Avoid dispatching multiple fetch pack threads

XRPLF · Sep 30, 2018 · 4dcb3c9 · 4dcb3c9
1 parent b0092ae
commit 4dcb3c9
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Showing 2 changed files with 12 additions and 7 deletions.
diff --git a/src/ripple/app/ledger/LedgerMaster.h b/src/ripple/app/ledger/LedgerMaster.h
@@ -337,6 +337,8 @@ class LedgerMaster
     int     mPathFindThread {0};    // Pathfinder jobs dispatched
     bool    mPathFindNewRequest {false};
 
+    std::atomic_flag mGotFetchPackThread = ATOMIC_FLAG_INIT; // GotFetchPack jobs dispatched
+
     std::atomic <std::uint32_t> mPubLedgerClose {0};
     std::atomic <LedgerIndex> mPubLedgerSeq {0};
     std::atomic <std::uint32_t> mValidLedgerSign {0};

diff --git a/src/ripple/app/ledger/impl/LedgerMaster.cpp b/src/ripple/app/ledger/impl/LedgerMaster.cpp
@@ -1790,13 +1790,16 @@ LedgerMaster::gotFetchPack (
     bool progress,
     std::uint32_t seq)
 {
-    // FIXME: Calling this function more than once will result in
-    // InboundLedgers::gotFetchPack being called more than once
-    // which is expensive. A flag should track whether we've already dispatched
-
-    app_.getJobQueue().addJob (
-        jtLEDGER_DATA, "gotFetchPack",
-        [&] (Job&) { app_.getInboundLedgers().gotFetchPack(); });
+    if (!mGotFetchPackThread.test_and_set(std::memory_order_acquire))
+    {
+        app_.getJobQueue().addJob (
+            jtLEDGER_DATA, "gotFetchPack",
+            [&] (Job&)
+            {
+                app_.getInboundLedgers().gotFetchPack();
+                mGotFetchPackThread.clear(std::memory_order_release);
+            });
+    }
 }
 
 void