Eran's Interview Question

mem.c

// Implement a memory manager that takes a large contiguous block of memory and manages allocations
// and deallocations on it.
// The entire buffer needs to be available for allocation. You can use whatever extra memory you need to manage it.
//
// Clearly document design choices, algorithm and possible optimizations.
// While we require you to implement one memory allocation algorithm,
// also document future looking design considerations.
// There are many ways to implement this memory manager. It is important for us to know why you implemented it the way you did, 
// whats the pros and cons to your implementation, etc.
//
// While the interface below is written in C, feel free to implement the MemoryManager in the language of your choosing. 
// If you need to change the interface due to language limitations (for example, not all languages have pointers) 
// or for any other reason - please explain your reasoning for the change.
// For example:
//   - if we wanted to use a different memory management strategy, how would we make that change.
//   - if we wanted thread safety any other considerations you can think of.
//
// *** Requirements *** 
// 1. Working code (obviously).
// 2. Unit tests (using a unit testing library of your choosing)
// 3. Documentation (as describe in the 2nd paragraph above) 
//

class MemoryManager {
  public:
    // buffer is a large chunk of contiguous memory.
    // num_bytes is the size of the buffer.
    MemoryManager(char * buffer, int num_bytes);

    // Allocate memory of size 'size'. Use malloc() like semantics.
    char* Alloc(int size);

    // Free up previously allocated memory.  Use free() like semantics.
    void Free(char*);
};