[PATCH] part of implimenting a monotonic clock in rtems part of this is not the final patch.
Christian Mauderer
oss at c-mauderer.de
Sat Jun 12 09:31:01 UTC 2021
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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