Incremental improvements to path finding memory usage:

* Abort background path finding when closed or disconnected
* Exit pathfinding job thread if there are no requests left
* Don't bother creating the path find job if there are no requests
* Refactor to remove circular dependency between InfoSub and PathRequest

Builds/CMake/RippledCore.cmake

@@ -733,6 +733,7 @@ if (tests)
     src/test/basics/contract_test.cpp
     src/test/basics/FeeUnits_test.cpp
     src/test/basics/hardened_hash_test.cpp
+    src/test/basics/join_test.cpp
     src/test/basics/mulDiv_test.cpp
     src/test/basics/tagged_integer_test.cpp
     #[===============================[

src/ripple/app/ledger/LedgerHolder.h

@@ -20,6 +20,7 @@
 #ifndef RIPPLE_APP_LEDGER_LEDGERHOLDER_H_INCLUDED
 #define RIPPLE_APP_LEDGER_LEDGERHOLDER_H_INCLUDED
 
+#include <ripple/basics/CountedObject.h>
 #include <ripple/basics/contract.h>
 #include <mutex>
 
@@ -35,7 +36,7 @@ namespace ripple {
                 way the object always holds a value. We can use the
                 genesis ledger in all cases.
 */
-class LedgerHolder
+class LedgerHolder : public CountedObject<LedgerHolder>
 {
 public:
     // Update the held ledger

src/ripple/app/ledger/LedgerReplay.h

@@ -20,6 +20,7 @@
 #ifndef RIPPLE_APP_LEDGER_LEDGERREPLAY_H_INCLUDED
 #define RIPPLE_APP_LEDGER_LEDGERREPLAY_H_INCLUDED
 
+#include <ripple/basics/CountedObject.h>
 #include <cstdint>
 #include <map>
 #include <memory>
@@ -29,7 +30,7 @@ namespace ripple {
 class Ledger;
 class STTx;
 
-class LedgerReplay
+class LedgerReplay : public CountedObject<LedgerReplay>
 {
     std::shared_ptr<Ledger const> parent_;
     std::shared_ptr<Ledger const> replay_;

src/ripple/app/ledger/impl/LedgerMaster.cpp

@@ -261,8 +261,13 @@ LedgerMaster::getPublishedLedgerAge()
     std::chrono::seconds ret = app_.timeKeeper().closeTime().time_since_epoch();
     ret -= pubClose;
     ret = (ret > 0s) ? ret : 0s;
+    static std::chrono::seconds lastRet = -1s;
 
+    if (ret != lastRet)
+    {
         JLOG(m_journal.trace()) << "Published ledger age is " << ret.count();
+        lastRet = ret;
+    }
     return ret;
 }
 
@@ -287,8 +292,13 @@ LedgerMaster::getValidatedLedgerAge()
     std::chrono::seconds ret = app_.timeKeeper().closeTime().time_since_epoch();
     ret -= valClose;
     ret = (ret > 0s) ? ret : 0s;
+    static std::chrono::seconds lastRet = -1s;
 
+    if (ret != lastRet)
+    {
         JLOG(m_journal.trace()) << "Validated ledger age is " << ret.count();
+        lastRet = ret;
+    }
     return ret;
 }
 
@@ -1483,12 +1493,14 @@ LedgerMaster::updatePaths()
         if (app_.getOPs().isNeedNetworkLedger())
         {
             --mPathFindThread;
+            JLOG(m_journal.debug()) << "Need network ledger for updating paths";
             return;
         }
     }
 
     while (!app_.getJobQueue().isStopping())
     {
+        JLOG(m_journal.debug()) << "updatePaths running";
         std::shared_ptr<ReadView const> lastLedger;
         {
             std::lock_guard ml(m_mutex);
@@ -1506,6 +1518,7 @@ LedgerMaster::updatePaths()
             else
             {  // Nothing to do
                 --mPathFindThread;
+                JLOG(m_journal.debug()) << "Nothing to do for updating paths";
                 return;
             }
         }
@@ -1527,7 +1540,31 @@ LedgerMaster::updatePaths()
 
         try
         {
-            app_.getPathRequests().updateAll(lastLedger);
+            auto& pathRequests = app_.getPathRequests();
+            {
+                std::lock_guard ml(m_mutex);
+                if (!pathRequests.requestsPending())
+                {
+                    --mPathFindThread;
+                    JLOG(m_journal.debug())
+                        << "No path requests found. Nothing to do for updating "
+                           "paths. "
+                        << mPathFindThread << " jobs remaining";
+                    return;
+                }
+            }
+            JLOG(m_journal.debug()) << "Updating paths";
+            pathRequests.updateAll(lastLedger);
+
+            std::lock_guard ml(m_mutex);
+            if (!pathRequests.requestsPending())
+            {
+                JLOG(m_journal.debug())
+                    << "No path requests left. No need for further updating "
+                       "paths";
+                --mPathFindThread;
+                return;
+            }
         }
         catch (SHAMapMissingNode const& mn)
         {
@@ -1587,8 +1624,11 @@ LedgerMaster::newPFWork(
     const char* name,
     std::unique_lock<std::recursive_mutex>&)
 {
-    if (mPathFindThread < 2)
+    if (mPathFindThread < 2 && app_.getPathRequests().requestsPending())
     {
+        JLOG(m_journal.debug())
+            << "newPFWork: Creating job. path find threads: "
+            << mPathFindThread;
         if (app_.getJobQueue().addJob(
                 jtUPDATE_PF, name, [this]() { updatePaths(); }))
         {

src/ripple/app/misc/CanonicalTXSet.h

@@ -20,6 +20,7 @@
 #ifndef RIPPLE_APP_MISC_CANONICALTXSET_H_INCLUDED
 #define RIPPLE_APP_MISC_CANONICALTXSET_H_INCLUDED
 
+#include <ripple/basics/CountedObject.h>
 #include <ripple/protocol/RippleLedgerHash.h>
 #include <ripple/protocol/STTx.h>
 #include <ripple/protocol/SeqProxy.h>
@@ -34,7 +35,7 @@ namespace ripple {
 
 */
 // VFALCO TODO rename to SortedTxSet
-class CanonicalTXSet
+class CanonicalTXSet : public CountedObject<CanonicalTXSet>
 {
 private:
     class Key

src/ripple/app/misc/OrderBook.h

@@ -20,10 +20,12 @@
 #ifndef RIPPLE_APP_MISC_ORDERBOOK_H_INCLUDED
 #define RIPPLE_APP_MISC_ORDERBOOK_H_INCLUDED
 
+#include <ripple/basics/CountedObject.h>
+
 namespace ripple {
 
 /** Describes a serialized ledger entry for an order book. */
-class OrderBook
+class OrderBook : public CountedObject<OrderBook>
 {
 public:
     using pointer = std::shared_ptr<OrderBook>;

src/ripple/app/paths/PathRequest.cpp

@@ -441,7 +441,7 @@ PathRequest::parseJson(Json::Value const& jvParams)
 }
 
 Json::Value
-PathRequest::doClose(Json::Value const&)
+PathRequest::doClose()
 {
     JLOG(m_journal.debug()) << iIdentifier << " closed";
     std::lock_guard sl(mLock);
@@ -457,13 +457,20 @@ PathRequest::doStatus(Json::Value const&)
     return jvStatus;
 }
 
+void
+PathRequest::doAborting() const
+{
+    JLOG(m_journal.info()) << iIdentifier << " aborting early";
+}
+
 std::unique_ptr<Pathfinder> const&
 PathRequest::getPathFinder(
     std::shared_ptr<RippleLineCache> const& cache,
     hash_map<Currency, std::unique_ptr<Pathfinder>>& currency_map,
     Currency const& currency,
     STAmount const& dst_amount,
-    int const level)
+    int const level,
+    std::function<bool(void)> const& continueCallback)
 {
     auto i = currency_map.find(currency);
     if (i != currency_map.end())
@@ -477,8 +484,8 @@ PathRequest::getPathFinder(
         dst_amount,
         saSendMax,
         app_);
-    if (pathfinder->findPaths(level))
+    if (pathfinder->findPaths(level, continueCallback))
-        pathfinder->computePathRanks(max_paths_);
+        pathfinder->computePathRanks(max_paths_, continueCallback);
     else
         pathfinder.reset();  // It's a bad request - clear it.
     return currency_map[currency] = std::move(pathfinder);
@@ -488,7 +495,8 @@ bool
 PathRequest::findPaths(
     std::shared_ptr<RippleLineCache> const& cache,
     int const level,
-    Json::Value& jvArray)
+    Json::Value& jvArray,
+    std::function<bool(void)> const& continueCallback)
 {
     auto sourceCurrencies = sciSourceCurrencies;
     if (sourceCurrencies.empty() && saSendMax)
@@ -515,22 +523,33 @@ PathRequest::findPaths(
     hash_map<Currency, std::unique_ptr<Pathfinder>> currency_map;
     for (auto const& issue : sourceCurrencies)
     {
+        if (continueCallback && !continueCallback())
+            break;
         JLOG(m_journal.debug())
             << iIdentifier
             << " Trying to find paths: " << STAmount(issue, 1).getFullText();
 
         auto& pathfinder = getPathFinder(
-            cache, currency_map, issue.currency, dst_amount, level);
+            cache,
+            currency_map,
+            issue.currency,
+            dst_amount,
+            level,
+            continueCallback);
         if (!pathfinder)
         {
-            assert(false);
+            assert(continueCallback && !continueCallback());
             JLOG(m_journal.debug()) << iIdentifier << " No paths found";
             continue;
         }
 
         STPath fullLiquidityPath;
         auto ps = pathfinder->getBestPaths(
-            max_paths_, fullLiquidityPath, mContext[issue], issue.account);
+            max_paths_,
+            fullLiquidityPath,
+            mContext[issue],
+            issue.account,
+            continueCallback);
         mContext[issue] = ps;
 
         auto& sourceAccount = !isXRP(issue.account)
@@ -628,7 +647,10 @@ PathRequest::findPaths(
 }
 
 Json::Value
-PathRequest::doUpdate(std::shared_ptr<RippleLineCache> const& cache, bool fast)
+PathRequest::doUpdate(
+    std::shared_ptr<RippleLineCache> const& cache,
+    bool fast,
+    std::function<bool(void)> const& continueCallback)
 {
     using namespace std::chrono;
     JLOG(m_journal.debug())
@@ -699,7 +721,7 @@ PathRequest::doUpdate(std::shared_ptr<RippleLineCache> const& cache, bool fast)
     JLOG(m_journal.debug()) << iIdentifier << " processing at level " << iLevel;
 
     Json::Value jvArray = Json::arrayValue;
-    if (findPaths(cache, iLevel, jvArray))
+    if (findPaths(cache, iLevel, jvArray, continueCallback))
     {
         bLastSuccess = jvArray.size() != 0;
         newStatus[jss::alternatives] = std::move(jvArray);
@@ -730,7 +752,7 @@ PathRequest::doUpdate(std::shared_ptr<RippleLineCache> const& cache, bool fast)
 }
 
 InfoSub::pointer
-PathRequest::getSubscriber()
+PathRequest::getSubscriber() const
 {
     return wpSubscriber.lock();
 }

src/ripple/app/paths/PathRequest.h

@@ -43,9 +43,9 @@ class PathRequests;
 // Return values from parseJson <0 = invalid, >0 = valid
 #define PFR_PJ_INVALID -1
 #define PFR_PJ_NOCHANGE 0
-#define PFR_PJ_CHANGE 1
 
-class PathRequest : public std::enable_shared_from_this<PathRequest>,
+class PathRequest final : public InfoSubRequest,
+                          public std::enable_shared_from_this<PathRequest>,
                           public CountedObject<PathRequest>
 {
 public:
@@ -55,8 +55,6 @@ public:
     using wref = const wptr&;
 
 public:
-    // VFALCO TODO Break the cyclic dependency on InfoSub
-
     // path_find semantics
     // Subscriber is updated
     PathRequest(
@@ -91,15 +89,20 @@ public:
     doCreate(std::shared_ptr<RippleLineCache> const&, Json::Value const&);
 
     Json::Value
-    doClose(Json::Value const&);
+    doClose() override;
     Json::Value
-    doStatus(Json::Value const&);
+    doStatus(Json::Value const&) override;
+    void
+    doAborting() const;
 
     // update jvStatus
     Json::Value
-    doUpdate(std::shared_ptr<RippleLineCache> const&, bool fast);
+    doUpdate(
+        std::shared_ptr<RippleLineCache> const&,
+        bool fast,
+        std::function<bool(void)> const& continueCallback = {});
     InfoSub::pointer
-    getSubscriber();
+    getSubscriber() const;
     bool
     hasCompletion();
 
@@ -113,13 +116,18 @@ private:
         hash_map<Currency, std::unique_ptr<Pathfinder>>&,
         Currency const&,
         STAmount const&,
-        int const);
+        int const,
+        std::function<bool(void)> const&);
 
     /** Finds and sets a PathSet in the JSON argument.
         Returns false if the source currencies are inavlid.
     */
     bool
-    findPaths(std::shared_ptr<RippleLineCache> const&, int const, Json::Value&);
+    findPaths(
+        std::shared_ptr<RippleLineCache> const&,
+        int const,
+        Json::Value&,
+        std::function<bool(void)> const&);
 
     int
     parseJson(Json::Value const&);
@@ -156,7 +164,7 @@ private:
     int iLevel;
     bool bLastSuccess;
 
-    int iIdentifier;
+    int const iIdentifier;
 
     std::chrono::steady_clock::time_point const created_;
     std::chrono::steady_clock::time_point quick_reply_;

src/ripple/app/paths/PathRequests.cpp

@@ -40,8 +40,12 @@ PathRequests::getLineCache(
 {
     std::lock_guard sl(mLock);
 
-    std::uint32_t lineSeq = mLineCache ? mLineCache->getLedger()->seq() : 0;
+    auto lineCache = lineCache_.lock();
-    std::uint32_t lgrSeq = ledger->seq();
+
+    std::uint32_t const lineSeq = lineCache ? lineCache->getLedger()->seq() : 0;
+    std::uint32_t const lgrSeq = ledger->seq();
+    JLOG(mJournal.debug()) << "getLineCache has cache for " << lineSeq
+                           << ", considering " << lgrSeq;
 
     if ((lineSeq == 0) ||                         // no ledger
         (authoritative && (lgrSeq > lineSeq)) ||  // newer authoritative ledger
@@ -49,9 +53,15 @@ PathRequests::getLineCache(
          ((lgrSeq + 8) < lineSeq)) ||  // we jumped way back for some reason
         (lgrSeq > (lineSeq + 8)))      // we jumped way forward for some reason
     {
-        mLineCache = std::make_shared<RippleLineCache>(ledger);
+        JLOG(mJournal.debug())
+            << "getLineCache creating new cache for " << lgrSeq;
+        // Assign to the local before the member, because the member is a
+        // weak_ptr, and will immediately discard it if there are no other
+        // references.
+        lineCache_ = lineCache = std::make_shared<RippleLineCache>(
+            ledger, app_.journal("RippleLineCache"));
     }
-    return mLineCache;
+    return lineCache;
 }
 
 void
@@ -78,8 +88,20 @@ PathRequests::updateAll(std::shared_ptr<ReadView const> const& inLedger)
 
     int processed = 0, removed = 0;
 
+    auto getSubscriber =
+        [](PathRequest::pointer const& request) -> InfoSub::pointer {
+        if (auto ipSub = request->getSubscriber();
+            ipSub && ipSub->getRequest() == request)
+        {
+            return ipSub;
+        }
+        request->doAborting();
+        return nullptr;
+    };
+
     do
     {
+        JLOG(mJournal.trace()) << "updateAll looping";
         for (auto const& wr : requests)
         {
             if (app_.getJobQueue().isStopping())
@@ -87,27 +109,42 @@ PathRequests::updateAll(std::shared_ptr<ReadView const> const& inLedger)
 
             auto request = wr.lock();
             bool remove = true;
+            JLOG(mJournal.trace())
+                << "updateAll request " << (request ? "" : "not ") << "found";
 
             if (request)
             {
+                auto continueCallback = [&getSubscriber, &request]() {
+                    // This callback is used by doUpdate to determine whether to
+                    // continue working. If getSubscriber returns null, that
+                    // indicates that this request is no longer relevant.
+                    return (bool)getSubscriber(request);
+                };
                 if (!request->needsUpdate(
                         newRequests, cache->getLedger()->seq()))
                     remove = false;
                 else
                 {
-                    if (auto ipSub = request->getSubscriber())
+                    if (auto ipSub = getSubscriber(request))
                     {
                         if (!ipSub->getConsumer().warn())
                         {
-                            Json::Value update =
+                            // Release the shared ptr to the subscriber so that
-                                request->doUpdate(cache, false);
+                            // it can be freed if the client disconnects, and
+                            // thus fail to lock later.
+                            ipSub.reset();
+                            Json::Value update = request->doUpdate(
+                                cache, false, continueCallback);
                             request->updateComplete();
                             update[jss::type] = "path_find";
+                            if ((ipSub = getSubscriber(request)))
+                            {
                                 ipSub->send(update, false);
                                 remove = false;
                                 ++processed;
                             }
                         }
+                    }
                     else if (request->hasCompletion())
                     {
                         // One-shot request with completion function
@@ -178,6 +215,13 @@ PathRequests::updateAll(std::shared_ptr<ReadView const> const& inLedger)
                            << " processed and " << removed << " removed";
 }
 
+bool
+PathRequests::requestsPending() const
+{
+    std::lock_guard sl(mLock);
+    return !requests_.empty();
+}
+
 void
 PathRequests::insertPathRequest(PathRequest::pointer const& req)
 {
@@ -211,7 +255,7 @@ PathRequests::makePathRequest(
 
     if (valid)
     {
-        subscriber->setPathRequest(req);
+        subscriber->setRequest(req);
         insertPathRequest(req);
         app_.getLedgerMaster().newPathRequest();
     }
@@ -258,7 +302,8 @@ PathRequests::doLegacyPathRequest(
     std::shared_ptr<ReadView const> const& inLedger,
     Json::Value const& request)
 {
-    auto cache = std::make_shared<RippleLineCache>(inLedger);
+    auto cache = std::make_shared<RippleLineCache>(
+        inLedger, app_.journal("RippleLineCache"));
 
     auto req = std::make_shared<PathRequest>(
         app_, [] {}, consumer, ++mLastIdentifier, *this, mJournal);

src/ripple/app/paths/PathRequests.h

@@ -51,6 +51,9 @@ public:
     void
     updateAll(std::shared_ptr<ReadView const> const& ledger);
 
+    bool
+    requestsPending() const;
+
     std::shared_ptr<RippleLineCache>
     getLineCache(
         std::shared_ptr<ReadView const> const& ledger,
@@ -109,11 +112,11 @@ private:
     std::vector<PathRequest::wptr> requests_;
 
     // Use a RippleLineCache
-    std::shared_ptr<RippleLineCache> mLineCache;
+    std::weak_ptr<RippleLineCache> lineCache_;
 
     std::atomic<int> mLastIdentifier;
 
-    std::recursive_mutex mLock;
+    std::recursive_mutex mutable mLock;
 };
 
 }  // namespace ripple

src/ripple/app/paths/Pathfinder.cpp

@@ -24,6 +24,7 @@
 #include <ripple/app/paths/RippleLineCache.h>
 #include <ripple/app/paths/impl/PathfinderUtils.h>
 #include <ripple/basics/Log.h>
+#include <ripple/basics/join.h>
 #include <ripple/core/Config.h>
 #include <ripple/core/JobQueue.h>
 #include <ripple/json/to_string.h>
@@ -191,8 +192,11 @@ Pathfinder::Pathfinder(
 }
 
 bool
-Pathfinder::findPaths(int searchLevel)
+Pathfinder::findPaths(
+    int searchLevel,
+    std::function<bool(void)> const& continueCallback)
 {
+    JLOG(j_.trace()) << "findPaths start";
     if (mDstAmount == beast::zero)
     {
         // No need to send zero money.
@@ -316,10 +320,13 @@ Pathfinder::findPaths(int searchLevel)
     // Now iterate over all paths for that paymentType.
     for (auto const& costedPath : mPathTable[paymentType])
     {
+        if (continueCallback && !continueCallback())
+            return false;
         // Only use paths with at most the current search level.
         if (costedPath.searchLevel <= searchLevel)
         {
-            addPathsForType(costedPath.type);
+            JLOG(j_.trace()) << "findPaths trying payment type " << paymentType;
+            addPathsForType(costedPath.type, continueCallback);
 
             if (mCompletePaths.size() > PATHFINDER_MAX_COMPLETE_PATHS)
                 break;
@@ -401,7 +408,9 @@ Pathfinder::getPathLiquidity(
 }
 
 void
-Pathfinder::computePathRanks(int maxPaths)
+Pathfinder::computePathRanks(
+    int maxPaths,
+    std::function<bool(void)> const& continueCallback)
 {
     mRemainingAmount = convertAmount(mDstAmount, convert_all_);
 
@@ -439,7 +448,7 @@ Pathfinder::computePathRanks(int maxPaths)
         JLOG(j_.debug()) << "Default path causes exception";
     }
 
-    rankPaths(maxPaths, mCompletePaths, mPathRanks);
+    rankPaths(maxPaths, mCompletePaths, mPathRanks, continueCallback);
 }
 
 static bool
@@ -480,8 +489,11 @@ void
 Pathfinder::rankPaths(
     int maxPaths,
     STPathSet const& paths,
-    std::vector<PathRank>& rankedPaths)
+    std::vector<PathRank>& rankedPaths,
+    std::function<bool(void)> const& continueCallback)
 {
+    JLOG(j_.trace()) << "rankPaths with " << paths.size() << " candidates, and "
+                     << maxPaths << " maximum";
     rankedPaths.clear();
     rankedPaths.reserve(paths.size());
 
@@ -499,6 +511,8 @@ Pathfinder::rankPaths(
 
     for (int i = 0; i < paths.size(); ++i)
     {
+        if (continueCallback && !continueCallback())
+            return;
         auto const& currentPath = paths[i];
         if (!currentPath.empty())
         {
@@ -554,7 +568,8 @@ Pathfinder::getBestPaths(
     int maxPaths,
     STPath& fullLiquidityPath,
     STPathSet const& extraPaths,
-    AccountID const& srcIssuer)
+    AccountID const& srcIssuer,
+    std::function<bool(void)> const& continueCallback)
 {
     JLOG(j_.debug()) << "findPaths: " << mCompletePaths.size() << " paths and "
                      << extraPaths.size() << " extras";
@@ -567,7 +582,7 @@ Pathfinder::getBestPaths(
         isXRP(mSrcCurrency) || (srcIssuer == mSrcAccount);
 
     std::vector<PathRank> extraPathRanks;
-    rankPaths(maxPaths, extraPaths, extraPathRanks);
+    rankPaths(maxPaths, extraPaths, extraPathRanks, continueCallback);
 
     STPathSet bestPaths;
 
@@ -582,6 +597,8 @@ Pathfinder::getBestPaths(
     while (pathsIterator != mPathRanks.end() ||
            extraPathsIterator != extraPathRanks.end())
     {
+        if (continueCallback && !continueCallback())
+            break;
         bool usePath = false;
         bool useExtraPath = false;
 
@@ -692,7 +709,8 @@ Pathfinder::getPathsOut(
     Currency const& currency,
     AccountID const& account,
     bool isDstCurrency,
-    AccountID const& dstAccount)
+    AccountID const& dstAccount,
+    std::function<bool(void)> const& continueCallback)
 {
     Issue const issue(currency, account);
 
@@ -755,17 +773,26 @@ void
 Pathfinder::addLinks(
     STPathSet const& currentPaths,  // The paths to build from
     STPathSet& incompletePaths,     // The set of partial paths we add to
-    int addFlags)
+    int addFlags,
+    std::function<bool(void)> const& continueCallback)
 {
     JLOG(j_.debug()) << "addLink< on " << currentPaths.size()
                      << " source(s), flags=" << addFlags;
     for (auto const& path : currentPaths)
-        addLink(path, incompletePaths, addFlags);
+    {
+        if (continueCallback && !continueCallback())
+            return;
+        addLink(path, incompletePaths, addFlags, continueCallback);
+    }
 }
 
 STPathSet&
-Pathfinder::addPathsForType(PathType const& pathType)
+Pathfinder::addPathsForType(
+    PathType const& pathType,
+    std::function<bool(void)> const& continueCallback)
 {
+    JLOG(j_.warn()) << "addPathsForType "
+                    << CollectionAndDelimiter(pathType, ", ");
     // See if the set of paths for this type already exists.
     auto it = mPaths.find(pathType);
     if (it != mPaths.end())
@@ -774,13 +801,16 @@ Pathfinder::addPathsForType(PathType const& pathType)
     // Otherwise, if the type has no nodes, return the empty path.
     if (pathType.empty())
         return mPaths[pathType];
+    if (continueCallback && !continueCallback())
+        return mPaths[{}];
 
     // Otherwise, get the paths for the parent PathType by calling
     // addPathsForType recursively.
     PathType parentPathType = pathType;
     parentPathType.pop_back();
 
-    STPathSet const& parentPaths = addPathsForType(parentPathType);
+    STPathSet const& parentPaths =
+        addPathsForType(parentPathType, continueCallback);
     STPathSet& pathsOut = mPaths[pathType];
 
     JLOG(j_.debug()) << "getPaths< adding onto '"
@@ -800,26 +830,38 @@ Pathfinder::addPathsForType(PathType const& pathType)
             break;
 
         case nt_ACCOUNTS:
-            addLinks(parentPaths, pathsOut, afADD_ACCOUNTS);
+            addLinks(parentPaths, pathsOut, afADD_ACCOUNTS, continueCallback);
             break;
 
         case nt_BOOKS:
-            addLinks(parentPaths, pathsOut, afADD_BOOKS);
+            addLinks(parentPaths, pathsOut, afADD_BOOKS, continueCallback);
             break;
 
         case nt_XRP_BOOK:
-            addLinks(parentPaths, pathsOut, afADD_BOOKS | afOB_XRP);
+            addLinks(
+                parentPaths,
+                pathsOut,
+                afADD_BOOKS | afOB_XRP,
+                continueCallback);
             break;
 
         case nt_DEST_BOOK:
-            addLinks(parentPaths, pathsOut, afADD_BOOKS | afOB_LAST);
+            addLinks(
+                parentPaths,
+                pathsOut,
+                afADD_BOOKS | afOB_LAST,
+                continueCallback);
             break;
 
         case nt_DESTINATION:
             // FIXME: What if a different issuer was specified on the
             // destination amount?
             // TODO(tom): what does this even mean?  Should it be a JIRA?
-            addLinks(parentPaths, pathsOut, afADD_ACCOUNTS | afAC_LAST);
+            addLinks(
+                parentPaths,
+                pathsOut,
+                afADD_ACCOUNTS | afAC_LAST,
+                continueCallback);
             break;
     }
 
@@ -890,7 +932,8 @@ void
 Pathfinder::addLink(
     const STPath& currentPath,   // The path to build from
     STPathSet& incompletePaths,  // The set of partial paths we add to
-    int addFlags)
+    int addFlags,
+    std::function<bool(void)> const& continueCallback)
 {
     auto const& pathEnd = currentPath.empty() ? mSource : currentPath.back();
     auto const& uEndCurrency = pathEnd.getCurrency();
@@ -903,7 +946,8 @@ Pathfinder::addLink(
     // rather than the ultimate destination?
     bool const hasEffectiveDestination = mEffectiveDst != mDstAccount;
 
-    JLOG(j_.trace()) << "addLink< flags=" << addFlags << " onXRP=" << bOnXRP;
+    JLOG(j_.trace()) << "addLink< flags=" << addFlags << " onXRP=" << bOnXRP
+                     << " completePaths size=" << mCompletePaths.size();
     JLOG(j_.trace()) << currentPath.getJson(JsonOptions::none);
 
     if (addFlags & afADD_ACCOUNTS)
@@ -939,6 +983,8 @@ Pathfinder::addLink(
 
                 for (auto const& rs : rippleLines)
                 {
+                    if (continueCallback && !continueCallback())
+                        return;
                     auto const& acct = rs.getAccountIDPeer();
 
                     if (hasEffectiveDestination && (acct == mDstAccount))
@@ -1002,7 +1048,8 @@ Pathfinder::addLink(
                                 uEndCurrency,
                                 acct,
                                 bIsEndCurrency,
-                                mEffectiveDst);
+                                mEffectiveDst,
+                                continueCallback);
                             if (out)
                                 candidates.push_back({out, acct});
                         }
@@ -1030,6 +1077,8 @@ Pathfinder::addLink(
                     auto it = candidates.begin();
                     while (count-- != 0)
                     {
+                        if (continueCallback && !continueCallback())
+                            return;
                         // Add accounts to incompletePaths
                         STPathElement pathElement(
                             STPathElement::typeAccount,
@@ -1074,6 +1123,8 @@ Pathfinder::addLink(
 
             for (auto const& book : books)
             {
+                if (continueCallback && !continueCallback())
+                    return;
                 if (!currentPath.hasSeen(
                         xrpAccount(),
                         book->getCurrencyOut(),

src/ripple/app/paths/Pathfinder.h

@@ -22,6 +22,7 @@
 
 #include <ripple/app/ledger/Ledger.h>
 #include <ripple/app/paths/RippleLineCache.h>
+#include <ripple/basics/CountedObject.h>
 #include <ripple/core/LoadEvent.h>
 #include <ripple/protocol/STAmount.h>
 #include <ripple/protocol/STPathSet.h>
@@ -34,7 +35,7 @@ namespace ripple {
 
     @see RippleCalc
 */
-class Pathfinder
+class Pathfinder : public CountedObject<Pathfinder>
 {
 public:
     /** Construct a pathfinder without an issuer.*/
@@ -56,11 +57,15 @@ public:
     initPathTable();
 
     bool
-    findPaths(int searchLevel);
+    findPaths(
+        int searchLevel,
+        std::function<bool(void)> const& continueCallback = {});
 
     /** Compute the rankings of the paths. */
     void
-    computePathRanks(int maxPaths);
+    computePathRanks(
+        int maxPaths,
+        std::function<bool(void)> const& continueCallback = {});
 
     /* Get the best paths, up to maxPaths in number, from mCompletePaths.
 
@@ -72,7 +77,8 @@ public:
         int maxPaths,
         STPath& fullLiquidityPath,
         STPathSet const& extraPaths,
-        AccountID const& srcIssuer);
+        AccountID const& srcIssuer,
+        std::function<bool(void)> const& continueCallback = {});
 
     enum NodeType {
         nt_SOURCE,     // The source account: with an issuer account, if needed.
@@ -127,7 +133,9 @@ private:
 
     // Add all paths of one type to mCompletePaths.
     STPathSet&
-    addPathsForType(PathType const& type);
+    addPathsForType(
+        PathType const& type,
+        std::function<bool(void)> const& continueCallback);
 
     bool
     issueMatchesOrigin(Issue const&);
@@ -137,20 +145,23 @@ private:
         Currency const& currency,
         AccountID const& account,
         bool isDestCurrency,
-        AccountID const& dest);
+        AccountID const& dest,
+        std::function<bool(void)> const& continueCallback);
 
     void
     addLink(
         STPath const& currentPath,
         STPathSet& incompletePaths,
-        int addFlags);
+        int addFlags,
+        std::function<bool(void)> const& continueCallback);
 
     // Call addLink() for each path in currentPaths.
     void
     addLinks(
         STPathSet const& currentPaths,
         STPathSet& incompletePaths,
-        int addFlags);
+        int addFlags,
+        std::function<bool(void)> const& continueCallback);
 
     // Compute the liquidity for a path.  Return tesSUCCESS if it has has enough
     // liquidity to be worth keeping, otherwise an error.
@@ -178,7 +189,8 @@ private:
     rankPaths(
         int maxPaths,
         STPathSet const& paths,
-        std::vector<PathRank>& rankedPaths);
+        std::vector<PathRank>& rankedPaths,
+        std::function<bool(void)> const& continueCallback);
 
     AccountID mSrcAccount;
     AccountID mDstAccount;

src/ripple/app/paths/RippleLineCache.cpp

@@ -23,12 +23,22 @@
 
 namespace ripple {
 
-RippleLineCache::RippleLineCache(std::shared_ptr<ReadView const> const& ledger)
+RippleLineCache::RippleLineCache(
+    std::shared_ptr<ReadView const> const& ledger,
+    beast::Journal j)
+    : journal_(j)
 {
-    // We want the caching that OpenView provides
+    mLedger = ledger;
-    // And we need to own a shared_ptr to the input view
+
-    // VFALCO TODO This should be a CachedLedger
+    JLOG(journal_.debug()) << "RippleLineCache created for ledger "
-    mLedger = std::make_shared<OpenView>(&*ledger, ledger);
+                           << mLedger->info().seq;
+}
+
+RippleLineCache::~RippleLineCache()
+{
+    JLOG(journal_.debug()) << "~RippleLineCache destroyed for ledger "
+                           << mLedger->info().seq << " with " << lines_.size()
+                           << " accounts";
 }
 
 std::vector<PathFindTrustLine> const&
@@ -43,6 +53,13 @@ RippleLineCache::getRippleLines(AccountID const& accountID)
     if (inserted)
         it->second = PathFindTrustLine::getItems(accountID, *mLedger);
 
+    JLOG(journal_.debug()) << "RippleLineCache getRippleLines for ledger "
+                           << mLedger->info().seq << " found "
+                           << it->second.size() << " lines for "
+                           << (inserted ? "new " : "existing ") << accountID
+                           << " out of a total of " << lines_.size()
+                           << " accounts";
+
     return it->second;
 }
 

src/ripple/app/paths/RippleLineCache.h

@@ -33,10 +33,13 @@
 namespace ripple {
 
 // Used by Pathfinder
-class RippleLineCache : public CountedObject<RippleLineCache>
+class RippleLineCache final : public CountedObject<RippleLineCache>
 {
 public:
-    explicit RippleLineCache(std::shared_ptr<ReadView const> const& l);
+    explicit RippleLineCache(
+        std::shared_ptr<ReadView const> const& l,
+        beast::Journal j);
+    ~RippleLineCache();
 
     std::shared_ptr<ReadView const> const&
     getLedger() const
@@ -53,7 +56,9 @@ private:
     ripple::hardened_hash<> hasher_;
     std::shared_ptr<ReadView const> mLedger;
 
-    struct AccountKey
+    beast::Journal journal_;
+
+    struct AccountKey final : public CountedObject<AccountKey>
     {
         AccountID account_;
         std::size_t hash_value_;

src/ripple/basics/join.h

@@ -0,0 +1,108 @@
+//------------------------------------------------------------------------------
+/*
+This file is part of rippled: https://github.com/ripple/rippled
+Copyright (c) 2022 Ripple Labs Inc.
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose  with  or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef JOIN_H_INCLUDED
+#define JOIN_H_INCLUDED
+
+#include <string>
+
+namespace ripple {
+
+template <class Stream, class Iter>
+Stream&
+join(Stream& s, Iter iter, Iter end, std::string const& delimiter)
+{
+    if (iter == end)
+        return s;
+    s << *iter;
+    for (++iter; iter != end; ++iter)
+        s << delimiter << *iter;
+    return s;
+}
+
+template <class Collection>
+class CollectionAndDelimiter
+{
+public:
+    Collection const& collection;
+    std::string const delimiter;
+
+    explicit CollectionAndDelimiter(Collection const& c, std::string delim)
+        : collection(c), delimiter(std::move(delim))
+    {
+    }
+
+    template <class Stream>
+    friend Stream&
+    operator<<(Stream& s, CollectionAndDelimiter const& cd)
+    {
+        return join(
+            s,
+            std::begin(cd.collection),
+            std::end(cd.collection),
+            cd.delimiter);
+    }
+};
+
+template <class Collection, std::size_t N>
+class CollectionAndDelimiter<Collection[N]>
+{
+public:
+    Collection const* collection;
+    std::string const delimiter;
+
+    explicit CollectionAndDelimiter(Collection const c[N], std::string delim)
+        : collection(c), delimiter(std::move(delim))
+    {
+    }
+
+    template <class Stream>
+    friend Stream&
+    operator<<(Stream& s, CollectionAndDelimiter const& cd)
+    {
+        return join(s, cd.collection, cd.collection + N, cd.delimiter);
+    }
+};
+
+// Specialization for const char* strings
+template <std::size_t N>
+class CollectionAndDelimiter<char[N]>
+{
+public:
+    char const* collection;
+    std::string const delimiter;
+
+    explicit CollectionAndDelimiter(char const c[N], std::string delim)
+        : collection(c), delimiter(std::move(delim))
+    {
+    }
+
+    template <class Stream>
+    friend Stream&
+    operator<<(Stream& s, CollectionAndDelimiter const& cd)
+    {
+        auto end = cd.collection + N;
+        if (N > 0 && *(end - 1) == '\0')
+            --end;
+        return join(s, cd.collection, end, cd.delimiter);
+    }
+};
+
+}  // namespace ripple
+
+#endif

src/ripple/core/Job.h

@@ -20,6 +20,7 @@
 #ifndef RIPPLE_CORE_JOB_H_INCLUDED
 #define RIPPLE_CORE_JOB_H_INCLUDED
 
+#include <ripple/basics/CountedObject.h>
 #include <ripple/core/ClosureCounter.h>
 #include <ripple/core/LoadMonitor.h>
 #include <functional>
@@ -92,7 +93,7 @@ enum JobType {
     jtNS_WRITE,
 };
 
-class Job
+class Job : public CountedObject<Job>
 {
 public:
     using clock_type = std::chrono::steady_clock;

src/ripple/net/InfoSub.h

@@ -33,7 +33,18 @@ namespace ripple {
 // Operations that clients may wish to perform against the network
 // Master operational handler, server sequencer, network tracker
 
-class PathRequest;
+class InfoSubRequest
+{
+public:
+    using pointer = std::shared_ptr<InfoSubRequest>;
+
+    virtual ~InfoSubRequest() = default;
+
+    virtual Json::Value
+    doClose() = 0;
+    virtual Json::Value
+    doStatus(Json::Value const&) = 0;
+};
 
 /** Manages a client's subscription to data feeds.
  */
@@ -205,13 +216,13 @@ public:
     deleteSubAccountHistory(AccountID const& account);
 
     void
-    clearPathRequest();
+    clearRequest();
 
     void
-    setPathRequest(const std::shared_ptr<PathRequest>& req);
+    setRequest(const std::shared_ptr<InfoSubRequest>& req);
 
-    std::shared_ptr<PathRequest> const&
+    std::shared_ptr<InfoSubRequest> const&
-    getPathRequest();
+    getRequest();
 
 protected:
     std::mutex mLock;
@@ -221,7 +232,7 @@ private:
     Source& m_source;
     hash_set<AccountID> realTimeSubscriptions_;
     hash_set<AccountID> normalSubscriptions_;
-    std::shared_ptr<PathRequest> mPathRequest;
+    std::shared_ptr<InfoSubRequest> request_;
     std::uint64_t mSeq;
     hash_set<AccountID> accountHistorySubscriptions_;
 

src/ripple/net/impl/InfoSub.cpp

@@ -119,21 +119,21 @@ InfoSub::deleteSubAccountHistory(AccountID const& account)
 }
 
 void
-InfoSub::clearPathRequest()
+InfoSub::clearRequest()
 {
-    mPathRequest.reset();
+    request_.reset();
 }
 
 void
-InfoSub::setPathRequest(const std::shared_ptr<PathRequest>& req)
+InfoSub::setRequest(const std::shared_ptr<InfoSubRequest>& req)
 {
-    mPathRequest = req;
+    request_ = req;
 }
 
-const std::shared_ptr<PathRequest>&
+const std::shared_ptr<InfoSubRequest>&
-InfoSub::getPathRequest()
+InfoSub::getRequest()
 {
-    return mPathRequest;
+    return request_;
 }
 
 }  // namespace ripple

src/ripple/protocol/Book.h

@@ -20,6 +20,7 @@
 #ifndef RIPPLE_PROTOCOL_BOOK_H_INCLUDED
 #define RIPPLE_PROTOCOL_BOOK_H_INCLUDED
 
+#include <ripple/basics/CountedObject.h>
 #include <ripple/protocol/Issue.h>
 #include <boost/utility/base_from_member.hpp>
 
@@ -29,7 +30,7 @@ namespace ripple {
     The order book is a pair of Issues called in and out.
     @see Issue.
 */
-class Book
+class Book final : public CountedObject<Book>
 {
 public:
     Issue in;

src/ripple/protocol/STAmount.h

@@ -20,6 +20,7 @@
 #ifndef RIPPLE_PROTOCOL_STAMOUNT_H_INCLUDED
 #define RIPPLE_PROTOCOL_STAMOUNT_H_INCLUDED
 
+#include <ripple/basics/CountedObject.h>
 #include <ripple/basics/IOUAmount.h>
 #include <ripple/basics/LocalValue.h>
 #include <ripple/basics/XRPAmount.h>
@@ -40,7 +41,7 @@ namespace ripple {
 // Wire form:
 // High 8 bits are (offset+142), legal range is, 80 to 22 inclusive
 // Low 56 bits are value, legal range is 10^15 to (10^16 - 1) inclusive
-class STAmount : public STBase
+class STAmount final : public STBase, public CountedObject<STAmount>
 {
 public:
     using mantissa_type = std::uint64_t;

src/ripple/protocol/STPathSet.h

@@ -20,6 +20,7 @@
 #ifndef RIPPLE_PROTOCOL_STPATHSET_H_INCLUDED
 #define RIPPLE_PROTOCOL_STPATHSET_H_INCLUDED
 
+#include <ripple/basics/CountedObject.h>
 #include <ripple/json/json_value.h>
 #include <ripple/protocol/SField.h>
 #include <ripple/protocol/STBase.h>
@@ -30,7 +31,7 @@
 
 namespace ripple {
 
-class STPathElement
+class STPathElement final : public CountedObject<STPathElement>
 {
     unsigned int mType;
     AccountID mAccountID;
@@ -114,7 +115,7 @@ private:
     get_hash(STPathElement const& element);
 };
 
-class STPath
+class STPath final : public CountedObject<STPath>
 {
     std::vector<STPathElement> mPath;
 
@@ -172,7 +173,7 @@ public:
 //------------------------------------------------------------------------------
 
 // A set of zero or more payment paths
-class STPathSet final : public STBase
+class STPathSet final : public STBase, public CountedObject<STPathSet>
 {
     std::vector<STPath> value;
 

src/ripple/rpc/handlers/PathFind.cpp

@@ -51,25 +51,25 @@ doPathFind(RPC::JsonContext& context)
     if (sSubCommand == "create")
     {
         context.loadType = Resource::feeHighBurdenRPC;
-        context.infoSub->clearPathRequest();
+        context.infoSub->clearRequest();
         return context.app.getPathRequests().makePathRequest(
             context.infoSub, lpLedger, context.params);
     }
 
     if (sSubCommand == "close")
     {
-        PathRequest::pointer request = context.infoSub->getPathRequest();
+        InfoSubRequest::pointer request = context.infoSub->getRequest();
 
         if (!request)
             return rpcError(rpcNO_PF_REQUEST);
 
-        context.infoSub->clearPathRequest();
+        context.infoSub->clearRequest();
-        return request->doClose(context.params);
+        return request->doClose();
     }
 
     if (sSubCommand == "status")
     {
-        PathRequest::pointer request = context.infoSub->getPathRequest();
+        InfoSubRequest::pointer request = context.infoSub->getRequest();
 
         if (!request)
             return rpcError(rpcNO_PF_REQUEST);

src/ripple/rpc/impl/TransactionSign.cpp

@@ -223,7 +223,8 @@ checkPayment(
             if (auto ledger = app.openLedger().current())
             {
                 Pathfinder pf(
-                    std::make_shared<RippleLineCache>(ledger),
+                    std::make_shared<RippleLineCache>(
+                        ledger, app.journal("RippleLineCache")),
                     srcAddressID,
                     *dstAccountID,
                     sendMax.issue().currency,

src/test/basics/join_test.cpp

@@ -0,0 +1,105 @@
+//------------------------------------------------------------------------------
+/*
+This file is part of rippled: https://github.com/ripple/rippled
+Copyright (c) 2022 Ripple Labs Inc.
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose  with  or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <test/jtx/Account.h>
+
+#include <ripple/basics/join.h>
+#include <ripple/beast/unit_test.h>
+
+namespace ripple {
+namespace test {
+
+struct join_test : beast::unit_test::suite
+{
+    void
+    run() override
+    {
+        auto test = [this](auto collectionanddelimiter, std::string expected) {
+            std::stringstream ss;
+            // Put something else in the buffer before and after to ensure that
+            // the << operator returns the stream correctly.
+            ss << "(" << collectionanddelimiter << ")";
+            auto const str = ss.str();
+            BEAST_EXPECT(str.substr(1, str.length() - 2) == expected);
+            BEAST_EXPECT(str.front() == '(');
+            BEAST_EXPECT(str.back() == ')');
+        };
+
+        // C++ array
+        test(
+            CollectionAndDelimiter(std::array<int, 4>{2, -1, 5, 10}, "/"),
+            "2/-1/5/10");
+        // One item C++ array edge case
+        test(
+            CollectionAndDelimiter(std::array<std::string, 1>{"test"}, " & "),
+            "test");
+        // Empty C++ array edge case
+        test(CollectionAndDelimiter(std::array<int, 0>{}, ","), "");
+        {
+            // C-style array
+            char letters[4]{'w', 'a', 's', 'd'};
+            test(CollectionAndDelimiter(letters, std::to_string(0)), "w0a0s0d");
+        }
+        {
+            // Auto sized C-style array
+            std::string words[]{"one", "two", "three", "four"};
+            test(CollectionAndDelimiter(words, "\n"), "one\ntwo\nthree\nfour");
+        }
+        {
+            // One item C-style array edge case
+            std::string words[]{"thing"};
+            test(CollectionAndDelimiter(words, "\n"), "thing");
+        }
+        // Initializer list
+        test(
+            CollectionAndDelimiter(std::initializer_list<size_t>{19, 25}, "+"),
+            "19+25");
+        // vector
+        test(
+            CollectionAndDelimiter(std::vector<int>{0, 42}, std::to_string(99)),
+            "09942");
+        {
+            // vector with one item edge case
+            using namespace jtx;
+            test(
+                CollectionAndDelimiter(
+                    std::vector<Account>{Account::master}, "xxx"),
+                Account::master.human());
+        }
+        // empty vector edge case
+        test(CollectionAndDelimiter(std::vector<uint256>{}, ","), "");
+        // C-style string
+        test(CollectionAndDelimiter("string", " "), "s t r i n g");
+        // Empty C-style string edge case
+        test(CollectionAndDelimiter("", "*"), "");
+        // Single char C-style string edge case
+        test(CollectionAndDelimiter("x", "*"), "x");
+        // std::string
+        test(CollectionAndDelimiter(std::string{"string"}, "-"), "s-t-r-i-n-g");
+        // Empty std::string edge case
+        test(CollectionAndDelimiter(std::string{""}, "*"), "");
+        // Single char std::string edge case
+        test(CollectionAndDelimiter(std::string{"y"}, "*"), "y");
+    }
+};  // namespace test
+
+BEAST_DEFINE_TESTSUITE(join, ripple_basics, ripple);
+
+}  // namespace test
+}  // namespace ripple

src/test/jtx/impl/paths.cpp

@@ -33,7 +33,8 @@ paths::operator()(Env& env, JTx& jt) const
     auto const to = env.lookup(jv[jss::Destination].asString());
     auto const amount = amountFromJson(sfAmount, jv[jss::Amount]);
     Pathfinder pf(
-        std::make_shared<RippleLineCache>(env.current()),
+        std::make_shared<RippleLineCache>(
+            env.current(), env.app().journal("RippleLineCache")),
         from,
         to,
         in_.currency,

src/test/rpc/GetCounts_test.cpp

@@ -35,6 +35,9 @@ class GetCounts_test : public beast::unit_test::suite
 
         Json::Value result;
         {
+            using namespace std::chrono_literals;
+            // Add a little delay so the App's "uptime" will have a value.
+            std::this_thread::sleep_for(1s);
             // check counts with no transactions posted
             result = env.rpc("get_counts")[jss::result];
             BEAST_EXPECT(result[jss::status] == "success");