Alexander Mihajlovic f19787bb84 posix: Fix calculation of clock base in clock_settime ... Previous version calculated rt_clock_base incorrectly by subtracting clock_gettime from the specified time. Effectively the following formula was used. rt_clock_base := new_time - clock_gettime() This is clearly incorrect when we consider what should happen if we call clock_settime with the result of clock_gettime. It ought to be approximately a no-op, but instead we end up zeroing the clock. rt_clock_base := clock_gettime() - clock_gettime() = 0 This patch fixes clock_settime by instead using k_uptime_get to calculate rt_clock_base, like so: rt_clock_base := new_time - k_uptime_get() Trying the earlier thought experiment we get: rt_clock_base := clock_gettime() - k_uptime_get() Using the definition of clock_gettime this expands to: rt_clock_base := (rt_clock_base + k_uptime_get()) - k_uptime_get() The two k_uptime_get() terms cancel out, leaving: rt_clock_base := rt_clock_base I.e. the no-op that we expect when calling clock_settime with the result of clock_gettime. Note: The bug is only observable when rt_clock_base is non-zero. So when clock_settime is called for the first time, it will appear to work correctly since rt_clock_base is initialized to 0. Signed-off-by: Alexander Mihajlovic <alexander.mihajlovic@endian.se>		2019-05-21 08:24:59 -04:00
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clock.c	posix: Fix calculation of clock base in clock_settime	2019-05-21 08:24:59 -04:00
CMakeLists.txt
fs.c
Kconfig	lib/posix: correct the meaning of CONFIG_MAX_PTHREAD_COUNT	2019-05-11 08:24:36 -04:00
mqueue.c
pthread_barrier.c
pthread_common.c
pthread_cond.c
pthread_key.c
pthread_mutex.c
pthread_rwlock.c
pthread_sched.c
pthread.c	lib/posix: correct the meaning of CONFIG_MAX_PTHREAD_COUNT	2019-05-11 08:24:36 -04:00
semaphore.c
sleep.c
timer.c