From 5ddf53936258aab16ad8a345c1c5673e1e50edb9 Mon Sep 17 00:00:00 2001
From: David Smith <David.Smith@cern.ch>
Date: Fri, 16 Jun 2023 15:43:00 +0200
Subject: [PATCH] [XrdCl] Fix potential stream timeout when a new request is
 sent to an idle stream

---
 src/XrdCl/XrdClSIDManager.cc      | 18 ++++++++++++++++++
 src/XrdCl/XrdClSIDManager.hh      |  6 ++++++
 src/XrdCl/XrdClXRootDTransport.cc | 12 +++++++-----
 3 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/src/XrdCl/XrdClSIDManager.cc b/src/XrdCl/XrdClSIDManager.cc
index 2a40c935067..8718d0eabac 100644
--- a/src/XrdCl/XrdClSIDManager.cc
+++ b/src/XrdCl/XrdClSIDManager.cc
@@ -18,6 +18,8 @@
 
 #include "XrdCl/XrdClSIDManager.hh"
 
+#include <algorithm>
+
 namespace XrdCl
 {
   //----------------------------------------------------------------------------
@@ -48,6 +50,7 @@ namespace XrdCl
     }
 
     memcpy( sid, &allocSID, 2 );
+    pAllocTime[allocSID] = time(0);
     return Status();
   }
 
@@ -60,6 +63,7 @@ namespace XrdCl
     uint16_t relSID = 0;
     memcpy( &relSID, sid, 2 );
     pFreeSIDs.push_back( relSID );
+    pAllocTime.erase( relSID );
   }
 
   //----------------------------------------------------------------------------
@@ -71,6 +75,20 @@ namespace XrdCl
     uint16_t tiSID = 0;
     memcpy( &tiSID, sid, 2 );
     pTimeOutSIDs.insert( tiSID );
+    pAllocTime.erase( tiSID );
+  }
+
+  //----------------------------------------------------------------------------
+  // Check if any SID was allocated at or before a given time
+  //----------------------------------------------------------------------------
+  bool SIDManager::IsAnySIDOldAs( const time_t tlim ) const
+  {
+    XrdSysMutexHelper scopedLock( pMutex );
+    return std::any_of( pAllocTime.begin(), pAllocTime.end(),
+                        [tlim](const auto& p)
+    {
+      return p.second <= tlim;
+    } );
   }
 
   //----------------------------------------------------------------------------
diff --git a/src/XrdCl/XrdClSIDManager.hh b/src/XrdCl/XrdClSIDManager.hh
index 0fcdb11f5ce..0eccf4b7098 100644
--- a/src/XrdCl/XrdClSIDManager.hh
+++ b/src/XrdCl/XrdClSIDManager.hh
@@ -83,6 +83,11 @@ namespace XrdCl
       //------------------------------------------------------------------------
       void TimeOutSID( uint8_t sid[2] );
 
+      //----------------------------------------------------------------------------
+      //! Check if any SID was allocated at or before a given time
+      //----------------------------------------------------------------------------
+      bool IsAnySIDOldAs( const time_t tlim ) const;
+
       //------------------------------------------------------------------------
       //! Check if a SID is timed out
       //------------------------------------------------------------------------
@@ -113,6 +118,7 @@ namespace XrdCl
       uint16_t GetNumberOfAllocatedSIDs() const;
 
     private:
+      std::unordered_map<uint16_t, time_t> pAllocTime;
       std::list<uint16_t>  pFreeSIDs;
       std::set<uint16_t>   pTimeOutSIDs;
       uint16_t             pSIDCeiling;
diff --git a/src/XrdCl/XrdClXRootDTransport.cc b/src/XrdCl/XrdClXRootDTransport.cc
index 2fcaeb923db..0caad99a00f 100644
--- a/src/XrdCl/XrdClXRootDTransport.cc
+++ b/src/XrdCl/XrdClXRootDTransport.cc
@@ -795,20 +795,22 @@ namespace XrdCl
 
     XrdSysMutexHelper scopedLock( info->mutex );
 
-    uint16_t allocatedSIDs = info->sidManager->GetNumberOfAllocatedSIDs();
+    const time_t now  = time(0);
+    const bool anySID =
+      info->sidManager->IsAnySIDOldAs( now - streamTimeout );
 
     log->Dump( XRootDTransportMsg, "[%s] Stream inactive since %d seconds, "
-               "stream timeout: %d, allocated SIDs: %d, wait barrier: %s",
+               "stream timeout: %d, any SID: %d, wait barrier: %s",
                info->streamName.c_str(), inactiveTime, streamTimeout,
-               allocatedSIDs, Utils::TimeToString(info->waitBarrier).c_str() );
+               anySID, Utils::TimeToString(info->waitBarrier).c_str() );
 
     if( inactiveTime < streamTimeout )
       return Status();
 
-    if( time(0) < info->waitBarrier )
+    if( now < info->waitBarrier )
       return Status();
 
-    if( !allocatedSIDs )
+    if( !anySID )
       return Status();
 
     return Status( stError, errSocketTimeout );