As of now, both the old and new ztest framework don't have a logic to
launch static threads. Static threads can only be launched by Zephyr
itself during boot. If a test interact with static threads, when it
is executed multiple times without reboot, only the first few runs can
have static threads to interact with. After the static threads exit,
later runs will have nothing to interact with, which can lead to failure.
One unfortunate example is the sys_mutex test.
This commit replaces static threads with dynamic thread to make the test
repeatable. In future, maybe static threads launching logic should be
covered by the ztest framework so richer scenarios can be tested.
Signed-off-by: Ming Shao <ming.shao@intel.com>
2daae30ec3