Priority in FreeRTOS

[hs2 (Hartmut Schaefer)]

When multiple tasks of different priorities are waiting to acquire the semaphore, the highest priority task will be unblocked and allowed to proceed once the semaphore becomes available.

That’s right. Waiting resp. blocking and unblocking only happens if the semaphore count already dropped down to 0 when a task wanted to aquire/take it.

This mechanism ensures that even if a lower priority task is currently holding the semaphore, a higher priority task attempting to acquire it will preempt the lower priority task.

That’s only right if the semaphore was not yet counted down to 0 means no task is actually holding the semaphore. Otherwise the task attempting to aquired the semaphore is blocked regardless of its priority.

Again a (counting) semaphore is semantically and also technically different to a mutex.
Which bigger problem do you want to solve ? Is it similar to the train station example in the post mentioned before ?