Handle case when active_peers is empty.

[simgrid.git] / examples / s4u / app-bittorrent / s4u_peer.cpp

diff --git a/examples/s4u/app-bittorrent/s4u_peer.cpp b/examples/s4u/app-bittorrent/s4u_peer.cpp
index 79157bc..a9c38f8 100644 (file)
--- a/examples/s4u/app-bittorrent/s4u_peer.cpp
+++ b/examples/s4u/app-bittorrent/s4u_peer.cpp
@@ -18,7 +18,6 @@ XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_bt_peer, "Messages specific for the peers");
 #define FILE_PIECES 10UL
 #define PIECES_BLOCKS 5UL
 #define BLOCK_SIZE 16384
-static const unsigned long int FILE_SIZE = FILE_PIECES * PIECES_BLOCKS * BLOCK_SIZE;
 
 /** Number of blocks asked by each request */
 #define BLOCKS_REQUESTED 2
@@ -547,8 +546,13 @@ void Peer::updateChokedPeers()
   round_                  = (round_ + 1) % 3;
   Connection* chosen_peer = nullptr;
   // select first active peer and remove it from the set
-  Connection* choked_peer = *(active_peers.begin());
-  active_peers.erase(choked_peer);
+  Connection* choked_peer;
+  if (active_peers.empty()) {
+    choked_peer = nullptr;
+  } else {
+    choked_peer = *active_peers.begin();
+    active_peers.erase(choked_peer);
+  }
 
   /**If we are currently seeding, we unchoke the peer which has been unchoked the last time.*/
   if (hasFinished()) {