Add rtems_clock_ticks_later(), rtems_clock_ticks_later_us() and rtems_clock_ticks_later_us().
FIXME: Patch is incomplete. Documentation and tests are missing. Just for API review. --- cpukit/rtems/include/rtems/rtems/clock.h | 66 ++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) diff --git a/cpukit/rtems/include/rtems/rtems/clock.h b/cpukit/rtems/include/rtems/rtems/clock.h index ff71665..cee930e 100644 --- a/cpukit/rtems/include/rtems/rtems/clock.h +++ b/cpukit/rtems/include/rtems/rtems/clock.h @@ -34,6 +34,7 @@ #include <rtems/score/tod.h> #include <rtems/rtems/status.h> #include <rtems/rtems/types.h> +#include <rtems/config.h> #include <sys/time.h> /* struct timeval */ @@ -160,6 +161,71 @@ RTEMS_INLINE_ROUTINE rtems_interval rtems_clock_get_ticks_since_boot(void) } /** + * @brief Returns the ticks counter value delta ticks in the future. + * + * @param[in] delta The ticks delta value. + * + * @return The tick counter value delta ticks in the future. + */ +RTEMS_INLINE_ROUTINE rtems_interval rtems_clock_ticks_later( + rtems_interval delta +) +{ + return _Watchdog_Ticks_since_boot + delta; +} + +/** + * @brief Returns the ticks counter value at least delta microseconds in the + * future. + * + * @param[in] delta The delta value in microseconds. + * + * @return The tick counter value at least delta microseconds in the future. + */ +RTEMS_INLINE_ROUTINE rtems_interval rtems_clock_ticks_later_us( + rtems_interval delta +) +{ + rtems_interval us_per_tick = rtems_configuration_get_microseconds_per_tick(); + + return _Watchdog_Ticks_since_boot + (delta + us_per_tick - 1) / us_per_tick; +} + +/** + * @brief Returns true if the current ticks counter value indicates a time + * before the time specified by the ticks value and false otherwise. + * + * @param[in] ticks The ticks value. + * + * This can be used to write busy loops with a timeout. + * + * @code + * status busy( void ) + * { + * rtems_interval timeout = rtems_clock_ticks_later_us( 10000 ); + * + * do { + * if ( ok() ) { + * return success; + * } + * } while ( rtems_clock_ticks_before( timeout ) ); + * + * return timeout; + * } + * @endcode + * + * @retval true The current ticks counter value indicates a time before the + * time specified by the ticks value. + * @retval false Otherwise. + */ +RTEMS_INLINE_ROUTINE bool rtems_clock_ticks_before( + rtems_interval ticks +) +{ + return ( (int32_t) ticks - (int32_t) _Watchdog_Ticks_since_boot ) > 0; +} + +/** * @brief Obtain Ticks Per Seconds * * This routine implements the rtems_clock_get_ticks_per_second -- 1.8.4.5 _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel