[PATCH] libstdc++: testsuite: call sched_yield for nonpreemptive targets

[Alexandre Oliva <oliva@adacore.com>]

As in the gcc testsuite, systems without preemptive multi-threading
require sched_yield calls to be placed at points in which a context
switch might be needed to enable the test to complete.

Regstrapped on x86_64-linux-gnu, also tested with a cross to
aarch64-rtems6.  Ok to install?


for  libstdc++-v3/ChangeLog

	* testsuite/30_threads/this_thread/60421.cc (test02): Call
	sched_yield.
---
 .../testsuite/30_threads/this_thread/60421.cc      |    1 +
 1 file changed, 1 insertion(+)

diff --git a/libstdc++-v3/testsuite/30_threads/this_thread/60421.cc b/libstdc++-v3/testsuite/30_threads/this_thread/60421.cc
index ad6f9aeffcc80..12dbeba1cc492 100644
--- a/libstdc++-v3/testsuite/30_threads/this_thread/60421.cc
+++ b/libstdc++-v3/testsuite/30_threads/this_thread/60421.cc
@@ -59,6 +59,7 @@ test02()
   while (!sleeping)
   {
     // Wait for the thread to start sleeping.
+    sched_yield ();
   }
   while (sleeping)
   {

-- 
Alexandre Oliva, happy hacker                https://FSFLA.org/blogs/lxo/
   Free Software Activist                       GNU Toolchain Engineer
Disinformation flourishes because many people care deeply about injustice
but very few check the facts.  Ask me about <https://stallmansupport.org>