From 461de5f101fcd4c44aa7573610a6c6d028704dbb Mon Sep 17 00:00:00 2001
From: "Martin D. Weinberg" <weinberg@astro.umass.edu>
Date: Tue, 5 Mar 2024 21:48:55 -0500
Subject: [PATCH] Add an MPI exclusion to allow 2d basis construction to work
 with single process pyEXP runs

---
 exputil/BiorthCyl.cc | 34 ++++++++++++++++++++++------------
 exputil/EmpCyl2d.cc  | 15 +++++----------
 include/BiorthCyl.H  |  2 +-
 3 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/exputil/BiorthCyl.cc b/exputil/BiorthCyl.cc
index 859dc13d9..2eecc84a9 100644
--- a/exputil/BiorthCyl.cc
+++ b/exputil/BiorthCyl.cc
@@ -30,6 +30,14 @@ using namespace __EXP__;	// For reference to n-body globals
 // Constructor
 BiorthCyl::BiorthCyl(const YAML::Node& conf) : conf(conf)
 {
+  // Check whether MPI is initialized.  Use flag to suppress MPI calls
+  // if MPI is not active.
+  //
+  int flag;
+  MPI_Initialized(&flag);
+  if (flag) use_mpi = true;
+  else      use_mpi = false;
+
   // Read and assign parameters
   //
   try {
@@ -110,7 +118,7 @@ BiorthCyl::BiorthCyl(const YAML::Node& conf) : conf(conf)
 			   << std::string(60, '-') << std::endl
 			   << conf
 			   << std::string(60, '-') << std::endl;
-    MPI_Finalize();
+    if (use_mpi) MPI_Finalize();
     exit(-1);
   }
 
@@ -231,16 +239,18 @@ void BiorthCyl::create_tables()
 
   if (verbose and myid==0) std::cout << std::endl;
 
-  for (int m=0; m<=mmax; m++) {
-    for (int n=0; n<nmax; n++) {
-      MPI_Allreduce(MPI_IN_PLACE, dens  [m][n].data(), numx*numy,
-		    MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
-      MPI_Allreduce(MPI_IN_PLACE, pot   [m][n].data(), numx*numy,
-		    MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
-      MPI_Allreduce(MPI_IN_PLACE, rforce[m][n].data(), numx*numy,
-		    MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
-      MPI_Allreduce(MPI_IN_PLACE, zforce[m][n].data(), numx*numy,
-		    MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
+  if (use_mpi) {
+    for (int m=0; m<=mmax; m++) {
+      for (int n=0; n<nmax; n++) {
+	MPI_Allreduce(MPI_IN_PLACE, dens  [m][n].data(), numx*numy,
+		      MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
+	MPI_Allreduce(MPI_IN_PLACE, pot   [m][n].data(), numx*numy,
+		      MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
+	MPI_Allreduce(MPI_IN_PLACE, rforce[m][n].data(), numx*numy,
+		      MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
+	MPI_Allreduce(MPI_IN_PLACE, zforce[m][n].data(), numx*numy,
+		      MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
+      }
     }
   }
 
@@ -595,7 +605,7 @@ bool BiorthCyl::ReadH5Cache()
       double v; HighFive::Attribute vv = h5file.getAttribute(name); vv.read(v);
       if (fabs(value - v) < 1.0e-16) return true;
       else {
-	if (myid==0) std::cout << "---- BiortyCyl::ReadH5Cache: wanted "
+	if (myid==0) std::cout << "---- BiorthCyl::ReadH5Cache: wanted "
 			       << name << "=" << value
 			       << " but found "
 			       << name << "=" << v << std::endl;
diff --git a/exputil/EmpCyl2d.cc b/exputil/EmpCyl2d.cc
index 9247bd0d3..fd3408eaa 100644
--- a/exputil/EmpCyl2d.cc
+++ b/exputil/EmpCyl2d.cc
@@ -357,8 +357,7 @@ class EmpCyl2d::ExponCyl : public EmpCyl2d::ModelCyl
 		  << std::string(60, '-') << std::endl
 		  << conf                 << std::endl
 		  << std::string(60, '-') << std::endl;
-      MPI_Finalize();
-      exit(-1);
+      throw std::runtime_error("EmpCyl2d::ExponCyl: error parsing YAML config");
     }
   }
 
@@ -416,8 +415,7 @@ class EmpCyl2d::KuzminCyl : public EmpCyl2d::ModelCyl
 		  << std::string(60, '-') << std::endl
 		  << conf                 << std::endl
 		  << std::string(60, '-') << std::endl;
-      MPI_Finalize();
-      exit(-1);
+      throw std::runtime_error("EmpCyl2d::KuzminCyl: error parsing YAML config");
     }
   }
 
@@ -475,8 +473,7 @@ class EmpCyl2d::MestelCyl : public EmpCyl2d::ModelCyl
 		  << std::string(60, '-') << std::endl
 		  << conf                 << std::endl
 		  << std::string(60, '-') << std::endl;
-      MPI_Finalize();
-      exit(-1);
+      throw std::runtime_error("EmpCyl2d::MestelCyl: error parsing YAML config");
     }
   }
 
@@ -586,8 +583,7 @@ class EmpCyl2d::ZangCyl : public EmpCyl2d::MestelCyl
 		  << std::string(60, '-') << std::endl
 		  << conf                 << std::endl
 		  << std::string(60, '-') << std::endl;
-      MPI_Finalize();
-      exit(-1);
+      throw std::runtime_error("EmpCyl2d::ZangCyl: error parsing YAML config");
     }
   }
 
@@ -690,8 +686,7 @@ std::shared_ptr<EmpCyl2d::ModelCyl> EmpCyl2d::createModel()
 		<< std::string(60, '-') << std::endl
 		<< Params               << std::endl
 		<< std::string(60, '-') << std::endl;
-    MPI_Finalize();
-    exit(-1);
+    throw std::runtime_error("EmpCyl2d::createModel: error parsing YAML config");
   }
 }
 
diff --git a/include/BiorthCyl.H b/include/BiorthCyl.H
index da3cd51f5..e8700e378 100644
--- a/include/BiorthCyl.H
+++ b/include/BiorthCyl.H
@@ -48,7 +48,7 @@ protected:
   int mmax, nmax, numr, nmaxfid, mmin, mlim, nmin, nlim, knots, NQDHT;
   double rcylmin, rcylmax, scale, acyltbl, acylcut, Ninner, Mouter;
 
-  bool EVEN_M, verbose, logr;
+  bool EVEN_M, verbose, logr, use_mpi;
   
   //@{
   //! Grid parameters