Add set_alert_notify to python bindings (#3066)

bindings/python/src/session.cpp

@@ -388,6 +388,20 @@ namespace
     }
 #endif // TORRENT_ABI_VERSION
 
+    void alert_notify(object cb)
+    {
+        lock_gil lock;
+        if (cb)
+        {
+            cb();
+        }
+    }
+
+    void set_alert_notify(lt::session& s, object cb)
+    {
+        s.set_alert_notify(std::bind(&alert_notify, cb));
+    }
+
     alert const*
     wait_for_alert(lt::session& s, int ms)
     {
@@ -987,6 +1001,7 @@ void bind_session()
         .def("save_state", &save_state, (arg("entry"), arg("flags") = 0xffffffff))
         .def("pop_alerts", &pop_alerts)
         .def("wait_for_alert", &wait_for_alert, return_internal_reference<>())
+        .def("set_alert_notify", &set_alert_notify)
         .def("add_extension", &add_extension)
 #if TORRENT_ABI_VERSION == 1
 #if TORRENT_USE_I2P

bindings/python/test.py

@@ -15,6 +15,7 @@ import subprocess as sub
 import sys
 import inspect
 import pickle
+import threading
 
 # include terminal interface for travis parallel executions of scripts which use
 # terminal features: fix multiple stdin assignment at termios.tcgetattr
@@ -398,6 +399,18 @@ class test_alerts(unittest.TestCase):
                 print(a.message())
             time.sleep(0.1)
 
+    def test_alert_notify(self):
+        ses = lt.session(settings)
+        event = threading.Event()
+
+        def callback():
+            event.set()
+
+        ses.set_alert_notify(callback)
+        ses.async_add_torrent(
+            {"ti": lt.torrent_info("base.torrent"), "save_path": "."})
+        event.wait()
+
 
 class test_bencoder(unittest.TestCase):