split underflow monitor into its own class

src/main/java/org/cobbzilla/util/daemon/ZillaRuntime.java

@@ -70,7 +70,7 @@ public class ZillaRuntime {
             sleep(100, "terminate: waiting for thread to exit: "+thread);
         }
         if (thread.isAlive()) {
-            if (verbose && log.isWarnEnabled()) log.warn("terminate: thread did not respond to interrupt, killing: "+thread+" with stack "+stacktrace(thread)+" from "+stacktrace());
+            if (verbose && log.isWarnEnabled()) log.warn("terminate: thread did not respond to interrupt, killing: "+thread+" with stack "+stacktrace(thread)+"\nfrom: "+stacktrace());
             thread.stop();
             return false;
         } else {

src/main/java/org/cobbzilla/util/io/multi/MultiUnderflowHandler.java

@@ -4,52 +4,27 @@ import lombok.Getter;
 import lombok.Setter;
 import lombok.experimental.Accessors;
 import lombok.extern.slf4j.Slf4j;
-import org.cobbzilla.util.daemon.SimpleDaemon;
 import org.cobbzilla.util.io.regex.MultiUnderflowException;
 
 import java.io.IOException;
-import java.util.Iterator;
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import static java.util.UUID.randomUUID;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.cobbzilla.util.daemon.ZillaRuntime.now;
-import static org.cobbzilla.util.daemon.ZillaRuntime.terminate;
 import static org.cobbzilla.util.system.Sleep.sleep;
 
 @Slf4j @Accessors(chain=true)
-public class MultiUnderflowHandler extends SimpleDaemon {
+public class MultiUnderflowHandler {
 
-    private final static Map<String, MultiUnderflowHandler> handlers = new ConcurrentHashMap<>();
+    private final MultiUnderflowHandlerMonitor monitor;
 
-    @Getter @Setter private static long checkInterval = SECONDS.toMillis(20);
-    private static final long TERMINATE_TIMEOUT = SECONDS.toMillis(2);
-
-    @Override protected long getSleepTime() { return checkInterval; }
-
-    @Override protected void process() {
-        if (log.isTraceEnabled()) log.trace("process: examining "+handlers.size()+" underflow handlers");
-        for (Iterator<MultiUnderflowHandler> iter = handlers.values().iterator(); iter.hasNext(); ) {
-            final MultiUnderflowHandler underflow = iter.next();
-            if (underflow.closed()) {
-                if (log.isDebugEnabled()) log.debug("process: removing closed handler: name="+underflow.getHandlerName()+" thread="+underflow.getThread());
-                iter.remove();
-
-            } else if (underflow.getLastRead() > 0 && !underflow.getThread().isAlive()) {
-                if (log.isDebugEnabled()) log.debug("process: removing dead thread: name="+underflow.getHandlerName()+" thread="+underflow.getThread());
-                iter.remove();
-
-            } else if (now() - underflow.getLastRead() > underflow.getUnderflowTimeout()) {
-                iter.remove();
-                if (log.isErrorEnabled()) log.error("process: underflow timed out, terminating: name="+underflow.getHandlerName()+" thread="+underflow.getThread());
-                terminate(underflow.getThread(), TERMINATE_TIMEOUT);
-            }
-        }
+    public MultiUnderflowHandler (MultiUnderflowHandlerMonitor m) {
+        this.monitor = m;
+        m.start();
     }
 
-    public MultiUnderflowHandler () { start(); }
+    public MultiUnderflowHandler () { this(MultiUnderflowHandlerMonitor.DEFAULT_UNDERFLOW_MONITOR); }
 
     @Getter private final String id = randomUUID().toString();
     @Getter @Setter private String handlerName;
@@ -70,7 +45,7 @@ public class MultiUnderflowHandler extends SimpleDaemon {
         if (thread == null) {
             thread = Thread.currentThread();
             lastRead = now();
-            handlers.put(id, this);
+            monitor.register(this);
         }
         if (firstUnderflow == 0) {
             if (log.isDebugEnabled()) log.debug(handlerName+": first data underflow");
@@ -89,7 +64,7 @@ public class MultiUnderflowHandler extends SimpleDaemon {
         lastRead = now();
         if (thread == null) {
             thread = Thread.currentThread();
-            handlers.put(id, this);
+            monitor.register(this);
         }
         firstUnderflow = 0;
         underflowSleep = minUnderflowSleep;
@@ -99,7 +74,7 @@ public class MultiUnderflowHandler extends SimpleDaemon {
         if (!closed()) {
             closed.set(true);
             if (log.isDebugEnabled()) log.debug(handlerName + ": closing");
-            handlers.remove(id);
+            monitor.unregister(this);
         }
     }
 

src/main/java/org/cobbzilla/util/io/multi/MultiUnderflowHandlerMonitor.java

@@ -0,0 +1,52 @@
+package org.cobbzilla.util.io.multi;
+
+import lombok.Getter;
+import lombok.Setter;
+import lombok.extern.slf4j.Slf4j;
+import org.cobbzilla.util.daemon.SimpleDaemon;
+
+import java.util.Iterator;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static org.cobbzilla.util.daemon.ZillaRuntime.now;
+import static org.cobbzilla.util.daemon.ZillaRuntime.terminate;
+
+@Slf4j
+public class MultiUnderflowHandlerMonitor extends SimpleDaemon {
+
+    public static final MultiUnderflowHandlerMonitor DEFAULT_UNDERFLOW_MONITOR = new MultiUnderflowHandlerMonitor();
+
+    private final Map<String, MultiUnderflowHandler> handlers = new ConcurrentHashMap<>();
+
+    @Getter @Setter private static long checkInterval = SECONDS.toMillis(20);
+    private static final long TERMINATE_TIMEOUT = SECONDS.toMillis(2);
+
+    @Override protected long getSleepTime() { return checkInterval; }
+
+    @Override protected void process() {
+        if (log.isTraceEnabled()) log.trace("process: examining "+handlers.size()+" underflow handlers");
+        for (Iterator<MultiUnderflowHandler> iter = handlers.values().iterator(); iter.hasNext(); ) {
+            final MultiUnderflowHandler underflow = iter.next();
+            if (underflow.closed()) {
+                if (log.isDebugEnabled()) log.debug("process: removing closed handler: name="+underflow.getHandlerName()+" thread="+underflow.getThread());
+                iter.remove();
+
+            } else if (underflow.getLastRead() > 0 && !underflow.getThread().isAlive()) {
+                if (log.isDebugEnabled()) log.debug("process: removing dead thread: name="+underflow.getHandlerName()+" thread="+underflow.getThread());
+                iter.remove();
+
+            } else if (now() - underflow.getLastRead() > underflow.getUnderflowTimeout()) {
+                iter.remove();
+                if (log.isErrorEnabled()) log.error("process: underflow timed out, terminating: name="+underflow.getHandlerName()+" thread="+underflow.getThread());
+                terminate(underflow.getThread(), TERMINATE_TIMEOUT);
+            }
+        }
+    }
+
+    public void register(MultiUnderflowHandler underflow) { handlers.put(underflow.getId(), underflow); }
+
+    public void unregister(MultiUnderflowHandler underflow) { handlers.remove(underflow.getId()); }
+
+}

src/test/java/org/cobbzilla/util/io/regex/RegexFilterReaderTest.java

@@ -5,7 +5,7 @@ import org.apache.commons.io.IOUtils;
 import org.cobbzilla.util.io.BlockedInputStream;
 import org.cobbzilla.util.io.multi.MultiReader;
 import org.cobbzilla.util.io.multi.MultiStream;
-import org.cobbzilla.util.io.multi.MultiUnderflowHandler;
+import org.cobbzilla.util.io.multi.MultiUnderflowHandlerMonitor;
 import org.junit.Test;
 
 import java.io.*;
@@ -192,7 +192,7 @@ public class RegexFilterReaderTest {
         final InputStream stream2 = new ByteArrayInputStream("some test data2 ".repeat(1000).getBytes());
         final InputStream stream3 = new BlockedInputStream();
 
-        MultiUnderflowHandler.setCheckInterval(1000);
+        MultiUnderflowHandlerMonitor.setCheckInterval(1000);
         final MultiStream multiStream = new MultiStream(stream1);
         multiStream.getUnderflow()
                 .setMinUnderflowSleep(1000)