score: Add and use _Thread_Dispatch_direct()

This function is useful for operations which synchronously block, e.g.
self restart, self deletion, yield, sleep.  It helps to detect if these
operations are called in the wrong context.  Since the thread dispatch
necessary indicator is not used, this is more robust in some SMP
situations.

Update #2751.

cpukit/posix/src/nanosleep.c

@@ -96,7 +96,7 @@ static inline int nanosleep_yield( struct timespec *rmtp )
   executing = _Thread_Get_executing();
   cpu_self = _Thread_Dispatch_disable();
   _Thread_Yield( executing );
-  _Thread_Dispatch_enable( cpu_self );
+  _Thread_Dispatch_direct( cpu_self );
   if ( rmtp ) {
     rmtp->tv_sec = 0;
     rmtp->tv_nsec = 0;

cpukit/posix/src/sched_yield.c

@@ -30,6 +30,6 @@ int sched_yield( void )
 
   cpu_self = _Thread_Dispatch_disable();
     _Thread_Yield( _Per_CPU_Get_executing( cpu_self ) );
-  _Thread_Dispatch_enable( cpu_self );
+  _Thread_Dispatch_direct( cpu_self );
   return 0;
 }

cpukit/rtems/src/taskwakeafter.c

@@ -48,6 +48,6 @@ rtems_status_code rtems_task_wake_after(
         ticks
       );
     }
-  _Thread_Dispatch_enable( cpu_self );
+  _Thread_Dispatch_direct( cpu_self );
   return RTEMS_SUCCESSFUL;
 }

cpukit/sapi/src/interrtext.c

@@ -56,7 +56,8 @@ static const char *const internal_error_text[] = {
   "INTERNAL_ERROR_RTEMS_INIT_TASK_ENTRY_IS_NULL",
   "INTERNAL_ERROR_POSIX_INIT_THREAD_ENTRY_IS_NULL",
   "INTERNAL_ERROR_THREAD_QUEUE_DEADLOCK",
-  "INTERNAL_ERROR_THREAD_QUEUE_ENQUEUE_STICKY_FROM_BAD_STATE"
+  "INTERNAL_ERROR_THREAD_QUEUE_ENQUEUE_STICKY_FROM_BAD_STATE",
+  "INTERNAL_ERROR_BAD_THREAD_DISPATCH_DISABLE_LEVEL"
 };
 
 const char *rtems_internal_error_text( rtems_fatal_code error )

cpukit/score/include/rtems/score/interr.h

@@ -165,7 +165,8 @@ typedef enum {
   INTERNAL_ERROR_RTEMS_INIT_TASK_ENTRY_IS_NULL,
   INTERNAL_ERROR_POSIX_INIT_THREAD_ENTRY_IS_NULL,
   INTERNAL_ERROR_THREAD_QUEUE_DEADLOCK,
-  INTERNAL_ERROR_THREAD_QUEUE_ENQUEUE_STICKY_FROM_BAD_STATE
+  INTERNAL_ERROR_THREAD_QUEUE_ENQUEUE_STICKY_FROM_BAD_STATE,
+  INTERNAL_ERROR_BAD_THREAD_DISPATCH_DISABLE_LEVEL
 } Internal_errors_Core_list;
 
 typedef CPU_Uint32ptr Internal_errors_t;

cpukit/score/include/rtems/score/threaddispatch.h

@@ -94,6 +94,20 @@ RTEMS_INLINE_ROUTINE void _Thread_Dispatch_initialization( void )
  */
 void _Thread_Dispatch( void );
 
+/**
+ * @brief Directly do a thread dispatch.
+ *
+ * Must be called with a thread dispatch disable level of one, otherwise the
+ * INTERNAL_ERROR_BAD_THREAD_DISPATCH_DISABLE_LEVEL will occur.  This function
+ * is useful for operations which synchronously block, e.g. self restart, self
+ * deletion, yield, sleep.
+ *
+ * @param[in] cpu_self The current processor.
+ *
+ * @see _Thread_Dispatch().
+ */
+void _Thread_Dispatch_direct( Per_CPU_Control *cpu_self );
+
 /**
  * @brief Performs a thread dispatch on the current processor.
  *

cpukit/score/src/threaddispatch.c

@@ -233,3 +233,19 @@ void _Thread_Dispatch( void )
     _ISR_Local_enable( level );
   }
 }
+
+void _Thread_Dispatch_direct( Per_CPU_Control *cpu_self )
+{
+  ISR_Level level;
+
+  if ( cpu_self->thread_dispatch_disable_level != 1 ) {
+    _Terminate(
+      INTERNAL_ERROR_CORE,
+      0,
+      INTERNAL_ERROR_BAD_THREAD_DISPATCH_DISABLE_LEVEL
+    );
+  }
+
+  _ISR_Local_disable( level );
+  _Thread_Do_dispatch( cpu_self, level );
+}

cpukit/score/src/threadrestart.c

@@ -344,14 +344,8 @@ void _Thread_Life_action_handler(
 
   if ( _Thread_Is_life_terminating( previous_life_state ) ) {
     cpu_self = _Thread_Wait_for_join( executing, cpu_self );
-
     _Thread_Make_zombie( executing );
-
-    /* FIXME: Workaround for https://devel.rtems.org/ticket/2751 */
-    cpu_self->dispatch_necessary = true;
-
-    _Assert( cpu_self->heir != executing );
-    _Thread_Dispatch_enable( cpu_self );
+    _Thread_Dispatch_direct( cpu_self );
     RTEMS_UNREACHABLE();
   }
 

testsuites/sptests/Makefile.am

@@ -33,6 +33,7 @@ _SUBDIRS = \
     spsignal_err01 spport_err01 spmsgq_err01 spmsgq_err02 spsem_err01 \
     spsem_err02 sptask_err01 spevent_err03 sptask_err03 sptask_err02 \
     sptask_err04 spclock_err01
+_SUBDIRS += spfatal29
 _SUBDIRS += spmutex01
 _SUBDIRS += spextensions01
 _SUBDIRS += spsysinit01

testsuites/sptests/configure.ac

@@ -193,6 +193,7 @@ spfatal20/Makefile
 spfatal24/Makefile
 spfatal25/Makefile
 spfatal27/Makefile
+spfatal29/Makefile
 spfifo01/Makefile
 spfifo02/Makefile
 spfifo03/Makefile

testsuites/sptests/spfatal29/Makefile.am

@@ -0,0 +1,19 @@
+rtems_tests_PROGRAMS = spfatal29
+spfatal29_SOURCES = ../spfatal_support/init.c ../spfatal_support/system.h testcase.h
+
+dist_rtems_tests_DATA = spfatal29.scn spfatal29.doc
+
+include $(RTEMS_ROOT)/make/custom/@RTEMS_BSP@.cfg
+include $(top_srcdir)/../automake/compile.am
+include $(top_srcdir)/../automake/leaf.am
+
+AM_CPPFLAGS += -I$(top_srcdir)/../support/include
+
+LINK_OBJS = $(spfatal29_OBJECTS)
+LINK_LIBS = $(spfatal29_LDLIBS)
+
+spfatal29$(EXEEXT): $(spfatal29_OBJECTS) $(spfatal29_DEPENDENCIES)
+	@rm -f spfatal29$(EXEEXT)
+	$(make-exe)
+
+include $(top_srcdir)/../automake/local.am

testsuites/sptests/spfatal29/spfatal29.doc

@@ -0,0 +1,11 @@
+This file describes the directives and concepts tested by this test set.
+
+test set name: spfatal29
+
+directives:
+
+  - _Thread_Dispatch_force()
+
+concepts:
+
+  - Provoke the INTERNAL_ERROR_BAD_THREAD_DISPATCH_DISABLE_LEVEL fatal error.

testsuites/sptests/spfatal29/spfatal29.scn

@@ -0,0 +1,3 @@
+*** BEGIN OF TEST SPFATAL 29 ***
+Fatal error (yield in interrupt context) hit
+*** END OF TEST SPFATAL 29 ***

testsuites/sptests/spfatal29/testcase.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2016 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#define FATAL_ERROR_TEST_NAME            "29"
+#define FATAL_ERROR_DESCRIPTION          "yield in interrupt context"
+#define FATAL_ERROR_EXPECTED_SOURCE      INTERNAL_ERROR_CORE
+#define FATAL_ERROR_EXPECTED_IS_INTERNAL FALSE
+#define FATAL_ERROR_EXPECTED_ERROR       INTERNAL_ERROR_BAD_THREAD_DISPATCH_DISABLE_LEVEL
+
+#define CONFIGURE_MAXIMUM_TIMERS 1
+
+static void timer(rtems_id id, void *arg)
+{
+  rtems_task_wake_after(RTEMS_YIELD_PROCESSOR);
+}
+
+void force_error()
+{
+  rtems_status_code sc;
+  rtems_id id;
+
+  sc = rtems_timer_create(
+    rtems_build_name('T', 'I', 'M', 'E'),
+    &id
+  );
+  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
+  sc = rtems_timer_fire_after(id, 1, timer, NULL);
+  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
+  sc = rtems_task_delete(RTEMS_SELF);
+  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+}

testsuites/sptests/spinternalerror02/init.c

@@ -36,7 +36,7 @@ static void test_internal_error_text(void)
   } while ( text != text_last );
 
   rtems_test_assert(
-    error - 3 == INTERNAL_ERROR_THREAD_QUEUE_ENQUEUE_STICKY_FROM_BAD_STATE
+    error - 3 == INTERNAL_ERROR_BAD_THREAD_DISPATCH_DISABLE_LEVEL
   );
 }