[newlib-cygwin] Cygwin: testsuite: Fix for limited thread priority values

[Jon Turney <jturney@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=7fcb2cd4a17bd5e07e104f8c82e403c25847c053

commit 7fcb2cd4a17bd5e07e104f8c82e403c25847c053
Author: Jon Turney <jon.turney@dronecode.org.uk>
Date:   Thu Sep 1 12:13:50 2022 +0100

    Cygwin: testsuite: Fix for limited thread priority values
    
    Windows only supports 7 thread priority levels, which we map onto the 32
    required by POSIX.  So, only a subset of values will be returned exactly
    by by +pthread_getschedparam() after pthread_setschedparam().
    
    Adjust tests priority1, priority2 and inherit1 so the only check for
    round-tripping priority values which can be exactly represented.
    
    Future work: Check we provide the 32 levels required by POSIX.

Diff:
---
 winsup/testsuite/winsup.api/pthread/inherit1.c  | 12 +++++++++++-
 winsup/testsuite/winsup.api/pthread/priority1.c | 16 ++++++++++++++--
 winsup/testsuite/winsup.api/pthread/priority2.c | 16 ++++++++++++++--
 3 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/winsup/testsuite/winsup.api/pthread/inherit1.c b/winsup/testsuite/winsup.api/pthread/inherit1.c
index 16c3f534b..e77483e89 100644
--- a/winsup/testsuite/winsup.api/pthread/inherit1.c
+++ b/winsup/testsuite/winsup.api/pthread/inherit1.c
@@ -50,6 +50,15 @@ void * func(void * arg)
   return (void *) (size_t)param.sched_priority;
 }
 
+// Windows only supports 7 thread priority levels, which we map onto the 32
+// required by POSIX.  So only a subset of values will be returned exactly by by
+// pthread_getschedparam() after pthread_setschedparam().
+int doable_pri(int pri)
+{
+  return (pri == 2) || (pri == 12) || (pri == 14) || (pri == 16) || (pri == 18)
+    || (pri == 20) || (pri == 30);
+}
+
 int
 main()
 {
@@ -81,7 +90,8 @@ main()
       assert(pthread_setschedparam(mainThread, SCHED_FIFO, &mainParam) == 0);
       assert(pthread_getschedparam(mainThread, &policy, &mainParam) == 0);
       assert(policy == SCHED_FIFO);
-      assert(mainParam.sched_priority == prio);
+      if (doable_pri(prio))
+        assert(mainParam.sched_priority == prio);
 
       for (param.sched_priority = prio;
            param.sched_priority <= maxPrio;
diff --git a/winsup/testsuite/winsup.api/pthread/priority1.c b/winsup/testsuite/winsup.api/pthread/priority1.c
index a1e8d051d..4ce3e389c 100644
--- a/winsup/testsuite/winsup.api/pthread/priority1.c
+++ b/winsup/testsuite/winsup.api/pthread/priority1.c
@@ -50,7 +50,16 @@ void * func(void * arg)
   assert(policy == SCHED_FIFO);
   return (void *)(size_t)param.sched_priority;
 }
- 
+
+// Windows only supports 7 thread priority levels, which we map onto the 32
+// required by POSIX.  So only a subset of values will be returned exactly by by
+// pthread_getschedparam() after pthread_setschedparam().
+int doable_pri(int pri)
+{
+  return (pri == 2) || (pri == 12) || (pri == 14) || (pri == 16) || (pri == 18)
+    || (pri == 20) || (pri == 30);
+}
+
 int
 main()
 {
@@ -61,6 +70,8 @@ main()
   int maxPrio = sched_get_priority_max(SCHED_FIFO);
   int minPrio = sched_get_priority_min(SCHED_FIFO);
 
+  // assert((maxPrio - minPrio) >= 32);
+
   assert(pthread_attr_init(&attr) == 0);
   assert(pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED) == 0);
 
@@ -71,7 +82,8 @@ main()
       assert(pthread_attr_setschedparam(&attr, &param) == 0);
       assert(pthread_create(&t, &attr, func, NULL) == 0);
       pthread_join(t, &result);
-      assert((int)(size_t) result == param.sched_priority);
+      if (doable_pri(param.sched_priority))
+	assert((int)(size_t) result == param.sched_priority);
     }
 
   return 0;
diff --git a/winsup/testsuite/winsup.api/pthread/priority2.c b/winsup/testsuite/winsup.api/pthread/priority2.c
index 0534e7ba1..dec2827f8 100644
--- a/winsup/testsuite/winsup.api/pthread/priority2.c
+++ b/winsup/testsuite/winsup.api/pthread/priority2.c
@@ -54,7 +54,16 @@ void * func(void * arg)
   assert(policy == SCHED_FIFO);
   return (void *) (size_t)param.sched_priority;
 }
- 
+
+// Windows only supports 7 thread priority levels, which we map onto the 32
+// required by POSIX.  So only a subset of values will be returned exactly by by
+// pthread_getschedparam() after pthread_setschedparam().
+int doable_pri(int pri)
+{
+  return (pri == 2) || (pri == 12) || (pri == 14) || (pri == 16) || (pri == 18)
+    || (pri == 20) || (pri == 30);
+}
+
 int
 main()
 {
@@ -64,6 +73,8 @@ main()
   int maxPrio = sched_get_priority_max(SCHED_FIFO);
   int minPrio = sched_get_priority_min(SCHED_FIFO);
 
+  // assert((maxPrio - minPrio) >= 32);
+
   for (param.sched_priority = minPrio;
        param.sched_priority <= maxPrio;
        param.sched_priority++)
@@ -73,7 +84,8 @@ main()
       assert(pthread_setschedparam(t, SCHED_FIFO, &param) == 0);
       assert(pthread_mutex_unlock(&startMx) == 0);
       pthread_join(t, &result);
-      assert((int)(size_t)result == param.sched_priority);
+      if (doable_pri(param.sched_priority))
+	assert((int)(size_t)result == param.sched_priority);
     }
 
   return 0;