Before using a memory partition, it must be created. This allows µC/OS-III to know something about the memory partition so that it can manage their allocation and deallocation. Once created, a memory partition is as shown in the figure below. Calling OSMemCreate() creates a memory partition.
(1) When creating a partition, the application code supplies the address of a memory partition control block (OS_MEM). Typically, this memory control block is allocated from static memory, however it can also be obtained from the heap by calling malloc(). The application code should however never deallocate it.
(2) OSMemCreate() organizes the continuous memory provided into a singly linked list and stores the pointer to the beginning of the list in the OS_MEM structure.
(3) Each memory block must be large enough to hold a pointer. Given the nature of the linked list, a block needs to be able to point to the next block.
The listing below indicates how to create a memory partition with µC/OS-III.
The listing below shows how to create a memory partition with µC/OS-III, but this time, using malloc() to allocate storage. Do not deallocate the memory control block or the storage for the partition.