From 4ed593abf617b987ee87ba7d9b0f5a1e7d39ac98 Mon Sep 17 00:00:00 2001
From: Belonogov Nikolay <nikolai.belonogov@vk.team>
Date: Thu, 16 Nov 2023 16:59:41 +0300
Subject: [PATCH] Fix infinite loop when retrying to get a connection

- Fix infinite loop
- CHANGELOG.md

Closes #440
---
 CHANGELOG.md                                  |  1 +
 ...arantoolConnectionSelectionStrategies.java | 37 ++++++++++++-------
 2 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index badb249e5..5eacd0b70 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 ### Bugfixes
 
 - Fix Instant converter to parse 8 bytes datetime ([#408](https://github.com/tarantool/cartridge-java/issues/408))
+- Fix infinite loop when retrying to get a connection ([#440](https://github.com/tarantool/cartridge-java/issues/440))
 
 ### Internal and API changes
 
diff --git a/src/main/java/io/tarantool/driver/api/connection/TarantoolConnectionSelectionStrategies.java b/src/main/java/io/tarantool/driver/api/connection/TarantoolConnectionSelectionStrategies.java
index 659fda020..7ee840544 100644
--- a/src/main/java/io/tarantool/driver/api/connection/TarantoolConnectionSelectionStrategies.java
+++ b/src/main/java/io/tarantool/driver/api/connection/TarantoolConnectionSelectionStrategies.java
@@ -38,9 +38,11 @@ static final class RoundRobinStrategy implements ConnectionSelectionStrategy {
 
         private final TarantoolConnectionIterator connectionIterator;
         private final AtomicInteger available;
+        private final int connectionsCount;
 
         RoundRobinStrategy(Collection<TarantoolConnection> connections) {
-            this.available = new AtomicInteger(connections.size());
+            this.connectionsCount = connections.size();
+            this.available = new AtomicInteger(this.connectionsCount);
             this.connectionIterator = new TarantoolConnectionIterator(connections.stream()
                 .peek(conn -> conn.addConnectionCloseListener(c -> available.getAndDecrement()))
                 .collect(Collectors.toList()));
@@ -48,12 +50,15 @@ static final class RoundRobinStrategy implements ConnectionSelectionStrategy {
 
         @Override
         public TarantoolConnection next() throws NoAvailableConnectionsException {
-            if (available.get() > 0) {
-                while (connectionIterator.hasNext()) {
-                    TarantoolConnection connection = connectionIterator.next();
-                    if (connection.isConnected()) {
-                        return connection;
-                    }
+            int attempts = 0;
+            while (available.get() > 0 && connectionIterator.hasNext()) {
+                TarantoolConnection connection = connectionIterator.next();
+                if (connection.isConnected()) {
+                    return connection;
+                }
+
+                if (++attempts > connectionsCount) {
+                    break;
                 }
             }
             throw new NoAvailableConnectionsException();
@@ -84,10 +89,12 @@ static final class ParallelRoundRobinStrategy implements ConnectionSelectionStra
         private final TarantoolClientConfig config;
         private final CyclingIterator<TarantoolConnectionIterator> iteratorsIterator;
         private final AtomicInteger available;
+        private final int connectionsCount;
 
         ParallelRoundRobinStrategy(TarantoolClientConfig config, Collection<TarantoolConnection> connections) {
             this.config = config;
-            this.available = new AtomicInteger(connections.size());
+            this.connectionsCount = connections.size();
+            this.available = new AtomicInteger(this.connectionsCount);
             this.iteratorsIterator = new CyclingIterator<>(populateIterators(connections));
         }
 
@@ -106,12 +113,14 @@ private Collection<TarantoolConnectionIterator> populateIterators(
 
         @Override
         public TarantoolConnection next() throws NoAvailableConnectionsException {
-            if (available.get() > 0) {
-                while (iteratorsIterator.hasNext()) {
-                    TarantoolConnection connection = iteratorsIterator.next().next();
-                    if (connection.isConnected()) {
-                        return connection;
-                    }
+            int attempts = 0;
+            while (available.get() > 0 && iteratorsIterator.hasNext()) {
+                TarantoolConnection connection = iteratorsIterator.next().next();
+                if (connection.isConnected()) {
+                    return connection;
+                }
+                if (++attempts > connectionsCount) {
+                    break;
                 }
             }
             throw new NoAvailableConnectionsException();