(1) In µC/OS-III, there is no “accept” API, since this feature is built into the OSMutexPend() by specifying the OS_OPT_PEND_NON_BLOCKING option. (2) In µC/OS-II, OSMutexCreate() returns the address of an OS_EVENT , which is used as the “handle” to the message mailbox. In µC/OS-III, the application must allocate storage for an OS_MUTEX , which serves the same purpose as the OS_EVENT . The benefit in µC/OS-III is that it is not necessary to predetermine the number of mutual-exclusion semaphores at compile time. (3) µC/OS-III returns additional information when a mutex is released. The releaser takes a snapshot of the current time stamp and stores it in the OS_MUTEX . The new owner of the mutex therefore knows when the mutex was released. (4) µC/OS-III does not provide query services as they were rarely used. |