The build state is managed by the `BuildState` class.
An instance is created for each build in the build definition, once per build execution and is discarded at the end of the execution. 

The build state also includes what is currently called the "Gradle state". The Gradle state is being merged into the build state and is mostly empty.

### Project state

  boolean isRunning();

  /** Returns the lifecycle state of the service. */
  State state();

  /**
   * If the service is {@linkplain State#STARTING starting} or {@linkplain State#RUNNING running},
   * this initiates service shutdown and returns immediately. If the service is {@linkplain
   * State#NEW new}, it is {@linkplain State#TERMINATED terminated} without having been started nor

  boolean isRunning();

  /** Returns the lifecycle state of the service. */
  State state();

  /**
   * If the service is {@linkplain State#STARTING starting} or {@linkplain State#RUNNING running},
   * this initiates service shutdown and returns immediately. If the service is {@linkplain
   * State#NEW new}, it is {@linkplain State#TERMINATED terminated} without having been started nor

    @Override
    public void running() {
      ServiceManagerState state = this.state.get();
      if (state != null) {
        state.transitionService(service, STARTING, RUNNING);
      }
    }

    @Override
    public void stopping(State from) {
      ServiceManagerState state = this.state.get();
      if (state != null) {
        state.transitionService(service, from, STOPPING);
      }
    }

    @Override
    public void running() {
      ServiceManagerState state = this.state.get();
      if (state != null) {
        state.transitionService(service, STARTING, RUNNING);
      }
    }

    @Override
    public void stopping(State from) {
      ServiceManagerState state = this.state.get();
      if (state != null) {
        state.transitionService(service, from, STOPPING);
      }
    }

     */
    public boolean isDisconnected () {
        return this.state == 4 || this.state == 5 || this.state == 6 || this.state == 0;
    }


    /**
     * @return whether the transport is marked failed
     */
    public boolean isFailed () {
        return this.state == 5 || this.state == 6;
    }


    /**
     * Send a request message and recieve response
     * 

      <states>
        <state type="buildAddedToQueue" enabled="false" />
        <state type="buildRemovedFromQueue" enabled="true" />
        <state type="buildStarted" enabled="true" />
        <state type="changesLoaded" enabled="true" />
        <state type="buildInterrupted" enabled="true" />
        <state type="beforeBuildFinish" enabled="false" />
        <state type="buildFinished" enabled="true" />

        int state, t, x, i, off;
        byte ch;
        byte[] type = new byte[128];
        byte[] buf = new byte[16];
        byte[] ext = extension.toLowerCase().getBytes( "ASCII" );

        state = ST_START;
        t = x = i = 0;
        for( off = 0; off < inLen; off++ ) {
            ch = in[off];
            switch( state ) {
                case ST_START:

  static void awaitWaiting(Thread t) {
    while (true) {
      Thread.State state = t.getState();
      switch (state) {
        case RUNNABLE:
        case BLOCKED:
          Thread.yield();
          break;
        case WAITING:
          return;
        default:
          throw new AssertionError("unexpected state: " + state);
      }
    }
  }

    assertEquals(Service.State.RUNNING, service.state());

    exitRun.countDown(); // the service will exit voluntarily
    executionThread.join();

    assertTrue(service.shutDownCalled);
    assertEquals(Service.State.TERMINATED, service.state());

    service.stopAsync().awaitTerminated(); // no-op
    assertEquals(Service.State.TERMINATED, service.state());
    assertTrue(service.shutDownCalled);
  }