use a consistent random number generator to make simulations deterministic

include/libtorrent/random.hpp

@@ -36,4 +36,5 @@ POSSIBILITY OF SUCH DAMAGE.
 namespace libtorrent
 {
 	boost::uint32_t TORRENT_EXTRA_EXPORT random();
+	boost::uint32_t TORRENT_EXTRA_EXPORT randint(int i);
 }

src/http_connection.cpp

@@ -40,6 +40,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/resolver_interface.hpp"
 #include "libtorrent/settings_pack.hpp"
 #include "libtorrent/aux_/time.hpp"
+#include "libtorrent/random.hpp"
 
 #if defined TORRENT_ASIO_DEBUGGING
 #include "libtorrent/debug.hpp"
@@ -552,7 +553,7 @@ void http_connection::on_resolve(error_code const& e
 		return;
 	}
 
-	std::random_shuffle(m_endpoints.begin(), m_endpoints.end());
+	std::random_shuffle(m_endpoints.begin(), m_endpoints.end(), randint);
 
 	// The following statement causes msvc to crash (ICE). Since it's not
 	// necessary in the vast majority of cases, just ignore the endpoint

src/piece_picker.cpp

@@ -1564,7 +1564,7 @@ namespace libtorrent
 			, end(m_priority_boundries.end()); i != end; ++i)
 		{
 			if (start == *i) continue;
-			std::random_shuffle(&m_pieces[0] + start, &m_pieces[0] + *i);
+			std::random_shuffle(&m_pieces[0] + start, &m_pieces[0] + *i, randint);
 			start = *i;
 		}
 

src/random.cpp

@@ -94,5 +94,10 @@ namespace libtorrent
 
 #endif // TORRENT_BUILD_SIMULATOR
 
+	boost::uint32_t TORRENT_EXTRA_EXPORT randint(int i)
+	{
+		return random() % i;
+	}
+
 }
 

src/session_impl.cpp

@@ -3765,7 +3765,7 @@ retry:
 		// unchoked
 
 		// avoid having a bias towards peers that happen to be sorted first
-		std::random_shuffle(opt_unchoke.begin(), opt_unchoke.end());
+		std::random_shuffle(opt_unchoke.begin(), opt_unchoke.end(), randint);
 
 		// sort all candidates based on when they were last optimistically
 		// unchoked.

src/torrent.cpp

@@ -7305,7 +7305,7 @@ namespace libtorrent
 		// if we didn't save 100 peers, fill in with second choice peers
 		if (num_saved_peers < 100)
 		{
-			std::random_shuffle(deferred_peers.begin(), deferred_peers.end());
+			std::random_shuffle(deferred_peers.begin(), deferred_peers.end(), randint);
 			for (std::vector<torrent_peer const*>::const_iterator i = deferred_peers.begin()
 				, end(deferred_peers.end()); i != end && num_saved_peers < 100; ++i)
 			{
@@ -10339,7 +10339,7 @@ namespace libtorrent
 				if (p->is_seed()) seeds.push_back(p);
 			}
 
-			std::random_shuffle(seeds.begin(), seeds.end());
+			std::random_shuffle(seeds.begin(), seeds.end(), randint);
 			TORRENT_ASSERT(to_disconnect <= int(seeds.size()));
 			for (int i = 0; i < to_disconnect; ++i)
 				seeds[i]->disconnect(errors::upload_upload_connection
@@ -10497,7 +10497,7 @@ namespace libtorrent
 			--pieces[i->piece].first;
 		}
 
-		std::random_shuffle(pieces.begin(), pieces.end());
+		std::random_shuffle(pieces.begin(), pieces.end(), randint);
 		std::stable_sort(pieces.begin(), pieces.end()
 			, boost::bind(&std::pair<int, int>::first, _1) <
 			boost::bind(&std::pair<int, int>::first, _2));

src/torrent_info.cpp

@@ -40,6 +40,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/file.hpp"
 #include "libtorrent/utf8.hpp"
 #include "libtorrent/time.hpp"
+#include "libtorrent/random.hpp"
 #include "libtorrent/invariant_check.hpp"
 #include "libtorrent/aux_/session_settings.hpp"
 #include "libtorrent/aux_/escape_string.hpp" // maybe_url_encode
@@ -1501,12 +1502,12 @@ namespace libtorrent
 				{
 					if (stop->tier != current_tier)
 					{
-						std::random_shuffle(start, stop);
+						std::random_shuffle(start, stop, randint);
 						start = stop;
 						current_tier = stop->tier;
 					}
 				}
-				std::random_shuffle(start, stop);
+				std::random_shuffle(start, stop, randint);
 			}
 		}