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os_mem.c contains code for the µC/OS-III fixed-size memory manager, see Memory Management API Changes.
os_mon.c contains code that manages 'Monitors' in µC/OS-III, see Monitors.os_msg.c contains code to handle messages. µC/OS-III provides message queues and task specific message queues. os_msg.c provides common code for these two services. See Message Passing.
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