tree 5106529b29f2f41bf7129f236f0533c56e2cc725
parent 3f4037b951f07d929f292e1f064cac7332199f55
author Yong Cong Sin <ycsin@meta.com> 1735033291 +0800
committer github-actions[bot] <github-actions[bot]@users.noreply.github.com> 1736142884 +0000

lib: os: mpsc_pbuf: do not wait when spinlock is held

Check if the spinlock is held before attempting to wait by
taking the semaphore, as that would cause a context switch which
isn't allowed and will trigger an assertion error when
`CONFIG_SPIN_VALIDATE` is enabled.

Logging in spinlock-held context when the log buffer is full can lead
to an infinite assertion error loop, as the logging subsys attempts to
allocate buffer when there's none available, it will try to wait for
one and thus triggers the assertion error, the error message will be
printed through the logging sybsys but there's no buffer available,
so it will try to wait for one and triggers another assertion error..
This loop just goes on and on forever, and nothing gets printed to
the terminal.

Added a test to validate the fix.

Signed-off-by: Yong Cong Sin <ycsin@meta.com>
Signed-off-by: Yong Cong Sin <yongcong.sin@gmail.com>
Signed-off-by: Maxim Adelman <imax@meta.com>
(cherry picked from commit 1a578eb72c9dffe74aa3bc47b48400525096218e)