src/dolda/jsvc/ThreadContext.java

   1 package dolda.jsvc;
   2
   3 import java.util.logging.*;
   4 import java.lang.reflect.*;
   5
   6 public class ThreadContext extends ThreadGroup {
   7     private Logger logger = Logger.getLogger("dolda.jsvc.context");
   8     private ThreadGroup workers;
   9     private long reqs = 0;
  10     public final Responder root;
  11
  12     public ThreadContext(ThreadGroup parent, String name, Class<?> bootclass) {
  13         super((parent == null)?(Thread.currentThread().getThreadGroup()):parent, name);
  14         workers = new ThreadGroup(this, "Worker threads") {
  15                 public void uncaughtException(Thread t, Throwable e) {
  16                     logger.log(Level.SEVERE, "Worker thread terminated with an uncaught exception", e);
  17                 }
  18             };
  19         root = bootstrap(bootclass);
  20     }
  21
  22     public void uncaughtException(Thread t, Throwable e) {
  23         logger.log(Level.SEVERE, "Service thread " + t.toString() + " terminated with an uncaught exception", e);
  24     }
  25
  26     public void shutdown() {
  27         if(root instanceof ContextResponder)
  28             ((ContextResponder)root).destroy();
  29         try {
  30             long last = 0;
  31             while(true) {
  32                 long now = System.currentTimeMillis();
  33                 if(now - last > 10000) {
  34                     interrupt();
  35                     last = now;
  36                 }
  37                 Thread[] th = new Thread[1];
  38                 if(enumerate(th) < 1)
  39                     break;
  40                 th[0].join(10000);
  41             }
  42         } catch(InterruptedException e) {
  43             logger.log(Level.WARNING, "Interrupted while trying to shut down all service threads. Some may remain.", e);
  44         }
  45         destroy();
  46     }
  47
  48     public RequestThread respond(Request req) {
  49         return(new RequestThread(root, req, workers, "Worker thread " + reqs++));
  50     }
  51
  52     private Responder bootstrap(final Class<?> bootclass) {
  53         final Throwable[] err = new Throwable[1];
  54         final Responder[] res = new Responder[1];
  55         Thread boot = new Thread(this, "JSvc boot thread") {
  56                 public void run() {
  57                     try {
  58                         Method cm = bootclass.getMethod("responder");
  59                         Object resp = cm.invoke(null);
  60                         if(!(resp instanceof Responder))
  61                             throw(new ClassCastException("JSvc bootstrapper did not return a responder"));
  62                         res[0] = (Responder)resp;
  63                     } catch(NoSuchMethodException e) {
  64                         logger.log(Level.SEVERE, "Invalid JSvc bootstrapper specified", e);
  65                         err[0] = e;
  66                     } catch(IllegalAccessException e) {
  67                         logger.log(Level.SEVERE, "Invalid JSvc bootstrapper specified", e);
  68                         err[0] = e;
  69                     } catch(InvocationTargetException e) {
  70                         logger.log(Level.SEVERE, "JSvc bootstrapper failed", e);
  71                         err[0] = e;
  72                     }
  73                 }
  74             };
  75         boot.start();
  76         try {
  77             boot.join();
  78         } catch(InterruptedException e) {
  79             logger.log(Level.WARNING, "Interrupted during bootstrapping", e);
  80             boot.interrupt();
  81             Thread.currentThread().interrupt();
  82         }
  83         if(err[0] != null)
  84             throw(new RuntimeException(err[0]));
  85         if(res[0] == null) {
  86             logger.log(Level.SEVERE, "No responder returned in spite of no error having happened.");
  87             throw(new NullPointerException("No responder returned in spite of no error having happened."));
  88         }
  89         return(res[0]);
  90     }
  91 }