...
µC/OS-III allows OSSchedLock() to be nested up to 250 levels deep. Scheduling is enabled when an equal number of OSSchedUnlock() calls have been made.
Arguments
p_err
is a pointer to a variable that will contain an error code returned by this function.
...
If OS_CFG_CALLED_FROM_ISR_CHK_EN set to 1 in os_cfg.h: if you attempted to call OSSchedLock() from an ISR.
Returned Value
None
Notes/Warnings
After calling OSSchedLock(), the application must not make system calls that suspend execution of the current task; that is, the application cannot call OSTimeDly(), OSTimeDlyHMSM(), OSFlagPend(), OSSemPend(), OSMutexPend(), or OSQPend(). Since the scheduler is locked out, no other task is allowed to run, and the system will lock up.