From f459beb7f9ad44f4441af774dc21c3ca8136fd08 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ian@davenant.relativity.greenend.org.uk>
Date: Sun, 28 Sep 2008 12:11:27 +0100
Subject: [PATCH] do not have threads at all if NPROCESSORS=1

---
 parallel.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/parallel.c b/parallel.c
index 3c94607..a79a370 100644
--- a/parallel.c
+++ b/parallel.c
@@ -20,6 +20,7 @@ typedef struct {
   pthread_t thread;
 } PerThread;
 
+#if NPROCESSORS != 1
 static void *routine(void *thread_v) {
   PerThread *t= thread_v;
   ForAllThreads *a= t->allthreads;
@@ -28,6 +29,7 @@ static void *routine(void *thread_v) {
 
   return 0;
 }
+#endif
 
 void inparallel(const struct Vertices *vertices,
 		Computation *separately,
@@ -37,14 +39,15 @@ void inparallel(const struct Vertices *vertices,
 
   ForAllThreads allthreads;
   SecData secdatas[nsections];
-  PerThread threads[nsections];
-
-  int s, r;
 
   allthreads.vertices= vertices;
   allthreads.separately= separately;
   allthreads.gendata= gendata;
 
+#if NPROCESSORS != 1
+  PerThread threads[nsections];
+  int s, r;
+
   for (s=0; s<nsections; s++) {
     threads[s].allthreads= &allthreads;
     threads[s].section= s;
@@ -58,4 +61,8 @@ void inparallel(const struct Vertices *vertices,
     if (r) diee("pthread_join");
     combine(vertices, s, threads[s].secdata, gendata);
   }
+#else
+  separately(vertices, 0, &secdatas[0], gendata);
+  combine(vertices, 0, &secdatas[0], gendata);
+#endif
 }
-- 
2.30.2