ptr"). The "msg" parameter maybe NULL to indicate that the message
should be dropped.
- The return values are the same as for the sys_arch_sem_wait()
- function and the function must not return zero even if a message was
- present in the mailbox and the time spent waiting was zero
- milliseconds.
+ The return values are the same as for the sys_arch_sem_wait() function:
+ Number of milliseconds spent waitng or 0xffffffff if there was a timeout.
Note that a function with a similar name, sys_mbox_fetch(), is
implemented by lwIP.