From 680ebe51b060d217fb9a317dfb29985da70a6141 Mon Sep 17 00:00:00 2001
From: Andreas Schildbach <andreas@schildbach.de>
Date: Wed, 21 Oct 2015 18:00:38 +0200
Subject: [PATCH] Make peer discovery timeout configurable. Add milliseconds to
 error message if timeout kicks in.

---
 .../main/java/org/bitcoinj/core/PeerGroup.java   | 16 +++++++++++++---
 .../net/discovery/MultiplexingDiscovery.java     |  3 ++-
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/core/src/main/java/org/bitcoinj/core/PeerGroup.java b/core/src/main/java/org/bitcoinj/core/PeerGroup.java
index 2cafb7ea..c96e0b5b 100644
--- a/core/src/main/java/org/bitcoinj/core/PeerGroup.java
+++ b/core/src/main/java/org/bitcoinj/core/PeerGroup.java
@@ -79,6 +79,8 @@ public class PeerGroup implements TransactionBroadcaster {
     public static final int DEFAULT_CONNECTIONS = 12;
     private static final int TOR_TIMEOUT_SECONDS = 60;
     private volatile int vMaxPeersToDiscoverCount = 100;
+    private static final long DEFAULT_PEER_DISCOVERY_TIMEOUT_MILLIS = 5000;
+    private volatile long vPeerDiscoveryTimeoutMillis = DEFAULT_PEER_DISCOVERY_TIMEOUT_MILLIS;
 
     protected final ReentrantLock lock = Threading.lock("peergroup");
 
@@ -420,6 +422,13 @@ public class PeerGroup implements TransactionBroadcaster {
         return result;
     }
 
+    /**
+     * This is how many milliseconds we wait for peer discoveries to return their results.
+     */
+    public void setPeerDiscoveryTimeoutMillis(long peerDiscoveryTimeoutMillis) {
+        this.vPeerDiscoveryTimeoutMillis = peerDiscoveryTimeoutMillis;
+    }
+
     /**
      * Adjusts the desired number of connections that we will create to peers. Note that if there are already peers
      * open and the new value is lower than the current number of peers, those connections will be terminated. Likewise
@@ -786,11 +795,12 @@ public class PeerGroup implements TransactionBroadcaster {
         // Don't hold the lock whilst doing peer discovery: it can take a long time and cause high API latency.
         checkState(!lock.isHeldByCurrentThread());
         int maxPeersToDiscoverCount = this.vMaxPeersToDiscoverCount;
+        long peerDiscoveryTimeoutMillis = this.vPeerDiscoveryTimeoutMillis;
         long start = System.currentTimeMillis();
         final List<PeerAddress> addressList = Lists.newLinkedList();
         for (PeerDiscovery peerDiscovery : peerDiscoverers /* COW */) {
             InetSocketAddress[] addresses;
-            addresses = peerDiscovery.getPeers(5, TimeUnit.SECONDS);
+            addresses = peerDiscovery.getPeers(peerDiscoveryTimeoutMillis, TimeUnit.MILLISECONDS);
             for (InetSocketAddress address : addresses) addressList.add(new PeerAddress(address));
             if (addressList.size() >= maxPeersToDiscoverCount) break;
         }
@@ -808,8 +818,8 @@ public class PeerGroup implements TransactionBroadcaster {
                 });
             }
         }
-        log.info("Peer discovery took {}msec and returned {} items",
-                System.currentTimeMillis() - start, addressList.size());
+        log.info("Peer discovery took {}ms and returned {} items", System.currentTimeMillis() - start,
+                addressList.size());
         return addressList.size();
     }
 
diff --git a/core/src/main/java/org/bitcoinj/net/discovery/MultiplexingDiscovery.java b/core/src/main/java/org/bitcoinj/net/discovery/MultiplexingDiscovery.java
index db6e3b7d..6855dbee 100644
--- a/core/src/main/java/org/bitcoinj/net/discovery/MultiplexingDiscovery.java
+++ b/core/src/main/java/org/bitcoinj/net/discovery/MultiplexingDiscovery.java
@@ -82,7 +82,8 @@ public class MultiplexingDiscovery implements PeerDiscovery {
                 Collections.addAll(addrs, inetAddresses);
             }
             if (addrs.size() == 0)
-                throw new PeerDiscoveryException("No peer discovery returned any results: check internet connection?");
+                throw new PeerDiscoveryException("No peer discovery returned any results in "
+                        + timeoutUnit.toMillis(timeoutValue) + "ms. Check internet connection?");
             Collections.shuffle(addrs);
             vThreadPool.shutdownNow();
             return addrs.toArray(new InetSocketAddress[addrs.size()]);