Add r/w lock around marker file operations and commands

DynmapCore/src/main/java/org/dynmap/markers/impl/MarkerAPIImpl.java

@@ -46,11 +46,13 @@ import org.dynmap.markers.PlayerSet;
 import org.dynmap.markers.PolyLineMarker;
 import org.dynmap.utils.BufferOutputStream;
 import org.dynmap.web.Json;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
  * Implementation class for MarkerAPI - should not be called directly
  */
 public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
+    private ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
     private File markerpersist;
     private File markerpersist_old;
     private File markerdir; /* Local store for markers (internal) */
@@ -336,6 +338,8 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
         public void run() {
             if(stop)
                 return;
+            lock.readLock().lock();
+            try {
                 /* Write markers first - drives JSON updates too */
                 if(dirty_markers) {
                     doSaveMarkers();
@@ -348,6 +352,9 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
                     }
                     dirty_worlds.clear();
                 }
+            } finally {
+                lock.readLock().unlock();
+            }
             core.getServer().scheduleServerTask(this, 20);
         }
     }
@@ -412,17 +419,26 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
         plugin.events.removeListener("worldactivated", api);
 
         stop = true;
+        lock.readLock().lock();
+        try {
             if(dirty_markers) {
                 doSaveMarkers();
                 dirty_markers = false;
             }
-        
+        } finally {
+            lock.readLock().unlock();
+        }
+        lock.writeLock().lock();
+        try {
             for(MarkerIconImpl icn : markericons.values())
                 icn.cleanup();
             markericons.clear();
             for(MarkerSetImpl set : markersets.values())
                 set.cleanup();
             markersets.clear();
+        } finally {
+            lock.writeLock().unlock();
+        }
     }
 
     private MarkerIcon createBuiltinMarkerIcon(String id, String label) {
@@ -668,8 +684,9 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
     private boolean loadMarkers() {        
         ConfigurationNode conf = new ConfigurationNode(api.markerpersist);  /* Make configuration object */
         conf.load();    /* Load persistence */
+        lock.writeLock().lock();
+        try {
             /* Get icons */
-        
             ConfigurationNode icons = conf.getNode("icons");
             if(icons == null) return false;
             for(String id : icons.keySet()) {
@@ -698,6 +715,9 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
                     }
                 }
             }
+        } finally {
+            lock.writeLock().unlock();
+        }
         
         return true;
     }
@@ -1104,7 +1124,43 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
         if (!commands.contains(c)) {
             return false;
         }
-        /* Process commands */
+        /* Process commands read commands */
+        api.lock.readLock().lock();
+        try {
+            /* List markers */
+            if(c.equals("list") && plugin.checkPlayerPermission(sender, "marker.list")) {
+                return processListMarker(plugin, sender, cmd, commandLabel, args);
+            }
+            /* List icons */
+            else if(c.equals("icons") && plugin.checkPlayerPermission(sender, "marker.icons")) {
+                return processListIcon(plugin, sender, cmd, commandLabel, args);
+            }
+            /* List sets */
+            else if(c.equals("listsets") && plugin.checkPlayerPermission(sender, "marker.listsets")) {
+                return processListSet(plugin, sender, cmd, commandLabel, args);
+            }
+            /* List areas */
+            else if(c.equals("listareas") && plugin.checkPlayerPermission(sender, "marker.listareas")) {
+                return processListArea(plugin, sender, cmd, commandLabel, args);
+            }
+            /* List poly-lines */
+            else if(c.equals("listlines") && plugin.checkPlayerPermission(sender, "marker.listlines")) {
+                return processListLine(plugin, sender, cmd, commandLabel, args);
+            }
+            /* List circles */
+            else if(c.equals("listcircles") && plugin.checkPlayerPermission(sender, "marker.listcircles")) {
+                return processListCircle(plugin, sender, cmd, commandLabel, args);
+            }
+            /* Get label for given item - must have ID and type parameter */
+            else if(c.equals("getlabel") && plugin.checkPlayerPermission(sender, "marker.getlabel")) {
+                return processGetLabel(plugin, sender, cmd, commandLabel, args);
+            }
+        } finally {
+            api.lock.readLock().unlock();
+        }
+        // Handle modify commands
+        api.lock.writeLock().lock();
+        try {
             if(c.equals("add") && api.core.checkPlayerPermission(sender, "marker.add")) {
                 return processAddMarker(plugin, sender, cmd, commandLabel, args, player);
             }
@@ -1120,14 +1176,6 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
             else if(c.equals("delete") && plugin.checkPlayerPermission(sender, "marker.delete")) {
                 return processDeleteMarker(plugin, sender, cmd, commandLabel, args);
             }
-        /* List markers */
-        else if(c.equals("list") && plugin.checkPlayerPermission(sender, "marker.list")) {
-            return processListMarker(plugin, sender, cmd, commandLabel, args);
-        }
-        /* List icons */
-        else if(c.equals("icons") && plugin.checkPlayerPermission(sender, "marker.icons")) {
-            return processListIcon(plugin, sender, cmd, commandLabel, args);
-        }
             else if(c.equals("addset") && plugin.checkPlayerPermission(sender, "marker.addset")) {
                 return processAddSet(plugin, sender, cmd, commandLabel, args, player);
             }
@@ -1137,10 +1185,6 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
             else if(c.equals("deleteset") && plugin.checkPlayerPermission(sender, "marker.deleteset")) {
                 return processDeleteSet(plugin, sender, cmd, commandLabel, args);
             }
-        /* List sets */
-        else if(c.equals("listsets") && plugin.checkPlayerPermission(sender, "marker.listsets")) {
-            return processListSet(plugin, sender, cmd, commandLabel, args);
-        }
             /* Add new icon */
             else if(c.equals("addicon") && plugin.checkPlayerPermission(sender, "marker.addicon")) {
                 return processAddIcon(plugin, sender, cmd, commandLabel, args);
@@ -1161,10 +1205,6 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
             else if(c.equals("addarea") && plugin.checkPlayerPermission(sender, "marker.addarea")) {
                 return processAddArea(plugin, sender, cmd, commandLabel, args, player);
             }
-        /* List areas */
-        else if(c.equals("listareas") && plugin.checkPlayerPermission(sender, "marker.listareas")) {
-            return processListArea(plugin, sender, cmd, commandLabel, args);
-        }
             /* Delete area - must have ID parameter */
             else if(c.equals("deletearea") && plugin.checkPlayerPermission(sender, "marker.deletearea")) {
                 return processDeleteArea(plugin, sender, cmd, commandLabel, args);
@@ -1176,10 +1216,6 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
             else if(c.equals("addline") && plugin.checkPlayerPermission(sender, "marker.addline")) {
                 return processAddLine(plugin, sender, cmd, commandLabel, args, player);
             }
-        /* List poly-lines */
-        else if(c.equals("listlines") && plugin.checkPlayerPermission(sender, "marker.listlines")) {
-            return processListLine(plugin, sender, cmd, commandLabel, args);
-        }
             /* Delete poly-line - must have ID parameter */
             else if(c.equals("deleteline") && plugin.checkPlayerPermission(sender, "marker.deleteline")) {
                 return processDeleteLine(plugin, sender, cmd, commandLabel, args);
@@ -1191,10 +1227,6 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
             else if(c.equals("addcircle") && plugin.checkPlayerPermission(sender, "marker.addcircle")) {
                 return processAddCircle(plugin, sender, cmd, commandLabel, args, player);
             }
-        /* List circles */
-        else if(c.equals("listcircles") && plugin.checkPlayerPermission(sender, "marker.listcircles")) {
-            return processListCircle(plugin, sender, cmd, commandLabel, args);
-        }
             /* Delete circle - must have ID parameter */
             else if(c.equals("deletecircle") && plugin.checkPlayerPermission(sender, "marker.deletecircle")) {
                 return processDeleteCircle(plugin, sender, cmd, commandLabel, args);
@@ -1223,13 +1255,12 @@ public class MarkerAPIImpl implements MarkerAPI, Event.Listener<DynmapWorld> {
             else if(c.equals("importlabel") && plugin.checkPlayerPermission(sender, "marker.importlabel")) {
                 return processImportLabel(plugin, sender, cmd, commandLabel, args);
             }
-        /* Get label for given item - must have ID and type parameter */
-        else if(c.equals("getlabel") && plugin.checkPlayerPermission(sender, "marker.getlabel")) {
-            return processGetLabel(plugin, sender, cmd, commandLabel, args);
-        }
             else {
                 return false;
             }
+        } finally {
+            api.lock.writeLock().unlock();
+        }
     }
 
     private static boolean processAddMarker(DynmapCore plugin, DynmapCommandSender sender, String cmd, String commandLabel, String[] args, DynmapPlayer player) {