java里的 thread 源码

/**
     * Constructs a new {@code Thread} with no {@code Runnable} object and a
     * newly generated name. The new {@code Thread} will belong to the same
     * {@code ThreadGroup} as the {@code Thread} calling this constructor.
     *
     * @see java.lang.ThreadGroup
     * @see java.lang.Runnable
     */
    public Thread() {
        create(null, null, null, 0);
    }

    /**
     * Constructs a new {@code Thread} with a {@code Runnable} object and a
     * newly generated name. The new {@code Thread} will belong to the same
     * {@code ThreadGroup} as the {@code Thread} calling this constructor.
     *
     * @param runnable
     *            a {@code Runnable} whose method <code>run</code> will be
     *            executed by the new {@code Thread}
     *
     * @see java.lang.ThreadGroup
     * @see java.lang.Runnable
     */
    public Thread(Runnable runnable) {
        create(null, runnable, null, 0);
    }

    /**
     * Constructs a new {@code Thread} with a {@code Runnable} object and name
     * provided. The new {@code Thread} will belong to the same {@code
     * ThreadGroup} as the {@code Thread} calling this constructor.
     *
     * @param runnable
     *            a {@code Runnable} whose method <code>run</code> will be
     *            executed by the new {@code Thread}
     * @param threadName
     *            the name for the {@code Thread} being created
     *
     * @see java.lang.ThreadGroup
     * @see java.lang.Runnable
     */
    public Thread(Runnable runnable, String threadName) {
        if (threadName == null) {
            throw new NullPointerException();
        }

        create(null, runnable, threadName, 0);
    }

    /**
     * Constructs a new {@code Thread} with no {@code Runnable} object and the
     * name provided. The new {@code Thread} will belong to the same {@code
     * ThreadGroup} as the {@code Thread} calling this constructor.
     *
     * @param threadName
     *            the name for the {@code Thread} being created
     *
     * @see java.lang.ThreadGroup
     * @see java.lang.Runnable
     *
     */
    public Thread(String threadName) {
        if (threadName == null) {
            throw new NullPointerException();
        }

        create(null, null, threadName, 0);

    }