[core] Fixed clearing errored group in connecting (#1683)

srtcore/api.cpp

@@ -1344,11 +1344,13 @@ int CUDTUnited::groupConnect(CUDTGroup* pg, SRT_SOCKGROUPCONFIG* targets, int ar
     const bool was_empty = g.groupEmpty();
 
     // In case the group was retried connection, clear first all epoll readiness.
-    m_EPoll.update_events(g.id(), g.m_sPollID, SRT_EPOLL_ERR, false);
-    if (was_empty)
+    const int ncleared = m_EPoll.update_events(g.id(), g.m_sPollID, SRT_EPOLL_ERR, false);
+    if (was_empty || ncleared)
     {
+        HLOGC(aclog.Debug, log << "srt_connect/group: clearing IN/OUT because was_empty=" << was_empty << " || ncleared=" << ncleared);
         // IN/OUT only in case when the group is empty, otherwise it would
         // clear out correct readiness resulting from earlier calls.
+        // This also should happen if ERR flag was set, as IN and OUT could be set, too.
         m_EPoll.update_events(g.id(), g.m_sPollID, SRT_EPOLL_IN | SRT_EPOLL_OUT, false);
     }
     SRTSOCKET retval = -1;

srtcore/epoll.cpp

@@ -838,6 +838,7 @@ int CEPoll::update_events(const SRTSOCKET& uid, std::set<int>& eids, const int e
         return -1; // still, ignored.
     }
 
+    int nupdated = 0;
     vector<int> lost;
 
     IF_HEAVY_LOGGING(ostringstream debug);
@@ -901,6 +902,7 @@ int CEPoll::update_events(const SRTSOCKET& uid, std::set<int>& eids, const int e
         // - if enable, it will set event flags, possibly in a new notice object
         // - if !enable, it will clear event flags, possibly remove notice if resulted in 0
         ed.updateEventNotice(*pwait, uid, events, enable);
+        ++nupdated;
 
         HLOGC(eilog.Debug, log << debug.str() << ": E" << (*i)
                 << " TRACKING: " << ed.DisplayEpollWatch());
@@ -909,7 +911,7 @@ int CEPoll::update_events(const SRTSOCKET& uid, std::set<int>& eids, const int e
     for (vector<int>::iterator i = lost.begin(); i != lost.end(); ++ i)
         eids.erase(*i);
 
-    return 0;
+    return nupdated;
 }
 
 // Debug use only.

srtcore/epoll.h

@@ -465,12 +465,13 @@ friend class CRendezvousQueue;
 
 public: // for CUDT to acknowledge IO status
 
-   /// Update events available for a UDT socket.
+   /// Update events available for a UDT socket. At the end this function
+   /// counts the number of updated EIDs with given events.
    /// @param [in] uid UDT socket ID.
    /// @param [in] eids EPoll IDs to be set
    /// @param [in] events Combination of events to update
    /// @param [in] enable true -> enable, otherwise disable
-   /// @return 0 if success, otherwise an error number
+   /// @return -1 if invalid events, otherwise the number of changes
 
    int update_events(const SRTSOCKET& uid, std::set<int>& eids, int events, bool enable);
 

testing/testmedia.cpp

@@ -1148,6 +1148,15 @@ void SrtCommon::OpenGroupClient()
                     NULL, NULL,
                     NULL, NULL) != -1)
         {
+            Verb() << "[C]" << VerbNoEOL;
+            for (int i = 0; i < len1; ++i)
+                Verb() << " " << ready_conn[i] << VerbNoEOL;
+            Verb() << "[E]" << VerbNoEOL;
+            for (int i = 0; i < len2; ++i)
+                Verb() << " " << ready_err[i] << VerbNoEOL;
+
+            Verb() << "";
+
             // We are waiting for one entity to be ready so it's either
             // in one or the other
             if (find(ready_err, ready_err+len2, m_sock) != ready_err+len2)
@@ -1174,8 +1183,7 @@ void SrtCommon::OpenGroupClient()
                         --transmit_retry_connect;
 
 
-                    Verb() << "...all links timeout, retrying in 250ms (" << transmit_retry_connect << ")...";
-                    std::this_thread::sleep_for(std::chrono::milliseconds(250));
+                    Verb() << "...all links timeout, retrying NOW (" << transmit_retry_connect << ")...";
                     goto Connect_Again;
                 }