Merge "logd: better drop message merging" (76ed92c3) · Commits · e / os / android_system_core

logd/LogBuffer.cpp

+70 −18

Original line number	Original line	Diff line number	Diff line
	@@ -226,6 +226,68 @@ LogBufferElementCollection::iterator LogBuffer::erase(LogBufferElementCollection
	return it;		return it;
	}		}

			// Define a temporary mechanism to report the last LogBufferElement pointer
			// for the specified uid, pid and tid. Used below to help merge-sort when
			// pruning for worst UID.
			class LogBufferElementKey {
			const union {
			struct {
			uint16_t uid;
			uint16_t pid;
			uint16_t tid;
			uint16_t padding;
			} __packed;
			uint64_t value;
			} __packed;

			public:
			LogBufferElementKey(uid_t u, pid_t p, pid_t t):uid(u),pid(p),tid(t),padding(0) { }
			LogBufferElementKey(uint64_t k):value(k) { }

			uint64_t getKey() { return value; }
			};

			struct LogBufferElementEntry {
			const uint64_t key;
			LogBufferElement *last;

			public:
			LogBufferElementEntry(const uint64_t &k, LogBufferElement *e):key(k),last(e) { }

			const uint64_t&getKey() const { return key; }

			LogBufferElement *getLast() { return last; }
			};

			struct LogBufferElementLast : public android::BasicHashtable<uint64_t, LogBufferElementEntry> {

			bool merge(LogBufferElement *e, unsigned short dropped) {
			LogBufferElementKey key(e->getUid(), e->getPid(), e->getTid());
			android::hash_t hash = android::hash_type(key.getKey());
			ssize_t index = find(-1, hash, key.getKey());
			if (index != -1) {
			LogBufferElementEntry &entry = editEntryAt(index);
			LogBufferElement *l = entry.getLast();
			unsigned short d = l->getDropped();
			if ((dropped + d) > USHRT_MAX) {
			removeAt(index);
			} else {
			l->setDropped(dropped + d);
			return true;
			}
			}
			return false;
			}

			size_t add(LogBufferElement *e) {
			LogBufferElementKey key(e->getUid(), e->getPid(), e->getTid());
			android::hash_t hash = android::hash_type(key.getKey());
			return android::BasicHashtable<uint64_t, LogBufferElementEntry>::
			add(hash, LogBufferElementEntry(key.getKey(), e));
			}

			};

	// prune "pruneRows" of type "id" from the buffer.		// prune "pruneRows" of type "id" from the buffer.
	//		//
	// mLogElementsLock must be held when this function is called.		// mLogElementsLock must be held when this function is called.
	@@ -301,7 +363,7 @@ void LogBuffer::prune(log_id_t id, unsigned long pruneRows, uid_t caller_uid) {

	bool kick = false;		bool kick = false;
	bool leading = true;		bool leading = true;
	LogBufferElement *last = NULL;		LogBufferElementLast last;
	for(it = mLogElements.begin(); it != mLogElements.end();) {		for(it = mLogElements.begin(); it != mLogElements.end();) {
	LogBufferElement e = it;		LogBufferElement e = it;

	@@ -322,24 +384,18 @@ void LogBuffer::prune(log_id_t id, unsigned long pruneRows, uid_t caller_uid) {
	continue;		continue;
	}		}

	pid_t pid = e->getPid();

	// merge any drops		// merge any drops
	if (last && dropped		if (dropped && last.merge(e, dropped)) {
	&& ((dropped + last->getDropped()) < USHRT_MAX)
	&& (last->getPid() == pid)
	&& (last->getTid() == e->getTid())) {
	it = mLogElements.erase(it);		it = mLogElements.erase(it);
	stats.erase(e);		stats.erase(e);
	delete e;		delete e;
	last->setDropped(dropped + last->getDropped());
	continue;		continue;
	}		}

	leading = false;		leading = false;

	if (hasBlacklist && mPrune.naughty(e)) {		if (hasBlacklist && mPrune.naughty(e)) {
	last = NULL;		last.clear();
	it = erase(it);		it = erase(it);
	if (dropped) {		if (dropped) {
	continue;		continue;
	@@ -361,13 +417,13 @@ void LogBuffer::prune(log_id_t id, unsigned long pruneRows, uid_t caller_uid) {
	}		}

	if (dropped) {		if (dropped) {
	last = e;		last.add(e);
	++it;		++it;
	continue;		continue;
	}		}

	if (e->getUid() != worst) {		if (e->getUid() != worst) {
	last = NULL;		last.clear();
	++it;		++it;
	continue;		continue;
	}		}
	@@ -382,17 +438,12 @@ void LogBuffer::prune(log_id_t id, unsigned long pruneRows, uid_t caller_uid) {
	unsigned short len = e->getMsgLen();		unsigned short len = e->getMsgLen();
	stats.drop(e);		stats.drop(e);
	e->setDropped(1);		e->setDropped(1);
	// merge any drops		if (last.merge(e, 1)) {
	if (last
	&& (last->getDropped() < (USHRT_MAX - 1))
	&& (last->getPid() == pid)
	&& (last->getTid() == e->getTid())) {
	it = mLogElements.erase(it);		it = mLogElements.erase(it);
	stats.erase(e);		stats.erase(e);
	delete e;		delete e;
	last->setDropped(last->getDropped() + 1);
	} else {		} else {
	last = e;		last.add(e);
	++it;		++it;
	}		}
	if (worst_sizes < second_worst_sizes) {		if (worst_sizes < second_worst_sizes) {
	@@ -400,6 +451,7 @@ void LogBuffer::prune(log_id_t id, unsigned long pruneRows, uid_t caller_uid) {
	}		}
	worst_sizes -= len;		worst_sizes -= len;
	}		}
			last.clear();

	if (!kick \|\| !mPrune.worstUidEnabled()) {		if (!kick \|\| !mPrune.worstUidEnabled()) {
	break; // the following loop will ask bad clients to skip/drop		break; // the following loop will ask bad clients to skip/drop