1Title: Timer Starvation test 2 3The purpose of the test is to detect whether the timer implementation 4correctly handles situations where only one timeout is present, and that 5timeout is repeatedly rescheduled before it has a chance to fire. In 6some implementations this may prevent the timer interrupt handler from 7ever being invoked, which in turn prevents an announcement of ticks. 8Lack of tick announcement propagates into a monotonic increase in the 9value returned by sys_clock_elapsed(). 10 11This test is not run in automatic test suites because it generally takes 12minutes, hours, or days to fail, depending on the hardware clock rate 13and the tick rate. By default the test passes if one hour passes 14without detecting a failure. 15 16Failure will occur when some counter wraps around. This may be a 17hardware timer counter, a timer driver internal calculation of 18unannounced cycles, or the Zephyr measurement of unannounced ticks. 19 20For example a system that uses a 32768-Hz internal timer counter with 2124-bit resolution and determines elapsed time by a 24-bit unsigned 22difference between the current and last-recorded counter value will fail 23at 512 s when the updated counter value is observed to be less than the 24last recorded counter. 25 26Systems that use a 32-bit counter of 80 MHz ticks would fail after 2753.687 s. 28
