java/src/main/com/google/appengine/tools/development/InstanceHolder.java

   1 package com.google.appengine.tools.development;
   2
   3 /**
   4  * Holder for per server instance state.
   5  */
   6 interface InstanceHolder {
   7
   8   /**
   9    * Returns the {@link ContainerService} for this instance.
  10    */
  11   ContainerService getContainerService();
  12
  13   /**
  14    * Returns the id for this instance.
  15    */
  16   int getInstance();
  17
  18   /**
  19    * Returns true if this is the main instance, meaning the load balancing
  20    * instance for a {@link ManualServer} and the only instance for an
  21    * {@link AutomaticServer}.
  22    */
  23   boolean isMainInstance();
  24
  25   /**
  26    * Starts the instance.
  27    */
  28   void startUp() throws Exception;
  29
  30   /**
  31    * Acquire a serving permit for this instance. This may block and have side effects such as
  32    * sending a startUp request.
  33    */
  34   boolean acquireServingPermit();
  35
  36   /**
  37    * Returns true if this instance is a load balancing server.
  38    */
  39   boolean isServerLoadBalancingServer();
  40
  41   /**
  42    * Returns true if this instance expects an internally generated
  43    * "_ah/start" requests to be sent.
  44    */
  45   boolean expectsGeneratedStartRequest();
  46
  47   /**
  48    * Returns true if this instance is in the STOPPED state.
  49    */
  50   boolean isStopped();
  51
  52   /**
  53    * Creates a network connection for this instance.
  54    * @throws Exception
  55    */
  56   public void createConnection() throws Exception;
  57
  58 }