[PATCH] part of implimenting a monotonic clock in rtems part of this is not the final patch.

zack_on_the_speed_chanel zack_on_the_speed_chanel at protonmail.ch
Mon Jun 14 20:14:32 UTC 2021


I've made most of the corrections to the code. I fixed up the formatting but I still don't know if I have to add anything for the settime and delete_timer(). i assume as the monotonic clock only affects the value I think it's all I have to do. I also can try to modify a posix test to check my theory.

Thanks
Zack

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‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐

On Saturday, June 12th, 2021 at 9:31 AM, Christian Mauderer <oss at c-mauderer.de> wrote:

> Hello Zack,
>
> I don't really know a lot about the timer toppic. So this is more of a
>
> style and general suggestion review.
>
> On 09/06/2021 20:27, zack wrote:
>
> > From: zack zack_on_the_speed_chanel at protonmail.ch
> >
> > cpukit/include/rtems/posix/timer.h | 6 ++-
> >
> > cpukit/posix/src/psxtimercreate.c | 5 +-
> >
> > cpukit/posix/src/timergettime.c | 61 ++++++++++++++++++++---
> >
> > testsuites/psxtests/psxtimer02/psxtimer.c | 26 +++++++---
> >
> > 4 files changed, 81 insertions(+), 17 deletions(-)
> >
> > diff --git a/cpukit/include/rtems/posix/timer.h b/cpukit/include/rtems/posix/timer.h
> >
> > index bcbf07a65a..f8cf6115b2 100644
> >
> > --- a/cpukit/include/rtems/posix/timer.h
> >
> > +++ b/cpukit/include/rtems/posix/timer.h
> >
> > @@ -21,7 +21,7 @@
> >
> > #include <rtems/score/objectdata.h>
> >
> > #include <rtems/score/watchdog.h>
> > ----------------------------------------------------------------------
>
> I think the blank line separated rtems includes from others. So please
>
> don't remove it.
>
> > +#include <time.h>
> >
> > #include <pthread.h>
> >
> > #ifdef __cplusplus
> >
> > @@ -47,7 +47,9 @@ typedef struct {
> >
> > struct itimerspec timer_data; /* Timing data of the timer /
> >
> > uint32_t ticks; / Number of ticks of the initialization /
> >
> > uint32_t overrun; / Number of expirations of the timer */
> >
> > -   struct timespec time; /* Time at which the timer was started */
> >
> > -   struct timespec time; /* Time at which the timer was started */
>
> Not sure what changed in that line. Looks like a whitespace change.
>
> Please avoid these.
>
> > -   clockid_t clock_type;
>
> Why a blank line?
>
> > } POSIX_Timer_Control;
> >
> > /**
> >
> > diff --git a/cpukit/posix/src/psxtimercreate.c b/cpukit/posix/src/psxtimercreate.c
> >
> > index a63cf1d100..e78c359bd5 100644
> >
> > --- a/cpukit/posix/src/psxtimercreate.c
> >
> > +++ b/cpukit/posix/src/psxtimercreate.c
> >
> > @@ -40,7 +40,7 @@ int timer_create(
> >
> > {
> >
> > POSIX_Timer_Control *ptimer;
> >
> > -   if ( clock_id != CLOCK_REALTIME )
> >
> > -   if ( clock_id != CLOCK_REALTIME || clock_id != CLOCK_MONOTONIC )
>
> Not sure about that one. It's allways a bit difficult whith these
>
> constructions but I think this one is allways true and therefore will
>
> allways return an error.
>
> Let's assume clock_id is CLOCK_MONOTONIC. In that case (clock_id !=
>
> CLOCK_REALTIME) is true which means that the function will return with
>
> an error. The same works for CLOCK_RREALTIME and the second condition.
>
> If you apply De Morgan to the term you see that
>
> (clock_id != CLOCK_REALTIME || clock_id != CLOCK_MONOTONIC)
>
> is the same as
>
> !(clock_id == CLOCK_REALTIME && clock_id == CLOCK_MONOTONIC)
>
> The two inner comparisons are exclusive. So that won't work.
>
> What you most likely want is a
>
> !(clock_id == CLOCK_REALTIME || clock_id == CLOCK_MONOTONIC)
>
> or with De Morgan again:
>
> (clock_id != CLOCK_REALTIME && clock_id != CLOCK_MONOTONIC)
>
> >       rtems_set_errno_and_return_minus_one( EINVAL );
> >
> >     if ( !timerid )
> >
> >
> > @@ -91,7 +91,8 @@ int timer_create(
> >
> > ptimer->timer_data.it_value.tv_nsec = 0;
> >
> > ptimer->timer_data.it_interval.tv_sec = 0;
> >
> > ptimer->timer_data.it_interval.tv_nsec = 0;
> > ----------------------------------------------------------------------------------------------------------------------------------------------------------------------
> >
> > -   ptimer->clock_type=clock_id;
> >
> > -   _Watchdog_Preinitialize( &ptimer->Timer, _Per_CPU_Get_snapshot() );
> >
> >     _Watchdog_Initialize( &ptimer->Timer, _POSIX_Timer_TSR );
> >
> >     _Objects_Open_u32(&_POSIX_Timer_Information, &ptimer->Object, 0);
> >
> >     diff --git a/cpukit/posix/src/timergettime.c b/cpukit/posix/src/timergettime.c
> >
> >     index ee2a566f0e..62011cde58 100644
> >
> >     --- a/cpukit/posix/src/timergettime.c
> >
> >     +++ b/cpukit/posix/src/timergettime.c
> >
> >     @@ -28,6 +28,7 @@
> >
> >     #include <rtems/score/todimpl.h>
> >
> >     #include <rtems/score/watchdogimpl.h>
> >
> >     #include <rtems/seterr.h>
> >
> >     +#include <rtems/timespec.h>
> >
> >     /*
> >
> >     -            - When a timer is initialized, the value of the time in
> >
> >
> >
> > @@ -43,21 +44,67 @@ int timer_gettime(
> >
> > {
> >
> > POSIX_Timer_Control *ptimer;
> >
> > ISR_lock_Context lock_context;
> >
> > -   uint64_t now;
> >
> >     uint32_t remaining;
> >
> > -       Per_CPU_Control *cpu;
> >
> >
> > -       struct  timespec * now; // get time now either with
> >
> >
> > -       struct  timespec * expire; // expire
> >
> >
> >
> > -       struct  timespec * result;// get remaining time
> >
> >
> >
> >     if ( !value )
> >
> >
> > -   rtems_set_errno_and_return_minus_one( EINVAL );
> >
> > -   rtems_set_errno_and_return_minus_one( EINVAL );
> >
> >     ptimer = _POSIX_Timer_Get( timerid, &lock_context );
> >
> >
> > -   if ( ptimer != NULL ) {
> > -   Per_CPU_Control *cpu;
> >
> > -   if(ptimer== NULL ){
>
> Style: There should be a space before the ==
>
> > -   rtems_set_errno_and_return_minus_one( EINVAL );
> > -   }
> >
> > +if ( ptimer->clock_type ==CLOCK_REALTIME) {
>
> Style again: Space after ==
>
> Why that many blank lines?
>
> > -   cpu = _POSIX_Timer_Acquire_critical( ptimer, &lock_context );
> >
> > -            _TOD_Get(now); // get current time
> >
> >
> > -          rtems_timespec_from_ticks (ptimer->Timer.expire,expire ); // get the time to expire
> >
> >
>
> That are C++ style comments. We normally have C-Style comments in RTEMS
>
> only. Beneath that the comments exceed the line length. And some of them
>
> are quite superflous. A _TOD_Get(now) doesn't need any comment. The line
>
> is already telling that.
>
> Again: Blank lines. I won't mention the further blank lines below!
>
> > -   if (now->tv_nsec+now->tv_sec > expire->tv_nsec+expire->tv_sec) { // check if the time expired
> >
> > -          rtems_timespec_subtract (now ,expire , result); //
> >
> >
>
> Empty comment at the end of the line?
>
> > -        remaining = (uint32_t) result->tv_nsec+result->tv_sec;
> >
> >
> > -   } else {
> >
> > -        remaining = 0;
> >
> >
> > -   }
> >
> > -   _Timespec_From_ticks( remaining, &value->it_value );
> >
> > -   value->it_interval = ptimer->timer_data.it_interval;
> >
> >
> > -   _POSIX_Timer_Release( cpu, &lock_context );
> >
> > -   return 0;
> >
> > -   }
> >
> >
> > +if ( ptimer->clock_type ==CLOCK_MONOTONIC) {
>
> Odd indentation and missing blank before the closing bracket.
>
> Indentation and some blanks on brackets seems to be a problem on quite
>
> some more lines too.
>
> > -       cpu = _POSIX_Timer_Acquire_critical( ptimer, &lock_context );
> >
> >
> >
> > -   now = cpu->Watchdog.ticks;
> >
> > -         _Timecounter_Nanouptime(now );
> >
> >
> > -          rtems_timespec_from_ticks (ptimer->Timer.expire,expire );
> >
> >
> >
> > -   if (now->tv_nsec+now->tv_sec > expire->tv_nsec+expire->tv_sec) {
> >
> > -          rtems_timespec_subtract (now, expire, result);
> >
> >
> >
> > -   if ( now < ptimer->Timer.expire ) {
> > -        remaining = (uint32_t) ( ptimer->Timer.expire - now );
> >
> >
> >
> > -        remaining = (uint32_t) result->tv_nsec+result->tv_sec;
> >         } else {
> >           remaining = 0;
> >         }
> >
> >
> >
> > diff --git a/testsuites/psxtests/psxtimer02/psxtimer.c b/testsuites/psxtests/psxtimer02/psxtimer.c
> >
> > index 9f79d33c42..029e638c76 100644
> >
> > --- a/testsuites/psxtests/psxtimer02/psxtimer.c
> >
> > +++ b/testsuites/psxtests/psxtimer02/psxtimer.c
> >
> > @@ -59,17 +59,31 @@ void *POSIX_Init (
> >
> > fatal_posix_service_status_errno( status, EINVAL, "bad clock id" );
> >
> >     puts( "timer_create - bad timer id pointer - EINVAL" );
> >
> >
> > -   status = timer_create( CLOCK_REALTIME, &event, NULL );
> >
> > -   status = timer_create( CLOCK_MONOTONIC, &event, NULL );
> >
> >     fatal_posix_service_status_errno( status, EINVAL, "bad timer id" );
>
> It seems that you replace the test for REALTIME timers. Are they no
>
> longer supported with your changes? I'm not sure whether that is a good
>
> idea because it would break all existing applications that use REALTIME
>
> timer.
>
> >     puts( "timer_create - OK" );
> >
> >
> > -   status = timer_create( CLOCK_REALTIME, NULL, &timer );
> >
> > -   status = timer_create( CLOCK_MONOTONIC, NULL, &timer );
> >
> >     posix_service_failed( status, "timer_create OK" );
> >
> >     puts( "timer_create - too many - EAGAIN" );
> >
> >
> > -   status = timer_create( CLOCK_REALTIME, NULL, &timer1 );
> >
> > -   status = timer_create( CLOCK_MONOTONIC, NULL, &timer1 );
> >
> >     fatal_posix_service_status_errno( status, EAGAIN, "too many" );
> >
> >
> > -   puts( "timer_create (monotonic) - bad timer id pointer - EINVAL" );
> >
> > -   status = timer_create( CLOCK_MONOTONIC, &event, NULL );
> >
> > -   fatal_posix_service_status_errno( status, EINVAL, "bad timer id" );
> >
> >
> > -   puts( "timer_create (Monotonic) - OK" );
> >
> > -   status = timer_create( CLOCK_MONOTONIC, NULL, &timer );
> >
> > -   posix_service_failed( status, "timer_create OK" );
> >
> >
> > -   puts( "timer_create (monotonic)- too many - EAGAIN" );
> >
> > -   status = timer_create( CLOCK_MONOTONIC, NULL, &timer1 );
> >
> > -   fatal_posix_service_status_errno( status, EAGAIN, "too many" );
> >
> >
> > -   puts( "timer_delete - bad id - EINVAL" );
> >
> >     status = timer_delete( timer1 + 1 );
> >
> >     fatal_posix_service_status_errno( status, EINVAL, "bad id" );
> >
> >     @@ -100,14 +114,14 @@ void *POSIX_Init (
> >
> >     status = timer_settime( timer, TIMER_ABSTIME, &itimer, NULL );
> >
> >     fatal_posix_service_status_errno( status, EINVAL, "bad itimer value #2" );
> >
> >
> > -   clock_gettime( CLOCK_REALTIME, &now );
> >
> > -   clock_gettime( CLOCK_MONOTONIC, &now );
> >
> >     itimer.it_value = now;
> >
> >     itimer.it_value.tv_sec = itimer.it_value.tv_sec - 1;
> >
> >     puts( "timer_settime - bad itimer value - previous time - EINVAL" );
> >
> >     status = timer_settime( timer, TIMER_ABSTIME, &itimer, NULL );
> >
> >     fatal_posix_service_status_errno( status, EINVAL, "bad itimer value #3" );
> >
> > -   clock_gettime( CLOCK_REALTIME, &now );
> >
> > -   clock_gettime( CLOCK_MONOTONIC, &now );
> >
> >     itimer.it_value = now;
> >
> >     itimer.it_value.tv_sec = itimer.it_value.tv_sec + 1;
> >
> >     puts( "timer_settime - bad id - EINVAL" );
> >
> >     @@ -129,4 +143,4 @@ void *POSIX_Init (
> >
> >     TEST_END();
> >
> >     rtems_test_exit (0);
> >
> >     -}
> >
> >     +}
> >
> >     \ No newline at end of file
> >
>
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