sched_getcpu() and pthread_setaffinity_np() are non-portable

Reported by Yuri Victorovich, on FreeBSD.

* configure.ac: Test for them.
* spot/mc/mc_instanciator.hh: Only use them if they are present.
* NEWS: Mention the fix.

NEWS

@@ -5,6 +5,9 @@ New in spot 2.10.1.dev  (not yet released)
   - twa_graph::purge_dead_states() now also removes edges labeled by
     bddfalse.
 
+  - only use sched_getcpu() and pthread_setaffinity_np() when they are
+    available.
+
 New in spot 2.10.1  (2021-11-19)
 
   Build:

configure.ac

@@ -148,7 +148,12 @@ CHECK_ATOMIC
 AX_CHECK_BUDDY
 
 AC_CHECK_HEADERS([sys/times.h valgrind/memcheck.h spawn.h])
-AC_CHECK_FUNCS([times kill alarm sigaction])
+AC_CHECK_FUNCS([times kill alarm sigaction sched_getcpu])
+
+oLIBS=$LIBS
+LIBS="$LIBS -lpthread"
+AC_CHECK_FUNCS([pthread_setaffinity_np])
+LIBS=$oLIBS
 
 LT_CONFIG_LTDL_DIR([ltdl])
 LT_INIT([win32-dll])

spot/mc/mc_instanciator.hh

@@ -19,6 +19,8 @@
 
 #pragma once
 
+#include <spot/misc/common.hh>
+#include <spot/misc/_config.h>
 #include <string>
 #include <thread>
 #include <vector>
@@ -31,7 +33,6 @@
 #include <spot/mc/cndfs.hh>
 #include <spot/mc/bloemen.hh>
 #include <spot/mc/bloemen_ec.hh>
-#include <spot/misc/common.hh>
 #include <spot/misc/timer.hh>
 
 namespace spot
@@ -115,7 +116,7 @@ namespace spot
       {
         threads[i] = std::thread ([&swarmed, &iomutex, i, &barrier]
         {
-#if defined(unix) || defined(__unix__) || defined(__unix)
+#ifdef SPOT_HAVE_SCHED_GETCPU
             {
               std::lock_guard<std::mutex> iolock(iomutex);
               std::cout << "Thread #" << i
@@ -129,8 +130,8 @@ namespace spot
             swarmed[i]->run();
          });
 
-#if defined(unix) || defined(__unix__) || defined(__unix)
-        //  Pins threads to a dedicated core.
+#ifdef SPOT_PTHREAD_SETAFFINITY_NP
+        //  Pin threads to a dedicated core.
         cpu_set_t cpuset;
         CPU_ZERO(&cpuset);
         CPU_SET(i, &cpuset);