
		size_t handleAuthor(const FormatEntry &fmtEntry, String8 *body);
		};

		}; // class NBLog

		} // namespace android

media/audioserver/Android.mk

+1 −0

Original line number	Diff line number	Diff line
		@@ -12,6 +12,7 @@ LOCAL_SHARED_LIBRARIES := \
		libcutils \
		liblog \
		libmedialogservice \
		libnbaio \
		libradioservice \
		libsoundtriggerservice \
		libutils \

media/libnbaio/NBLog.cpp

+213 −41

Original line number	Diff line number	Diff line
		@@ -29,6 +29,8 @@
		#include <utils/Log.h>
		#include <utils/String8.h>

		#include <queue>

		namespace android {

		int NBLog::Entry::readAt(size_t offset) const
		@@ -48,6 +50,75 @@ int NBLog::Entry::readAt(size_t offset) const

		// ---------------------------------------------------------------------------

		NBLog::FormatEntry::FormatEntry(const uint8_t *entry) : mEntry(entry) {
		ALOGW_IF(entry[0] != EVENT_START_FMT,
		"Created format entry with invalid event type %d",
		entry[0]);
		}

		const char *NBLog::FormatEntry::formatString() const {
		return (const char*) mEntry + 2;
		}

		size_t NBLog::FormatEntry::formatStringLength() const {
		return mEntry[1];
		}

		const uint8_t *NBLog::FormatEntry::args() const {
		const uint8_t *ptr = mEntry + mEntry[1] + NBLog::Entry::kOverhead;
		if (ptr[0] != EVENT_TIMESTAMP) { // skip author if present
		ptr += ptr[1] + NBLog::Entry::kOverhead;
		}
		return ptr + ptr[1] + NBLog::Entry::kOverhead;
		}

		timespec NBLog::FormatEntry::timestamp() const {
		const uint8_t *ptr = mEntry + mEntry[1] + NBLog::Entry::kOverhead;
		if (ptr[0] != EVENT_TIMESTAMP) { // skip authors if present
		ptr += ptr[1] + NBLog::Entry::kOverhead;
		}
		// by this point, we should be standing in the timestamp entry
		return ((struct timespec) (&ptr[2]));
		}

		pid_t NBLog::FormatEntry::author() const {
		size_t authorOffset = mEntry[1] + NBLog::Entry::kOverhead;
		// return -1 if the entry has no author
		if (mEntry[authorOffset] != EVENT_AUTHOR) {
		return -1;
		}
		return (pid_t)(mEntry + authorOffset + 2);
		}

		size_t NBLog::FormatEntry::copyTo(std::unique_ptr<audio_utils_fifo_writer> &dst, int author) const {
		// copy fmt start entry
		size_t entryOffset = copyEntry(dst, mEntry);
		// insert author entry
		size_t authorEntrySize = NBLog::Entry::kOverhead + sizeof(author);
		uint8_t authorEntry[authorEntrySize];
		authorEntry[0] = EVENT_AUTHOR;
		authorEntry[1] = authorEntry[authorEntrySize - 1] = sizeof(author);
		(int) (&authorEntry[2]) = author;
		dst->write(authorEntry, authorEntrySize);
		// copy rest of entries
		Event lastEvent = EVENT_TIMESTAMP;
		while (lastEvent != EVENT_END_FMT) {
		lastEvent = (Event) mEntry[entryOffset];
		entryOffset += copyEntry(dst, mEntry + entryOffset);
		}
		return entryOffset;
		}


		size_t NBLog::FormatEntry::copyEntry(std::unique_ptr<audio_utils_fifo_writer> &dst,
		const uint8_t *src) const {
		size_t length = src[1] + NBLog::Entry::kOverhead;
		dst->write(src, length);
		return length;
		}

		// ---------------------------------------------------------------------------

		#if 0 // FIXME see note in NBLog.h
		NBLog::Timeline::Timeline(size_t size, void *shared)
		: mSize(roundup(size)), mOwn(shared == NULL),
		@@ -463,43 +534,44 @@ NBLog::Reader::~Reader()
		delete mFifo;
		}

		void NBLog::Reader::dump(int fd, size_t indent)
		std::unique_ptr<NBLog::Reader::Snapshot> NBLog::Reader::getSnapshot()
		{
		if (mFifoReader == NULL) {
		return;
		return std::unique_ptr<NBLog::Reader::Snapshot>(new Snapshot());
		}
		// make a copy to avoid race condition with writer
		size_t capacity = mFifo->capacity();

		// TODO Stack-based allocation of large objects may fail.
		// Currently the log buffers are a page or two, which should be safe.
		// But if the log buffers ever get a lot larger,
		// then change this to allocate from heap when necessary.
		static size_t kReasonableStackObjectSize = 32768;
		ALOGW_IF(capacity > kReasonableStackObjectSize, "Stack-based allocation of object may fail");
		uint8_t copy[capacity];
		std::unique_ptr<Snapshot> snapshot(new Snapshot(capacity));

		size_t lost;
		ssize_t actual = mFifoReader->read(copy, capacity, NULL /timeout/, &lost);
		ssize_t actual = mFifoReader->read((void) snapshot->mData, capacity, NULL /timeout*/,
		&(snapshot->mLost));
		ALOG_ASSERT(actual <= capacity);
		size_t avail = actual > 0 ? (size_t) actual : 0;
		size_t i = avail;
		snapshot->mAvail = actual > 0 ? (size_t) actual : 0;
		return snapshot;
		}

		void NBLog::Reader::dump(int fd, size_t indent, NBLog::Reader::Snapshot &snapshot)
		{
		size_t i = snapshot.available();
		const uint8_t *snapData = snapshot.data();
		Event event;
		size_t length;
		struct timespec ts;
		time_t maxSec = -1;
		while (i >= Entry::kOverhead) {
		length = copy[i - 1];
		if (length + Entry::kOverhead > i \|\| copy[i - length - 2] != length) {
		length = snapData[i - 1];
		if (length + Entry::kOverhead > i \|\| snapData[i - length - 2] != length) {

		break;
		}
		event = (Event) copy[i - length - Entry::kOverhead];
		event = (Event) snapData[i - length - Entry::kOverhead];
		if (event == EVENT_TIMESTAMP) {
		if (length != sizeof(struct timespec)) {
		// corrupt
		break;
		}
		memcpy(&ts, &copy[i - length - 1], sizeof(struct timespec));
		memcpy(&ts, &snapData[i - length - 1], sizeof(struct timespec));
		if (ts.tv_sec > maxSec) {
		maxSec = ts.tv_sec;
		}
		@@ -509,7 +581,7 @@ void NBLog::Reader::dump(int fd, size_t indent)
		mFd = fd;
		mIndent = indent;
		String8 timestamp, body;
		lost += i;
		size_t lost = snapshot.lost() + i;
		if (lost > 0) {
		body.appendFormat("warning: lost %zu bytes worth of events", lost);
		// TODO timestamp empty here, only other choice to wait for the first timestamp event in the
		@@ -525,10 +597,10 @@ void NBLog::Reader::dump(int fd, size_t indent)
		timestamp.appendFormat("[%*s]", (int) width + 4, "");
		}
		bool deferredTimestamp = false;
		while (i < avail) {
		event = (Event) copy[i];
		length = copy[i + 1];
		const void *data = &copy[i + 2];
		while (i < snapshot.available()) {
		event = (Event) snapData[i];
		length = snapData[i + 1];
		const void *data = &snapData[i + 2];
		size_t advance = length + Entry::kOverhead;
		switch (event) {
		case EVENT_STRING:
		@@ -544,11 +616,11 @@ void NBLog::Reader::dump(int fd, size_t indent)
		size_t j = i;
		for (;;) {
		j += sizeof(struct timespec) + 3 /Entry::kOverhead?/;
		if (j >= avail \|\| (Event) copy[j] != EVENT_TIMESTAMP) {
		if (j >= snapshot.available() \|\| (Event) snapData[j] != EVENT_TIMESTAMP) {
		break;
		}
		struct timespec tsNext;
		memcpy(&tsNext, &copy[j + 2], sizeof(struct timespec));
		memcpy(&tsNext, &snapData[j + 2], sizeof(struct timespec));
		if (tsNext.tv_sec != ts.tv_sec) {
		break;
		}
		@@ -594,8 +666,7 @@ void NBLog::Reader::dump(int fd, size_t indent)
		appendPID(&body, data, length);
		break;
		case EVENT_START_FMT:
		advance += handleFormat((const char*) &copy[i + 2], length,
		&copy[i + Entry::kOverhead + length], &timestamp, &body);
		advance += handleFormat(FormatEntry(snapData + i), &timestamp, &body);
		break;
		case EVENT_END_FMT:
		body.appendFormat("warning: got to end format event");
		@@ -617,6 +688,13 @@ void NBLog::Reader::dump(int fd, size_t indent)
		}
		}

		void NBLog::Reader::dump(int fd, size_t indent)
		{
		// get a snapshot, dump it
		std::unique_ptr<Snapshot> snap = getSnapshot();
		dump(fd, indent, *snap);
		}

		void NBLog::Reader::dumpLine(const String8 &timestamp, String8 &body)
		{
		if (mFd >= 0) {
		@@ -656,17 +734,23 @@ void NBLog::appendPID(String8 body, const void data, size_t length) {
		body->appendFormat("<PID: %d, name: %.*s>", id, (int) (length - sizeof(pid_t)), name);
		}

		int NBLog::handleFormat(const char fmt, size_t fmt_length, const uint8_t data,
		String8 timestamp, String8 body) {
		if (data[0] != EVENT_TIMESTAMP) {
		ALOGW("NBLog Reader Expected timestamp event %d, got %d", EVENT_TIMESTAMP, data[0]);
		}
		struct timespec ts;
		memcpy(&ts, &data[2], sizeof(ts));
		int NBLog::Reader::handleFormat(const FormatEntry &fmtEntry, String8 timestamp, String8 body) {
		// log timestamp
		struct timespec ts = fmtEntry.timestamp();
		timestamp->clear();
		timestamp->appendFormat("[%d.%03d]", (int) ts.tv_sec,
		(int) (ts.tv_nsec / 1000000));
		size_t data_offset = Entry::kOverhead + sizeof ts;
		size_t fullLength = NBLog::Entry::kOverhead + sizeof(ts);

		// log author (if present)
		fullLength += handleAuthor(fmtEntry, body);

		// log string
		const uint8_t *args = fmtEntry.args();
		size_t args_offset = 0;

		const char* fmt = fmtEntry.formatString();
		size_t fmt_length = fmtEntry.formatStringLength();

		for (size_t fmt_offset = 0; fmt_offset < fmt_length; ++fmt_offset) {
		if (fmt[fmt_offset] != '%') {
		@@ -681,20 +765,20 @@ int NBLog::handleFormat(const char fmt, size_t fmt_length, const uint8_t data,
		continue;
		}

		NBLog::Event event = (NBLog::Event) data[data_offset];
		size_t length = data[data_offset + 1];
		NBLog::Event event = (NBLog::Event) args[args_offset];
		size_t length = args[args_offset + 1];

		// TODO check length for event type is correct
		if(length != data[data_offset + length + 2]) {
		if(length != args[args_offset + length + 2]) {
		ALOGW("NBLog Reader received different lengths %zu and %d for event %d", length,
		data[data_offset + length + 2], event);
		args[args_offset + length + 2], event);
		body->append("<invalid entry>");
		++fmt_offset;
		continue;
		}

		// TODO: implement more complex formatting such as %.3f
		void * datum = (void*) &data[data_offset + 2]; // pointer to the current event data
		void * datum = (void*) &args[args_offset + 2]; // pointer to the current event args
		switch(fmt[fmt_offset])
		{
		case 's': // string
		@@ -731,10 +815,98 @@ int NBLog::handleFormat(const char fmt, size_t fmt_length, const uint8_t data,
		ALOGW("NBLog Reader encountered unknown character %c", fmt[fmt_offset]);
		}

		data_offset += length + Entry::kOverhead;
		args_offset += length + Entry::kOverhead;

		}
		fullLength += args_offset + Entry::kOverhead;
		return fullLength;
		}

		// ---------------------------------------------------------------------------

		NBLog::Merger::Merger(const void *shared, size_t size):
		mBuffer(NULL),
		mShared((Shared *) shared),
		mFifo(mShared != NULL ?
		new audio_utils_fifo(size, sizeof(uint8_t),
		mShared->mBuffer, mShared->mRear, NULL /throttlesFront/) : NULL),
		mFifoWriter(mFifo != NULL ? new audio_utils_fifo_writer(*mFifo) : NULL)
		{}

		void NBLog::Merger::addReader(const NBLog::NamedReader &reader) {
		mNamedReaders.push_back(reader);
		}

		// items placed in priority queue during merge
		// composed by a timestamp and the index of the snapshot where the timestamp came from
		struct MergeItem
		{
		struct timespec ts;
		int index;
		MergeItem(struct timespec ts, int index): ts(ts), index(index) {}
		};

		// operators needed for priority queue in merge
		bool operator>(const struct timespec &t1, const struct timespec &t2) {
		return t1.tv_sec > t2.tv_sec \|\| (t1.tv_sec == t2.tv_sec && t1.tv_nsec > t2.tv_nsec);
		}

		bool operator>(const struct MergeItem &i1, const struct MergeItem &i2) {
		return i1.ts > i2.ts \|\|
		(i1.ts.tv_sec == i2.ts.tv_sec && i1.ts.tv_nsec == i2.ts.tv_nsec && i1.index > i2.index);
		}

		// Merge registered readers, sorted by timestamp
		void NBLog::Merger::merge() {
		int nLogs = mNamedReaders.size();
		std::vector<std::unique_ptr<NBLog::Reader::Snapshot>> snapshots(nLogs);
		for (int i = 0; i < nLogs; ++i) {
		snapshots[i] = mNamedReaders[i].reader()->getSnapshot();
		}
		// initialize offsets
		std::vector<size_t> offsets(nLogs, 0);
		// TODO custom heap implementation could allow to update top, improving performance
		// for bursty buffers
		std::priority_queue<MergeItem, std::vector<MergeItem>, std::greater<MergeItem>> timestamps;
		for (int i = 0; i < nLogs; ++i)
		{
		if (snapshots[i]->available() > 0) {
		timespec ts = FormatEntry(snapshots[i]->data()).timestamp();
		MergeItem item(ts, i);
		timestamps.push(item);
		}
		}
		return data_offset + Entry::kOverhead; // data offset + size of END_FMT event

		while (!timestamps.empty()) {
		// find minimum timestamp
		int index = timestamps.top().index;
		// copy it to the log
		size_t length = FormatEntry(snapshots[index]->data() + offsets[index]).copyTo(
		mFifoWriter, index);
		// update data structures
		offsets[index] += length;
		ALOGW_IF(offsets[index] > snapshots[index]->available(), "Overflown snapshot capacity");
		timestamps.pop();
		if (offsets[index] != snapshots[index]->available()) {
		timespec ts = FormatEntry(snapshots[index]->data() + offsets[index]).timestamp();
		MergeItem item(ts, index);
		timestamps.emplace(item);
		}
		}
		}

		const std::vector<NBLog::NamedReader> *NBLog::Merger::getNamedReaders() const {
		return &mNamedReaders;
		}

		NBLog::MergeReader::MergeReader(const void *shared, size_t size, Merger &merger)
		: Reader(shared, size), mNamedReaders(merger.getNamedReaders()) {}

		size_t NBLog::MergeReader::handleAuthor(const NBLog::FormatEntry &fmtEntry, String8 *body) {
		int author = fmtEntry.author();
		const char* name = (*mNamedReaders)[author].name();
		body->appendFormat("%s: ", name);
		return NBLog::Entry::kOverhead + sizeof(author);
		}

		} // namespace android

services/medialog/MediaLogService.cpp

+19 −13

Original line number	Diff line number	Diff line
		@@ -26,7 +26,7 @@

		namespace android {

		static const char kDeadlockedString[] = "MediaLogService may be deadlocked\n";
		// static const char kDeadlockedString[] = "MediaLogService may be deadlocked\n";

		void MediaLogService::registerWriter(const sp<IMemory>& shared, size_t size, const char *name)
		{
		@@ -36,9 +36,10 @@ void MediaLogService::registerWriter(const sp<IMemory>& shared, size_t size, con
		return;
		}
		sp<NBLog::Reader> reader(new NBLog::Reader(shared, size));
		NamedReader namedReader(reader, name);
		NBLog::NamedReader namedReader(reader, name);
		Mutex::Autolock _l(mLock);
		mNamedReaders.add(namedReader);
		mMerger.addReader(namedReader);
		}

		void MediaLogService::unregisterWriter(const sp<IMemory>& shared)
		@@ -81,7 +82,8 @@ status_t MediaLogService::dump(int fd, const Vector<String16>& args __unused)
		return NO_ERROR;
		}

		Vector<NamedReader> namedReaders;
		#if 0
		Vector<NBLog::NamedReader> namedReaders;
		{
		bool locked = dumpTryLock(mLock);

		@@ -95,19 +97,23 @@ status_t MediaLogService::dump(int fd, const Vector<String16>& args __unused)
		}
		return NO_ERROR;
		}
		namedReaders = mNamedReaders;
		// namedReaders = mNamedReaders;
		// for (size_t i = 0; i < namedReaders.size(); i++) {
		// const NBLog::NamedReader& namedReader = namedReaders[i];
		// if (fd >= 0) {
		// dprintf(fd, "\n%s:\n", namedReader.name());
		// } else {
		// ALOGI("%s:", namedReader.name());
		// }
		// namedReader.reader()->dump(fd, 0 /indent/);
		// }

		mLock.unlock();
		}
		#endif

		for (size_t i = 0; i < namedReaders.size(); i++) {
		const NamedReader& namedReader = namedReaders[i];
		if (fd >= 0) {
		dprintf(fd, "\n%s:\n", namedReader.name());
		} else {
		ALOGI("%s:", namedReader.name());
		}
		namedReader.reader()->dump(fd, 0 /indent/);
		}
		mMerger.merge();
		mMergeReader.dump(fd);
		return NO_ERROR;
		}

services/medialog/MediaLogService.h

+14 −16

Original line number	Diff line number	Diff line
		@@ -27,8 +27,13 @@ class MediaLogService : public BinderService<MediaLogService>, public BnMediaLog
		{
		friend class BinderService<MediaLogService>; // for MediaLogService()
		public:
		MediaLogService() : BnMediaLogService() { }
		virtual ~MediaLogService() { }
		MediaLogService() :
		BnMediaLogService(),
		mMergerShared((NBLog::Shared*) malloc(NBLog::Timeline::sharedSize(kMergeBufferSize))),
		mMerger(mMergerShared, kMergeBufferSize),
		mMergeReader(mMergerShared, kMergeBufferSize, mMerger)
		{ALOGI("Nico creating MergeReader");}
		virtual ~MediaLogService() { free(mMergerShared); }
		virtual void onFirstRef() { }

		static const char* getServiceName() { return "media.log"; }
		@@ -47,23 +52,16 @@ private:
		// Internal dump
		static const int kDumpLockRetries = 50;
		static const int kDumpLockSleepUs = 20000;
		static const size_t kMergeBufferSize = 16 * 1024; // TODO determine good value for this
		static bool dumpTryLock(Mutex& mutex);

		Mutex mLock;
		class NamedReader {
		public:
		NamedReader() : mReader(0) { mName[0] = '\0'; } // for Vector
		NamedReader(const sp<NBLog::Reader>& reader, const char *name) : mReader(reader)
		{ strlcpy(mName, name, sizeof(mName)); }
		~NamedReader() { }
		const sp<NBLog::Reader>& reader() const { return mReader; }
		const char* name() const { return mName; }
		private:
		sp<NBLog::Reader> mReader;
		static const size_t kMaxName = 32;
		char mName[kMaxName];
		};
		Vector<NamedReader> mNamedReaders;

		Vector<NBLog::NamedReader> mNamedReaders;

		NBLog::Shared *mMergerShared;
		NBLog::Merger mMerger;
		NBLog::MergeReader mMergeReader;
		};

		} // namespace android