[rtems commit] score: PR2179: Fix initially locked PI mutex

Sebastian Huber sebh at rtems.org
Wed Aug 20 06:09:33 UTC 2014


Module:    rtems
Branch:    master
Commit:    bba3507723041f451c9da1ecee43819bcbe57f23
Changeset: http://git.rtems.org/rtems/commit/?id=bba3507723041f451c9da1ecee43819bcbe57f23

Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
Date:      Tue Aug 19 17:43:36 2014 +0200

score: PR2179: Fix initially locked PI mutex

---

 cpukit/score/src/coremutex.c     |   15 +++++++++++----
 testsuites/sptests/sp51/init.c   |   36 ++++++++++++++++++++++++++++++++++++
 testsuites/sptests/sp51/sp51.doc |    3 +++
 3 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/cpukit/score/src/coremutex.c b/cpukit/score/src/coremutex.c
index e13c7aa..949aa70 100644
--- a/cpukit/score/src/coremutex.c
+++ b/cpukit/score/src/coremutex.c
@@ -39,10 +39,14 @@ CORE_mutex_Status _CORE_mutex_Initialize(
   the_mutex->Attributes    = *the_mutex_attributes;
 
   if ( initially_locked ) {
+    bool is_priority_ceiling =
+      _CORE_mutex_Is_priority_ceiling( &the_mutex->Attributes );
+
     the_mutex->nest_count = 1;
     the_mutex->holder     = executing;
-    if ( _CORE_mutex_Is_inherit_priority( &the_mutex->Attributes ) ||
-         _CORE_mutex_Is_priority_ceiling( &the_mutex->Attributes ) ) {
+
+    if (  is_priority_ceiling ||
+         _CORE_mutex_Is_inherit_priority( &the_mutex->Attributes ) ) {
       Priority_Control ceiling = the_mutex->Attributes.priority_ceiling;
 
       /*
@@ -52,7 +56,7 @@ CORE_mutex_Status _CORE_mutex_Initialize(
        */
       _Thread_Disable_dispatch();
 
-      if ( executing->current_priority < ceiling ) {
+      if ( is_priority_ceiling && executing->current_priority < ceiling ) {
         _Thread_Enable_dispatch();
         return CORE_MUTEX_STATUS_CEILING_VIOLATED;
       }
@@ -65,7 +69,10 @@ CORE_mutex_Status _CORE_mutex_Initialize(
 
       executing->resource_count++;
 
-      _Thread_Change_priority( executing, ceiling, false );
+      if ( is_priority_ceiling ) {
+        _Thread_Change_priority( executing, ceiling, false );
+      }
+
       _Thread_Enable_dispatch();
     }
   } else {
diff --git a/testsuites/sptests/sp51/init.c b/testsuites/sptests/sp51/init.c
index 98d362f..48f0146 100644
--- a/testsuites/sptests/sp51/init.c
+++ b/testsuites/sptests/sp51/init.c
@@ -18,6 +18,40 @@ const char rtems_test_name[] = "SP 51";
 /* forward declarations to avoid warnings */
 rtems_task Init(rtems_task_argument argument);
 
+static void test_create_initially_locked_prio_inherit_sema(void)
+{
+  rtems_status_code   sc;
+  rtems_id            id;
+  rtems_task_priority prio_a;
+  rtems_task_priority prio_b;
+  rtems_task_priority prio_ceiling = 0;
+
+  sc = rtems_task_set_priority(RTEMS_SELF, RTEMS_CURRENT_PRIORITY, &prio_a);
+  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
+  rtems_test_assert(prio_a != prio_ceiling);
+
+  sc = rtems_semaphore_create(
+    rtems_build_name( 'S', 'E', 'M', 'A' ),
+    0,
+    RTEMS_BINARY_SEMAPHORE | RTEMS_PRIORITY | RTEMS_INHERIT_PRIORITY,
+    prio_ceiling,
+    &id
+  );
+  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
+  sc = rtems_task_set_priority(RTEMS_SELF, RTEMS_CURRENT_PRIORITY, &prio_b);
+  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
+  rtems_test_assert(prio_a == prio_b);
+
+  sc = rtems_semaphore_release(id);
+  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
+  sc = rtems_semaphore_delete(id);
+  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+}
+
 rtems_task Init(
   rtems_task_argument argument
 )
@@ -57,6 +91,8 @@ rtems_task Init(
   fatal_directive_status(
     sc, RTEMS_NOT_OWNER_OF_RESOURCE, "rtems_semaphore_release" );
 
+  test_create_initially_locked_prio_inherit_sema();
+
   TEST_END();
   rtems_test_exit( 0 );
 }
diff --git a/testsuites/sptests/sp51/sp51.doc b/testsuites/sptests/sp51/sp51.doc
index a1003db..fac5534 100644
--- a/testsuites/sptests/sp51/sp51.doc
+++ b/testsuites/sptests/sp51/sp51.doc
@@ -23,3 +23,6 @@ concepts:
 
 + Ensure the when the binary semaphore lock fails to acquire the mutex,
   it is an error to release it since the lock failed.
+
++ Verify that creation of an initially locked priority inheritance mutex does
+  not change the priority of the executing thread.



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