Fixed the kernel shutdown hanging due to the synchronized lock

aionnetwork · Mar 18, 2020 · 24ecb9f · 24ecb9f
1 parent 12f8c0d
commit 24ecb9f
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Showing 2 changed files with 27 additions and 8 deletions.
diff --git a/modAionImpl/src/org/aion/zero/impl/blockchain/AionBlockchainImpl.java b/modAionImpl/src/org/aion/zero/impl/blockchain/AionBlockchainImpl.java
@@ -10,6 +10,7 @@
 
 import java.util.EnumMap;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.ReentrantLock;
 import org.aion.log.LogUtil;
 import org.aion.zero.impl.blockchain.AionHub.BestBlockImportCallback;
@@ -204,6 +205,7 @@ public class AionBlockchainImpl implements IAionBlockchain {
     private SelfNodeStatusCallback callback;
     private BestBlockImportCallback bestBlockCallback;
     ReentrantLock blockChainCoreLock = new ReentrantLock();
+    private AtomicBoolean shutDownFlag = new AtomicBoolean();
 
     /**
      * The constructor for the blockchain initialization {@see AionHub}.
@@ -921,14 +923,19 @@ public ImportResult tryToConnect(final Block block) {
     public ImportResult tryToConnect(final BlockWrapper blockWrapper) {
         blockChainCoreLock.lock();
         try {
-            checkKernelShutdownForCLI();
-            return tryToConnectWithTimedExecution(blockWrapper).getLeft();
+            if (!checkKernelShutdownForCLI()) {
+                return tryToConnectWithTimedExecution(blockWrapper).getLeft();
+            } else {
+                // Return a result and then shutdown the kernel in the finally condition
+                return ImportResult.KERNEL_EXIT;
+            }
         } finally{
             blockChainCoreLock.unlock();
+            checkKernelExit();
         }
     }
 
-    private void checkKernelShutdownForCLI() {
+    private boolean checkKernelShutdownForCLI() {
         if (bestBlock.getNumber() == shutdownHook) {
             LOG.info("Shutting down and dumping heap as indicated by CLI request since block number {} was reached.", shutdownHook);
 
@@ -938,12 +945,14 @@ private void checkKernelShutdownForCLI() {
                 LOG.error("Unable to dump heap due to exception:", e);
             }
 
-            // requested shutdown
-            System.exit(SystemExitCodes.NORMAL);
+            shutDownFlag.set(true);
+            return true;
         } else if (enableFullSyncCheck && reachedFullSync) {
             LOG.info("Shutting down as indicated by CLI request sync to the top {} was reached.", bestBlock.getNumber());
-            System.exit(SystemExitCodes.NORMAL);
+            shutDownFlag.set(true);
+            return true;
         }
+        return false;
     }
 
     /**
@@ -965,7 +974,9 @@ public Triple<Long, Set<ByteArrayWrapper>, ImportResult> tryToConnect(final List
             ImportResult importResult = null;
             Set<ByteArrayWrapper> imported = new HashSet<>();
             for (Block block : blockRange) {
-                checkKernelShutdownForCLI();
+                if (checkKernelShutdownForCLI()) {
+                    break;
+                }
 
                 Pair<ImportResult, Long> result = tryToConnectWithTimedExecution(new BlockWrapper(block));
                 importResult = result.getLeft();
@@ -994,6 +1005,7 @@ public Triple<Long, Set<ByteArrayWrapper>, ImportResult> tryToConnect(final List
             return Triple.of(bestBlock.getNumber(), imported, importResult);
         } finally{
             blockChainCoreLock.unlock();
+            checkKernelExit();
         }
     }
 
@@ -2746,4 +2758,10 @@ public void load(AionGenesis genesis, Logger genLOG) {
             }
         }
     }
+
+    private void checkKernelExit() {
+        if (shutDownFlag.get()) {
+            System.exit(SystemExitCodes.NORMAL);
+        }
+    }
 }
diff --git a/modAionImpl/src/org/aion/zero/impl/core/ImportResult.java b/modAionImpl/src/org/aion/zero/impl/core/ImportResult.java
@@ -7,7 +7,8 @@ public enum ImportResult {
     EXIST,
     NO_PARENT,
     INVALID_BLOCK,
-    CONSENSUS_BREAK;
+    CONSENSUS_BREAK,
+    KERNEL_EXIT;
 
     public boolean isSuccessful() {
         return equals(IMPORTED_BEST) || equals(IMPORTED_NOT_BEST);