Define GC_get_parallel and GC_set_markers_count in single-threaded GC

These are no-op definitions in case of the collector is built as
a single-threaded one.  This is useful for single threaded clients
to be able to call these functions regardless of the collector is
multi-threaded or not.

* include/gc/gc.h [GC_THREADS] (GC_parallel): Reformat comment.
* include/gc/gc.h (GC_get_parallel, GC_set_markers_count): Declare
unconditionally.
* misc.c [!PARALLEL_MARK] (GC_set_markers_count): Define (as no-op).
* misc.c [!THREADS] (GC_get_parallel): Define (return 0).
* pthread_support.c (GC_set_markers_count): Define only if
PARALLEL_MARK; remove GC_ATTR_UNUSED.
* win32_threads.c (GC_set_markers_count): Likewise.
* tests/initfromthread.c (main): Call GC_get_suspend_signal() instead
of GC_get_parallel().

1 files changed, 6 insertions, 8 deletions

diff --git a/win32_threads.c b/win32_threads.c
index 2a415ac7..96f82068 100644
--- a/win32_threads.c
+++ b/win32_threads.c
@@ -2505,6 +2505,12 @@ GC_INNER void GC_get_next_stack(char *start, char *limit,
   static unsigned required_markers_cnt = 0;
                         /* The default value (0) means the number of    */
                         /* markers should be selected automatically.    */
+
+  GC_API void GC_CALL GC_set_markers_count(unsigned markers)
+  {
+    /* The same implementation as in pthread_support.c. */
+    required_markers_cnt = markers < MAX_MARKERS ? markers : MAX_MARKERS;
+  }
 #endif /* PARALLEL_MARK */
 
   /* We have no DllMain to take care of new threads.  Thus we   */
@@ -2742,14 +2748,6 @@ GC_INNER void GC_get_next_stack(char *start, char *limit,
 
 #endif /* GC_WINMAIN_REDIRECT */
 
-GC_API void GC_CALL GC_set_markers_count(unsigned markers GC_ATTR_UNUSED)
-{
-  /* The same implementation as in pthread_support.c.   */
-# ifdef PARALLEL_MARK
-    required_markers_cnt = markers < MAX_MARKERS ? markers : MAX_MARKERS;
-# endif
-}
-
 GC_INNER void GC_thr_init(void)
 {
   struct GC_stack_base sb;