AthenaMP: Make sure SharedEvtQueueProvider gets a positive definite chunk size

AthenaMP: Make sure SharedEvtQueueProvider gets a positive definite chunk size

Control/AthenaMP/python/AthenaMPConfig.py

@@ -74,6 +74,9 @@ def AthenaMPCfg(flags):
 
     # Compute event chunk size
     chunk_size = getChunkSize(flags)
+    if chunk_size < 1:
+        msg.warning('Nonpositive ChunkSize (%i) caught, setting it to 1', chunk_size)
+        chunk_size = 1
 
     # Configure Strategy
     debug_worker = flags.Concurrency.DebugWorkers

Control/AthenaMP/python/PyComps.py

@@ -58,6 +58,9 @@ class MpEvtLoopMgr(AthMpEvtLoopMgr):
         event_range_channel = jp.AthenaMPFlags.EventRangeChannel()
 
         chunk_size = getChunkSize()
+        if chunk_size < 1:
+            msg.warning('Nonpositive ChunkSize (%i) caught, setting it to 1', chunk_size)
+            chunk_size = 1
         
         debug_worker = jp.ConcurrencyFlags.DebugWorkers()
         use_shared_reader = jp.AthenaMPFlags.UseSharedReader()

Control/AthenaMPTools/src/SharedEvtQueueProvider.cxx

@@ -66,6 +66,11 @@ int SharedEvtQueueProvider::makePool(int maxevt, int nprocs, const std::string&
     return -1;
   }
 
+  if(m_nChunkSize<=0) {
+    ATH_MSG_ERROR( "Non-positive chunk size requested: " << m_nChunkSize);
+    return -1;
+  }
+
   m_nEvtRequested = maxevt;
   m_nprocs = (nprocs==-1?sysconf(_SC_NPROCESSORS_ONLN):nprocs);
   m_nprocesses = m_nprocs;