Jacobi method is iterative scheme for solving linear system of equations. As discretization of partial differential results typically in such a system, Jacobi method can be used for numerical solution of partial differential equations.
The code jacobi.cpp / jacobi.F90 solves two dimensional Poisson equation
The source term b is read from a file input.dat, and the two dimensional array u is then solved using the Jacobi method.
The computations are already parallelized with OpenMP. However, the parallel region misses
some critical execution control constructs (barrier, master, critical) and does not
work correctly when run with more than a single thread.
Add appropriate execution controls within the parallel region in the main routine so that
the code works with arbitrary number of threads, and gives same results both in parallel and
in serial.