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//==========================================================================

//

//      time.cxx

//

//      POSIX time functions implementation

//

//==========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

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// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):           nickg

// Contributors:        nickg

// Date:                2000-03-27

// Purpose:             POSIX time functions implementation

// Description:         This file contains the implementation of the POSIX time

//                      functions.

//              

//              

//

//####DESCRIPTIONEND####

//

//==========================================================================

#include <pkgconf/posix.h>

#ifdef CYGPKG_POSIX_CLOCKS

#include <pkgconf/hal.h>

#include <pkgconf/kernel.h>

#include <cyg/kernel/ktypes.h>          // base kernel types

#include <cyg/infra/cyg_trac.h>         // tracing macros

#include <cyg/infra/cyg_ass.h>          // assertion macros

#include "pprivate.h"                   // POSIX private header

#include <time.h>                       // our header

#include <cyg/kernel/thread.hxx>

#include <cyg/kernel/clock.hxx>

#include <cyg/kernel/thread.inl>

#include <cyg/kernel/clock.inl>

// -------------------------------------------------------------------------

// Internal definitions

// Handle entry to a pthread package function. 

#define TIME_ENTRY() CYG_REPORT_FUNCTYPE( "returning %d" );

// Do a time package defined return. This requires the error code

// to be placed in errno, and if it is non-zero, -1 returned as the

// result of the function. This also gives us a place to put any

// generic tidyup handling needed for things like signal delivery and

// cancellation.

#define TIME_RETURN(err)                        \

CYG_MACRO_START                                 \

    int __retval = 0;                           \

    if( err != 0 ) __retval = -1, errno = err;  \

    CYG_REPORT_RETVAL( __retval );              \

    return __retval;                            \

CYG_MACRO_END

//==========================================================================

// Timer control structures

#ifdef CYGPKG_POSIX_TIMERS

typedef struct

{

    timer_t             id;             // id value for checking

    Cyg_Alarm           *alarm;         // eCos alarm object

    cyg_bool            armed;          // is alarm enabled?

    cyg_bool            pending;        // is expiry pending?

    int                 overrun;        // Overrun count

    struct sigevent     sigev;          // Sigevent to raise on expiry

    // Space for alarm object

    cyg_uint8           alarm_obj[sizeof(Cyg_Alarm)];

} posix_timer;

// Mutex for controlling access to shared data structures

static Cyg_Mutex timer_mutex CYGBLD_POSIX_INIT;

// Array of timer objects

static posix_timer timer_table[_POSIX_TIMER_MAX];

// Index of next timer to allocate from array

static int timer_next = 0;

// This is used to make timer_t values unique even when reusing

// a table slot. This allows _POSIX_TIMER_MAX to range

// up to 1024.

#define TIMER_ID_COOKIE_INC 0x00000400

#define TIMER_ID_COOKIE_MASK (TIMER_ID_COOKIE_INC-1)

static timer_t timer_id_cookie = TIMER_ID_COOKIE_INC;

#endif // ifdef CYGPKG_POSIX_TIMERS

//-----------------------------------------------------------------------------

// new operator to allow us to invoke the constructor on

// posix_timer.alarm_obj.

inline void *operator new(size_t size,  cyg_uint8 *ptr) { return (void *)ptr; };

//==========================================================================

// Time conversion variables

// These are used to interconvert between ticks and POSIX timespecs.

// Converters from sec and ns to ticks

static struct Cyg_Clock::converter ns_converter, sec_converter;

// Converters from ticks to sec and ns

static struct Cyg_Clock::converter ns_inverter, sec_inverter;

// tickns is the number of nanoseconds per tick.

static cyg_tick_count tickns;

static cyg_bool converters_initialized = false;

//==========================================================================

// Local functions

static void init_converters()

{

    if( !converters_initialized )

    {

        // Create the converters we need.

        Cyg_Clock::real_time_clock->get_other_to_clock_converter( 1, &ns_converter );

        Cyg_Clock::real_time_clock->get_other_to_clock_converter( 1000000000, &sec_converter );

        Cyg_Clock::real_time_clock->get_clock_to_other_converter( 1, &ns_inverter );

        Cyg_Clock::real_time_clock->get_clock_to_other_converter( 1000000000, &sec_inverter );

        tickns = Cyg_Clock::convert( 1, &ns_inverter );

        converters_initialized = true;

    }

}

static cyg_bool valid_timespec( const struct timespec *tp )

{

    // Fail a NULL pointer

    if( tp == NULL ) return false;

    // Fail illegal nanosecond values

    if( tp->tv_nsec < 0 || tp->tv_nsec > 1000000000 )

        return false;

    return true;

}

externC cyg_tick_count cyg_timespec_to_ticks( const struct timespec *tp,

                                              cyg_bool roundup)

{

    init_converters();

    // Short circuit zero timespecs

    if( tp->tv_sec == 0 && tp->tv_nsec == 0 )

    {

        return 0;

    }

    // Convert the seconds field to ticks.

    cyg_tick_count ticks = Cyg_Clock::convert( tp->tv_sec, &sec_converter );

    if( roundup )

    {

        // Convert the nanoseconds. We add (tickns-1) to round the value up

        // to the next whole tick.

        ticks += Cyg_Clock::convert( (cyg_tick_count)tp->tv_nsec+tickns-1, &ns_converter );

    }

    else

    {

        // Convert the nanoseconds. This will round down to nearest whole tick.

        ticks += Cyg_Clock::convert( (cyg_tick_count)tp->tv_nsec, &ns_converter );

    }

    return ticks;

}

externC void cyg_ticks_to_timespec( cyg_tick_count ticks, struct timespec *tp )

{

    init_converters();

    // short circuit zero ticks values

    if( ticks == 0 )

    {

        tp->tv_sec = 0;

        tp->tv_nsec = 0;

        return;

    }

    // Convert everything to nanoseconds with a long long. For 64-bits,

    // this is safe for 544 years. We'll think about it more closer to

    // the time...

    unsigned long long nsecs = Cyg_Clock::convert( ticks, &ns_inverter );

    tp->tv_sec = (long)(nsecs / 1000000000ll);

    tp->tv_nsec = (long)(nsecs % 1000000000ll);

    CYG_POSTCONDITION(valid_timespec(tp), "Failed to make valid timespec!");

}

//==========================================================================

// Startup routine.

externC void cyg_posix_clock_start()

{

    init_converters();

}

#ifdef CYGPKG_POSIX_TIMERS

//==========================================================================

// Alarm action routine

// This is called each time an alarm set up by a timer expires.

static void alarm_action( Cyg_Alarm *alarm, CYG_ADDRWORD data )

{

    posix_timer *timer = (posix_timer *)data;

    if( timer->pending )

    {

        // If the pending flag is already set, count an overrun and

        // do not bother to try and deliver the expiry.

        timer->overrun++;

    }

    else

    {

        if( timer->sigev.sigev_notify == SIGEV_SIGNAL )

        {

            // Set the expiry pending and wake a thread to

            // deliver the signal.

            timer->pending = true;

            sigset_t mask;

            sigemptyset( &mask );

            sigaddset( &mask, timer->sigev.sigev_signo );

            cyg_posix_signal_sigwait();

            cyg_posix_pthread_release_thread( &mask );

        }

        else if( timer->sigev.sigev_notify == SIGEV_THREAD )

        {

            // Thread style notification

            // FIXME: implement SIGEV_THREAD

        }

        // else do nothing

    }

}

//==========================================================================

// Timer ASR routine

externC void cyg_posix_timer_asr( pthread_info *self )

{

    // Loop over the timers looking for any that have an

    // expiry pending and call cyg_sigqueue() for each.

    for( int i = 0; i < _POSIX_TIMER_MAX; i++ )

    {

        posix_timer *timer = &timer_table[i];

        if( timer->id != 0 && timer->pending )

        {

            timer->pending = false;

            // Call into signal subsystem...

            cyg_sigqueue( &timer->sigev, SI_TIMER );

            timer->overrun = 0;

        }

    }

}

#endif // ifdef CYGPKG_POSIX_TIMERS

//==========================================================================

// Clock functions

//-----------------------------------------------------------------------------

// Set the clocks current time

externC int clock_settime( clockid_t clock_id, const struct timespec *tp)

{

    TIME_ENTRY();

    if( clock_id != CLOCK_REALTIME )

        TIME_RETURN(EINVAL);

    if( !valid_timespec( tp ) )

        TIME_RETURN(EINVAL);

    cyg_tick_count ticks = cyg_timespec_to_ticks( tp );

    Cyg_Clock::real_time_clock->set_value( ticks );

    TIME_RETURN(0);

}

//-----------------------------------------------------------------------------

// Get the clocks current time

externC int clock_gettime( clockid_t clock_id, struct timespec *tp)

{

    TIME_ENTRY();

    if( clock_id != CLOCK_REALTIME )

        TIME_RETURN(EINVAL);

    if( tp == NULL )

        TIME_RETURN(EINVAL);

    cyg_tick_count ticks = Cyg_Clock::real_time_clock->current_value();

    cyg_ticks_to_timespec( ticks, tp );

    TIME_RETURN(0);

}

//-----------------------------------------------------------------------------

// Get the clocks resolution

externC int clock_getres( clockid_t clock_id, struct timespec *tp)

{

    TIME_ENTRY();

    if( clock_id != CLOCK_REALTIME )

        TIME_RETURN(EINVAL);

    if( tp == NULL )

        TIME_RETURN(EINVAL);

    // Get the resolution of 1 tick

    cyg_ticks_to_timespec( 1, tp );

    TIME_RETURN(0);

}

//==========================================================================

// Timer functions

#ifdef CYGPKG_POSIX_TIMERS

//-----------------------------------------------------------------------------

// Create a timer based on the given clock.

externC int timer_create( clockid_t clock_id,

                          struct sigevent *evp,

                          timer_t *timer_id)

{

    TIME_ENTRY();

    if( clock_id != CLOCK_REALTIME )

        TIME_RETURN(EINVAL);

    timer_mutex.lock();

    posix_timer *timer;

    int next = timer_next;

    // Look for an unused slot in the table

    while( timer_table[next].id != 0 )

    {

        next++;

        if( next >= _POSIX_TIMER_MAX )

            next = 0;

        if( next == timer_next )

        {

            timer_mutex.unlock();

            TIME_RETURN(EAGAIN);

        }

    }

    timer = &timer_table[next];

    timer_next = next;

    // Make sure we never allocate a zero timer id.

    while( timer->id == 0 )

    {

        timer_id_cookie += TIMER_ID_COOKIE_INC;

        timer->id        = next+timer_id_cookie;

    }

    if( evp == NULL )

    {

        // If no evp is supplied, set up the timer

        // to use a default set.

        timer->sigev.sigev_notify               = SIGEV_SIGNAL;

        timer->sigev.sigev_signo                = SIGALRM;

        timer->sigev.sigev_value.sival_int      = timer->id;

    }

    else timer->sigev = *evp;

    timer->alarm        = new( timer->alarm_obj )

                               Cyg_Alarm( Cyg_Clock::real_time_clock,

                                          alarm_action,

                                          (CYG_ADDRWORD)timer );

    timer->armed        = false;

    timer->overrun      = 0;

    *timer_id = timer->id;

    timer_mutex.unlock();

    TIME_RETURN(0);

}

//-----------------------------------------------------------------------------

// Delete the timer

externC int timer_delete( timer_t timerid )

{

    int err = EINVAL;

    TIME_ENTRY();

    posix_timer *timer = &timer_table[timerid & TIMER_ID_COOKIE_MASK];

    timer_mutex.lock();

    if( timer->id == timerid )

    {

        // This is a valid timer, disable the kernel

        // alarm and delete it.

        // disable alarm

        timer->alarm->disable();

        // destroy it

        timer->alarm->~Cyg_Alarm();

        // Mark POSIX timer free

        timer->id = 0;

        err = 0;

    }

    timer_mutex.unlock();

    TIME_RETURN( err );

}

//-----------------------------------------------------------------------------

// Set the expiration time of the timer.

externC int timer_settime( timer_t timerid, int flags,

                           const struct itimerspec *value,

                           struct itimerspec *ovalue )

{

    int err = EINVAL;

    TIME_ENTRY();

    if( value == NULL )

        TIME_RETURN(EINVAL);

    // convert trigger and interval values to ticks.

    cyg_tick_count trigger = cyg_timespec_to_ticks( &value->it_value, true );

    cyg_tick_count interval = cyg_timespec_to_ticks( &value->it_interval, true );

    posix_timer *timer = &timer_table[timerid & TIMER_ID_COOKIE_MASK];

    timer_mutex.lock();

    if( timer->id == timerid )

    {

        // disable the timer

        timer->alarm->disable();

        if( ovalue != NULL )

        {

            cyg_tick_count otrigger, ointerval;

            timer->alarm->get_times( &otrigger, &ointerval );

            if( timer->armed )

            {

                // convert absolute trigger time to interval until next trigger

                otrigger -= Cyg_Clock::real_time_clock->current_value();

            }

            else otrigger = 0;

            // convert ticks to timespecs

            cyg_ticks_to_timespec( otrigger, &ovalue->it_value );

            cyg_ticks_to_timespec( ointerval, &ovalue->it_interval );

        }

        if( trigger == 0 )

        {

            // Mark timer disarmed

            timer->armed = false;

        }

        else

        {

            // If the ABSTIME flag is not set, add the current time

            if( (flags & TIMER_ABSTIME) == 0 )

                trigger += Cyg_Clock::real_time_clock->current_value();

            // Set the alarm running.

            timer->alarm->initialize( trigger, interval );

            // Mark timer armed

            timer->armed = true;

        }

        err = 0;

    }

    timer_mutex.unlock();

    TIME_RETURN(err);

}

//-----------------------------------------------------------------------------

// Get current timer values

externC int timer_gettime( timer_t timerid, struct itimerspec *value )

{

    int err = EINVAL;

    TIME_ENTRY();

    if( value == NULL )

        TIME_RETURN(EINVAL);

    posix_timer *timer = &timer_table[timerid & TIMER_ID_COOKIE_MASK];

    timer_mutex.lock();

    if( timer->id == timerid )

    {

        cyg_tick_count trigger, interval;

        timer->alarm->get_times( &trigger, &interval );

        if( timer->armed )

        {

            // convert absolute trigger time to interval until next trigger

            trigger -= Cyg_Clock::real_time_clock->current_value();

        }

        else trigger = 0;

        // convert ticks to timespecs

        cyg_ticks_to_timespec( trigger, &value->it_value );

        cyg_ticks_to_timespec( interval, &value->it_interval );

        err = 0;

    }

    timer_mutex.unlock();

    TIME_RETURN(err);

}

//-----------------------------------------------------------------------------

// Get number of missed triggers

externC int timer_getoverrun( timer_t timerid )

{

    int overrun = 0;

    TIME_ENTRY();

    posix_timer *timer = &timer_table[timerid & TIMER_ID_COOKIE_MASK];

    timer_mutex.lock();

    if( timer->id == timerid )

    {

        overrun = timer->overrun;

    }

    timer_mutex.unlock();

    CYG_REPORT_RETVAL(overrun);

    return overrun;

}

#endif // ifdef CYGPKG_POSIX_TIMERS

//==========================================================================

// Nanosleep

// Sleep for the given time.

externC int nanosleep( const struct timespec *rqtp,

                       struct timespec *rmtp)

{

    cyg_tick_count ticks, now, then;

    TIME_ENTRY();

    // check for cancellation first.

    PTHREAD_TESTCANCEL();

    // Fail an invalid timespec

    if( !valid_timespec( rqtp ) )

        TIME_RETURN(EINVAL);

    // Return immediately for a zero delay.

    if( rqtp->tv_sec == 0 && rqtp->tv_nsec == 0 )

        TIME_RETURN(0);

    // Convert timespec to ticks

    ticks = cyg_timespec_to_ticks( rqtp, true );

    CYG_ASSERT( ticks != 0, "Zero tick count");

    Cyg_Thread *self = Cyg_Thread::self();

    // Do the delay, keeping track of how long we actually slept for.

    then = Cyg_Clock::real_time_clock->current_value();

    self->delay( ticks );

    now = Cyg_Clock::real_time_clock->current_value();

    if( rmtp != NULL && (then+ticks) > now )

    {

        // We woke up early, return the time left.

        // FIXME: strictly we only need to do this if we were woken

        //        by a signal.

        // Calculate remaining number of ticks.

        ticks -= (now-then);

        cyg_ticks_to_timespec( ticks, rmtp );

    }

    // check if we were woken up because we were cancelled.

    PTHREAD_TESTCANCEL();

    TIME_RETURN(0);

}

// -------------------------------------------------------------------------

// Wait for a signal, or the given number of seconds

externC unsigned int sleep( unsigned int seconds )

{

    TIME_ENTRY();

    struct timespec timeout;

    timeout.tv_sec = seconds;

    timeout.tv_nsec = 0;

    if( nanosleep( &timeout, &timeout ) != 0 )

    {

        CYG_REPORT_RETVAL(timeout.tv_sec);

        return timeout.tv_sec;

    }

    TIME_RETURN(0);

}

#endif // ifdef CYGPKG_POSIX_CLOCKS

// -------------------------------------------------------------------------

// EOF time.cxx