+static sigjmp_buf jmpbuf1; /* where to jump to if we are ready when the */
+ /* SIGUSR1 arrives from the previous slave */
+static int caught2; /* have we caught the signal to proceed? */
+static int ready2; /* have we reached the lock point without having */
+ /* received the SIGUSR2 signal from the prev slave? */
+static sigjmp_buf jmpbuf2; /* where to jump to if we are ready when the */