[PATCH] sptests: add test for priority inversion with multiple locks

Gedare Bloom gedare at rtems.org
Sat May 18 18:57:14 UTC 2013


---
 testsuites/sptests/Makefile.am         |    2 +-
 testsuites/sptests/configure.ac        |    1 +
 testsuites/sptests/spsem01/Makefile.am |   21 +++++
 testsuites/sptests/spsem01/init.c      |  154 ++++++++++++++++++++++++++++++++
 testsuites/sptests/spsem01/spsem01.doc |   19 ++++
 testsuites/sptests/spsem01/spsem01.scn |   16 ++++
 6 files changed, 212 insertions(+), 1 deletions(-)
 create mode 100644 testsuites/sptests/spsem01/Makefile.am
 create mode 100644 testsuites/sptests/spsem01/init.c
 create mode 100644 testsuites/sptests/spsem01/spsem01.doc
 create mode 100644 testsuites/sptests/spsem01/spsem01.scn

diff --git a/testsuites/sptests/Makefile.am b/testsuites/sptests/Makefile.am
index 4b0fff6..9acf477 100644
--- a/testsuites/sptests/Makefile.am
+++ b/testsuites/sptests/Makefile.am
@@ -25,7 +25,7 @@ SUBDIRS = \
     spintrcritical09 spintrcritical10 spintrcritical11 spintrcritical12 \
     spintrcritical13 spintrcritical14 spintrcritical15 spintrcritical16 \
     spintrcritical17 spintrcritical18 spmkdir spmountmgr01 spheapprot \
-    spsimplesched01 spsimplesched02 spsimplesched03 spnsext01 \
+    spsem01 spsimplesched01 spsimplesched02 spsimplesched03 spnsext01 \
     spedfsched01 spedfsched02 spedfsched03 \
     spcbssched01 spcbssched02 spcbssched03 spqreslib sptimespec01 \
     spatomic01 spatomic02 spatomic03 spatomic04 spatomic05 \
diff --git a/testsuites/sptests/configure.ac b/testsuites/sptests/configure.ac
index ba3aa92..9f40fa1 100644
--- a/testsuites/sptests/configure.ac
+++ b/testsuites/sptests/configure.ac
@@ -188,6 +188,7 @@ spprintk/Makefile
 spprivenv01/Makefile
 spqreslib/Makefile
 sprbtree01/Makefile
+spsem01/Makefile
 spsimplesched01/Makefile
 spsimplesched02/Makefile
 spsimplesched03/Makefile
diff --git a/testsuites/sptests/spsem01/Makefile.am b/testsuites/sptests/spsem01/Makefile.am
new file mode 100644
index 0000000..a957b05
--- /dev/null
+++ b/testsuites/sptests/spsem01/Makefile.am
@@ -0,0 +1,21 @@
+
+rtems_tests_PROGRAMS = spsem01
+spsem01_SOURCES = init.c
+
+dist_rtems_tests_DATA = spsem01.scn
+dist_rtems_tests_DATA += spsem01.doc
+
+include $(RTEMS_ROOT)/make/custom/@RTEMS_BSP at .cfg
+include $(top_srcdir)/../automake/compile.am
+include $(top_srcdir)/../automake/leaf.am
+
+AM_CPPFLAGS += -I$(top_srcdir)/../support/include
+
+LINK_OBJS = $(spsem01_OBJECTS)
+LINK_LIBS = $(spsem01_LDLIBS)
+
+spsem01$(EXEEXT): $(spsem01_OBJECTS) $(spsem01_DEPENDENCIES)
+	@rm -f spsem01$(EXEEXT)
+	$(make-exe)
+
+include $(top_srcdir)/../automake/local.am
diff --git a/testsuites/sptests/spsem01/init.c b/testsuites/sptests/spsem01/init.c
new file mode 100644
index 0000000..4a123f4
--- /dev/null
+++ b/testsuites/sptests/spsem01/init.c
@@ -0,0 +1,154 @@
+/*
+ * Copyright (c) 2013 Gedare Bloom.
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#include <rtems.h>
+
+#include <stdio.h>
+#include "tmacros.h"
+
+/* configuration information */
+#define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER
+#define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER
+#define CONFIGURE_RTEMS_INIT_TASKS_TABLE
+#define CONFIGURE_EXTRA_TASK_STACKS (RTEMS_MINIMUM_STACK_SIZE * 3)
+#define CONFIGURE_MAXIMUM_TASKS 3
+#define CONFIGURE_MAXIMUM_SEMAPHORES 2
+#define CONFIGURE_INIT
+#include <rtems/confdefs.h>
+
+rtems_task Task01(rtems_task_argument ignored);
+rtems_task Task02(rtems_task_argument ignored);
+rtems_task Init(rtems_task_argument ignored);
+
+static int getprio(void)
+{
+  rtems_status_code status;
+  rtems_task_priority pri;
+
+  status = rtems_task_set_priority(RTEMS_SELF, RTEMS_CURRENT_PRIORITY, &pri);
+  directive_failed( status, "rtems_task_set_priority");
+  return (int)pri;
+}
+
+rtems_id   Task_id[2];
+rtems_name Task_name[2];
+
+rtems_id   sem_id[2];
+rtems_name sem_name[2];
+
+rtems_task Init(rtems_task_argument ignored)
+{
+  rtems_status_code status;
+  rtems_attribute sem_attr;
+
+  printf("\n*** TEST SEMAPHORE01 ***\n");
+
+  sem_attr = RTEMS_INHERIT_PRIORITY | RTEMS_BINARY_SEMAPHORE | RTEMS_PRIORITY;
+
+  sem_name[0] = rtems_build_name( 'S','0',' ',' ');
+  status = rtems_semaphore_create(
+    sem_name[0],
+    1,
+    sem_attr,
+    0,
+    &sem_id[0]
+  );
+  directive_failed( status, "rtems_semaphore_create of S0");
+  printf("init: S0 created\n");
+
+  sem_name[1] = rtems_build_name( 'S','1',' ',' ');
+  status = rtems_semaphore_create(
+    sem_name[1],
+    1,
+    sem_attr,
+    0,
+    &sem_id[1]
+  );
+  directive_failed( status, "rtems_semaphore_create of S1");
+  printf("init: S1 created\n");
+
+  Task_name[0] = rtems_build_name( 'T','A','0','1');
+  status = rtems_task_create(
+    Task_name[0],
+    36,
+    RTEMS_MINIMUM_STACK_SIZE*2,
+    RTEMS_DEFAULT_MODES,
+    RTEMS_DEFAULT_ATTRIBUTES,
+    &Task_id[0]
+  );
+  directive_failed( status, "rtems_task_create of TA01");
+  printf("init: TA01 created with priority 36\n");
+
+  Task_name[1] = rtems_build_name( 'T','A','0','2');
+  status = rtems_task_create(
+    Task_name[1],
+    34,
+    RTEMS_MINIMUM_STACK_SIZE*2,
+    RTEMS_DEFAULT_MODES,
+    RTEMS_DEFAULT_ATTRIBUTES,
+    &Task_id[1]
+  );
+  directive_failed( status , "rtems_task_create of TA02\n");
+  printf("init: TA02 created with priority 34\n");
+
+  status = rtems_task_start( Task_id[0], Task01, 0);
+  directive_failed( status, "rtems_task_start of TA01");
+
+  status = rtems_task_delete( RTEMS_SELF);
+  directive_failed( status, "rtems_task_delete of INIT");
+}
+
+/* Task01 starts with priority 36 */
+rtems_task Task01(rtems_task_argument ignored)
+{
+  rtems_status_code status;
+  printf("TA01: started with priority %d\n", getprio());
+
+  status = rtems_semaphore_obtain( sem_id[0], RTEMS_WAIT, 0 );
+  directive_failed( status, "rtems_semaphore_obtain of S0\n");
+  printf("TA01: priority %d, holding S0\n", getprio());
+
+  status = rtems_semaphore_obtain( sem_id[1], RTEMS_WAIT, 0 );
+  directive_failed( status, "rtems_semaphore_obtain of S1");
+  printf("TA01: priority %d, holding S0, S1\n", getprio());
+
+  /* Start Task 2 (TA02) with priority 34. It will run immediately. */
+  status = rtems_task_start( Task_id[1], Task02, 0);
+  directive_failed( status, "rtems_task_start of TA02\n");
+
+  status = rtems_semaphore_release(sem_id[1]);
+  directive_failed( status, "rtems_semaphore_release of S1\n");
+  printf("TA01: priority %d, holding S0\n", getprio());
+
+  status = rtems_semaphore_release(sem_id[0]);
+  directive_failed( status, "rtems_semaphore_release of S0\n");
+  printf("TA01: priority %d\n", getprio());
+
+  printf("TA01: exiting\n");
+  printf("*** END OF SEMAPHORE01 ***\n");
+  status = rtems_task_delete( RTEMS_SELF);
+  directive_failed( status, "rtems_task_delete TA01");
+}
+
+/* TA02 starts at Task02 with priority 34 */
+rtems_task Task02(rtems_task_argument ignored)
+{
+  rtems_status_code status;
+
+  printf("TA02: started with priority %d\n", getprio());
+
+  /* Obtain S1, which should be held by TA01 by now */
+  status = rtems_semaphore_obtain( sem_id[1], RTEMS_WAIT, 0 );
+  directive_failed( status, " rtems_semaphore_obtain S1");
+  printf("TA02: priority %d, holding S1\n", getprio());
+
+  printf("TA02: exiting\n");
+  status = rtems_task_delete( RTEMS_SELF);
+  directive_failed( status, "rtems_task_delete TA02");
+}
+
diff --git a/testsuites/sptests/spsem01/spsem01.doc b/testsuites/sptests/spsem01/spsem01.doc
new file mode 100644
index 0000000..8a09526
--- /dev/null
+++ b/testsuites/sptests/spsem01/spsem01.doc
@@ -0,0 +1,19 @@
+This test exposes a potential priority inversion when priority inheritance is
+used and multiple locks are acquired by a low priority task. The scenario
+consists of 2 tasks of different priority and 2 semaphore/mutexes using
+priority inheritance. The scenario is:
+
+Task 1 has priority 36.  Task 2 has priority 34.
+
+1. Task 1 obtains semaphore S1.
+2. Task 1 obtains semaphore S2
+3. Task 2 preempts Task 1.
+4. Task 2 blocks on S2.  Task 1 inherits priority 34.
+5. Task 1 resumes. Task 1 releases S2. Task 1 continues to run at priority 34.
+6. Task 1 releases S1. Task 1 changes priority back to 36.
+7. Task 2 now preempts Task 1 and begins operating again.
+
+During steps 5-6 Task 1 executes when Task 2 should be able to execute.
+
+Stepping down the priority of Task 1 when it releases S2 back to its original
+priority when it obtained S2 fixes the priority inversion.
diff --git a/testsuites/sptests/spsem01/spsem01.scn b/testsuites/sptests/spsem01/spsem01.scn
new file mode 100644
index 0000000..54efd16
--- /dev/null
+++ b/testsuites/sptests/spsem01/spsem01.scn
@@ -0,0 +1,16 @@
+*** TEST SEMAPHORE01 ***
+init: S0 created
+init: S1 created
+init: TA01 created with priority 36
+init: TA02 created with priority 34
+TA01: started with priority 36
+TA01: priority 36, holding S0
+TA01: priority 36, holding S0, S1
+TA02: started with priority 34
+TA02: priority 34, holding S1
+TA02: exiting
+TA01: priority 36, holding S0
+TA01: priority 36
+TA01: exiting
+*** END OF SEMAPHORE01 ***
+
-- 
1.7.1




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