From 704b985121fd18a66aa35c54751e574d4fcd88fa Mon Sep 17 00:00:00 2001
From: Ivan Vilata-i-Balaguer <ivan@selidor.net>
Date: Thu, 5 May 2016 09:36:49 +0200
Subject: [PATCH] Avoid race condition on timer creation in
 ``PeerExchangeHandler.sendGetPeersRequest()``

If the timer is created after sending the message and establishing callbacks, they may have already run on timer creation so it would be pointless (and issue a warning when triggered).
---
 .../peerexchange/PeerExchangeHandler.java     | 31 ++++++++++---------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/network/src/main/java/io/bitsquare/p2p/peers/peerexchange/PeerExchangeHandler.java b/network/src/main/java/io/bitsquare/p2p/peers/peerexchange/PeerExchangeHandler.java
index 8cf25d0b77..73cc630f8c 100644
--- a/network/src/main/java/io/bitsquare/p2p/peers/peerexchange/PeerExchangeHandler.java
+++ b/network/src/main/java/io/bitsquare/p2p/peers/peerexchange/PeerExchangeHandler.java
@@ -84,6 +84,22 @@ class PeerExchangeHandler implements MessageListener {
         if (!stopped) {
             if (networkNode.getNodeAddress() != null) {
                 GetPeersRequest getPeersRequest = new GetPeersRequest(networkNode.getNodeAddress(), nonce, peerManager.getConnectedNonSeedNodeReportedPeers(nodeAddress));
+
+                if (timeoutTimer == null) {  // setup before sending to avoid race conditions
+                    timeoutTimer = UserThread.runAfter(() -> {
+                                if (!stopped) {
+                                    String errorMessage = "A timeout occurred at sending getPeersRequest:" + getPeersRequest + " for nodeAddress:" + nodeAddress;
+                                    log.info(errorMessage + " / PeerExchangeHandler=" +
+                                            PeerExchangeHandler.this);
+                                    log.info("timeoutTimer called on " + this);
+                                    handleFault(errorMessage, CloseConnectionReason.SEND_MSG_TIMEOUT, nodeAddress);
+                                } else {
+                                    log.trace("We have stopped that handler already. We ignore that timeoutTimer.run call.");
+                                }
+                            },
+                            TIME_OUT_SEC, TimeUnit.SECONDS);
+                }
+
                 SettableFuture<Connection> future = networkNode.sendMessage(nodeAddress, getPeersRequest);
                 Futures.addCallback(future, new FutureCallback<Connection>() {
                     @Override
@@ -116,21 +132,6 @@ class PeerExchangeHandler implements MessageListener {
                         }
                     }
                 });
-
-                if (timeoutTimer == null) {
-                    timeoutTimer = UserThread.runAfter(() -> {
-                                if (!stopped) {
-                                    String errorMessage = "A timeout occurred at sending getPeersRequest:" + getPeersRequest + " for nodeAddress:" + nodeAddress;
-                                    log.info(errorMessage + " / PeerExchangeHandler=" +
-                                            PeerExchangeHandler.this);
-                                    log.info("timeoutTimer called on " + this);
-                                    handleFault(errorMessage, CloseConnectionReason.SEND_MSG_TIMEOUT, nodeAddress);
-                                } else {
-                                    log.trace("We have stopped that handler already. We ignore that timeoutTimer.run call.");
-                                }
-                            },
-                            TIME_OUT_SEC, TimeUnit.SECONDS);
-                }
             } else {
                 log.debug("My node address is still null at sendGetPeersRequest. We ignore that call.");
             }