online: Use same number of threads as openmp.

algo/ca/TrackingChain.cxx

@@ -13,6 +13,7 @@
 #include "CaHit.h"
 #include "CaInitManager.h"
 #include "CaParameters.h"
+#include "compat/OpenMP.h"
 #include "yaml/Yaml.h"
 
 #include <boost/archive/binary_oarchive.hpp>
@@ -83,7 +84,8 @@ void TrackingChain::Init()
 
   // ------ Initialize CA framework
   fCaMonitor.Reset();
-  fCaFramework.SetNofThreads(Opts().NumOMPThreads() == std::nullopt ? 1 : *(Opts().NumOMPThreads()));
+  fCaFramework.SetNofThreads(Opts().NumOMPThreads() == std::nullopt ? openmp::GetMaxThreads()
+                                                                    : *(Opts().NumOMPThreads()));
   fCaFramework.ReceiveParameters(std::move(parameters));
   fCaFramework.Init(ca::Framework::TrackingMode::kMcbm);