score: Use priority inheritance for thread join

Threads may join the thread termination of another thread using the
pthread_join() or rtems_task_delete() directives.  The thread cancel operation
used a special case priority boosting mechanism implemented by
_Thread_Raise_real_priority().  The problem was that this approach

* is not transitive,

* does not account for priority adjustments of the calling task
  while waiting for the join,

* does not support clustered scheduling, and

* does not detect deadlocks.

All these problems are fixed by using a priority inheritance thread queue for
the join operation.

Close #4679.

1 files changed, 19 insertions, 14 deletions

diff --git a/testsuites/smptests/smppsxmutex01/init.c b/testsuites/smptests/smppsxmutex01/init.c
index f5aacb42d8..0022e81b5f 100644
--- a/testsuites/smptests/smppsxmutex01/init.c
+++ b/testsuites/smptests/smppsxmutex01/init.c
@@ -55,25 +55,11 @@ static test_context test_instance;
 static void *thread_b(void *arg)
 {
   test_context *ctx;
-  rtems_id scheduler_b_id;
-  rtems_status_code sc;
-  rtems_task_priority prio;
   int prio_ceiling;
   int eno;
 
   ctx = arg;
 
-  rtems_test_assert(rtems_scheduler_get_processor() == 0);
-
-  sc = rtems_scheduler_ident(SCHED_B, &scheduler_b_id);
-  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
-
-  sc = rtems_task_set_priority(pthread_self(), RTEMS_CURRENT_PRIORITY, &prio);
-  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
-
-  sc = rtems_task_set_scheduler(pthread_self(), scheduler_b_id, prio);
-  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
-
   rtems_test_assert(rtems_scheduler_get_processor() == 1);
 
   eno = pthread_mutex_init(&ctx->mtx_b, &ctx->mtx_attr);
@@ -132,8 +118,24 @@ static void test(test_context *ctx)
   rtems_test_assert(eno == 0);
 
   if (cpu_count > 1) {
+    rtems_id scheduler_a_id;
+    rtems_id scheduler_b_id;
+    rtems_status_code sc;
+    rtems_task_priority prio;
     void *exit_code;
 
+    sc = rtems_scheduler_ident(SCHED_A, &scheduler_a_id);
+    rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
+    sc = rtems_scheduler_ident(SCHED_B, &scheduler_b_id);
+    rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
+    sc = rtems_task_set_priority(pthread_self(), RTEMS_CURRENT_PRIORITY, &prio);
+    rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
+    sc = rtems_task_set_scheduler(pthread_self(), scheduler_b_id, prio);
+    rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
     eno = pthread_create(&ctx->thread_b, NULL, thread_b, ctx);
     rtems_test_assert(eno == 0);
 
@@ -141,6 +143,9 @@ static void test(test_context *ctx)
     eno = pthread_join(ctx->thread_b, &exit_code);
     rtems_test_assert(eno == 0);
     rtems_test_assert(exit_code == ctx);
+
+    sc = rtems_task_set_scheduler(pthread_self(), scheduler_a_id, prio);
+    rtems_test_assert(sc == RTEMS_SUCCESSFUL);
   }
 
   eno = pthread_mutex_destroy(&ctx->mtx_a);