Rewrite the notification code to use smart pointers. This fixes several

fatal race conditions in notifications. This makes failure to remove a notification non-fatal (it will remove itself harmlessly when an attempt is made to notify it).
2025-11-26 05:55:51 +00:00 · 2013-02-26 00:11:23 -08:00
parent 5fb29bb859
commit c570cca15e
8 changed files with 209 additions and 140 deletions
--- a/src/cpp/ripple/NetworkOPs.cpp
+++ b/src/cpp/ripple/NetworkOPs.cpp
@@ -40,6 +40,9 @@ NetworkOPs::NetworkOPs(boost::asio::io_service& io_service, LedgerMaster* pLedge
 {
 }

+uint64 InfoSub::sSeq = 0;
+boost::mutex InfoSub::sSeqLock;
+
 std::string NetworkOPs::strOperatingMode()
 {
 	static const char*	paStatusToken[] = {
@@ -1028,10 +1031,19 @@ void NetworkOPs::pubServer()
 		jvObj["load_base"]		= (mLastLoadBase = theApp->getFeeTrack().getLoadBase());
 		jvObj["load_factor"]	= (mLastLoadFactor = theApp->getFeeTrack().getLoadFactor());

-		BOOST_FOREACH(InfoSub* ispListener, mSubServer)
+		NetworkOPs::subMapType::const_iterator it = mSubServer.begin();
+		while (it != mSubServer.end())
 		{
-			ispListener->send(jvObj, true);
+			InfoSub::pointer p = it->second.lock();
+			if (p)
+			{
+				p->send(jvObj, true);
+				++it;
+			}
+			else
+				it = mSubServer.erase(it);
 		}
+
 	}
 }

@@ -1285,9 +1297,17 @@ void NetworkOPs::pubProposedTransaction(Ledger::ref lpCurrent, const SerializedT

 	{
 		boost::recursive_mutex::scoped_lock	sl(mMonitorLock);
-		BOOST_FOREACH(InfoSub* ispListener, mSubRTTransactions)
+		NetworkOPs::subMapType::const_iterator it = mSubRTTransactions.begin();
+		while (it != mSubRTTransactions.end())
 		{
-			ispListener->send(jvObj, true);
+			InfoSub::pointer p = it->second.lock();
+			if (p)
+			{
+				p->send(jvObj, true);
+				++it;
+			}
+			else
+				it = mSubRTTransactions.erase(it);
 		}
 	}
 	TransactionMetaSet::pointer ret;
@@ -1316,15 +1336,23 @@ void NetworkOPs::pubLedger(Ledger::ref lpAccepted)
 			jvObj["reserve_base"]	= Json::UInt(lpAccepted->getReserve(0));
 			jvObj["reserve_inc"]	= Json::UInt(lpAccepted->getReserveInc());

-			BOOST_FOREACH(InfoSub* ispListener, mSubLedger)
+			NetworkOPs::subMapType::const_iterator it = mSubLedger.begin();
+			while (it != mSubLedger.end())
 			{
-				ispListener->send(jvObj, true);
+				InfoSub::pointer p = it->second.lock();
+				if (p)
+				{
+					p->send(jvObj, true);
+					++it;
+				}
+				else
+					it = mSubLedger.erase(it);
 			}
 		}
 	}

 	// Don't lock since pubAcceptedTransaction is locking.
-	if (!mSubTransactions.empty() || !mSubRTTransactions.empty() || !mSubAccount.empty() || !mSubRTAccount.empty() || !mSubmitMap.empty() )
+	if (!mSubTransactions.empty() || !mSubRTTransactions.empty() || !mSubAccount.empty() || !mSubRTAccount.empty())
 	{
 		SHAMap&		txSet	= *lpAccepted->peekTransactionMap();

@@ -1390,14 +1418,30 @@ void NetworkOPs::pubAcceptedTransaction(Ledger::ref lpCurrent, const SerializedT
 	{
 		boost::recursive_mutex::scoped_lock	sl(mMonitorLock);

-		BOOST_FOREACH(InfoSub* ispListener, mSubTransactions)
+		NetworkOPs::subMapType::const_iterator it = mSubTransactions.begin();
+		while (it != mSubTransactions.end())
 		{
-			ispListener->send(jvObj, true);
+			InfoSub::pointer p = it->second.lock();
+			if (p)
+			{
+				p->send(jvObj, true);
+				++it;
+			}
+			else
+				it = mSubTransactions.erase(it);
 		}

-		BOOST_FOREACH(InfoSub* ispListener, mSubRTTransactions)
+		it = mSubRTTransactions.begin();
+		while (it != mSubRTTransactions.end())
 		{
-			ispListener->send(jvObj, true);
+			InfoSub::pointer p = it->second.lock();
+			if (p)
+			{
+				p->send(jvObj, true);
+				++it;
+			}
+			else
+				it = mSubRTTransactions.erase(it);
 		}
 	}
 	theApp->getOrderBookDB().processTxn(stTxn, terResult, meta, jvObj);
@@ -1407,7 +1451,7 @@ void NetworkOPs::pubAcceptedTransaction(Ledger::ref lpCurrent, const SerializedT

 void NetworkOPs::pubAccountTransaction(Ledger::ref lpCurrent, const SerializedTransaction& stTxn, TER terResult, bool bAccepted, TransactionMetaSet::pointer& meta)
 {
-	boost::unordered_set<InfoSub*>	notify;
+	boost::unordered_set<InfoSub::pointer>	notify;
 	int								iProposed	= 0;
 	int								iAccepted	= 0;

@@ -1425,10 +1469,18 @@ void NetworkOPs::pubAccountTransaction(Ledger::ref lpCurrent, const SerializedTr

 				if (simiIt != mSubRTAccount.end())
 				{
-					BOOST_FOREACH(InfoSub* ispListener, simiIt->second)
+					NetworkOPs::subMapType::const_iterator it = simiIt->second.begin();
+					while (it != simiIt->second.end())
 					{
-						++iProposed;
-						notify.insert(ispListener);
+						InfoSub::pointer p = it->second.lock();
+						if (p)
+						{
+							notify.insert(p);
+							++it;
+							++iProposed;
+						}
+						else
+							it = simiIt->second.erase(it);
 					}
 				}

@@ -1438,10 +1490,18 @@ void NetworkOPs::pubAccountTransaction(Ledger::ref lpCurrent, const SerializedTr

 					if (simiIt != mSubAccount.end())
 					{
-						BOOST_FOREACH(InfoSub* ispListener, simiIt->second)
+						NetworkOPs::subMapType::const_iterator it = simiIt->second.begin();
+						while (it != simiIt->second.end())
 						{
-							++iAccepted;
-							notify.insert(ispListener);
+							InfoSub::pointer p = it->second.lock();
+							if (p)
+							{
+								notify.insert(p);
+								++it;
+								++iAccepted;
+							}
+							else
+								it = simiIt->second.erase(it);
 						}
 					}
 				}
@@ -1450,16 +1510,15 @@ void NetworkOPs::pubAccountTransaction(Ledger::ref lpCurrent, const SerializedTr
 	}
 	cLog(lsINFO) << boost::str(boost::format("pubAccountTransaction: iProposed=%d iAccepted=%d") % iProposed % iAccepted);

-	// FIXME: This can crash. An InfoSub can go away while we hold a regular pointer to it.
 	if (!notify.empty())
 	{
 		Json::Value	jvObj	= transJson(stTxn, terResult, bAccepted, lpCurrent, "account");

 		if (meta) jvObj["meta"] = meta->getJson(0);

-		BOOST_FOREACH(InfoSub* ispListener, notify)
+		BOOST_FOREACH(InfoSub::ref isrListener, notify)
 		{
-			ispListener->send(jvObj, true);
+			isrListener->send(jvObj, true);
 		}
 	}
 }
@@ -1468,7 +1527,7 @@ void NetworkOPs::pubAccountTransaction(Ledger::ref lpCurrent, const SerializedTr
 // Monitoring
 //

-void NetworkOPs::subAccount(InfoSub* ispListener, const boost::unordered_set<RippleAddress>& vnaAccountIDs, uint32 uLedgerIndex, bool rt)
+void NetworkOPs::subAccount(InfoSub::ref isrListener, const boost::unordered_set<RippleAddress>& vnaAccountIDs, uint32 uLedgerIndex, bool rt)
 {
 	subInfoMapType& subMap = rt ? mSubRTAccount : mSubAccount;

@@ -1477,7 +1536,7 @@ void NetworkOPs::subAccount(InfoSub* ispListener, const boost::unordered_set<Rip
 	{
 		cLog(lsTRACE) << boost::str(boost::format("subAccount: account: %d") % naAccountID.humanAccountID());

-		ispListener->insertSubAccountInfo(naAccountID, uLedgerIndex);
+		isrListener->insertSubAccountInfo(naAccountID, uLedgerIndex);
 	}

 	boost::recursive_mutex::scoped_lock	sl(mMonitorLock);
@@ -1488,20 +1547,19 @@ void NetworkOPs::subAccount(InfoSub* ispListener, const boost::unordered_set<Rip
 		if (simIterator == subMap.end())
 		{
 			// Not found, note that account has a new single listner.
-			boost::unordered_set<InfoSub*>	usisElement;
-
-			usisElement.insert(ispListener);
+			subMapType	usisElement;
+			usisElement[isrListener->getSeq()] = isrListener;
 			subMap.insert(simIterator, make_pair(naAccountID.getAccountID(), usisElement));
 		}
 		else
 		{
 			// Found, note that the account has another listener.
-			simIterator->second.insert(ispListener);
+			simIterator->second[isrListener->getSeq()] = isrListener;
 		}
 	}
 }

-void NetworkOPs::unsubAccount(InfoSub* ispListener, const boost::unordered_set<RippleAddress>& vnaAccountIDs, bool rt)
+void NetworkOPs::unsubAccount(uint64 uSeq, const boost::unordered_set<RippleAddress>& vnaAccountIDs, bool rt)
 {
 	subInfoMapType& subMap = rt ? mSubRTAccount : mSubAccount;

@@ -1509,7 +1567,7 @@ void NetworkOPs::unsubAccount(InfoSub* ispListener, const boost::unordered_set<R
 	// FIXME: Don't we need to unsub?
 	// BOOST_FOREACH(const RippleAddress& naAccountID, vnaAccountIDs)
 	// {
-	//	ispListener->deleteSubAccountInfo(naAccountID);
+	//	isrListener->deleteSubAccountInfo(naAccountID);
 	// }

 	boost::recursive_mutex::scoped_lock	sl(mMonitorLock);
@@ -1527,7 +1585,7 @@ void NetworkOPs::unsubAccount(InfoSub* ispListener, const boost::unordered_set<R
 		else
 		{
 			// Found
-			simIterator->second.erase(ispListener);
+			simIterator->second.erase(uSeq);

 			if (simIterator->second.empty())
 			{
@@ -1538,17 +1596,17 @@ void NetworkOPs::unsubAccount(InfoSub* ispListener, const boost::unordered_set<R
 	}
 }

-bool NetworkOPs::subBook(InfoSub* ispListener, uint160 currencyIn, uint160 currencyOut, uint160 issuerIn, uint160 issuerOut)
+bool NetworkOPs::subBook(InfoSub::ref isrListener, uint160 currencyIn, uint160 currencyOut, uint160 issuerIn, uint160 issuerOut)
 {
 	BookListeners::pointer listeners=theApp->getOrderBookDB().makeBookListeners(currencyIn, currencyOut, issuerIn, issuerOut);
-	if(listeners) listeners->addSubscriber(ispListener);
+	if(listeners) listeners->addSubscriber(isrListener);
 	return(true);
 }

-bool NetworkOPs::unsubBook(InfoSub* ispListener, uint160 currencyIn, uint160 currencyOut, uint160 issuerIn, uint160 issuerOut)
+bool NetworkOPs::unsubBook(uint64 uSeq, uint160 currencyIn, uint160 currencyOut, uint160 issuerIn, uint160 issuerOut)
 {
 	BookListeners::pointer listeners=theApp->getOrderBookDB().getBookListeners(currencyIn, currencyOut, issuerIn, issuerOut);
-	if(listeners) listeners->removeSubscriber(ispListener);
+	if(listeners) listeners->removeSubscriber(uSeq);
 	return(true);
 }

@@ -1578,26 +1636,26 @@ void NetworkOPs::storeProposal(LedgerProposal::ref proposal, const RippleAddress
 InfoSub::~InfoSub()
 {
 	NetworkOPs& ops = theApp->getOPs();
-	ops.unsubTransactions(this);
-	ops.unsubRTTransactions(this);
-	ops.unsubLedger(this);
-	ops.unsubServer(this);
-	ops.unsubAccount(this, mSubAccountInfo, true);
-	ops.unsubAccount(this, mSubAccountInfo, false);
+	ops.unsubTransactions(mSeq);
+	ops.unsubRTTransactions(mSeq);
+	ops.unsubLedger(mSeq);
+	ops.unsubServer(mSeq);
+	ops.unsubAccount(mSeq, mSubAccountInfo, true);
+	ops.unsubAccount(mSeq, mSubAccountInfo, false);
 }

 #if 0
-void NetworkOPs::subAccountChanges(InfoSub* ispListener, const uint256 uLedgerHash)
+void NetworkOPs::subAccountChanges(InfoSub* isrListener, const uint256 uLedgerHash)
 {
 }

-void NetworkOPs::unsubAccountChanges(InfoSub* ispListener)
+void NetworkOPs::unsubAccountChanges(InfoSub* isrListener)
 {
 }
 #endif

 // <-- bool: true=added, false=already there
-bool NetworkOPs::subLedger(InfoSub* ispListener, Json::Value& jvResult)
+bool NetworkOPs::subLedger(InfoSub::ref isrListener, Json::Value& jvResult)
 {
 	Ledger::pointer lpClosed	= getClosedLedger();

@@ -1610,17 +1668,17 @@ bool NetworkOPs::subLedger(InfoSub* ispListener, Json::Value& jvResult)
 	jvResult["reserve_base"]	= Json::UInt(lpClosed->getReserve(0));
 	jvResult["reserve_inc"]		= Json::UInt(lpClosed->getReserveInc());

-	return mSubLedger.insert(ispListener).second;
+	return mSubLedger.insert(std::make_pair(isrListener->getSeq(), isrListener)).second;
 }

 // <-- bool: true=erased, false=was not there
-bool NetworkOPs::unsubLedger(InfoSub* ispListener)
+bool NetworkOPs::unsubLedger(uint64 uSeq)
 {
-	return !!mSubLedger.erase(ispListener);
+	return !!mSubLedger.erase(uSeq);
 }

 // <-- bool: true=added, false=already there
-bool NetworkOPs::subServer(InfoSub* ispListener, Json::Value& jvResult)
+bool NetworkOPs::subServer(InfoSub::ref isrListener, Json::Value& jvResult)
 {
 	uint256			uRandom;

@@ -1636,60 +1694,50 @@ bool NetworkOPs::subServer(InfoSub* ispListener, Json::Value& jvResult)
 	jvResult["load_base"]		= theApp->getFeeTrack().getLoadBase();
 	jvResult["load_factor"]		= theApp->getFeeTrack().getLoadFactor();

-	return mSubServer.insert(ispListener).second;
+	return mSubServer.insert(std::make_pair(isrListener->getSeq(), isrListener)).second;
 }

 // <-- bool: true=erased, false=was not there
-bool NetworkOPs::unsubServer(InfoSub* ispListener)
+bool NetworkOPs::unsubServer(uint64 uSeq)
 {
-	return !!mSubServer.erase(ispListener);
+	return !!mSubServer.erase(uSeq);
 }

 // <-- bool: true=added, false=already there
-bool NetworkOPs::subTransactions(InfoSub* ispListener)
+bool NetworkOPs::subTransactions(InfoSub::ref isrListener)
 {
-	return mSubTransactions.insert(ispListener).second;
+	return mSubTransactions.insert(std::make_pair(isrListener->getSeq(), isrListener)).second;
 }

 // <-- bool: true=erased, false=was not there
-bool NetworkOPs::unsubTransactions(InfoSub* ispListener)
+bool NetworkOPs::unsubTransactions(uint64 uSeq)
 {
-	return !!mSubTransactions.erase(ispListener);
+	return !!mSubTransactions.erase(uSeq);
 }

 // <-- bool: true=added, false=already there
-bool NetworkOPs::subRTTransactions(InfoSub* ispListener)
+bool NetworkOPs::subRTTransactions(InfoSub::ref isrListener)
 {
-	return mSubTransactions.insert(ispListener).second;
+	return mSubTransactions.insert(std::make_pair(isrListener->getSeq(), isrListener)).second;
 }

 // <-- bool: true=erased, false=was not there
-bool NetworkOPs::unsubRTTransactions(InfoSub* ispListener)
+bool NetworkOPs::unsubRTTransactions(uint64 uSeq)
 {
-	return !!mSubTransactions.erase(ispListener);
+	return !!mSubTransactions.erase(uSeq);
 }

-RPCSub* NetworkOPs::findRpcSub(const std::string& strUrl)
+InfoSub::pointer NetworkOPs::findRpcSub(const std::string& strUrl)
 {
-	RPCSub*								rspResult;
 	boost::recursive_mutex::scoped_lock	sl(mMonitorLock);

-	subRpcMapType::iterator	it;
-
-	it	= mRpcSubMap.find(strUrl);
-	if (it == mRpcSubMap.end())
-	{
-		rspResult = (RPCSub*)(0);
-	}
-	else
-	{
-		rspResult	= it->second;
-	}
-
-	return rspResult;
+	subRpcMapType::iterator	it = mRpcSubMap.find(strUrl);
+	if (it != mRpcSubMap.end())
+		return it->second;
+	return InfoSub::pointer();
 }

-RPCSub* NetworkOPs::addRpcSub(const std::string& strUrl, RPCSub* rspEntry)
+InfoSub::pointer NetworkOPs::addRpcSub(const std::string& strUrl, InfoSub::ref rspEntry)
 {
 	boost::recursive_mutex::scoped_lock	sl(mMonitorLock);

--- a/src/cpp/ripple/NetworkOPs.h
+++ b/src/cpp/ripple/NetworkOPs.h
@@ -23,8 +23,6 @@ class LedgerConsensus;

 DEFINE_INSTANCE(InfoSub);

-class RPCSub;
-
 class InfoSub : public IS_INSTANCE(InfoSub)
 {
 protected:
@@ -33,12 +31,30 @@ protected:

 	boost::mutex								mLockInfo;

+	uint64										mSeq;
+	static uint64								sSeq;
+	static boost::mutex							sSeqLock;
+
 public:
+	typedef boost::shared_ptr<InfoSub>			pointer;
+	typedef boost::weak_ptr<InfoSub>			wptr;
+	typedef const boost::shared_ptr<InfoSub>&	ref;
+
+	InfoSub()
+	{
+		boost::mutex::scoped_lock sl(sSeqLock);
+		mSeq = ++sSeq;
+	}

 	virtual ~InfoSub();

 	virtual	void send(const Json::Value& jvObj, bool broadcast) = 0;

+	uint64 getSeq()
+	{
+		return mSeq;
+	}
+
 	void onSendEmpty();

 	void insertSubAccountInfo(RippleAddress addr, uint32 uLedgerIndex)
@@ -66,15 +82,14 @@ public:
 		omFULL			= 3		// we have the ledger and can even validate
 	};

+	typedef boost::unordered_map<uint64, InfoSub::wptr>				subMapType;
+
 protected:
-	typedef boost::unordered_map<uint160,boost::unordered_set<InfoSub*> >				subInfoMapType;
-	typedef boost::unordered_map<uint160,boost::unordered_set<InfoSub*> >::value_type	subInfoMapValue;
-	typedef boost::unordered_map<uint160,boost::unordered_set<InfoSub*> >::iterator		subInfoMapIterator;
+	typedef boost::unordered_map<uint160, subMapType>				subInfoMapType;
+	typedef boost::unordered_map<uint160, subMapType>::value_type	subInfoMapValue;
+	typedef boost::unordered_map<uint160, subMapType>::iterator		subInfoMapIterator;

-	typedef boost::unordered_map<uint160,std::pair<InfoSub*,uint32> >					subSubmitMapType;
-	//typedef boost::unordered_map<OrderBook::pointer,boost::unordered_set<InfoSub*> >	subOrderMap;
-
-	typedef boost::unordered_map<std::string, RPCSub* >									subRpcMapType;
+	typedef boost::unordered_map<std::string, InfoSub::pointer>		subRpcMapType;

 	OperatingMode						mMode;
 	bool								mNeedNetworkLedger;
@@ -104,15 +119,14 @@ protected:
    boost::recursive_mutex								mMonitorLock;
 	subInfoMapType										mSubAccount;
 	subInfoMapType										mSubRTAccount;
-	subSubmitMapType									mSubmitMap;   // TODO: probably dump this
 	

 	subRpcMapType										mRpcSubMap;

-	boost::unordered_set<InfoSub*>						mSubLedger;				// accepted ledgers
-	boost::unordered_set<InfoSub*>						mSubServer;				// when server changes connectivity state
-	boost::unordered_set<InfoSub*>						mSubTransactions;		// all accepted transactions
-	boost::unordered_set<InfoSub*>						mSubRTTransactions;		// all proposed and accepted transactions
+	subMapType											mSubLedger;				// accepted ledgers
+	subMapType											mSubServer;				// when server changes connectivity state
+	subMapType											mSubTransactions;		// all accepted transactions
+	subMapType											mSubRTTransactions;		// all proposed and accepted transactions

 	boost::recursive_mutex								mWantedHashLock;
 	boost::unordered_set<uint256>						mWantedHashes;
@@ -292,26 +306,26 @@ public:
 	//
 	// Monitoring: subscriber side
 	//
-	void subAccount(InfoSub* ispListener, const boost::unordered_set<RippleAddress>& vnaAccountIDs, uint32 uLedgerIndex, bool rt);
-	void unsubAccount(InfoSub* ispListener, const boost::unordered_set<RippleAddress>& vnaAccountIDs, bool rt);
+	void subAccount(InfoSub::ref ispListener, const boost::unordered_set<RippleAddress>& vnaAccountIDs, uint32 uLedgerIndex, bool rt);
+	void unsubAccount(uint64 uListener, const boost::unordered_set<RippleAddress>& vnaAccountIDs, bool rt);

-	bool subLedger(InfoSub* ispListener, Json::Value& jvResult);
-	bool unsubLedger(InfoSub* ispListener);
+	bool subLedger(InfoSub::ref ispListener, Json::Value& jvResult);
+	bool unsubLedger(uint64 uListener);

-	bool subServer(InfoSub* ispListener, Json::Value& jvResult);
-	bool unsubServer(InfoSub* ispListener);
+	bool subServer(InfoSub::ref ispListener, Json::Value& jvResult);
+	bool unsubServer(uint64 uListener);

-	bool subBook(InfoSub* ispListener, uint160 currencyIn, uint160 currencyOut, uint160 issuerIn, uint160 issuerOut);
-	bool unsubBook(InfoSub* ispListener, uint160 currencyIn, uint160 currencyOut, uint160 issuerIn, uint160 issuerOut);
+	bool subBook(InfoSub::ref ispListener, uint160 currencyIn, uint160 currencyOut, uint160 issuerIn, uint160 issuerOut);
+	bool unsubBook(uint64 uListener, uint160 currencyIn, uint160 currencyOut, uint160 issuerIn, uint160 issuerOut);

-	bool subTransactions(InfoSub* ispListener);
-	bool unsubTransactions(InfoSub* ispListener);
+	bool subTransactions(InfoSub::ref ispListener);
+	bool unsubTransactions(uint64 uListener);

-	bool subRTTransactions(InfoSub* ispListener);
-	bool unsubRTTransactions(InfoSub* ispListener);
+	bool subRTTransactions(InfoSub::ref ispListener);
+	bool unsubRTTransactions(uint64 uListener);

-	RPCSub*	findRpcSub(const std::string& strUrl);
-	RPCSub*	addRpcSub(const std::string& strUrl, RPCSub* rspEntry);
+	InfoSub::pointer	findRpcSub(const std::string& strUrl);
+	InfoSub::pointer	addRpcSub(const std::string& strUrl, InfoSub::ref rspEntry);
 };

 #endif
--- a/src/cpp/ripple/OrderBookDB.cpp
+++ b/src/cpp/ripple/OrderBookDB.cpp
@@ -232,23 +232,31 @@ void OrderBookDB::processTxn(const SerializedTransaction& stTxn, TER terResult,T
 	}
 }

-void BookListeners::addSubscriber(InfoSub* sub)
+void BookListeners::addSubscriber(InfoSub::ref sub)
 {
-	mListeners.insert(sub);
+	mListeners[sub->getSeq()] = sub;
 }

-void BookListeners::removeSubscriber(InfoSub* sub)
+void BookListeners::removeSubscriber(uint64 seq)
 {
-	mListeners.erase(sub);
+	mListeners.erase(seq);
 }

 void BookListeners::publish(Json::Value& jvObj)
 {
 	//Json::Value jvObj=node.getJson(0);

-	BOOST_FOREACH(InfoSub* sub,mListeners)
+	NetworkOPs::subMapType::const_iterator it = mListeners.begin();
+	while (it != mListeners.end())
 	{
-		sub->send(jvObj, true);
+		InfoSub::pointer p = it->second.lock();
+		if (p)
+		{
+			p->send(jvObj, true);
+			++it;
+		}
+		else
+			it = mListeners.erase(it);
 	}
 }

--- a/src/cpp/ripple/OrderBookDB.h
+++ b/src/cpp/ripple/OrderBookDB.h
@@ -16,12 +16,12 @@

 class BookListeners
 {
-	boost::unordered_set<InfoSub*> mListeners;
+	boost::unordered_map<uint64, InfoSub::wptr> mListeners;
 public:
 	typedef boost::shared_ptr<BookListeners> pointer;

-	void addSubscriber(InfoSub* sub);
-	void removeSubscriber(InfoSub* sub);
+	void addSubscriber(InfoSub::ref sub);
+	void removeSubscriber(uint64 sub);
 	void publish(Json::Value& jvObj);
 };

--- a/src/cpp/ripple/RPCHandler.cpp
+++ b/src/cpp/ripple/RPCHandler.cpp
@@ -66,13 +66,11 @@ int iAdminGet(const Json::Value& jvRequest, const std::string& strRemoteIp)
 RPCHandler::RPCHandler(NetworkOPs* netOps)
 {
 	mNetOps		= netOps;
-	mInfoSub	= NULL;
 }

-RPCHandler::RPCHandler(NetworkOPs* netOps, InfoSub* infoSub)
+RPCHandler::RPCHandler(NetworkOPs* netOps, InfoSub::pointer infoSub) : mInfoSub(infoSub)
 {
 	mNetOps		= netOps;
-	mInfoSub	= infoSub;
 }

 Json::Value RPCHandler::transactionSign(Json::Value jvRequest, bool bSubmit)
@@ -2492,7 +2490,7 @@ rt_accounts
 */
 Json::Value RPCHandler::doSubscribe(Json::Value jvRequest)
 {
-	InfoSub*	ispSub;
+	InfoSub::pointer ispSub;
 	Json::Value jvResult(Json::objectValue);
 	uint32		uLedgerIndex = jvRequest.isMember("ledger_index") && jvRequest["ledger_index"].isNumeric()
 									? jvRequest["ledger_index"].asUInt()
@@ -2513,25 +2511,23 @@ Json::Value RPCHandler::doSubscribe(Json::Value jvRequest)
 		std::string	strUsername	= jvRequest.isMember("username") ? jvRequest["username"].asString() : "";
 		std::string	strPassword	= jvRequest.isMember("password") ? jvRequest["password"].asString() : "";

-		RPCSub	*rspSub	= mNetOps->findRpcSub(strUrl);
-		if (!rspSub)
+		ispSub	= mNetOps->findRpcSub(strUrl);
+		if (!ispSub)
 		{
 			cLog(lsDEBUG) << boost::str(boost::format("doSubscribe: building: %s") % strUrl);

-			rspSub	= mNetOps->addRpcSub(strUrl, new RPCSub(strUrl, strUsername, strPassword));
+			ispSub	= mNetOps->addRpcSub(strUrl, boost::make_shared<RPCSub>(strUrl, strUsername, strPassword));
 		}
 		else
 		{
 			cLog(lsTRACE) << boost::str(boost::format("doSubscribe: reusing: %s") % strUrl);

 			if (jvRequest.isMember("username"))
-				rspSub->setUsername(strUsername);
+				dynamic_cast<RPCSub*>(&*ispSub)->setUsername(strUsername);

 			if (jvRequest.isMember("password"))
-				rspSub->setPassword(strPassword);
+				dynamic_cast<RPCSub*>(&*ispSub)->setPassword(strPassword);
 		}
-
-		ispSub	= rspSub;
 	}
 	else
 	{
@@ -2631,7 +2627,7 @@ Json::Value RPCHandler::doSubscribe(Json::Value jvRequest)
 // FIXME: This leaks RPCSub objects for JSON-RPC.  Shouldn't matter for anyone sane.
 Json::Value RPCHandler::doUnsubscribe(Json::Value jvRequest)
 {
-	InfoSub*	ispSub;
+	InfoSub::pointer ispSub;
 	Json::Value jvResult(Json::objectValue);

 	if (!mInfoSub && !jvRequest.isMember("url"))
@@ -2647,11 +2643,9 @@ Json::Value RPCHandler::doUnsubscribe(Json::Value jvRequest)

 		std::string	strUrl	= jvRequest["url"].asString();

-		RPCSub	*rspSub	= mNetOps->findRpcSub(strUrl);
-		if (!rspSub)
+		ispSub	= mNetOps->findRpcSub(strUrl);
+		if (!ispSub)
 			return jvResult;
-
-		ispSub		= rspSub;
 	}
 	else
 	{
@@ -2668,19 +2662,19 @@ Json::Value RPCHandler::doUnsubscribe(Json::Value jvRequest)

 				if (streamName == "server")
 				{
-					mNetOps->unsubServer(ispSub);
+					mNetOps->unsubServer(ispSub->getSeq());
 				}
 				else if (streamName == "ledger")
 				{
-					mNetOps->unsubLedger(ispSub);
+					mNetOps->unsubLedger(ispSub->getSeq());
 				}
 				else if (streamName == "transactions")
 				{
-					mNetOps->unsubTransactions(ispSub);
+					mNetOps->unsubTransactions(ispSub->getSeq());
 				}
 				else if (streamName == "rt_transactions")
 				{
-					mNetOps->unsubRTTransactions(ispSub);
+					mNetOps->unsubRTTransactions(ispSub->getSeq());
 				}
 				else
 				{
@@ -2704,7 +2698,7 @@ Json::Value RPCHandler::doUnsubscribe(Json::Value jvRequest)
 		}
 		else
 		{
-			mNetOps->unsubAccount(ispSub, usnaAccoundIds, true);
+			mNetOps->unsubAccount(ispSub->getSeq(), usnaAccoundIds, true);
 		}
 	}

@@ -2718,7 +2712,7 @@ Json::Value RPCHandler::doUnsubscribe(Json::Value jvRequest)
 		}
 		else
 		{
-			mNetOps->unsubAccount(ispSub, usnaAccoundIds, false);
+			mNetOps->unsubAccount(ispSub->getSeq(), usnaAccoundIds, false);
 		}
 	}

@@ -2733,7 +2727,7 @@ Json::Value RPCHandler::doUnsubscribe(Json::Value jvRequest)
 			STAmount::issuerFromString(currencyOut,(*it)["CurrencyIn"].asString());
 			uint160 issuerIn=RippleAddress::createNodePublic( (*it)["IssuerIn"].asString() ).getAccountID();

-			mNetOps->unsubBook(ispSub,currencyIn,currencyOut,issuerIn,issuerOut);
+			mNetOps->unsubBook(ispSub->getSeq(), currencyIn, currencyOut, issuerIn, issuerOut);
 		}
 	}

--- a/src/cpp/ripple/RPCHandler.h
+++ b/src/cpp/ripple/RPCHandler.h
@@ -15,9 +15,9 @@ class InfoSub;

 class RPCHandler
 {
-	NetworkOPs*		mNetOps;
-	InfoSub*		mInfoSub;
-	int				mRole;
+	NetworkOPs*			mNetOps;
+	InfoSub::pointer	mInfoSub;
+	int					mRole;

 	typedef Json::Value (RPCHandler::*doFuncPtr)(Json::Value params);
 	enum {
@@ -115,7 +115,7 @@ public:
 	enum { GUEST, USER, ADMIN, FORBID };

 	RPCHandler(NetworkOPs* netOps);
-	RPCHandler(NetworkOPs* netOps, InfoSub* infoSub);
+	RPCHandler(NetworkOPs* netOps, InfoSub::pointer infoSub);

 	Json::Value doCommand(const Json::Value& jvRequest, int role);
 	Json::Value doRpcCommand(const std::string& strCommand, Json::Value& jvParams, int iRole);
--- a/src/cpp/ripple/RPCSub.h
+++ b/src/cpp/ripple/RPCSub.h
@@ -30,6 +30,9 @@ protected:
 	void	sendThread();

 public:
+	typedef boost::shared_ptr<RPCSub>	pointer;
+	typedef const pointer&				ref;
+
 	RPCSub(const std::string& strUrl, const std::string& strUsername, const std::string& strPassword);

 	virtual ~RPCSub() { ; }
--- a/src/cpp/ripple/WSConnection.h
+++ b/src/cpp/ripple/WSConnection.h
@@ -6,6 +6,7 @@

 #include <boost/weak_ptr.hpp>
 #include <boost/asio.hpp>
+#include <boost/enable_shared_from_this.hpp>

 #include "WSDoor.h"
 #include "Application.h"
@@ -28,7 +29,8 @@ class WSServerHandler;
 // - Subscriptions
 //
 template <typename endpoint_type>
-class WSConnection : public InfoSub, public IS_INSTANCE(WebSocketConnection)
+class WSConnection : public InfoSub, public IS_INSTANCE(WebSocketConnection),
+	public boost::enable_shared_from_this< WSConnection<endpoint_type> >
 {
 public:
 	typedef typename endpoint_type::connection_type connection;
@@ -101,7 +103,7 @@ public:
 			return jvResult;
 		}

-		RPCHandler	mRPCHandler(&mNetwork, this);
+		RPCHandler	mRPCHandler(&mNetwork, this->shared_from_this());
 		Json::Value	jvResult(Json::objectValue);

 		int iRole	= mHandler->getPublic()