3 files changed, 27 insertions, 17 deletions
diff --git a/gdbsupport/parallel-for.h b/gdbsupport/parallel-for.h
index ca03094..915814e 100644
--- a/gdbsupport/parallel-for.h
+++ b/gdbsupport/parallel-for.h
@@ -21,10 +21,7 @@
 #define GDBSUPPORT_PARALLEL_FOR_H
 
 #include <algorithm>
-#if CXX_STD_THREAD
-#include <thread>
 #include "gdbsupport/thread-pool.h"
-#endif
 
 namespace gdb
 {
@@ -41,7 +38,6 @@ template<class RandomIt, class RangeFunction>
 void
 parallel_for_each (RandomIt first, RandomIt last, RangeFunction callback)
 {
-#if CXX_STD_THREAD
   /* So we can use a local array below.  */
   const size_t local_max = 16;
   size_t n_threads = std::min (thread_pool::g_thread_pool->thread_count (),
@@ -70,15 +66,12 @@ parallel_for_each (RandomIt first, RandomIt last, RangeFunction callback)
 	  first = end;
 	}
     }
-#endif /* CXX_STD_THREAD */
 
   /* Process all the remaining elements in the main thread.  */
   callback (first, last);
 
-#if CXX_STD_THREAD
   for (int i = 0; i < n_actual_threads; ++i)
     futures[i].wait ();
-#endif /* CXX_STD_THREAD */
 }
 
 }
diff --git a/gdbsupport/thread-pool.cc b/gdbsupport/thread-pool.cc
index ce19ef2..7d44695 100644
--- a/gdbsupport/thread-pool.cc
+++ b/gdbsupport/thread-pool.cc
@@ -18,10 +18,10 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "common-defs.h"
+#include "gdbsupport/thread-pool.h"
 
 #if CXX_STD_THREAD
 
-#include "gdbsupport/thread-pool.h"
 #include "gdbsupport/alt-stack.h"
 #include "gdbsupport/block-signals.h"
 #include <algorithm>
@@ -67,6 +67,7 @@ set_thread_name (int (*set_name) (const char *), const char *name)
 }
 
 #endif	/* USE_PTHREAD_SETNAME_NP */
+#endif /* CXX_STD_THREAD */
 
 namespace gdb
 {
@@ -93,6 +94,7 @@ thread_pool::~thread_pool ()
 void
 thread_pool::set_thread_count (size_t num_threads)
 {
+#if CXX_STD_THREAD
   std::lock_guard<std::mutex> guard (m_tasks_mutex);
 
   /* If the new size is larger, start some new threads.  */
@@ -127,6 +129,9 @@ thread_pool::set_thread_count (size_t num_threads)
     }
 
   m_thread_count = num_threads;
+#else
+  /* No threads available, simply ignore the request.  */
+#endif /* CXX_STD_THREAD */
 }
 
 std::future<void>
@@ -135,20 +140,24 @@ thread_pool::post_task (std::function<void ()> &&func)
   std::packaged_task<void ()> t (std::move (func));
   std::future<void> f = t.get_future ();
 
-  if (m_thread_count == 0)
-    {
-      /* Just execute it now.  */
-      t ();
-    }
-  else
+#if CXX_STD_THREAD
+  if (m_thread_count != 0)
     {
       std::lock_guard<std::mutex> guard (m_tasks_mutex);
       m_tasks.emplace (std::move (t));
       m_tasks_cv.notify_one ();
     }
+  else
+#endif
+    {
+      /* Just execute it now.  */
+      t ();
+    }
   return f;
 }
 
+#if CXX_STD_THREAD
+
 void
 thread_pool::thread_function ()
 {
@@ -182,6 +191,6 @@ thread_pool::thread_function ()
     }
 }
 
-}
-
 #endif /* CXX_STD_THREAD */
+
+} /* namespace gdb */
diff --git a/gdbsupport/thread-pool.h b/gdbsupport/thread-pool.h
index 6821066..2672e4d 100644
--- a/gdbsupport/thread-pool.h
+++ b/gdbsupport/thread-pool.h
@@ -21,11 +21,13 @@
 #define GDBSUPPORT_THREAD_POOL_H
 
 #include <queue>
-#include <thread>
 #include <vector>
 #include <functional>
+#if CXX_STD_THREAD
+#include <thread>
 #include <mutex>
 #include <condition_variable>
+#endif
 #include <future>
 #include "gdbsupport/gdb_optional.h"
 
@@ -53,7 +55,11 @@ public:
   /* Return the number of executing threads.  */
   size_t thread_count () const
   {
+#if CXX_STD_THREAD
     return m_thread_count;
+#else
+    return 0;
+#endif
   }
 
   /* Post a task to the thread pool.  A future is returned, which can
@@ -64,6 +70,7 @@ private:
 
   thread_pool () = default;
 
+#if CXX_STD_THREAD
   /* The callback for each worker thread.  */
   void thread_function ();
 
@@ -83,6 +90,7 @@ private:
      between the main thread and the worker threads.  */
   std::condition_variable m_tasks_cv;
   std::mutex m_tasks_mutex;
+#endif /* CXX_STD_THREAD */
 };
 
 }