move session flags into the session_params object

ChangeLog

@@ -1,3 +1,4 @@
+	* move session_flags to session_params
 	* the entry class is now a standard variant type
 	* use std::string_view instead of boost counterpart
 	* libtorrent now requires C++17 to build

bindings/python/src/session.cpp

@@ -178,9 +178,10 @@ namespace
 	std::shared_ptr<lt::session> make_session(boost::python::dict sett
 		, session_flags_t const flags)
 	{
-		settings_pack p;
-		make_settings_pack(p, sett);
-		return std::make_shared<lt::session>(p, flags);
+		session_params p;
+		make_settings_pack(p.settings, sett);
+		p.flags = flags;
+		return std::make_shared<lt::session>(std::move(p));
 	}
 
 	void session_apply_settings(lt::session& ses, dict const& sett_dict)

include/libtorrent/session.hpp

@@ -129,15 +129,12 @@ namespace aux {
 		// In order to avoid a race condition between starting the session and
 		// configuring it, you can pass in a session_params object. Its settings
 		// will take effect before the session starts up.
-		//
-		// The overloads taking ``flags`` can be used to start a session in
-		// paused mode (by passing in ``session::paused``). Note that
-		// ``add_default_plugins`` do not have an affect on constructors that
-		// take a session_params object. It already contains the plugins to use.
 		explicit session(session_params const& params);
 		explicit session(session_params&& params);
-		session(session_params const& params, session_flags_t flags);
-		session(session_params&& params, session_flags_t flags);
+#if TORRENT_ABI_VERSION < 4
+		TORRENT_DEPRECATED session(session_params const& params, session_flags_t flags);
+		TORRENT_DEPRECATED session(session_params&& params, session_flags_t flags);
+#endif
 		session();
 
 		// Overload of the constructor that takes an external io_context to run
@@ -155,8 +152,10 @@ namespace aux {
 		// 	destruct the session_proxy object.
 		session(session_params&& params, io_context& ios);
 		session(session_params const& params, io_context& ios);
-		session(session_params&& params, io_context& ios, session_flags_t);
-		session(session_params const& params, io_context& ios, session_flags_t);
+#if TORRENT_ABI_VERSION < 4
+		TORRENT_DEPRECATED session(session_params&& params, io_context& ios, session_flags_t);
+		TORRENT_DEPRECATED session(session_params const& params, io_context& ios, session_flags_t);
+#endif
 
 		// hidden
 		session(session&&);

include/libtorrent/session_params.hpp

@@ -24,6 +24,7 @@ see LICENSE file.
 #include "libtorrent/session_types.hpp"
 #include "libtorrent/kademlia/dht_storage.hpp"
 #include "libtorrent/ip_filter.hpp"
+#include "libtorrent/session_types.hpp" // for session_flags_t
 
 #if TORRENT_ABI_VERSION <= 2
 #include "libtorrent/kademlia/dht_settings.hpp"
@@ -73,20 +74,13 @@ struct TORRENT_EXPORT session_params
 	// The settings to configure the session with
 	settings_pack settings;
 
+	// specifies flags affecting the session construction. E.g. they can be used
+	// to start a session in paused mode (by passing in ``session::paused``).
+	session_flags_t flags{};
+
 	// the plugins to add to the session as it is constructed
 	std::vector<std::shared_ptr<plugin>> extensions;
 
-#if TORRENT_ABI_VERSION <= 2
-
-#include "libtorrent/aux_/disable_deprecation_warnings_push.hpp"
-
-	// this is deprecated. Use the dht_* settings instead.
-	dht::dht_settings dht_settings;
-
-#include "libtorrent/aux_/disable_warnings_pop.hpp"
-
-#endif
-
 	// DHT node ID and node addresses to bootstrap the DHT with.
 	dht::dht_state dht_state;
 
@@ -105,6 +99,17 @@ struct TORRENT_EXPORT session_params
 	// the IP filter to use for the session. This restricts which peers are allowed
 	// to connect. As if passed to set_ip_filter().
 	libtorrent::ip_filter ip_filter;
+
+#if TORRENT_ABI_VERSION <= 2
+
+#include "libtorrent/aux_/disable_deprecation_warnings_push.hpp"
+
+	// this is deprecated. Use the dht_* settings instead.
+	dht::dht_settings dht_settings;
+
+#include "libtorrent/aux_/disable_warnings_pop.hpp"
+
+#endif
 };
 
 TORRENT_VERSION_NAMESPACE_3_END

simulation/test_session.cpp

@@ -224,7 +224,8 @@ TORRENT_TEST(tie_listen_ports)
 
 // make sure passing in the session::paused flag does indeed start the session
 // paused
-TORRENT_TEST(construct_paused_session)
+#if TORRENT_ABI_VERSION < 4
+TORRENT_TEST(construct_paused_session_deprecated)
 {
 	using namespace libtorrent;
 
@@ -252,3 +253,35 @@ TORRENT_TEST(construct_paused_session)
 
 	sim.run();
 }
+#endif
+
+TORRENT_TEST(construct_paused_session)
+{
+	using namespace libtorrent;
+
+	sim::default_config network_cfg;
+	sim::simulation sim{network_cfg};
+	sim::asio::io_context ios { sim, addr("50.0.0.1")};
+
+	lt::session_proxy zombie;
+
+	// create session
+	lt::session_params p;
+	p.settings = settings();
+	p.settings.set_str(settings_pack::listen_interfaces, "0.0.0.0:0");
+	p.settings.set_int(settings_pack::alert_mask, alert_category::error
+		| alert_category::status
+		| alert_category::torrent_log);
+	p.flags |= session::paused;
+
+	auto ses = std::make_shared<lt::session>(p, ios);
+
+	sim::timer t(sim, lt::seconds(30), [&](boost::system::error_code const&)
+	{
+		TEST_CHECK(ses->is_paused());
+		zombie = ses->abort();
+		ses.reset();
+	});
+
+	sim.run();
+}

src/session.cpp

@@ -259,6 +259,7 @@ namespace {
 #endif
 #endif
 
+		// TODO: start() should just use flags out of the session_params object,
 		m_impl = std::make_shared<aux::session_impl>(std::ref(*ios)
 			, std::move(params.settings)
 			, std::move(params.disk_io_constructor)
@@ -317,14 +318,15 @@ namespace {
 
 	session::session(session_params const& params)
 	{
-		start({}, session_params(params), nullptr);
+		start(params.flags, session_params(params), nullptr);
 	}
 
 	session::session(session_params&& params)
 	{
-		start({}, std::move(params), nullptr);
+		start(params.flags, std::move(params), nullptr);
 	}
 
+#if TORRENT_ABI_VERSION < 4
 	session::session(session_params const& params, session_flags_t const flags)
 	{
 		start(flags, session_params(params), nullptr);
@@ -334,23 +336,25 @@ namespace {
 	{
 		start(flags, std::move(params), nullptr);
 	}
+#endif
 
 	session::session()
 	{
 		session_params params;
-		start({}, std::move(params), nullptr);
+		start(params.flags, std::move(params), nullptr);
 	}
 
 	session::session(session_params&& params, io_context& ios)
 	{
-		start({}, std::move(params), &ios);
+		start(params.flags, std::move(params), &ios);
 	}
 
 	session::session(session_params const& params, io_context& ios)
 	{
-		start({}, session_params(params), &ios);
+		start(params.flags, session_params(params), &ios);
 	}
 
+#if TORRENT_ABI_VERSION < 4
 	session::session(session_params&& params, io_context& ios, session_flags_t const flags)
 	{
 		start(flags, std::move(params), &ios);
@@ -360,7 +364,7 @@ namespace {
 	{
 		start(flags, session_params(params), &ios);
 	}
-
+#endif
 
 #if TORRENT_ABI_VERSION <= 2
 	session::session(settings_pack&& pack, session_flags_t const flags)