thread-limit logic, finetuning + extended profile cache

brouter-core/src/main/java/btools/router/ProfileCache.java

@@ -13,16 +13,24 @@ import btools.expressions.BExpressionMetaData;
 
 public final class ProfileCache 
 {
-  private static BExpressionContextWay expctxWay;
-  private static BExpressionContextNode expctxNode;
  
   private static File lastLookupFile;
-  private static File lastProfileFile;
-
   private static long lastLookupTimestamp;
-  private static long lastProfileTimestamp;
 
-  private static boolean profilesBusy;
+  private BExpressionContextWay expctxWay;
+  private BExpressionContextNode expctxNode;
+  private File lastProfileFile;
+  private long lastProfileTimestamp;  
+  private boolean profilesBusy;
+  private long lastUseTime;
+    
+  private static ProfileCache[] apc = new ProfileCache[1];
+  private static boolean debug = Boolean.getBoolean( "debugProfileCache" );
+
+  public static synchronized void setSize( int size )
+  {
+    apc = new ProfileCache[size];
+  }
 
   public static synchronized boolean parseProfile( RoutingContext rc )
   {
@@ -43,20 +51,50 @@ public final class ProfileCache
       rc.profileTimestamp = profileFile.lastModified() + rc.getKeyValueChecksum()<<24;
       File lookupFile = new File( profileDir, "lookups.dat" );
       
+      // invalidate cache at lookup-table update
+      if ( !(lookupFile.equals( lastLookupFile ) && lookupFile.lastModified() == lastLookupTimestamp ) )
+      {
+        if ( lastLookupFile != null )
+        {
+          System.out.println( "******** invalidating profile-cache after lookup-file update ******** " );
+        }
+        apc = new ProfileCache[apc.length];
+        lastLookupFile = lookupFile;
+        lastLookupTimestamp = lookupFile.lastModified();
+      }
+      
+      ProfileCache lru = null;
+      int unusedSlot =-1;
+
       // check for re-use
-      if ( expctxWay != null && expctxNode != null && !profilesBusy )
+      for( int i=0; i<apc.length; i++)
       {
-        if ( profileFile.equals( lastProfileFile ) && lookupFile.equals( lastLookupFile ) )
+        ProfileCache pc = apc[i];
+        
+        if ( pc != null )
         {
-          if ( rc.profileTimestamp == lastProfileTimestamp
+          if ( (!pc.profilesBusy) && profileFile.equals( pc.lastProfileFile ) )
-            && lookupFile.lastModified() ==  lastLookupTimestamp )
           {
-            rc.expctxWay = expctxWay;
+            if ( rc.profileTimestamp == pc.lastProfileTimestamp )
-            rc.expctxNode = expctxNode;
+            {
-            profilesBusy = true;
+              rc.expctxWay = pc.expctxWay;
+              rc.expctxNode = pc.expctxNode;
               rc.readGlobalConfig();
+              pc.profilesBusy = true;
               return true;
             }
+            lru = pc; // name-match but timestamp-mismatch -> we overide this one
+            unusedSlot = -1;
+            break;
+          }
+          if ( lru == null || lru.lastUseTime > pc.lastUseTime )
+          {
+            lru = pc;
+          }
+        }
+        else if ( unusedSlot < 0 )
+        {
+          unusedSlot = i;
         }
       }
       
@@ -78,22 +116,45 @@ public final class ProfileCache
         rc.expctxWay.setAllTagsUsed();
       }
 
-      lastProfileTimestamp = rc.profileTimestamp;
+      if ( lru == null || unusedSlot >= 0 )
-      lastLookupTimestamp = lookupFile.lastModified();
+      {
-      lastProfileFile = profileFile;
+        lru = new ProfileCache();
-      lastLookupFile = lookupFile;
+        if ( unusedSlot >= 0 )
-      expctxWay = rc.expctxWay;
+        {
-      expctxNode = rc.expctxNode;
+          apc[unusedSlot] = lru;
-      profilesBusy = true;
+          if ( debug ) System.out.println( "******* adding new profile at idx=" + unusedSlot + " for " +  profileFile );            
+        }
+      }
+
+      if ( lru.lastProfileFile != null )
+      {
+        if ( debug ) System.out.println( "******* replacing profile of age " + ((System.currentTimeMillis()-lru.lastUseTime)/1000L) + " sec " + lru.lastProfileFile + "->" + profileFile );
+      }
+
+      lru.lastProfileTimestamp = rc.profileTimestamp;
+      lru.lastProfileFile = profileFile;
+      lru.expctxWay = rc.expctxWay;
+      lru.expctxNode = rc.expctxNode;
+      lru.profilesBusy = true;
+      lru.lastUseTime = System.currentTimeMillis();
       return false;
   }
 
   public static synchronized void releaseProfile( RoutingContext rc )
   {
-    // only the thread that holds the cached instance can release it
+    for( int i=0; i<apc.length; i++)
-    if ( rc.expctxWay == expctxWay && rc.expctxNode == expctxNode )
     {
-      profilesBusy = false;
+      ProfileCache pc = apc[i];
+        
+      if ( pc != null )
+      {
+        // only the thread that holds the cached instance can release it
+        if ( rc.expctxWay == pc.expctxWay && rc.expctxNode == pc.expctxNode )
+        {
+          pc.profilesBusy = false;
+          break;
+        }
+      }
     }
     rc.expctxWay = null;
     rc.expctxNode = null;

brouter-server/src/main/java/btools/server/RouteServer.java

@@ -20,12 +20,13 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.PriorityQueue;
 import java.util.StringTokenizer;
-import java.util.TreeMap;
 import java.util.zip.GZIPOutputStream;
 
 import btools.router.OsmNodeNamed;
 import btools.router.OsmTrack;
+import btools.router.ProfileCache;
 import btools.router.RoutingContext;
 import btools.router.RoutingEngine;
 import btools.server.request.ProfileUploadHandler;
@@ -33,7 +34,7 @@ import btools.server.request.RequestHandler;
 import btools.server.request.ServerHandler;
 import btools.util.StackSampler;
 
-public class RouteServer extends Thread
+public class RouteServer extends Thread implements Comparable<RouteServer>
 {
   public static final String PROFILE_UPLOAD_URL = "/brouter/profile";
   static final String HTTP_STATUS_OK = "200 OK";
@@ -47,8 +48,10 @@ public class RouteServer extends Thread
   private Socket clientSocket = null;
   private RoutingEngine cr = null;
   private volatile boolean terminated;
+  private long starttime;
 
   private static Object threadPoolSync = new Object();
+  private static boolean debug = Boolean.getBoolean( "debugThreadPool" );
 
   public void stopRouter()
   {
@@ -301,7 +304,9 @@ public class RouteServer extends Thread
 
         int maxthreads = Integer.parseInt( args[4] );
         
-        TreeMap<Long,RouteServer> threadMap = new TreeMap<Long,RouteServer>();
+        ProfileCache.setSize( 2*maxthreads );
+
+        PriorityQueue<RouteServer> threadQueue = new PriorityQueue<RouteServer>();
 
         ServerSocket serverSocket = args.length > 5 ? new ServerSocket(Integer.parseInt(args[3]),100,InetAddress.getByName(args[5])) : new ServerSocket(Integer.parseInt(args[3]));
 
@@ -317,43 +322,47 @@ public class RouteServer extends Thread
           System.out.println( "*** sampling stacks into stacks.txt *** ");
         }
 
-        long last_ts = 0;
         for (;;)
         {
           Socket clientSocket = serverSocket.accept();
           RouteServer server = new RouteServer();
           server.serviceContext = serviceContext;
           server.clientSocket = clientSocket;
+          server.starttime = System.currentTimeMillis();
 
           // kill an old thread if thread limit reached
           
-          cleanupThreadList( threadMap );
+          cleanupThreadQueue( threadQueue );
           
-          if ( threadMap.size() >= maxthreads )
+          
+          if ( debug ) System.out.println( "threadQueue.size()=" + threadQueue.size() );
+          if ( threadQueue.size() >= maxthreads )
           {
              synchronized( threadPoolSync )
              {
                // wait up to 2000ms (maybe notified earlier)
                // to prevent killing short-running threads
-               threadPoolSync.wait( 2000 );
+               long maxage = server.starttime - threadQueue.peek().starttime;
-             }
+               long maxWaitTime = 2000L-maxage;
-             cleanupThreadList( threadMap );
+               if ( debug ) System.out.println( "maxage=" + maxage + " maxWaitTime=" + maxWaitTime );
-             if ( threadMap.size() >= maxthreads )
+               if ( maxWaitTime > 0 )
                {
+                 threadPoolSync.wait( maxWaitTime );
+               }
+             }
+             cleanupThreadQueue( threadQueue );
+             if ( threadQueue.size() >= maxthreads )
+             {
+               if ( debug ) System.out.println( "stopping oldest thread..." );
                // no way... stop the oldest thread
-               Long k = threadMap.firstKey();
+               threadQueue.poll().stopRouter();
-               RouteServer victim = threadMap.get( k );
-               threadMap.remove( k );
-               victim.stopRouter();
              }
           }
 
-          long ts = System.currentTimeMillis();
+          threadQueue.add( server );
-          while ( ts <=  last_ts ) ts++;
-          threadMap.put( Long.valueOf( ts ), server );
-          last_ts = ts;
 
           server.start();
+          if ( debug ) System.out.println( "thread started..." );
         }
   }
 
@@ -423,16 +432,16 @@ public class RouteServer extends Thread
     bw.write( "\n" );
   }
 
-  private static void cleanupThreadList( TreeMap<Long, RouteServer> threadMap )
+  private static void cleanupThreadQueue( PriorityQueue<RouteServer> threadQueue )
   {
     for ( ;; )
     {
       boolean removedItem = false;
-      for ( Map.Entry<Long, RouteServer> e : threadMap.entrySet() )
+      for ( RouteServer t : threadQueue )
       {
-        if ( e.getValue().terminated )
+        if ( t.terminated )
         {
-          threadMap.remove( e.getKey() );
+          threadQueue.remove( t );
           removedItem = true;
           break;
         }
@@ -443,4 +452,11 @@ public class RouteServer extends Thread
       }
     }
   }
+  
+  @Override
+  public int compareTo( RouteServer t )
+  {
+    return starttime < t.starttime ? -1 : ( starttime > t.starttime ? 1 : 0 );
+  }
+  
 }