INTERFACE Topology;

IMPORT AlgGreedy, Graph, Rd, Thread;

TYPE
  Kind = { Grid, Torus, Butterfly, FromFile };

PROCEDURE FromName(nm: TEXT): Kind;

Return the topology type corresponding to the name nm. The valid names are the same as the names of the Topology.T enumerations, except that they begin with lower-case letters.

PROCEDURE NewGrid(
    alg: AlgGreedy.T;
    w, h: CARDINAL;
    maxQueueSize: CARDINAL;
    bounded: BOOLEAN)
  : Graph.T
  RAISES {Thread.Alerted};

Return a new graph whose topology is a grid with h rows and w columns. Each node is connected to its north, east, south, and west neighbors. MaxQueueSize is the maximum size of the queue at each node if bouned is true; otherwise, the queues are unbounded, but maxQueueSize is the maximum expected queue size. Generate the interesting events to construct this graph.

PROCEDURE NewTorus(
    alg: AlgGreedy.T;
    w, h: CARDINAL;
    maxQueueSize: CARDINAL;
    bounded: BOOLEAN)
  : Graph.T
  RAISES {Thread.Alerted};

Like NewGrid, but w + h extra edges are added so the topology is a toroidal grid.

PROCEDURE NewButterfly(
    alg: AlgGreedy.T;
    dim: CARDINAL;
    maxQueueSize: CARDINAL;
    bounded: BOOLEAN)
  : Graph.T
  RAISES {Thread.Alerted};

Return a new graph whose topology is a butterfly with dimension dim. The resulting graph is a grid of dim + 1 columns and 2^dim rows. There is an edge between (i, j) and (i', j') iff i + 1 = i' and either j = j' or the binary values for j and j' differ in the ith bit. The procedure generates the interesting events to construct the graph.

EXCEPTION BadGraph(TEXT);

The argument to the BadGraph exception is an error message describing why the graph cannot be created.

PROCEDURE NewFromFile(
    alg: AlgGreedy.T;
    rd: Rd.T;
    maxQueueSize: CARDINAL;
    bounded: BOOLEAN)
  : Graph.T
  RAISES {BadGraph, Thread.Alerted};

Return a new graph defined by the next s-expression in rd. MaxQueueSize and bounded are as in the NewGrid procedure above. Generate the interesting events to construct this graph.

END Topology.