CooCox CoOS User's Guide

CooCox CoOS can manage a total of 32 fixed-length partitions of different
size. You can create a partition of fixed length by calling
CoCreateMemPartition(). After being created successfully, you can allocate or
release the memory block by calling CoGetMemoryBuffer() and
CoFreeMemoryBuffer(). You can also get the number of free memory blocks in
current memory partition by calling CoGetFreeBlockNum().
Code 2 The creation and use of fixed-length partition
U8 memPartition[128*20];
OS_MMID memID;
void myTask (void* pdata)
{
U8* data;
memID = CoCreateMemPartition(memPartition,128,20);
if(CoGetFreeBlockNum(memID ) != 0)
{
data = (U8*)CoGetMemoryBuffer(memID );
}
..................
CoFreeMemoryBuffer(memID ,data);
}
4.2.2 Variable-length partition
From the implement of conventional dynamic memory shown above, we
can see that it need to operate the free list and the allocated list at the same
time while release the memory, which require a long operation time and has
impaction to the CPU. For these reasons, CooCox CoOS redesigns the list to
ensure that both the allocation and release of memory only require to search
just one list.
Free list
head
NULL
1 2 3 4
NULL
Allocated list
Figure 4.2.3 List of variable-length partition
From the figure we can see that all the free memory in the system can
separately form a one-way list so that it is more convenient to look up the list
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