2015 02 12

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Politecnico)di)Milano))Middleware)T echnologies)for)Distributed)Systems))) 12th)of)February)2015)Rules: •)You are not allowed to use books, notes, or other material. •)You can answer in Italian or English. •)Total time for the test: 1.5 hours. 1.)Implement the LindaSpace class in Java. It provides a method to add an integer into the space, a method to read an integer from the space (without removing it), and a method to get an integer from the space (effectively removing it). Methods read and get suspend the caller if the requested integer is not present in the space. When a new element is added into the space, priority must be given to the readers of that element with respect to the getters of the same element. 2.)Write in TinyOS a module PeriodicReader that periodically reads a sensor (wired to the Read<uint16_t> interface it uses) and returns the value read as an event. It must provide a method to start it (passing the reading period) and one to stop it. Write the interface and the implementation of the module. The following interfaces may help you: interface Timer<precision_tag> { command void startPeriodic(uint32_t dt); command void startOneShot(uint32_t dt); command void stop(); event void fired(); } interface Read<val_t> { command error_t read(); event void readDone(error_t err, val_t val); } 3.)Write the OpenMP code (the minimal fragment of code you need) that takes a matrix M of integers (of size ROWSxLINES), calculates the average avgM of the values in M and fills a matrix N with the difference, element by element between M[i][j] and avgM, i.e., N[i][j] = M[i][j]-avgM. 4.)Provide an in-depth explanation of the technical and architectural differences between SOAP-based services and REST-based services. When would it be preferable to use one solution, and when…