问从现有的文件描述符-c分配一个结构

EN

void *allocator_top; // Define a global pointer to top of the "heap" area.
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allocator_top = mmap(...); // Do this wherever you perform the mmap
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Xstruct * accessMem(){
    void *temp = allocator_top;
    // Need to check here if you have exceeded the amount of space mapped. If yes, you need to expand and add more pages.
    allocator_top += sizeof(Xstruct);
    return temp;
}