A GPU offloading mechanism for LHCb

The current computational infrastructure at LHCb is designed for sequential execution. It is possible to make use of modern multi-core machines by using multi-threaded algorithms and running multiple instances in parallel, but there is no way to make efficient use of specialized massively parallel hardware, such as graphical processing units and Intel Xeon/Phi. We extend the current infrastructure with an out-of-process computational server able to gather data from multiple instances and process them in large batches.