C++ coding
#ifndef HEAD_HPP #define HEAD_HPP #include <functional> #include <memory> #include <vector> /** * @class Head * * This class is an ABC that represents a read write * head on a hard drive platter. The pupose of this * class is to ensure: * 1. No two adjacent heads are active concurrently * 2. Allow the maximum amout of concurrency possible */ class Head { public: /** * @brief Execute an operation on this head * * This method must be implemented by any concrete class. It must * ensure that both of the the adjacent heads are not currenty active. * At that point, it can execute the function object and then release * any resources preventing the adjacent heads from acting. * * This function MUST be thread safe. Any number of threads may call this * function any number of times and behavior must be correct. * * @param action Function object that contains read/write/other action */ virtual void execute(std::function<void()> action) = 0; /** * @breif Static factory method * * This static method will create a number of head objects, connect * each of the heads in a way that they can lock out their right/left * neighbor, and return shared pointers to each created head in a vector. */ static std::vector<std::shared_ptr<Head>> makePlatter(int numHeads); protected: /** * @brief Protected constructor * * Since it is required that a Head have knowledge of their right/left * neighbor, it is wrong to create one in isolation. This will force * a user of this package to use the static factory method. */ Head(); }; #endif /* HEAD_HPP */