From ce135cc4a993e3be86be1246729eb4ead951e9bc Mon Sep 17 00:00:00 2001
From: davidjohnlong <david.long2@woodplc.com>
Date: Thu, 12 Mar 2020 17:02:22 +0000
Subject: [PATCH] Refactor fixed source sampling so call to custom library is
 made from call to sample_external_source()

---
 src/particle.cpp   |  7 +------
 src/simulation.cpp |  7 +------
 src/source.cpp     | 11 ++++++++---
 3 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/src/particle.cpp b/src/particle.cpp
index 3465d6e6c..96cf3fdcf 100644
--- a/src/particle.cpp
+++ b/src/particle.cpp
@@ -695,12 +695,7 @@ Particle::write_restart() const
         simulation::work_index[mpi::rank] + i;
       uint64_t seed = init_seed(id, STREAM_SOURCE);
       // re-sample source site
-      Particle::Bank site;
-      if (!settings::path_source_library.empty()) {
-        site = sample_custom_source_library(&seed);
-      } else {
-        site = sample_external_source(&seed);
-      }
+      auto site = sample_external_source(&seed);
       write_dataset(file_id, "weight", site.wgt);
       write_dataset(file_id, "energy", site.E);
       write_dataset(file_id, "xyz", site.r);
diff --git a/src/simulation.cpp b/src/simulation.cpp
index 2eeb7e3ce..64a7d0e80 100644
--- a/src/simulation.cpp
+++ b/src/simulation.cpp
@@ -457,12 +457,7 @@ void initialize_history(Particle* p, int64_t index_source)
       simulation::work_index[mpi::rank] + index_source;
     uint64_t seed = init_seed(id, STREAM_SOURCE);
     // sample from external source distribution or custom library then set
-    Particle::Bank site;
-    if (!settings::path_source_library.empty()) {
-      site = sample_custom_source_library(&seed);
-    } else {
-      site = sample_external_source(&seed);
-    }
+    auto site = sample_external_source(&seed);
     p->from_source(&site);
   } else if (settings::run_mode == RunMode::EIGENVALUE) {
     // set defaults for eigenvalue simulations from primary bank
diff --git a/src/source.cpp b/src/source.cpp
index 3b51b2373..21b12ed0d 100644
--- a/src/source.cpp
+++ b/src/source.cpp
@@ -44,7 +44,7 @@ std::vector<SourceDistribution> external_sources;
 
 namespace {
 
-typedef Particle::Bank (*sample_t)(uint64_t  &seed);
+using sample_t = Particle::Bank (*)(uint64_t* seed);
 sample_t custom_source_function;
 void* custom_source_library;
 
@@ -315,6 +315,11 @@ void initialize_source()
 
 Particle::Bank sample_external_source(uint64_t* seed)
 {
+  // return values from custom source if using
+  if (!settings::path_source_library.empty()) {
+    return sample_custom_source_library(seed);
+  }
+
   // Determine total source strength
   double total_strength = 0.0;
   for (auto& s : model::external_sources)
@@ -363,7 +368,7 @@ void load_custom_source_library()
   dlerror();
 
   // get the function from the library
-  //using sample_t = Particle::Bank (*)(uint64_t* seed);
+  using sample_t = Particle::Bank (*)(uint64_t* seed);
   custom_source_function = reinterpret_cast<sample_t>(dlsym(custom_source_library, "sample_source"));
 
   // check for any dlsym errors
@@ -386,7 +391,7 @@ void close_custom_source_library()
 
 Particle::Bank sample_custom_source_library(uint64_t* seed)
 {
-  return custom_source_function(*seed);
+  return custom_source_function(seed);
 }
 
 void fill_source_bank_custom_source()