/*
 * utiity function(s) for Java parallel programs
 */
package csci3366sample;

public class ThreadUtility {

    public static class Exception extends java.lang.Exception {
        public Exception(String message) {
            super(message);
        }
    }

    /* get number of threads from environment variable NUM_THREADS */
    public static int getNumThreads() throws Exception {
        return getIntegerEnv("NUM_THREADS");
    }

    /* get integer environment variable */
    public static int getIntegerEnv(String name) throws Exception {
        int n = 0;
        try {
            String s = System.getenv(name);
            if (s == null) {
                throw new Exception(
                    "environment variable " + name + " must be set");
            }
            else {
                n = Integer.parseInt(s);
            }
        }
        catch (NumberFormatException e) {
            throw new Exception("non-numeric value for " + name);
        }
        return n;
    }
}