From 5cdd61df59fc87e9f8dbbfb0f1ea1c535a3694f9 Mon Sep 17 00:00:00 2001
From: Fredrik Tolf <fredrik@dolda2000.com>
Date: Sat, 17 Oct 2009 17:48:06 +0200
Subject: [PATCH] Added timelimits to threads.

---
 src/dolda/jsvc/RequestThread.java |  6 +++
 src/dolda/jsvc/ThreadContext.java | 85 +++++++++++++++++++++++++++++++++++++++
 src/dolda/jsvc/util/Misc.java     |  9 +++++
 3 files changed, 100 insertions(+)

diff --git a/src/dolda/jsvc/RequestThread.java b/src/dolda/jsvc/RequestThread.java
index 7940748..6ada741 100644
--- a/src/dolda/jsvc/RequestThread.java
+++ b/src/dolda/jsvc/RequestThread.java
@@ -3,6 +3,7 @@ package dolda.jsvc;
 public class RequestThread extends Thread {
     private Request req;
     private Responder resp;
+    private long stime = 0;
     
     public RequestThread(Responder resp, Request req, ThreadGroup th, String name) {
 	super(th, name);
@@ -11,6 +12,7 @@ public class RequestThread extends Thread {
     }
     
     public void run() {
+	stime = System.currentTimeMillis();
 	resp.respond(req);
 	try {
 	    req.output().close();
@@ -22,4 +24,8 @@ public class RequestThread extends Thread {
     public static Request request() {
 	return(((RequestThread)Thread.currentThread()).req);
     }
+    
+    public long stime() {
+	return(stime);
+    }
 }
diff --git a/src/dolda/jsvc/ThreadContext.java b/src/dolda/jsvc/ThreadContext.java
index 486bc91..27d90bf 100644
--- a/src/dolda/jsvc/ThreadContext.java
+++ b/src/dolda/jsvc/ThreadContext.java
@@ -1,7 +1,9 @@
 package dolda.jsvc;
 
+import dolda.jsvc.util.Misc;
 import java.util.logging.*;
 import java.lang.reflect.*;
+import java.util.*;
 
 public class ThreadContext extends ThreadGroup {
     private Logger logger = Logger.getLogger("dolda.jsvc.context");
@@ -9,6 +11,8 @@ public class ThreadContext extends ThreadGroup {
     private long reqs = 0;
     private final ServerContext ctx;
     public final Responder root;
+    private int timelimit = 0;
+    private boolean forcelimit = false;
     
     public ThreadContext(ThreadGroup parent, String name, ServerContext ctx, Class<?> bootclass) {
 	super((parent == null)?(Thread.currentThread().getThreadGroup()):parent, name);
@@ -18,7 +22,88 @@ public class ThreadContext extends ThreadGroup {
 		    logger.log(Level.SEVERE, "Worker thread terminated with an uncaught exception", e);
 		}
 	    };
+	
+	int tl;
+	tl = Integer.parseInt(ctx.sysconfig("jsvc.timelimit", "0"));
+	if((tl > 0) && ((timelimit == 0) || (tl < timelimit)))
+	    timelimit = tl;
+	tl = Integer.parseInt(ctx.libconfig("jsvc.timelimit", "0"));
+	if((tl > 0) && ((timelimit == 0) || (tl < timelimit)))
+	    timelimit = tl;
+	forcelimit |= Misc.boolval(ctx.sysconfig("jsvc.forcelimit", "0"));
+	forcelimit |= Misc.boolval(ctx.libconfig("jsvc.forcelimit", "0"));
+	
 	root = bootstrap(bootclass);
+	
+	if(timelimit > 0)
+	    (new WatchDog()).start();
+    }
+    
+    private class WatchDog extends Thread {
+	private Map<RequestThread, State> state = new WeakHashMap<RequestThread, State>();
+	
+	private class State {
+	    String st = "running";
+	    long lastkill;
+	}
+	
+	private WatchDog() {
+	    super(ThreadContext.this, "Worker watchdog");
+	    setDaemon(true);
+	}
+	
+	@SuppressWarnings("deprecation")
+	private long ckthread(long now, RequestThread rt) {
+	    State st = state.get(rt);
+	    if(st == null) {
+		st = new State();
+		state.put(rt, st);
+	    }
+	    if(st.st == "running") {
+		if(now - rt.stime() > timelimit) {
+		    rt.interrupt();
+		    st.st = "interrupted";
+		    st.lastkill = now;
+		    return(5000);
+		} else {
+		    return(timelimit - (now - rt.stime()));
+		}
+	    } else if((st.st == "interrupted") || (st.st == "killed")) {
+		if(st.st == "killed")
+		    logger.log(Level.WARNING, "Thread " + rt + " refused to die; killing again");
+		if(now - st.lastkill > 5000) {
+		    rt.stop();
+		    st.st = "killed";
+		    st.lastkill = now;
+		} else {
+		    return(5000 - (now - st.lastkill));
+		}
+	    }
+	    return(timelimit);
+	}
+
+	public void run() {
+	    try {
+		while(true) {
+		    long next = timelimit;
+		    long now = System.currentTimeMillis();
+		    Thread[] w = new Thread[workers.activeCount() + 5];
+		    int num = workers.enumerate(w);
+		    for(int i = 0; i < num; i++) {
+			if(w[i] instanceof RequestThread){
+			    RequestThread rt = (RequestThread)w[i];
+			    if(rt.stime() > 0) {
+				long n = ckthread(now, rt);
+				if(n < next)
+				    next = n;
+			    }
+			}
+		    }
+		    Thread.sleep(next);
+		}
+	    } catch(InterruptedException e) {
+	    }
+	}
     }
     
     public void uncaughtException(Thread t, Throwable e) {
diff --git a/src/dolda/jsvc/util/Misc.java b/src/dolda/jsvc/util/Misc.java
index 122a654..63a10a7 100644
--- a/src/dolda/jsvc/util/Misc.java
+++ b/src/dolda/jsvc/util/Misc.java
@@ -122,4 +122,13 @@ public class Misc {
 	}
 	return(buf.toString());
     }
+    
+    public static boolean boolval(String val) {
+	val = val.trim().toLowerCase();
+	if(val.equals("1") || val.equals("on") || val.equals("true") || val.equals("yes") || val.equals("\u22a4"))
+	    return(true);
+	if(val.equals("0") || val.equals("off") || val.equals("false") || val.equals("no") || val.equals("\u22a5"))
+	    return(false);
+	throw(new IllegalArgumentException("value not recognized as boolean: " + val));
+    }
 }
-- 
2.11.0