mscgen

gistfile1.txt

msc {
  a,b,c;

  a->b  [label="ab()"] ;
  b->c  [label="bc(TRUE)"];
  c=>c  [label="process(1)"];
  c=>c  [label="process(2)"];
  ...;
  c=>c  [label="process(n)"];
  c=>c  [label="process(END)"];
  a<<=c [label="callback()"];
  ---   [label="If more to run", ID="*"];
  a->a  [label="next()"];
  a->c  [label="ac()"];
  b<-c  [label="cb(TRUE)"];
  b->b  [label="stalled(...)"];
  a<-b  [label="ab() = FALSE"];
}