sleep_manager_racecondition test fix for devices with low CPU clock
This RP contains fix for sleep_manager_racecondition test
for very slow devices (like NRF51). It fixes the test itself
as well as side effects of fix introduced in
#5046 (us ticker: fix fire interrupt handling)
The idea of the test was to test race condition between main thread
and interrupt handler calling the same function.
To efficiently test this, each handler call should interrupt
main thread to make race more likely.
On very slow devices (like NRF51) when we set very low ticker period
(e.g less then 1000us for NRF51) there is no much time for thread scheduling.
On such slow devices, setting period to 500 us cause that
main thread is scheduled very rarely and only handler is
constantly called making test unreliable.
Fix introduced in #5046 (us ticker: fix fire interrupt handling)
changed fire_interrupt function implementation causing more
interrupt tailing thus even less time for main thread scheduling.
After introduction of #5046 (us ticker: fix fire interrupt handling)
when running sleep_manager_racecondition test on NRF51
(with ticker1.attach_us(&sleep_manager_locking_irq_test, 500);)
test is failing with timeout due to the fact that interrupt
handler is constantly called and main thread is never scheduled.
Current behaviour ends up undefined when the constructor leaves early.
Now FilePath just discards leading slashes and otherwise asserts if the
path is bad.
How you write and ersae the flash on the NRF52 changes depending on
whether the SoftDevice is enabled or not.
This change does a runtime check before erasing and writing, and
then chooses the correct function to perform the action.
Rather than tracking all in-flight blocks blocks during a lookahead,
littlefs uses an ack scheme to mark the first allocated block that
hasn't reached the disk yet. littlefs assumes all blocks since the
last ack are bad or in-flight, and uses this to know when it's out
of storage.
However, these unacked allocations were still being populated in the
lookahead buffer. If the whole block device fits in the lookahead
buffer, _and_ littlefs managed to scan around the whole storage while
an unacked block was still in-flight, it would assume the block was
free and misallocate it.
The fix is to only fill the lookahead buffer up to the last ack.
The internal free structure was restructured to simplify the runtime
calculation of lookahead size.
Delta calculation from lp_ticker_set_interrupt() function:
delta_us = timestamp > now_us ? timestamp - now_us : (uint32_t)((uint64_t)timestamp + 0xFFFFFFFF - now_us);
Lets assume that timestam == now_us.
Expected delta value should be 0 and in this current version is 0xFFFFFFFF.
The following condition:
timestamp > now_us
should have the following form:
timestamp >= now_us
Additionally modified us ticker driver to provide the same logic.
In the 'Testing accuracy of equeue semaphore' test case result is printed out in each loop iteration.
Since debug prints should not exist in the final test version I suggest to print information only in case of failure.
Additionally time needed to print single info is equal to ~25 ms (K64F/GCC_ARM). The while loop is designed to execute until 20000 ms elapses, so this print has also impact on number of times the loop is executed (number of semaphore accuracy checks).
The rework includes the following:
1. Remove ticker overflow handling because upper layer (mbed_ticker_api.c) has done with it.
This makes us_ticker/lp_ticker implementation more succinct and avoids potential error.
2. Refine timer register access with low-power clock source
drewcassidy
Anna Bridge
Cruz Monrreal II
Maciej Bocianski
Andrew Leech
Mahesh Mahadevan
Christopher Haster
Jimmy Brisson
Martin Kojtal
Veijo Pesonen
Marcus Chang
jeromecoutant
Przemyslaw Stekiel
ccli8
PHST
Bilal