[PATCH] sptests: add test for priority inversion with multiple locks
Gedare Bloom
gedare at rtems.org
Sun May 19 02:45:32 UTC 2013
On May 18, 2013 3:06 PM, "Joel Sherrill" <Joel.Sherrill at oarcorp.com> wrote:
>
> When the other test works should we remove the original test submitted
with this code?
>
No. Even when we fix the bugs, the tests will probably help coverage and
avoid regressions. The fixes should at least be ported back to 4.10 too.
> I think we should switch to this as the default behavior when it works.
>
Agreed for priority semaphores. Although I wonder if a better solution
exists that does not need strict LIFO p/v operations.
> We do need to check coverage.
>
Ok. I stumbled on a compile error when turning on strict mutex. :(
I also noticed that sp36, which uses strict mutex, is disabled / missing
from Makefile.am.
-Gedare
>
>
> Gedare Bloom <gedare at rtems.org> wrote:
>
>
> 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.
>
> Using ENABLE_STRICT_ORDER_MUTEX=1 prevents the priority inversion.
>
> I hope to write another test soon that demonstrates a different
> priority inversion when there are 3 tasks and 2 mutexes while using
> the current implementation of strict order mutex.
>
> -Gedare
>
> On Sat, May 18, 2013 at 2:57 PM, Gedare Bloom <gedare at rtems.org> wrote:
> > ---
> > 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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