cleaner handling of gnunet-peerinfo results
[oweals/gnunet.git] / src / testing / testing_group.c
index e9bc05a7401e311b731bd5d12af207e7ae889d1e..d878ec1041235dc6519959c5b3f0d677a3c393fc 100644 (file)
@@ -27,7 +27,9 @@
 #include "gnunet_arm_service.h"
 #include "gnunet_testing_lib.h"
 
-#define VERBOSE_TESTING GNUNET_YES
+#define VERBOSE_TESTING GNUNET_NO
+
+#define DEBUG_CHURN GNUNET_NO
 
 /**
  * Lowest port used for GNUnet testing.  Should be high enough to not
@@ -46,7 +48,7 @@
 
 #define MAX_OUTSTANDING_CONNECTIONS 50
 
-#define CONNECT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 160)
+#define CONNECT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 300)
 
 #define CONNECT_ATTEMPTS 8
 
 typedef int (*GNUNET_TESTING_ConnectionProcessor)
 (struct GNUNET_TESTING_PeerGroup *pg, unsigned int first, unsigned int second);
 
+/**
+ * Context for handling churning a peer group
+ */
+struct ChurnContext
+{
+  /**
+   * Callback used to notify of churning finished
+   */
+  GNUNET_TESTING_NotifyCompletion cb;
+
+  /**
+   * Closure for callback
+   */
+  void *cb_cls;
+
+  /**
+   * Number of peers that still need to be started
+   */
+  unsigned int num_to_start;
+
+  /**
+   * Number of peers that still need to be stopped
+   */
+  unsigned int num_to_stop;
+  /**
+   * Number of peers that failed to start
+   */
+  unsigned int num_failed_start;
+
+  /**
+   * Number of peers that failed to stop
+   */
+  unsigned int num_failed_stop;
+};
+
 struct RestartContext
 {
   /**
@@ -164,7 +202,8 @@ struct PeerData
   struct GNUNET_CONTAINER_MultiHashMap *connect_peers_working_set;
 
   /**
-   * Total number of connections this peer has
+   * Temporary variable for topology creation, should be reset before
+   * creating any topology so the count is valid once finished.
    */
   int num_connections;
 };
@@ -239,6 +278,10 @@ struct GNUNET_TESTING_PeerGroup
    */
   unsigned int total;
 
+  /**
+   * At what time should we fail the peer startup process?
+   */
+  struct GNUNET_TIME_Absolute max_timeout;
 };
 
 /**
@@ -423,12 +466,14 @@ add_actual_connections(struct GNUNET_TESTING_PeerGroup *pg, unsigned int first,
   if (add_first)
     {
       GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(pg->peers[first].connect_peers, &hash_second, pg->peers[second].daemon, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
+      pg->peers[first].num_connections++;
       added++;
     }
 
   if (add_second)
     {
       GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(pg->peers[second].connect_peers, &hash_first, pg->peers[first].daemon, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
+      pg->peers[second].num_connections++;
       added++;
     }
 
@@ -507,8 +552,8 @@ add_allowed_connections(struct GNUNET_TESTING_PeerGroup *pg, unsigned int first,
       new_first->daemon = pg->peers[second].daemon;
       new_first->next = pg->peers[first].connected_peers;
       pg->peers[first].connected_peers = new_first;
-      pg->peers[first].num_connections++;
 #endif
+      pg->peers[first].num_connections++;
       added++;
     }
 
@@ -522,6 +567,7 @@ add_allowed_connections(struct GNUNET_TESTING_PeerGroup *pg, unsigned int first,
       pg->peers[second].connected_peers = new_second;
       pg->peers[first].num_connections++;
 #endif
+      pg->peers[second].num_connections++;
       added++;
     }
 
@@ -566,12 +612,14 @@ blacklist_connections(struct GNUNET_TESTING_PeerGroup *pg, unsigned int first, u
   if (add_first)
     {
       GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(pg->peers[first].blacklisted_peers, &hash_second, pg->peers[second].daemon, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
+      pg->peers[first].num_connections++;
       added++;
     }
 
   if (add_second)
     {
       GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(pg->peers[second].blacklisted_peers, &hash_first, pg->peers[first].daemon, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
+      pg->peers[second].num_connections++;
       added++;
     }
 
@@ -630,6 +678,7 @@ unblacklist_connections(struct GNUNET_TESTING_PeerGroup *pg, unsigned int first,
  * existing connections of the target peer.
  *
  * @param pg the peer group we are dealing with
+ * @param proc the connection processor to use
  *
  * @return the number of connections created
  */
@@ -1197,6 +1246,18 @@ friend_file_iterator (void *cls,
   return GNUNET_YES;
 }
 
+struct BlacklistContext
+{
+  /*
+   * The (open) file handle to write to
+   */
+  FILE *temp_file_handle;
+
+  /*
+   * The transport that this peer will be blacklisted on.
+   */
+  char *transport;
+};
 
 /**
  * Iterator for writing blacklist data to appropriate files.
@@ -1212,14 +1273,15 @@ blacklist_file_iterator (void *cls,
                          const GNUNET_HashCode * key,
                          void *value)
 {
-  FILE *temp_blacklist_handle = cls;
+  struct BlacklistContext *blacklist_ctx = cls;
+  //FILE *temp_blacklist_handle = cls;
   struct GNUNET_TESTING_Daemon *peer = value;
   struct GNUNET_PeerIdentity *temppeer;
   struct GNUNET_CRYPTO_HashAsciiEncoded peer_enc;
 
   temppeer = &peer->id;
   GNUNET_CRYPTO_hash_to_enc(&temppeer->hashPubKey, &peer_enc);
-  fprintf(temp_blacklist_handle, "tcp:%s\n", (char *)&peer_enc);
+  fprintf(blacklist_ctx->temp_file_handle, "%s:%s\n", blacklist_ctx->transport, (char *)&peer_enc);
 
   return GNUNET_YES;
 }
@@ -1334,6 +1396,7 @@ create_and_copy_friend_files (struct GNUNET_TESTING_PeerGroup *pg)
       count++;
       if (ret == GNUNET_SYSERR)
         {
+         /* FIXME: why sleep here? -CG */
           sleep(1);
         }
     }
@@ -1353,11 +1416,13 @@ create_and_copy_friend_files (struct GNUNET_TESTING_PeerGroup *pg)
  * to the appropriate place.
  *
  * @param pg the peer group we are dealing with
+ * @param transports space delimited list of transports to blacklist
  */
 static int
-create_and_copy_blacklist_files (struct GNUNET_TESTING_PeerGroup *pg)
+create_and_copy_blacklist_files (struct GNUNET_TESTING_PeerGroup *pg, char *transports)
 {
-  FILE *temp_friend_handle;
+  FILE *temp_file_handle;
+  static struct BlacklistContext blacklist_ctx;
   unsigned int pg_iter;
   char *temp_service_path;
   pid_t *pidarr;
@@ -1368,16 +1433,42 @@ create_and_copy_blacklist_files (struct GNUNET_TESTING_PeerGroup *pg)
   int count;
   int ret;
   int max_wait = 10;
+  int transport_len;
+  unsigned int i;
+  char *pos;
+  char *temp_transports;
 
   pidarr = GNUNET_malloc(sizeof(pid_t) * pg->total);
   for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
     {
       mytemp = GNUNET_DISK_mktemp("blacklist");
       GNUNET_assert(mytemp != NULL);
-      temp_friend_handle = fopen (mytemp, "wt");
-      GNUNET_assert(temp_friend_handle != NULL);
-      GNUNET_CONTAINER_multihashmap_iterate(pg->peers[pg_iter].blacklisted_peers, &blacklist_file_iterator, temp_friend_handle);
-      fclose(temp_friend_handle);
+      temp_file_handle = fopen (mytemp, "wt");
+      GNUNET_assert(temp_file_handle != NULL);
+      temp_transports = GNUNET_strdup(transports);
+      blacklist_ctx.temp_file_handle = temp_file_handle;
+      transport_len = strlen(temp_transports) + 1;
+      pos = NULL;
+
+      for (i = 0; i < transport_len; i++)
+      {
+        if ((temp_transports[i] == ' ') && (pos == NULL))
+          continue; /* At start of string (whitespace) */
+        else if ((temp_transports[i] == ' ') || (temp_transports[i] == '\0')) /* At end of string */
+        {
+          temp_transports[i] = '\0';
+          blacklist_ctx.transport = pos;
+          GNUNET_CONTAINER_multihashmap_iterate(pg->peers[pg_iter].blacklisted_peers, &blacklist_file_iterator, &blacklist_ctx);
+          pos = NULL;
+        } /* At beginning of actual string */
+        else if (pos == NULL)
+        {
+          pos = &temp_transports[i];
+        }
+      }
+
+      GNUNET_free_non_null(temp_transports);
+      fclose(temp_file_handle);
 
       if (GNUNET_OK !=
           GNUNET_CONFIGURATION_get_value_string(pg->peers[pg_iter].daemon->cfg, "PATHS", "SERVICEHOME", &temp_service_path))
@@ -1457,6 +1548,7 @@ create_and_copy_blacklist_files (struct GNUNET_TESTING_PeerGroup *pg)
       count++;
       if (ret == GNUNET_SYSERR)
         {
+         /* FIXME: why sleep here? -CG */
           sleep(1);
         }
     }
@@ -1599,12 +1691,11 @@ copy_allowed_topology (struct GNUNET_TESTING_PeerGroup *pg)
 }
 
 
-/*
+/**
  * Connect the topology as specified by the PeerConnection's
  * of each peer in the peer group
  *
  * @param pg the peer group we are dealing with
- *
  * @return the number of connections that will be attempted
  */
 static int
@@ -1644,7 +1735,7 @@ connect_topology (struct GNUNET_TESTING_PeerGroup *pg)
 }
 
 
-/*
+/**
  * Takes a peer group and creates a topology based on the
  * one specified.  Creates a topology means generates friend
  * files for the peers so they can only connect to those allowed
@@ -1658,6 +1749,8 @@ connect_topology (struct GNUNET_TESTING_PeerGroup *pg)
  * @param topology which topology to connect the peers in
  * @param restrict_topology allow only direct TCP connections in this topology
  *                          use GNUNET_TESTING_TOPOLOGY_NONE for no restrictions
+ * @param restrict_transports space delimited list of transports to blacklist
+ *                            to create restricted topology
  *
  * @return the maximum number of connections were all allowed peers
  *         connected to each other
@@ -1665,7 +1758,8 @@ connect_topology (struct GNUNET_TESTING_PeerGroup *pg)
 int
 GNUNET_TESTING_create_topology (struct GNUNET_TESTING_PeerGroup *pg,
                                 enum GNUNET_TESTING_Topology topology,
-                                enum GNUNET_TESTING_Topology restrict_topology)
+                                enum GNUNET_TESTING_Topology restrict_topology,
+                                char *restrict_transports)
 {
   int ret;
   int num_connections;
@@ -1763,15 +1857,10 @@ GNUNET_TESTING_create_topology (struct GNUNET_TESTING_PeerGroup *pg,
 #endif
     }
 
-  /**
-   * Use the create clique method to initially set all connections
-   * as blacklisted.
-   */
+  /* Use the create clique method to initially set all connections as blacklisted. */
   create_clique (pg, &blacklist_connections);
   unblacklisted_connections = 0;
-  /**
-   * Un-blacklist connections as per the topology specified
-   */
+  /* Un-blacklist connections as per the topology specified */
   switch (restrict_topology)
     {
     case GNUNET_TESTING_TOPOLOGY_CLIQUE:
@@ -1836,9 +1925,9 @@ GNUNET_TESTING_create_topology (struct GNUNET_TESTING_PeerGroup *pg,
       break;
     }
 
-  if (unblacklisted_connections > 0)
+  if ((unblacklisted_connections > 0) && (restrict_transports != NULL))
   {
-    ret = create_and_copy_blacklist_files(pg);
+    ret = create_and_copy_blacklist_files(pg, restrict_transports);
     if (ret != GNUNET_OK)
       {
 #if VERBOSE_TESTING
@@ -1855,8 +1944,6 @@ GNUNET_TESTING_create_topology (struct GNUNET_TESTING_PeerGroup *pg,
 #endif
       }
   }
-
-
   return num_connections;
 }
 
@@ -1904,6 +1991,50 @@ struct MinimumContext
    * Number of conns per peer
    */
   unsigned int num_to_add;
+
+  /**
+   * Permuted array of all possible connections.  Only add the Nth
+   * peer if it's in the Nth position.
+   */
+  unsigned int *pg_array;
+
+  /**
+   * What number is the current element we are iterating over?
+   */
+  unsigned int current;
+};
+
+struct DFSContext
+{
+  /**
+   * The peergroup
+   */
+  struct GNUNET_TESTING_PeerGroup *pg;
+
+  /**
+   * uid of the first peer
+   */
+  uint32_t first_uid;
+
+  /**
+   * uid of the second peer
+   */
+  uint32_t second_uid;
+
+  /**
+   * Peer data for first peer.
+   */
+  struct PeerData *first;
+
+  /**
+   * Which peer has been chosen as the one to add?
+   */
+  unsigned int chosen;
+
+  /**
+   * What number is the current element we are iterating over?
+   */
+  unsigned int current;
 };
 
 /**
@@ -1956,24 +2087,65 @@ minimum_connect_iterator (void *cls,
   struct MinimumContext *min_ctx = cls;
   uint32_t second_pos;
   GNUNET_HashCode first_hash;
+  unsigned int i;
 
   if (GNUNET_CONTAINER_multihashmap_size(min_ctx->first->connect_peers_working_set) < min_ctx->num_to_add)
   {
-    GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(min_ctx->first->connect_peers_working_set, key, value, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
-    GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(min_ctx->first->connect_peers_working_set, key, value, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
-    /* Now we have added this particular connection, remove it from the second peer's map so it's not double counted */
-    uid_from_hash(key, &second_pos);
-    hash_from_uid(min_ctx->first_uid, &first_hash);
-    GNUNET_assert(min_ctx->pg->total > second_pos);
-    GNUNET_assert(GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove(min_ctx->pg->peers[second_pos].connect_peers, &first_hash, min_ctx->first->daemon));
+    for (i = 0; i < min_ctx->num_to_add; i++)
+    {
+      if (min_ctx->pg_array[i] == min_ctx->current)
+      {
+        GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(min_ctx->first->connect_peers_working_set, key, value, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
+        uid_from_hash(key, &second_pos);
+        hash_from_uid(min_ctx->first_uid, &first_hash);
+        GNUNET_assert(min_ctx->pg->total > second_pos);
+        GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(min_ctx->pg->peers[second_pos].connect_peers_working_set, &first_hash, min_ctx->first->daemon, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
+        /* Now we have added this particular connection, remove it from the second peer's map so it's not double counted */
+        GNUNET_assert(GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove(min_ctx->pg->peers[second_pos].connect_peers, &first_hash, min_ctx->first->daemon));
+      }
+    }
+    min_ctx->current++;
     return GNUNET_YES;
   }
   else
     return GNUNET_NO; /* We can stop iterating, we have enough peers! */
 
+}
 
+
+/**
+ * Iterator for adding peers to a connection set based on a depth first search.
+ *
+ * @param cls closure, MinimumContext
+ * @param key the key the second daemon was stored under
+ * @param value the GNUNET_TESTING_Daemon that the first is to connect to
+ *
+ * @return GNUNET_YES to continue iteration
+ */
+static int
+dfs_connect_iterator (void *cls,
+                  const GNUNET_HashCode * key,
+                  void *value)
+{
+  struct DFSContext *dfs_ctx = cls;
+  GNUNET_HashCode first_hash;
+
+  if (dfs_ctx->current == dfs_ctx->chosen)
+    {
+      GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(dfs_ctx->first->connect_peers_working_set, key, value, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
+      uid_from_hash(key, &dfs_ctx->second_uid);
+      hash_from_uid(dfs_ctx->first_uid, &first_hash);
+      GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(dfs_ctx->pg->peers[dfs_ctx->second_uid].connect_peers_working_set, &first_hash, dfs_ctx->first->daemon, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
+      GNUNET_assert(GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove(dfs_ctx->pg->peers[dfs_ctx->second_uid].connect_peers, &first_hash, dfs_ctx->first->daemon));
+      /* Can't remove second from first yet because we are currently iterating, hence the return value in the DFSContext! */
+      return GNUNET_NO; /* We have found our peer, don't iterate more */
+    }
+
+  dfs_ctx->current++;
+  return GNUNET_YES;
 }
 
+
 /**
  * From the set of connections possible, choose percentage percent of connections
  * to actually connect.
@@ -1992,6 +2164,7 @@ choose_random_connections(struct GNUNET_TESTING_PeerGroup *pg, double percentage
       random_ctx.first_uid = pg_iter;
       random_ctx.first = &pg->peers[pg_iter];
       random_ctx.percentage = percentage;
+      random_ctx.pg = pg;
       pg->peers[pg_iter].connect_peers_working_set = GNUNET_CONTAINER_multihashmap_create(pg->total);
       GNUNET_CONTAINER_multihashmap_iterate(pg->peers[pg_iter].connect_peers, &random_connect_iterator, &random_ctx);
       /* Now remove the old connections */
@@ -2022,8 +2195,11 @@ choose_minimum(struct GNUNET_TESTING_PeerGroup *pg, unsigned int num)
   for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
     {
       minimum_ctx.first_uid = pg_iter;
+      minimum_ctx.pg_array = GNUNET_CRYPTO_random_permute(GNUNET_CRYPTO_QUALITY_WEAK, GNUNET_CONTAINER_multihashmap_size(pg->peers[pg_iter].connect_peers));
       minimum_ctx.first = &pg->peers[pg_iter];
+      minimum_ctx.pg = pg;
       minimum_ctx.num_to_add = num;
+      minimum_ctx.current = 0;
       pg->peers[pg_iter].connect_peers_working_set = GNUNET_CONTAINER_multihashmap_create(pg->total);
       GNUNET_CONTAINER_multihashmap_iterate(pg->peers[pg_iter].connect_peers, &minimum_connect_iterator, &minimum_ctx);
     }
@@ -2034,17 +2210,120 @@ choose_minimum(struct GNUNET_TESTING_PeerGroup *pg, unsigned int num)
       GNUNET_CONTAINER_multihashmap_destroy(pg->peers[pg_iter].connect_peers);
       /* And replace with the working set */
       pg->peers[pg_iter].connect_peers = pg->peers[pg_iter].connect_peers_working_set;
+      fprintf(stderr, "Finished! Hashmap size %u\n", GNUNET_CONTAINER_multihashmap_size(pg->peers[pg_iter].connect_peers));
     }
 
 }
 
 
-/*
- * @param pg the peer group struct representing the running peers
- * @param topology which topology to connect the peers in
- * @param options options for connecting the topology
- * @param option_modifier modifier for options that take a parameter
+static unsigned int count_workingset_connections(struct GNUNET_TESTING_PeerGroup *pg)
+{
+  unsigned int count;
+  unsigned int pg_iter;
+
+  count = 0;
+
+  for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
+    {
+      count += GNUNET_CONTAINER_multihashmap_size(pg->peers[pg_iter].connect_peers_working_set);
+    }
+
+  return count;
+}
+
+
+static unsigned int count_allowed_connections(struct GNUNET_TESTING_PeerGroup *pg)
+{
+  unsigned int count;
+  unsigned int pg_iter;
+
+  count = 0;
+
+  for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
+    {
+      count += GNUNET_CONTAINER_multihashmap_size(pg->peers[pg_iter].connect_peers);
+    }
+
+  return count;
+}
+
+/**
+ * From the set of connections possible, choose at least num connections per
+ * peer based on depth first traversal of peer connections.  If DFS leaves
+ * peers unconnected, ensure those peers get connections.
  *
+ * @param pg the peergroup we are dealing with
+ * @param num how many connections at least should each peer have (if possible)?
+ */
+void
+perform_dfs (struct GNUNET_TESTING_PeerGroup *pg, unsigned int num)
+{
+  struct DFSContext dfs_ctx;
+  uint32_t pg_iter;
+  uint32_t dfs_count;
+  uint32_t starting_peer;
+  uint32_t least_connections;
+  GNUNET_HashCode second_hash;
+
+  for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
+    {
+      pg->peers[pg_iter].connect_peers_working_set = GNUNET_CONTAINER_multihashmap_create(num);
+    }
+
+  starting_peer = 0;
+  dfs_count = 0;
+  while ((count_workingset_connections(pg) < num * pg->total) && (count_allowed_connections(pg) > 0))
+    {
+      if (dfs_count % pg->total == 0) /* Restart the DFS at some weakly connected peer */
+        {
+          least_connections = -1; /* Set to very high number */
+          for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
+            {
+              if (GNUNET_CONTAINER_multihashmap_size(pg->peers[pg_iter].connect_peers_working_set) < least_connections)
+                {
+                  starting_peer = pg_iter;
+                  least_connections = GNUNET_CONTAINER_multihashmap_size(pg->peers[pg_iter].connect_peers_working_set);
+                }
+            }
+        }
+
+      if (GNUNET_CONTAINER_multihashmap_size(pg->peers[starting_peer].connect_peers) == 0)  /* Ensure there is at least one peer left to connect! */
+        {
+          dfs_count = 0;
+          continue;
+        }
+
+      /* Choose a random peer from the chosen peers set of connections to add */
+      dfs_ctx.chosen = GNUNET_CRYPTO_random_u32(GNUNET_CRYPTO_QUALITY_WEAK, GNUNET_CONTAINER_multihashmap_size(pg->peers[starting_peer].connect_peers));
+      dfs_ctx.first_uid = starting_peer;
+      dfs_ctx.first = &pg->peers[starting_peer];
+      dfs_ctx.pg = pg;
+      dfs_ctx.current = 0;
+
+      GNUNET_CONTAINER_multihashmap_iterate(pg->peers[starting_peer].connect_peers, &dfs_connect_iterator, &dfs_ctx);
+      /* Remove the second from the first, since we will be continuing the search and may encounter the first peer again! */
+      hash_from_uid(dfs_ctx.second_uid, &second_hash);
+      GNUNET_assert(GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove(pg->peers[starting_peer].connect_peers, &second_hash, pg->peers[dfs_ctx.second_uid].daemon));
+      starting_peer = dfs_ctx.second_uid;
+    }
+
+  for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
+    {
+
+    }
+
+  for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
+    {
+      /* Remove the "old" connections */
+      GNUNET_CONTAINER_multihashmap_destroy(pg->peers[pg_iter].connect_peers);
+      /* And replace with the working set */
+      pg->peers[pg_iter].connect_peers = pg->peers[pg_iter].connect_peers_working_set;
+      fprintf(stderr, "Finished! Hashmap size %u\n", GNUNET_CONTAINER_multihashmap_size(pg->peers[pg_iter].connect_peers));
+    }
+
+}
+
+/**
  * There are many ways to connect peers that are supported by this function.
  * To connect peers in the same topology that was created via the
  * GNUNET_TESTING_create_topology, the topology variable must be set to
@@ -2053,6 +2332,11 @@ choose_minimum(struct GNUNET_TESTING_PeerGroup *pg, unsigned int num)
  * connected.  This could result in some connections being impossible,
  * because some topologies are non-deterministic.
  *
+ * @param pg the peer group struct representing the running peers
+ * @param topology which topology to connect the peers in
+ * @param options options for connecting the topology
+ * @param option_modifier modifier for options that take a parameter
+ * @return the number of connections that will be attempted, GNUNET_SYSERR on error
  */
 int
 GNUNET_TESTING_connect_topology (struct GNUNET_TESTING_PeerGroup *pg,
@@ -2060,8 +2344,6 @@ GNUNET_TESTING_connect_topology (struct GNUNET_TESTING_PeerGroup *pg,
                                  enum GNUNET_TESTING_TopologyOption options,
                                  double option_modifier)
 {
-  int num_connections;
-
   switch (topology)
       {
       case GNUNET_TESTING_TOPOLOGY_CLIQUE:
@@ -2069,80 +2351,81 @@ GNUNET_TESTING_connect_topology (struct GNUNET_TESTING_PeerGroup *pg,
         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                     _("Creating clique topology\n"));
   #endif
-        num_connections = create_clique (pg, &add_actual_connections);
+        create_clique (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_SMALL_WORLD_RING:
   #if VERBOSE_TESTING
         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                     _("Creating small world (ring) topology\n"));
   #endif
-        num_connections = create_small_world_ring (pg, &add_actual_connections);
+        create_small_world_ring (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_SMALL_WORLD:
   #if VERBOSE_TESTING
         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                     _("Creating small world (2d-torus) topology\n"));
   #endif
-        num_connections = create_small_world (pg, &add_actual_connections);
+        create_small_world (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_RING:
   #if VERBOSE_TESTING
         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                     _("Creating ring topology\n"));
   #endif
-        num_connections = create_ring (pg, &add_actual_connections);
+        create_ring (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_2D_TORUS:
   #if VERBOSE_TESTING
         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                     _("Creating 2d torus topology\n"));
   #endif
-        num_connections = create_2d_torus (pg, &add_actual_connections);
+        create_2d_torus (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_ERDOS_RENYI:
   #if VERBOSE_TESTING
         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                     _("Creating Erdos-Renyi topology\n"));
   #endif
-        num_connections = create_erdos_renyi (pg, &add_actual_connections);
+        create_erdos_renyi (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_INTERNAT:
   #if VERBOSE_TESTING
         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                     _("Creating InterNAT topology\n"));
   #endif
-        num_connections = create_nated_internet (pg, &add_actual_connections);
+        create_nated_internet (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_SCALE_FREE:
   #if VERBOSE_TESTING
         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                     _("Creating Scale Free topology\n"));
   #endif
-        num_connections = create_scale_free (pg, &add_actual_connections);
+        create_scale_free (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_NONE:
-        num_connections = copy_allowed_topology(pg);
+        copy_allowed_topology(pg);
         break;
       default:
-        GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Unknown topology specification, can't connect peers!\n");
+        GNUNET_log(GNUNET_ERROR_TYPE_WARNING, 
+                  _("Unknown topology specification, can't connect peers!\n"));
         return GNUNET_SYSERR;
       }
 
   switch (options)
     {
-    case GNUNET_TESTING_TOPOLOGY_OPTION_RANDOM: /* Create a random subset of total connections based on parameter */
+    case GNUNET_TESTING_TOPOLOGY_OPTION_RANDOM: 
       choose_random_connections(pg, option_modifier);
       break;
-    case GNUNET_TESTING_TOPOLOGY_OPTION_MINIMUM: /* Create at least X connections per peer (if possible!) */
+    case GNUNET_TESTING_TOPOLOGY_OPTION_MINIMUM: 
       choose_minimum(pg, (unsigned int)option_modifier);
       break;
-    case GNUNET_TESTING_TOPOLOGY_OPTION_DFS: /* Choose a random starting point, randomly walk graph, try to get each peer X connections */
-      //choose_dfs(pg, (int)option_modifier);
+    case GNUNET_TESTING_TOPOLOGY_OPTION_DFS: 
+      perform_dfs(pg, (int)option_modifier);
       break;
     case GNUNET_TESTING_TOPOLOGY_OPTION_NONE:
-      /* Fall through */
+      break;
     case GNUNET_TESTING_TOPOLOGY_OPTION_ALL:
-      /* Fall through */
+      break;
     default:
       break;
     }
@@ -2177,6 +2460,7 @@ GNUNET_TESTING_daemons_continue_startup(struct GNUNET_TESTING_PeerGroup *pg)
  * @param sched scheduler to use
  * @param cfg configuration template to use
  * @param total number of daemons to start
+ * @param timeout total time allowed for peers to start
  * @param hostkey_callback function to call on each peers hostkey generation
  *        if NULL, peers will be started by this call, if non-null,
  *        GNUNET_TESTING_daemons_continue_startup must be called after
@@ -2194,6 +2478,7 @@ struct GNUNET_TESTING_PeerGroup *
 GNUNET_TESTING_daemons_start (struct GNUNET_SCHEDULER_Handle *sched,
                               const struct GNUNET_CONFIGURATION_Handle *cfg,
                               unsigned int total,
+                              struct GNUNET_TIME_Relative timeout,
                               GNUNET_TESTING_NotifyHostkeyCreated hostkey_callback,
                               void *hostkey_cls,
                               GNUNET_TESTING_NotifyDaemonRunning cb,
@@ -2229,6 +2514,7 @@ GNUNET_TESTING_daemons_start (struct GNUNET_SCHEDULER_Handle *sched,
   pg->notify_connection = connect_callback;
   pg->notify_connection_cls = connect_callback_cls;
   pg->total = total;
+  pg->max_timeout = GNUNET_TIME_relative_to_absolute(timeout);
   pg->peers = GNUNET_malloc (total * sizeof (struct PeerData));
   if (NULL != hostnames)
     {
@@ -2330,6 +2616,7 @@ GNUNET_TESTING_daemons_start (struct GNUNET_SCHEDULER_Handle *sched,
       pg->peers[off].pg = pg;
       pg->peers[off].daemon = GNUNET_TESTING_daemon_start (sched,
                                                            pcfg,
+                                                           timeout,
                                                            hostname,
                                                            hostkey_callback,
                                                            hostkey_cls,
@@ -2359,7 +2646,9 @@ GNUNET_TESTING_daemon_get (struct GNUNET_TESTING_PeerGroup *pg, unsigned int pos
  * Prototype of a function that will be called when a
  * particular operation was completed the testing library.
  *
- * @param cls closure
+ * @param id id of the peer that was restarted
+ * @param cfg handle to the configuration of the peer
+ * @param d handle to the daemon that was restarted
  * @param emsg NULL on success
  */
 void restart_callback (void *cls,
@@ -2392,11 +2681,232 @@ void restart_callback (void *cls,
 
 }
 
+/**
+ * Callback for informing us about a successful
+ * or unsuccessful churn stop call.
+ *
+ * @param cls a ChurnContext
+ * @param emsg NULL on success, non-NULL on failure
+ *
+ */
+void
+churn_stop_callback (void *cls, const char *emsg)
+{
+  struct ChurnContext *churn_ctx = cls;
+  unsigned int total_left;
+  char *error_message;
+
+  error_message = NULL;
+  if (emsg != NULL)
+  {
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Churn stop callback failed with error `%s'\n", emsg);
+    churn_ctx->num_failed_stop++;
+  }
+  else
+  {
+    churn_ctx->num_to_stop--;
+  }
+
+#if DEBUG_CHURN
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Stopped peer, %d left.\n", churn_ctx->num_to_stop);
+#endif
+  total_left = (churn_ctx->num_to_stop - churn_ctx->num_failed_stop) + (churn_ctx->num_to_start - churn_ctx->num_failed_start);
+
+  if (total_left == 0)
+  {
+    if ((churn_ctx->num_failed_stop > 0) || (churn_ctx->num_failed_start > 0))
+      {
+        GNUNET_asprintf(&error_message, "Churn didn't complete successfully, %u peers failed to start %u peers failed to be stopped!", churn_ctx->num_failed_start, churn_ctx->num_failed_stop);
+      }
+    churn_ctx->cb(churn_ctx->cb_cls, error_message);
+    GNUNET_free_non_null(error_message);
+    GNUNET_free(churn_ctx);
+  }
+}
+
+/**
+ * Callback for informing us about a successful
+ * or unsuccessful churn start call.
+ *
+ * @param cls a ChurnContext
+ * @param id the peer identity of the started peer
+ * @param cfg the handle to the configuration of the peer
+ * @param d handle to the daemon for the peer
+ * @param emsg NULL on success, non-NULL on failure
+ *
+ */
+void
+churn_start_callback (void *cls,
+                      const struct GNUNET_PeerIdentity *id,
+                      const struct GNUNET_CONFIGURATION_Handle *cfg,
+                      struct GNUNET_TESTING_Daemon *d,
+                      const char *emsg)
+{
+  struct ChurnContext *churn_ctx = cls;
+  unsigned int total_left;
+  char *error_message;
+
+  error_message = NULL;
+  if (emsg != NULL)
+  {
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Churn stop callback failed with error `%s'\n", emsg);
+    churn_ctx->num_failed_start++;
+  }
+  else
+  {
+    churn_ctx->num_to_start--;
+  }
+
+#if DEBUG_CHURN
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Started peer, %d left.\n", churn_ctx->num_to_start);
+#endif
+
+  total_left = (churn_ctx->num_to_stop - churn_ctx->num_failed_stop) + (churn_ctx->num_to_start - churn_ctx->num_failed_start);
+
+  if (total_left == 0)
+  {
+    if ((churn_ctx->num_failed_stop > 0) || (churn_ctx->num_failed_start > 0))
+      GNUNET_asprintf(&error_message, "Churn didn't complete successfully, %u peers failed to start %u peers failed to be stopped!", churn_ctx->num_failed_start, churn_ctx->num_failed_stop);
+    churn_ctx->cb(churn_ctx->cb_cls, error_message);
+    GNUNET_free_non_null(error_message);
+    GNUNET_free(churn_ctx);
+  }
+
+}
+
+/**
+ * Simulate churn by stopping some peers (and possibly
+ * re-starting others if churn is called multiple times).  This
+ * function can only be used to create leave-join churn (peers "never"
+ * leave for good).  First "voff" random peers that are currently
+ * online will be taken offline; then "von" random peers that are then
+ * offline will be put back online.  No notifications will be
+ * generated for any of these operations except for the callback upon
+ * completion.
+ *
+ * @param pg handle for the peer group
+ * @param voff number of peers that should go offline
+ * @param von number of peers that should come back online;
+ *            must be zero on first call (since "testbed_start"
+ *            always starts all of the peers)
+ * @param timeout how long to wait for operations to finish before
+ *        giving up
+ * @param cb function to call at the end
+ * @param cb_cls closure for cb
+ */
+void
+GNUNET_TESTING_daemons_churn (struct GNUNET_TESTING_PeerGroup *pg,
+                              unsigned int voff,
+                              unsigned int von,
+                              struct GNUNET_TIME_Relative timeout,
+                              GNUNET_TESTING_NotifyCompletion cb,
+                              void *cb_cls)
+{
+  struct ChurnContext *churn_ctx;
+  unsigned int running;
+  unsigned int stopped;
+  unsigned int i;
+  unsigned int *running_arr;
+  unsigned int *stopped_arr;
+  unsigned int *running_permute;
+  unsigned int *stopped_permute;
+
+  running = 0;
+  stopped = 0;
+
+  if ((von == 0) && (voff == 0)) /* No peers at all? */
+    {
+      cb(cb_cls, NULL);
+      return;
+    }
+
+  for (i = 0; i < pg->total; i++)
+  {
+    if (pg->peers[i].daemon->running == GNUNET_YES)
+    {
+      running++;
+    }
+    else
+    {
+      stopped++;
+    }
+  }
+
+  if (voff > running)
+  {
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Trying to stop more peers than are currently running!\n");
+    cb(cb_cls, "Trying to stop more peers than are currently running!");
+    return;
+  }
+
+  if (von > stopped)
+  {
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Trying to start more peers than are currently stopped!\n");
+    cb(cb_cls, "Trying to start more peers than are currently stopped!");
+    return;
+  }
+
+  churn_ctx = GNUNET_malloc(sizeof(struct ChurnContext));
+  running_arr = GNUNET_malloc(running * sizeof(unsigned int));
+  stopped_arr = GNUNET_malloc(stopped * sizeof(unsigned int));
+
+  running_permute = NULL;
+  stopped_permute = NULL;
+
+  if (running > 0)
+    running_permute = GNUNET_CRYPTO_random_permute(GNUNET_CRYPTO_QUALITY_WEAK, running);
+  if (stopped > 0)
+    stopped_permute = GNUNET_CRYPTO_random_permute(GNUNET_CRYPTO_QUALITY_WEAK, stopped);
+
+  running = 0;
+  stopped = 0;
+
+  churn_ctx->num_to_start = von;
+  churn_ctx->num_to_stop = voff;
+  churn_ctx->cb = cb;
+  churn_ctx->cb_cls = cb_cls;  
+
+  for (i = 0; i < pg->total; i++)
+  {
+    if (pg->peers[i].daemon->running == GNUNET_YES)
+    {
+      running_arr[running] = i;
+      running++;
+    }
+    else
+    {
+      stopped_arr[stopped] = i;
+      stopped++;
+    }
+  }
+
+  for (i = 0; i < voff; i++)
+  {
+#if DEBUG_CHURN
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Stopping peer %d!\n", running_permute[i]);
+#endif
+    GNUNET_TESTING_daemon_stop(pg->peers[running_arr[running_permute[i]]].daemon, timeout, &churn_stop_callback, churn_ctx, GNUNET_NO, GNUNET_YES);
+  }
+
+  for (i = 0; i < von; i++)
+  {
+#if DEBUG_CHURN
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Starting up peer %d!\n", stopped_permute[i]);
+#endif
+    GNUNET_TESTING_daemon_start_stopped(pg->peers[stopped_arr[stopped_permute[i]]].daemon, timeout, &churn_start_callback, churn_ctx);
+  }
+
+  GNUNET_free(running_arr);
+  GNUNET_free(stopped_arr);
+  GNUNET_free_non_null(running_permute);
+  GNUNET_free_non_null(stopped_permute);
+}
+
+
 /**
  * Restart all peers in the given group.
  *
  * @param pg the handle to the peer group
- * @param timeout how long to wait on failure
  * @param callback function to call on completion (or failure)
  * @param callback_cls closure for the callback function
  */
@@ -2425,9 +2935,11 @@ GNUNET_TESTING_daemons_restart (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TEST
  * Shutdown all peers started in the given group.
  *
  * @param pg handle to the peer group
+ * @param timeout how long to wait for shutdown
+ *
  */
 void
-GNUNET_TESTING_daemons_stop (struct GNUNET_TESTING_PeerGroup *pg)
+GNUNET_TESTING_daemons_stop (struct GNUNET_TESTING_PeerGroup *pg, struct GNUNET_TIME_Relative timeout)
 {
   unsigned int off;
 
@@ -2439,13 +2951,16 @@ GNUNET_TESTING_daemons_stop (struct GNUNET_TESTING_PeerGroup *pg)
          as well... */
 
       if (NULL != pg->peers[off].daemon)
-        GNUNET_TESTING_daemon_stop (pg->peers[off].daemon, NULL, NULL, GNUNET_YES);
+        GNUNET_TESTING_daemon_stop (pg->peers[off].daemon, timeout, NULL, NULL, GNUNET_YES, GNUNET_NO);
       if (NULL != pg->peers[off].cfg)
         GNUNET_CONFIGURATION_destroy (pg->peers[off].cfg);
 
-      GNUNET_CONTAINER_multihashmap_destroy(pg->peers[off].allowed_peers);
-      GNUNET_CONTAINER_multihashmap_destroy(pg->peers[off].connect_peers);
-      GNUNET_CONTAINER_multihashmap_destroy(pg->peers[off].blacklisted_peers);
+      if (pg->peers[off].allowed_peers != NULL)
+        GNUNET_CONTAINER_multihashmap_destroy(pg->peers[off].allowed_peers);
+      if (pg->peers[off].connect_peers != NULL)
+        GNUNET_CONTAINER_multihashmap_destroy(pg->peers[off].connect_peers);
+      if (pg->peers[off].blacklisted_peers != NULL)
+        GNUNET_CONTAINER_multihashmap_destroy(pg->peers[off].blacklisted_peers);
 
     }
   GNUNET_free (pg->peers);