Solución ejercicio 4

    X = El proceso pasa a estado bloqueado.
    / = El proceso pasa a estado preparado.
    > = Fin de su ejecucion

    | #1| #2|   |   |   | #3| #1| #2|   |   |   | #3| #1|FIN|   |   |   |   |   |   |
  p1|---|---X   |   /   |---|---|---X   |   /   |---|--->   |   |   |   |   |   |   |
    |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
    |   |   | #1| #2| #3|   |   |   | #1| #2| #3|   |   | #1|FIN|   |   |   |   |   |
  p2|   |   |---|---|---X   /   |   |---|---|---X   /   |--->   |   |   |   |   |   |
    |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
    |___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|
    0   1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16  17  18  19  20

--Pneira 09:51 10 may 2011 (UTC)