diff --git a/classlib/src/main/java/org/teavm/classlib/impl/PlatformMarkerSupport.java b/classlib/src/main/java/org/teavm/classlib/impl/PlatformMarkerSupport.java
index 19adfc23d..e618d1635 100644
--- a/classlib/src/main/java/org/teavm/classlib/impl/PlatformMarkerSupport.java
+++ b/classlib/src/main/java/org/teavm/classlib/impl/PlatformMarkerSupport.java
@@ -70,7 +70,7 @@ public class PlatformMarkerSupport implements ClassHolderTransformer {
                 MarkerKind kind;
                 if (instruction instanceof InvokeInstruction) {
                     MethodReference methodRef = ((InvokeInstruction) instruction).getMethod();
-                    MethodReader method = hierarchy.getClassSource().resolveImplementation(methodRef);
+                    MethodReader method = hierarchy.resolve(methodRef);
                     if (method == null) {
                         continue;
                     }
@@ -94,7 +94,7 @@ public class PlatformMarkerSupport implements ClassHolderTransformer {
                     receiver = ((InvokeInstruction) instruction).getReceiver();
                 } else if (instruction instanceof GetFieldInstruction) {
                     FieldReference fieldRef = ((GetFieldInstruction) instruction).getField();
-                    FieldReader field = hierarchy.getClassSource().resolve(fieldRef);
+                    FieldReader field = hierarchy.resolve(fieldRef);
                     if (field == null) {
                         continue;
                     }
diff --git a/core/src/main/java/org/teavm/ast/FieldNode.java b/core/src/main/java/org/teavm/ast/FieldNode.java
index f02393edd..7113f86c1 100644
--- a/core/src/main/java/org/teavm/ast/FieldNode.java
+++ b/core/src/main/java/org/teavm/ast/FieldNode.java
@@ -18,21 +18,26 @@ package org.teavm.ast;
 import java.util.EnumSet;
 import java.util.Set;
 import org.teavm.model.ElementModifier;
+import org.teavm.model.FieldReference;
 import org.teavm.model.ValueType;
 
 public class FieldNode {
-    private String name;
+    private FieldReference reference;
     private ValueType type;
     private Set<ElementModifier> modifiers = EnumSet.noneOf(ElementModifier.class);
     private Object initialValue;
 
-    public FieldNode(String name, ValueType type) {
-        this.name = name;
+    public FieldNode(FieldReference reference, ValueType type) {
+        this.reference = reference;
         this.type = type;
     }
 
+    public FieldReference getReference() {
+        return reference;
+    }
+
     public String getName() {
-        return name;
+        return reference.getFieldName();
     }
 
     public Set<ElementModifier> getModifiers() {
diff --git a/core/src/main/java/org/teavm/ast/decompilation/Decompiler.java b/core/src/main/java/org/teavm/ast/decompilation/Decompiler.java
index 7c7db9474..fb2c8f157 100644
--- a/core/src/main/java/org/teavm/ast/decompilation/Decompiler.java
+++ b/core/src/main/java/org/teavm/ast/decompilation/Decompiler.java
@@ -199,7 +199,7 @@ public class Decompiler {
     public ClassNode decompile(ClassHolder cls) {
         ClassNode clsNode = new ClassNode(cls.getName(), cls.getParent());
         for (FieldHolder field : cls.getFields()) {
-            FieldNode fieldNode = new FieldNode(field.getName(), field.getType());
+            FieldNode fieldNode = new FieldNode(field.getReference(), field.getType());
             fieldNode.getModifiers().addAll(field.getModifiers());
             fieldNode.setInitialValue(field.getInitialValue());
             clsNode.getFields().add(fieldNode);
diff --git a/core/src/main/java/org/teavm/backend/javascript/codegen/DefaultNamingStrategy.java b/core/src/main/java/org/teavm/backend/javascript/codegen/DefaultNamingStrategy.java
index 352af216c..ca5e01ef0 100644
--- a/core/src/main/java/org/teavm/backend/javascript/codegen/DefaultNamingStrategy.java
+++ b/core/src/main/java/org/teavm/backend/javascript/codegen/DefaultNamingStrategy.java
@@ -25,8 +25,8 @@ public class DefaultNamingStrategy implements NamingStrategy {
     private final Map<String, String> aliases = new HashMap<>();
     private final Map<String, String> privateAliases = new HashMap<>();
     private final Map<String, String> classAliases = new HashMap<>();
-    private final Map<String, String> fieldAliases = new HashMap<>();
-    private final Map<String, String> staticFieldAliases = new HashMap<>();
+    private final Map<FieldReference, String> fieldAliases = new HashMap<>();
+    private final Map<FieldReference, String> staticFieldAliases = new HashMap<>();
     private final Map<String, String> functionAliases = new HashMap<>();
     private final Map<String, String> classInitAliases = new HashMap<>();
 
@@ -75,27 +75,32 @@ public class DefaultNamingStrategy implements NamingStrategy {
 
     @Override
     public String getNameFor(FieldReference field) {
-        String realCls = getRealFieldOwner(field.getClassName(), field.getFieldName());
-        if (!realCls.equals(field.getClassName())) {
-            String alias = getNameFor(new FieldReference(realCls, field.getFieldName()));
-            fieldAliases.put(field.getClassName() + "#" + field, alias);
-            return alias;
-        } else {
-            return fieldAliases.computeIfAbsent(realCls + "#" + field, key -> aliasProvider.getFieldAlias(field));
+        String alias = fieldAliases.get(field);
+        if (alias == null) {
+            FieldReference realField = getRealField(field);
+            if (realField.equals(field)) {
+                alias = aliasProvider.getFieldAlias(realField);
+            } else {
+                alias = getNameFor(realField);
+            }
+            fieldAliases.put(field, alias);
         }
+        return alias;
     }
 
     @Override
     public String getFullNameFor(FieldReference field) {
-        String realCls = getRealFieldOwner(field.getClassName(), field.getFieldName());
-        if (!realCls.equals(field.getClassName())) {
-            String alias = getNameFor(new FieldReference(realCls, field.getFieldName()));
-            staticFieldAliases.put(field.getClassName() + "#" + field, alias);
-            return alias;
-        } else {
-            return staticFieldAliases.computeIfAbsent(realCls + "#" + field,
-                    key -> aliasProvider.getStaticFieldAlias(field));
+        String alias = staticFieldAliases.get(field);
+        if (alias == null) {
+            FieldReference realField = getRealField(field);
+            if (realField.equals(field)) {
+                alias = aliasProvider.getStaticFieldAlias(realField);
+            } else {
+                alias = getNameFor(realField);
+            }
+            staticFieldAliases.put(field, alias);
         }
+        return alias;
     }
 
     @Override
@@ -127,20 +132,19 @@ public class DefaultNamingStrategy implements NamingStrategy {
         return null;
     }
 
-    private String getRealFieldOwner(String cls, String field) {
-        String initialCls = cls;
-        while (!fieldExists(cls, field)) {
-            ClassReader clsHolder = classSource.get(cls);
-            if (clsHolder == null || clsHolder.getParent() == null) {
-                return initialCls;
+    private FieldReference getRealField(FieldReference fieldRef) {
+        String initialCls = fieldRef.getClassName();
+        String cls = fieldRef.getClassName();
+        while (cls != null) {
+            ClassReader clsReader = classSource.get(cls);
+            if (clsReader != null) {
+                FieldReader fieldReader = clsReader.getField(fieldRef.getFieldName());
+                if (fieldReader != null) {
+                    return fieldReader.getReference();
+                }
             }
-            cls = clsHolder.getParent();
+            cls = clsReader.getParent();
         }
-        return cls;
-    }
-
-    private boolean fieldExists(String cls, String field) {
-        ClassReader classHolder = classSource.get(cls);
-        return classHolder != null && classHolder.getField(field) != null;
+        return fieldRef;
     }
 }
diff --git a/core/src/main/java/org/teavm/cache/AnnotationAwareCacheStatus.java b/core/src/main/java/org/teavm/cache/AnnotationAwareCacheStatus.java
index 2beabe74f..d07ce195a 100644
--- a/core/src/main/java/org/teavm/cache/AnnotationAwareCacheStatus.java
+++ b/core/src/main/java/org/teavm/cache/AnnotationAwareCacheStatus.java
@@ -20,6 +20,8 @@ import com.carrotsearch.hppc.ObjectByteMap;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Predicate;
+import org.teavm.model.ClassReader;
+import org.teavm.model.ClassReaderSource;
 import org.teavm.model.MethodReference;
 
 public final class AnnotationAwareCacheStatus implements CacheStatus {
@@ -32,10 +34,13 @@ public final class AnnotationAwareCacheStatus implements CacheStatus {
     private IncrementalDependencyProvider dependencyProvider;
     private List<Predicate<String>> synthesizedClasses = new ArrayList<>();
     private ObjectByteMap<String> classStatusCache = new ObjectByteHashMap<>();
+    private ClassReaderSource classSource;
 
-    public AnnotationAwareCacheStatus(CacheStatus underlyingStatus, IncrementalDependencyProvider dependencyProvider) {
+    public AnnotationAwareCacheStatus(CacheStatus underlyingStatus, IncrementalDependencyProvider dependencyProvider,
+            ClassReaderSource classSource) {
         this.underlyingStatus = underlyingStatus;
         this.dependencyProvider = dependencyProvider;
+        this.classSource = classSource;
     }
 
     public void addSynthesizedClasses(Predicate<String> synthesizedClasses) {
@@ -72,6 +77,18 @@ public final class AnnotationAwareCacheStatus implements CacheStatus {
             return STALE;
         }
 
+        ClassReader cls = classSource.get(className);
+        if (cls != null) {
+            if (cls.getParent() != null && getClassStatus(cls.getParent()) == STALE) {
+                return STALE;
+            }
+            for (String itf : cls.getInterfaces()) {
+                if (getClassStatus(cls.getParent()) == STALE) {
+                    return STALE;
+                }
+            }
+        }
+
         return FRESH;
     }
 
diff --git a/core/src/main/java/org/teavm/cache/InMemoryMethodNodeCache.java b/core/src/main/java/org/teavm/cache/InMemoryMethodNodeCache.java
index f1a78daee..1fe47c283 100644
--- a/core/src/main/java/org/teavm/cache/InMemoryMethodNodeCache.java
+++ b/core/src/main/java/org/teavm/cache/InMemoryMethodNodeCache.java
@@ -25,7 +25,9 @@ import org.teavm.model.MethodReference;
 
 public class InMemoryMethodNodeCache implements MethodNodeCache {
     private Map<MethodReference, RegularItem> cache = new HashMap<>();
+    private Map<MethodReference, RegularItem> newItems = new HashMap<>();
     private Map<MethodReference, AsyncItem> asyncCache = new HashMap<>();
+    private Map<MethodReference, AsyncItem> newAsyncItems = new HashMap<>();
 
     @Override
     public RegularMethodNode get(MethodReference methodReference, CacheStatus cacheStatus) {
@@ -43,7 +45,7 @@ public class InMemoryMethodNodeCache implements MethodNodeCache {
 
     @Override
     public void store(MethodReference methodReference, RegularMethodNode node, Supplier<String[]> dependencies) {
-        cache.put(methodReference, new RegularItem(node, dependencies.get().clone()));
+        newItems.put(methodReference, new RegularItem(node, dependencies.get().clone()));
     }
 
     @Override
@@ -62,7 +64,19 @@ public class InMemoryMethodNodeCache implements MethodNodeCache {
 
     @Override
     public void storeAsync(MethodReference methodReference, AsyncMethodNode node, Supplier<String[]> dependencies) {
-        asyncCache.put(methodReference, new AsyncItem(node, dependencies.get().clone()));
+        newAsyncItems.put(methodReference, new AsyncItem(node, dependencies.get().clone()));
+    }
+
+    public void commit() {
+        cache.putAll(newItems);
+        asyncCache.putAll(newAsyncItems);
+        newItems.clear();
+        newAsyncItems.clear();
+    }
+
+    public void discard() {
+        newItems.clear();
+        newAsyncItems.clear();
     }
 
     static final class RegularItem {
diff --git a/core/src/main/java/org/teavm/cache/InMemoryProgramCache.java b/core/src/main/java/org/teavm/cache/InMemoryProgramCache.java
index 919714072..ee3f4c26a 100644
--- a/core/src/main/java/org/teavm/cache/InMemoryProgramCache.java
+++ b/core/src/main/java/org/teavm/cache/InMemoryProgramCache.java
@@ -25,6 +25,7 @@ import org.teavm.model.ProgramCache;
 
 public class InMemoryProgramCache implements ProgramCache {
     private Map<MethodReference, Item> cache = new HashMap<>();
+    private Map<MethodReference, Item> newItems = new HashMap<>();
 
     @Override
     public Program get(MethodReference method, CacheStatus cacheStatus) {
@@ -42,7 +43,20 @@ public class InMemoryProgramCache implements ProgramCache {
 
     @Override
     public void store(MethodReference method, Program program, Supplier<String[]> dependencies) {
-        cache.put(method, new Item(program, dependencies.get().clone()));
+        newItems.put(method, new Item(program, dependencies.get().clone()));
+    }
+
+    public void commit() {
+        cache.putAll(newItems);
+        newItems.clear();
+    }
+
+    public int getPendingItemsCount() {
+        return newItems.size();
+    }
+
+    public void discard() {
+        newItems.clear();
     }
 
     static final class Item {
diff --git a/core/src/main/java/org/teavm/dependency/DependencyAgent.java b/core/src/main/java/org/teavm/dependency/DependencyAgent.java
index bed54fac3..4d844537d 100644
--- a/core/src/main/java/org/teavm/dependency/DependencyAgent.java
+++ b/core/src/main/java/org/teavm/dependency/DependencyAgent.java
@@ -88,7 +88,6 @@ public class DependencyAgent implements DependencyInfo, ServiceRepository {
         return analyzer.getClassLoader();
     }
 
-    @Override
     public ClassHierarchy getClassHierarchy() {
         return analyzer.getClassHierarchy();
     }
diff --git a/core/src/main/java/org/teavm/dependency/DependencyAnalyzer.java b/core/src/main/java/org/teavm/dependency/DependencyAnalyzer.java
index f742334eb..ff9ae1abe 100644
--- a/core/src/main/java/org/teavm/dependency/DependencyAnalyzer.java
+++ b/core/src/main/java/org/teavm/dependency/DependencyAnalyzer.java
@@ -214,7 +214,6 @@ public abstract class DependencyAnalyzer implements DependencyInfo {
         return classSource.isGeneratedClass(className);
     }
 
-    @Override
     public ClassHierarchy getClassHierarchy() {
         return classHierarchy;
     }
diff --git a/core/src/main/java/org/teavm/dependency/DependencyInfo.java b/core/src/main/java/org/teavm/dependency/DependencyInfo.java
index e63c6b88b..a4f41dfb0 100644
--- a/core/src/main/java/org/teavm/dependency/DependencyInfo.java
+++ b/core/src/main/java/org/teavm/dependency/DependencyInfo.java
@@ -17,7 +17,6 @@ package org.teavm.dependency;
 
 import java.util.Collection;
 import org.teavm.callgraph.CallGraph;
-import org.teavm.model.ClassHierarchy;
 import org.teavm.model.ClassReaderSource;
 import org.teavm.model.FieldReference;
 import org.teavm.model.MethodReference;
@@ -27,8 +26,6 @@ public interface DependencyInfo {
 
     ClassLoader getClassLoader();
 
-    ClassHierarchy getClassHierarchy();
-
     Collection<MethodReference> getReachableMethods();
 
     Collection<FieldReference> getReachableFields();
diff --git a/core/src/main/java/org/teavm/dependency/FastInstructionAnalyzer.java b/core/src/main/java/org/teavm/dependency/FastInstructionAnalyzer.java
index 24ad64673..6ae2fc6dd 100644
--- a/core/src/main/java/org/teavm/dependency/FastInstructionAnalyzer.java
+++ b/core/src/main/java/org/teavm/dependency/FastInstructionAnalyzer.java
@@ -22,7 +22,7 @@ import org.teavm.model.VariableReader;
 
 class FastInstructionAnalyzer extends AbstractInstructionAnalyzer {
     private FastDependencyAnalyzer dependencyAnalyzer;
-    private MethodReference callerMethod;
+    private CallLocation impreciseLocation;
 
     FastInstructionAnalyzer(FastDependencyAnalyzer dependencyAnalyzer) {
         this.dependencyAnalyzer = dependencyAnalyzer;
@@ -31,7 +31,7 @@ class FastInstructionAnalyzer extends AbstractInstructionAnalyzer {
     @Override
     protected void invokeSpecial(VariableReader receiver, VariableReader instance, MethodReference method,
             List<? extends VariableReader> arguments) {
-        CallLocation callLocation = getCallLocation();
+        CallLocation callLocation = impreciseLocation;
         if (instance == null) {
             dependencyAnalyzer.linkClass(method.getClassName()).initClass(callLocation);
         }
@@ -43,19 +43,14 @@ class FastInstructionAnalyzer extends AbstractInstructionAnalyzer {
     @Override
     protected void invokeVirtual(VariableReader receiver, VariableReader instance, MethodReference method,
             List<? extends VariableReader> arguments) {
-        dependencyAnalyzer.getVirtualCallConsumer(method).addLocation(getCallLocation());
-
-        dependencyAnalyzer.getClassSource().overriddenMethods(method).forEach(methodImpl -> {
-            dependencyAnalyzer.linkMethod(methodImpl.getReference()).addLocation(getCallLocation());
-        });
+        dependencyAnalyzer.getVirtualCallConsumer(method).addLocation(impreciseLocation);
     }
 
-
     @Override
     public void cloneArray(VariableReader receiver, VariableReader array) {
         DependencyNode arrayNode = getNode(array);
         MethodDependency cloneDep = getAnalyzer().linkMethod(CLONE_METHOD);
-        cloneDep.addLocation(getCallLocation());
+        cloneDep.addLocation(impreciseLocation);
         cloneDep.use();
     }
 
@@ -68,4 +63,15 @@ class FastInstructionAnalyzer extends AbstractInstructionAnalyzer {
     protected DependencyAnalyzer getAnalyzer() {
         return dependencyAnalyzer;
     }
+
+    @Override
+    protected CallLocation getCallLocation() {
+        return impreciseLocation;
+    }
+
+    @Override
+    public void setCaller(MethodReference caller) {
+        super.setCaller(caller);
+        impreciseLocation = new CallLocation(caller);
+    }
 }
diff --git a/core/src/main/java/org/teavm/dependency/FastVirtualCallConsumer.java b/core/src/main/java/org/teavm/dependency/FastVirtualCallConsumer.java
index 276ff68b4..124227fa1 100644
--- a/core/src/main/java/org/teavm/dependency/FastVirtualCallConsumer.java
+++ b/core/src/main/java/org/teavm/dependency/FastVirtualCallConsumer.java
@@ -28,7 +28,7 @@ class FastVirtualCallConsumer implements DependencyConsumer {
     private final MethodDescriptor methodDesc;
     private final DependencyAnalyzer analyzer;
     private final Map<MethodReference, CallLocation> callLocations = new LinkedHashMap<>();
-    private final Set<MethodDependency> methods = new LinkedHashSet<>();
+    private final Set<MethodDependency> methods = new LinkedHashSet<>(100, 0.5f);
 
     FastVirtualCallConsumer(DependencyNode node, MethodDescriptor methodDesc, DependencyAnalyzer analyzer) {
         this.node = node;
diff --git a/core/src/main/java/org/teavm/model/ClassHierarchy.java b/core/src/main/java/org/teavm/model/ClassHierarchy.java
index 506d77559..4013423cc 100644
--- a/core/src/main/java/org/teavm/model/ClassHierarchy.java
+++ b/core/src/main/java/org/teavm/model/ClassHierarchy.java
@@ -19,11 +19,14 @@ import com.carrotsearch.hppc.ObjectByteHashMap;
 import com.carrotsearch.hppc.ObjectByteMap;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 import org.teavm.common.OptionalPredicate;
 
 public class ClassHierarchy {
     private final ClassReaderSource classSource;
     private final Map<String, OptionalPredicate<String>> superclassPredicateCache = new HashMap<>();
+    private final Map<String, Map<MethodDescriptor, Optional<MethodReader>>> resolveMethodCache = new HashMap<>();
+    private final Map<String, Map<String, Optional<FieldReader>>> resolveFieldCache = new HashMap<>();
 
     public ClassHierarchy(ClassReaderSource classSource) {
         this.classSource = classSource;
@@ -62,6 +65,67 @@ public class ClassHierarchy {
         return getSuperclassPredicate(superType).test(subType, defaultValue);
     }
 
+    public MethodReader resolve(MethodReference method) {
+        return resolve(method.getClassName(), method.getDescriptor());
+    }
+
+    public MethodReader resolve(String className, MethodDescriptor method) {
+        Map<MethodDescriptor, Optional<MethodReader>> cache = resolveMethodCache.computeIfAbsent(className,
+                k -> new HashMap<>());
+        Optional<MethodReader> opt = cache.get(method);
+        if (opt == null) {
+            MethodReader reader = null;
+            ClassReader cls = classSource.get(className);
+            if (cls != null) {
+                reader = cls.getMethod(method);
+                if (reader == null && cls.getParent() != null) {
+                    reader = resolve(cls.getParent(), method);
+                }
+                if (reader == null) {
+                    for (String itf : cls.getInterfaces()) {
+                        reader = resolve(itf, method);
+                        if (reader != null) {
+                            break;
+                        }
+                    }
+                }
+            }
+            opt = Optional.ofNullable(reader);
+            cache.put(method, opt);
+        }
+        return opt.orElse(null);
+    }
+
+    public FieldReader resolve(FieldReference field) {
+        return resolve(field.getClassName(), field.getFieldName());
+    }
+
+    public FieldReader resolve(String className, String fieldName) {
+        Map<String, Optional<FieldReader>> cache = resolveFieldCache.computeIfAbsent(className,
+                k -> new HashMap<>());
+        Optional<FieldReader> opt = cache.get(fieldName);
+        if (opt == null) {
+            FieldReader reader = null;
+            ClassReader cls = classSource.get(className);
+            if (cls != null) {
+                if (cls.getParent() != null) {
+                    reader = resolve(cls.getParent(), fieldName);
+                }
+                if (reader == null) {
+                    for (String itf : cls.getInterfaces()) {
+                        reader = resolve(itf, fieldName);
+                        if (reader != null) {
+                            break;
+                        }
+                    }
+                }
+            }
+            opt = Optional.ofNullable(reader);
+            cache.put(fieldName, opt);
+        }
+        return opt.orElse(null);
+    }
+
     public OptionalPredicate<String> getSuperclassPredicate(String superclass) {
         return superclassPredicateCache.computeIfAbsent(superclass, SuperclassPredicate::new);
     }
diff --git a/core/src/main/java/org/teavm/model/analysis/ClassInference.java b/core/src/main/java/org/teavm/model/analysis/ClassInference.java
index f00e0bc88..8d250dded 100644
--- a/core/src/main/java/org/teavm/model/analysis/ClassInference.java
+++ b/core/src/main/java/org/teavm/model/analysis/ClassInference.java
@@ -67,6 +67,7 @@ import org.teavm.model.instructions.UnwrapArrayInstruction;
 
 public class ClassInference {
     private DependencyInfo dependencyInfo;
+    private ClassHierarchy hierarchy;
     private Graph assignmentGraph;
     private Graph cloneGraph;
     private Graph arrayGraph;
@@ -89,8 +90,9 @@ public class ClassInference {
 
     private static final int MAX_DEGREE = 3;
 
-    public ClassInference(DependencyInfo dependencyInfo) {
+    public ClassInference(DependencyInfo dependencyInfo, ClassHierarchy hierarchy) {
         this.dependencyInfo = dependencyInfo;
+        this.hierarchy = hierarchy;
     }
 
     public void infer(Program program, MethodReference methodReference) {
@@ -403,8 +405,6 @@ public class ClassInference {
     }
 
     private void propagateAlongCasts() {
-        ClassHierarchy hierarchy = dependencyInfo.getClassHierarchy();
-
         for (ValueCast cast : casts) {
             int fromNode = nodeMapping[packNodeAndDegree(cast.fromVariable, 0)];
             if (!formerNodeChanged[fromNode] && !nodeChanged[fromNode]) {
@@ -500,8 +500,6 @@ public class ClassInference {
     }
 
     private void propagateException(String thrownTypeName, BasicBlock block) {
-        ClassHierarchy hierarchy = dependencyInfo.getClassHierarchy();
-
         for (TryCatchBlock tryCatch : block.getTryCatchBlocks()) {
             String expectedType = tryCatch.getExceptionType();
             if (expectedType == null || hierarchy.isSuperType(expectedType, thrownTypeName, false)) {
diff --git a/core/src/main/java/org/teavm/model/emit/ProgramEmitter.java b/core/src/main/java/org/teavm/model/emit/ProgramEmitter.java
index 07c46e26b..2e7dad5a3 100644
--- a/core/src/main/java/org/teavm/model/emit/ProgramEmitter.java
+++ b/core/src/main/java/org/teavm/model/emit/ProgramEmitter.java
@@ -175,7 +175,7 @@ public final class ProgramEmitter {
     }
 
     public ValueEmitter getField(FieldReference field, ValueType type) {
-        FieldReader resolvedField = classSource.resolve(field);
+        FieldReader resolvedField = hierarchy.resolve(field);
         if (resolvedField != null) {
             field = resolvedField.getReference();
         }
@@ -198,7 +198,7 @@ public final class ProgramEmitter {
     }
 
     public ProgramEmitter setField(FieldReference field, ValueEmitter value) {
-        FieldReader resolvedField = classSource.resolve(field);
+        FieldReader resolvedField = hierarchy.resolve(field);
         if (resolvedField != null) {
             field = resolvedField.getReference();
         }
diff --git a/core/src/main/java/org/teavm/model/optimization/Inlining.java b/core/src/main/java/org/teavm/model/optimization/Inlining.java
index 30c12f6ca..7e94a2fa2 100644
--- a/core/src/main/java/org/teavm/model/optimization/Inlining.java
+++ b/core/src/main/java/org/teavm/model/optimization/Inlining.java
@@ -25,6 +25,7 @@ import java.util.Set;
 import java.util.stream.Collectors;
 import org.teavm.dependency.DependencyInfo;
 import org.teavm.model.BasicBlock;
+import org.teavm.model.ClassHierarchy;
 import org.teavm.model.ClassReader;
 import org.teavm.model.ClassReaderSource;
 import org.teavm.model.Incoming;
@@ -55,16 +56,24 @@ public class Inlining {
     private static final int MAX_DEPTH = 7;
     private IntArrayList depthsByBlock;
     private Set<Instruction> instructionsToSkip;
+    private ClassHierarchy hierarchy;
+    private ClassReaderSource classes;
+    private DependencyInfo dependencyInfo;
 
-    public void apply(Program program, MethodReference method, ClassReaderSource classes,
-            DependencyInfo dependencyInfo) {
+    public Inlining(ClassHierarchy hierarchy, DependencyInfo dependencyInfo) {
+        this.hierarchy = hierarchy;
+        this.classes = hierarchy.getClassSource();
+        this.dependencyInfo = dependencyInfo;
+    }
+
+    public void apply(Program program, MethodReference method) {
         depthsByBlock = new IntArrayList(program.basicBlockCount());
         for (int i = 0; i < program.basicBlockCount(); ++i) {
             depthsByBlock.add(0);
         }
         instructionsToSkip = new HashSet<>();
 
-        while (applyOnce(program, classes)) {
+        while (applyOnce(program)) {
             devirtualize(program, method, dependencyInfo);
         }
         depthsByBlock = null;
@@ -73,8 +82,8 @@ public class Inlining {
         new UnreachableBasicBlockEliminator().optimize(program);
     }
 
-    private boolean applyOnce(Program program, ClassReaderSource classSource) {
-        List<PlanEntry> plan = buildPlan(program, classSource, 0);
+    private boolean applyOnce(Program program) {
+        List<PlanEntry> plan = buildPlan(program, 0);
         if (plan.isEmpty()) {
             return false;
         }
@@ -210,7 +219,7 @@ public class Inlining {
         execPlan(program, planEntry.innerPlan, firstInlineBlock.getIndex());
     }
 
-    private List<PlanEntry> buildPlan(Program program, ClassReaderSource classSource, int depth) {
+    private List<PlanEntry> buildPlan(Program program, int depth) {
         if (depth >= MAX_DEPTH) {
             return Collections.emptyList();
         }
@@ -243,7 +252,7 @@ public class Inlining {
                     continue;
                 }
 
-                MethodReader invokedMethod = getMethod(classSource, invoke.getMethod());
+                MethodReader invokedMethod = getMethod(invoke.getMethod());
                 if (invokedMethod == null || invokedMethod.getProgram() == null
                         || invokedMethod.getProgram().basicBlockCount() == 0) {
                     instructionsToSkip.add(insn);
@@ -264,7 +273,7 @@ public class Inlining {
                 entry.targetBlock = block.getIndex();
                 entry.targetInstruction = insn;
                 entry.program = invokedProgram;
-                entry.innerPlan.addAll(buildPlan(invokedProgram, classSource, depth + 1));
+                entry.innerPlan.addAll(buildPlan(invokedProgram, depth + 1));
                 entry.depth = depth;
                 plan.add(entry);
             }
@@ -274,8 +283,8 @@ public class Inlining {
         return plan;
     }
 
-    private MethodReader getMethod(ClassReaderSource classSource, MethodReference methodRef) {
-        ClassReader cls = classSource.get(methodRef.getClassName());
+    private MethodReader getMethod(MethodReference methodRef) {
+        ClassReader cls = classes.get(methodRef.getClassName());
         return cls != null ? cls.getMethod(methodRef.getDescriptor()) : null;
     }
 
@@ -308,7 +317,7 @@ public class Inlining {
     }
 
     private void devirtualize(Program program, MethodReference method, DependencyInfo dependencyInfo) {
-        ClassInference inference = new ClassInference(dependencyInfo);
+        ClassInference inference = new ClassInference(dependencyInfo, hierarchy);
         inference.infer(program, method);
 
         for (BasicBlock block : program.getBasicBlocks()) {
diff --git a/core/src/main/java/org/teavm/model/util/AsyncMethodFinder.java b/core/src/main/java/org/teavm/model/util/AsyncMethodFinder.java
index 70ed8c28b..5f5d3a47d 100644
--- a/core/src/main/java/org/teavm/model/util/AsyncMethodFinder.java
+++ b/core/src/main/java/org/teavm/model/util/AsyncMethodFinder.java
@@ -46,6 +46,7 @@ public class AsyncMethodFinder {
     private Map<MethodReference, Boolean> asyncFamilyMethods = new HashMap<>();
     private Set<MethodReference> readonlyAsyncMethods = Collections.unmodifiableSet(asyncMethods);
     private Set<MethodReference> readonlyAsyncFamilyMethods = Collections.unmodifiableSet(asyncFamilyMethods.keySet());
+    private Map<MethodReference, Set<MethodReference>> overiddenMethodsCache = new HashMap<>();
     private CallGraph callGraph;
     private Diagnostics diagnostics;
     private ListableClassReaderSource classSource;
@@ -209,7 +210,7 @@ public class AsyncMethodFinder {
         if (cls == null) {
             return;
         }
-        for (MethodReference overriddenMethod : findOverriddenMethods(cls, methodRef)) {
+        for (MethodReference overriddenMethod : findOverriddenMethods(cls, methodRef.getDescriptor())) {
             addOverriddenToFamily(overriddenMethod);
         }
     }
@@ -232,7 +233,7 @@ public class AsyncMethodFinder {
         if (cls == null) {
             return false;
         }
-        for (MethodReference overriddenMethod : findOverriddenMethods(cls, methodRef)) {
+        for (MethodReference overriddenMethod : findOverriddenMethods(cls, methodRef.getDescriptor())) {
             if (addToFamily(overriddenMethod)) {
                 return true;
             }
@@ -240,44 +241,44 @@ public class AsyncMethodFinder {
         return false;
     }
 
-    private Set<MethodReference> findOverriddenMethods(ClassReader cls, MethodReference methodRef) {
+    private Set<MethodReference> findOverriddenMethods(ClassReader cls, MethodDescriptor methodDesc) {
         List<String> parents = new ArrayList<>();
         if (cls.getParent() != null) {
             parents.add(cls.getParent());
         }
         parents.addAll(cls.getInterfaces());
 
-        Set<MethodReference> visited = new HashSet<>();
+        Set<String> visited = new HashSet<>();
         Set<MethodReference> overridden = new HashSet<>();
         for (String parent : parents) {
-            findOverriddenMethods(new MethodReference(parent, methodRef.getDescriptor()), overridden, visited);
+            findOverriddenMethods(parent, methodDesc, overridden, visited);
         }
         return overridden;
     }
 
-    private void findOverriddenMethods(MethodReference methodRef, Set<MethodReference> result,
-            Set<MethodReference> visited) {
-        if (!visited.add(methodRef)) {
+    private void findOverriddenMethods(String className, MethodDescriptor methodDesc, Set<MethodReference> result,
+            Set<String> visited) {
+        if (!visited.add(className)) {
             return;
         }
-        if (methodRef.getName().equals("<init>") || methodRef.getName().equals("<clinit>")) {
+        if (methodDesc.getName().equals("<init>") || methodDesc.getName().equals("<clinit>")) {
             return;
         }
-        ClassReader cls = classSource.get(methodRef.getClassName());
+        ClassReader cls = classSource.get(className);
         if (cls == null) {
             return;
         }
-        MethodReader method = cls.getMethod(methodRef.getDescriptor());
+        MethodReader method = cls.getMethod(methodDesc);
         if (method != null) {
             if (!method.hasModifier(ElementModifier.STATIC) && !method.hasModifier(ElementModifier.FINAL)) {
-                result.add(methodRef);
+                result.add(method.getReference());
             }
         } else {
             if (cls.getParent() != null) {
-                findOverriddenMethods(new MethodReference(cls.getParent(), methodRef.getDescriptor()), result, visited);
+                findOverriddenMethods(cls.getParent(), methodDesc, result, visited);
             }
             for (String iface : cls.getInterfaces()) {
-                findOverriddenMethods(new MethodReference(iface, methodRef.getDescriptor()), result, visited);
+                findOverriddenMethods(iface, methodDesc, result, visited);
             }
         }
     }
diff --git a/core/src/main/java/org/teavm/model/util/MissingItemsProcessor.java b/core/src/main/java/org/teavm/model/util/MissingItemsProcessor.java
index bcd95a3e0..1ec9f645f 100644
--- a/core/src/main/java/org/teavm/model/util/MissingItemsProcessor.java
+++ b/core/src/main/java/org/teavm/model/util/MissingItemsProcessor.java
@@ -27,6 +27,7 @@ import org.teavm.model.optimization.UnreachableBasicBlockEliminator;
 
 public class MissingItemsProcessor {
     private DependencyInfo dependencyInfo;
+    private ClassHierarchy hierarchy;
     private Diagnostics diagnostics;
     private List<Instruction> instructionsToAdd = new ArrayList<>();
     private MethodHolder methodHolder;
@@ -35,9 +36,10 @@ public class MissingItemsProcessor {
     private Collection<MethodReference> reachableMethods;
     private Collection<FieldReference> reachableFields;
 
-    public MissingItemsProcessor(DependencyInfo dependencyInfo, Diagnostics diagnostics) {
+    public MissingItemsProcessor(DependencyInfo dependencyInfo, ClassHierarchy hierarchy, Diagnostics diagnostics) {
         this.dependencyInfo = dependencyInfo;
         this.diagnostics = diagnostics;
+        this.hierarchy = hierarchy;
         reachableClasses = dependencyInfo.getReachableClasses();
         reachableMethods = dependencyInfo.getReachableMethods();
         reachableFields = dependencyInfo.getReachableFields();
@@ -171,7 +173,7 @@ public class MissingItemsProcessor {
             return true;
         }
 
-        if (dependencyInfo.getClassSource().resolve(method) != null) {
+        if (hierarchy.resolve(method) != null) {
             return true;
         }
 
diff --git a/core/src/main/java/org/teavm/vm/TeaVM.java b/core/src/main/java/org/teavm/vm/TeaVM.java
index 40d8ad006..76442bc03 100644
--- a/core/src/main/java/org/teavm/vm/TeaVM.java
+++ b/core/src/main/java/org/teavm/vm/TeaVM.java
@@ -47,6 +47,7 @@ import org.teavm.dependency.MethodDependency;
 import org.teavm.diagnostics.AccumulationDiagnostics;
 import org.teavm.diagnostics.Diagnostics;
 import org.teavm.diagnostics.ProblemProvider;
+import org.teavm.model.ClassHierarchy;
 import org.teavm.model.ClassHolder;
 import org.teavm.model.ClassHolderSource;
 import org.teavm.model.ClassHolderTransformer;
@@ -372,7 +373,8 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
             return;
         }
 
-        cacheStatus = new AnnotationAwareCacheStatus(rawCacheStatus, dependencyAnalyzer.getIncrementalDependencies());
+        cacheStatus = new AnnotationAwareCacheStatus(rawCacheStatus, dependencyAnalyzer.getIncrementalDependencies(),
+                dependencyAnalyzer.getClassSource());
         cacheStatus.addSynthesizedClasses(dependencyAnalyzer::isSynthesizedClass);
 
         // Link
@@ -423,11 +425,12 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
     }
 
     @SuppressWarnings("WeakerAccess")
-    public ListableClassHolderSource link(DependencyInfo dependency) {
+    public ListableClassHolderSource link(DependencyAnalyzer dependency) {
         reportPhase(TeaVMPhase.LINKING, dependency.getReachableClasses().size());
         Linker linker = new Linker();
         MutableClassHolderSource cutClasses = new MutableClassHolderSource();
-        MissingItemsProcessor missingItemsProcessor = new MissingItemsProcessor(dependency, diagnostics);
+        MissingItemsProcessor missingItemsProcessor = new MissingItemsProcessor(dependency,
+                dependency.getClassHierarchy(), diagnostics);
         if (wasCancelled()) {
             return cutClasses;
         }
@@ -446,7 +449,10 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
             cutClasses.putClassHolder(cls);
             missingItemsProcessor.processClass(cls);
             linker.link(dependency, cls);
-            progressListener.progressReached(++index);
+            reportProgress(++index);
+            if (wasCancelled()) {
+                break;
+            }
         }
         return cutClasses;
     }
@@ -457,6 +463,12 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
         }
     }
 
+    private void reportProgress(int progress) {
+        if (progressListener.progressReached(progress) == TeaVMProgressFeedback.CANCEL) {
+            cancelled = true;
+        }
+    }
+
     private int devirtualize(int progress, ListableClassHolderSource classes, DependencyInfo dependency) {
         if (wasCancelled()) {
             return progress;
@@ -470,7 +482,7 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
                     devirtualization.apply(method);
                 }
             }
-            progressListener.progressReached(++index);
+            reportProgress(++index);
             if (wasCancelled()) {
                 break;
             }
@@ -485,19 +497,19 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
         }
 
         Map<MethodReference, Program> inlinedPrograms = new HashMap<>();
-        Inlining inlining = new Inlining();
+        Inlining inlining = new Inlining(new ClassHierarchy(classes), dependencyInfo);
         for (String className : classes.getClassNames()) {
             ClassHolder cls = classes.get(className);
             for (MethodHolder method : cls.getMethods()) {
                 if (method.getProgram() != null) {
                     Program program = ProgramUtils.copy(method.getProgram());
                     MethodOptimizationContextImpl context = new MethodOptimizationContextImpl(method, classes);
-                    inlining.apply(program, method.getReference(), classes, dependencyInfo);
+                    inlining.apply(program, method.getReference());
                     new UnusedVariableElimination().optimize(context, program);
                     inlinedPrograms.put(method.getReference(), program);
                 }
             }
-            progressListener.progressReached(++progress);
+            reportProgress(++progress);
             if (wasCancelled()) {
                 break;
             }
@@ -521,7 +533,7 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
             for (MethodHolder method : cls.getMethods()) {
                 processMethod(method, classSource);
             }
-            progressListener.progressReached(++progress);
+            reportProgress(++progress);
             if (wasCancelled()) {
                 break;
             }
diff --git a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingDependencyListener.java b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingDependencyListener.java
index d84eb1186..b2c02989b 100644
--- a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingDependencyListener.java
+++ b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingDependencyListener.java
@@ -46,6 +46,7 @@ public class MetaprogrammingDependencyListener extends AbstractDependencyListene
 
         MetaprogrammingImpl.classLoader = proxyClassLoader;
         MetaprogrammingImpl.classSource = agent.getClassSource();
+        MetaprogrammingImpl.hierarchy = agent.getClassHierarchy();
         MetaprogrammingImpl.incrementaDependencies = agent.getIncrementalCache();
         MetaprogrammingImpl.agent = agent;
         MetaprogrammingImpl.reflectContext = new ReflectContext(agent.getClassHierarchy(), proxyClassLoader);
diff --git a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingImpl.java b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingImpl.java
index 54c005448..597997e3e 100644
--- a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingImpl.java
+++ b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingImpl.java
@@ -36,6 +36,7 @@ import org.teavm.metaprogramming.reflect.ReflectMethod;
 import org.teavm.model.AccessLevel;
 import org.teavm.model.BasicBlock;
 import org.teavm.model.CallLocation;
+import org.teavm.model.ClassHierarchy;
 import org.teavm.model.ClassHolder;
 import org.teavm.model.ClassReaderSource;
 import org.teavm.model.ElementModifier;
@@ -63,6 +64,7 @@ public final class MetaprogrammingImpl {
     static Map<String, Integer> proxySuffixGenerators = new HashMap<>();
     static ClassLoader classLoader;
     static ClassReaderSource classSource;
+    static ClassHierarchy hierarchy;
     static IncrementalDependencyRegistration incrementaDependencies;
     static ReflectContext reflectContext;
     static DependencyAgent agent;
@@ -87,7 +89,7 @@ public final class MetaprogrammingImpl {
             return var != null ? new ValueImpl<>(var, varContext, valueImpl.type) : null;
         } else {
             Fragment fragment = (Fragment) computation;
-            MethodReader method = classSource.resolve(fragment.method);
+            MethodReader method = hierarchy.resolve(fragment.method);
             generator.addProgram(method.getProgram(), fragment.capturedValues);
             return new ValueImpl<>(generator.getResultVar(), varContext, fragment.method.getReturnType());
         }
@@ -95,7 +97,7 @@ public final class MetaprogrammingImpl {
 
     public static void emit(Action action) {
         Fragment fragment = (Fragment) action;
-        MethodReader method = classSource.resolve(fragment.method);
+        MethodReader method = hierarchy.resolve(fragment.method);
         generator.addProgram(method.getProgram(), fragment.capturedValues);
     }
 
@@ -121,7 +123,7 @@ public final class MetaprogrammingImpl {
 
         if (value instanceof Fragment) {
             Fragment fragment = (Fragment) value;
-            MethodReader method = classSource.resolve(fragment.method);
+            MethodReader method = hierarchy.resolve(fragment.method);
             generator.addProgram(method.getProgram(), fragment.capturedValues);
             generator.blockIndex = generator.returnBlockIndex;
 
diff --git a/tests/src/test/java/org/teavm/dependency/DependencyTest.java b/tests/src/test/java/org/teavm/dependency/DependencyTest.java
index 86577dedb..852363bb5 100644
--- a/tests/src/test/java/org/teavm/dependency/DependencyTest.java
+++ b/tests/src/test/java/org/teavm/dependency/DependencyTest.java
@@ -33,6 +33,7 @@ import org.teavm.backend.javascript.JavaScriptTarget;
 import org.teavm.common.DisjointSet;
 import org.teavm.diagnostics.Problem;
 import org.teavm.model.BasicBlock;
+import org.teavm.model.ClassHierarchy;
 import org.teavm.model.ClassHolderSource;
 import org.teavm.model.Instruction;
 import org.teavm.model.MethodHolder;
@@ -145,7 +146,8 @@ public class DependencyTest {
 
     private void processAssertions(List<Assertion> assertions, MethodDependencyInfo methodDep,
             DependencyInfo dependencyInfo, Program program) {
-        ClassInference classInference = new ClassInference(dependencyInfo);
+        ClassInference classInference = new ClassInference(dependencyInfo, new ClassHierarchy(
+                dependencyInfo.getClassSource()));
         classInference.infer(program, methodDep.getReference());
 
         for (Assertion assertion : assertions) {
diff --git a/tests/src/test/java/org/teavm/incremental/IncrementalTest.java b/tests/src/test/java/org/teavm/incremental/IncrementalTest.java
index dfebb8a0a..4f00b576f 100644
--- a/tests/src/test/java/org/teavm/incremental/IncrementalTest.java
+++ b/tests/src/test/java/org/teavm/incremental/IncrementalTest.java
@@ -213,6 +213,8 @@ public class IncrementalTest {
             if (!problems.isEmpty()) {
                 fail("Compiler error generating file '" + name + "'\n" + buildErrorMessage(vm));
             }
+            astCache.commit();
+            programCache.commit();
         }
 
         private String buildErrorMessage(TeaVM vm) {
diff --git a/tools/cli/src/main/java/org/teavm/cli/TeaVMDevServerRunner.java b/tools/cli/src/main/java/org/teavm/cli/TeaVMDevServerRunner.java
index 8073ac924..123d6f837 100644
--- a/tools/cli/src/main/java/org/teavm/cli/TeaVMDevServerRunner.java
+++ b/tools/cli/src/main/java/org/teavm/cli/TeaVMDevServerRunner.java
@@ -114,6 +114,7 @@ public final class TeaVMDevServerRunner {
 
         devServer.setIndicator(commandLine.hasOption("indicator"));
         devServer.setReloadedAutomatically(commandLine.hasOption("auto-reload"));
+        devServer.setVerbose(commandLine.hasOption('v'));
         if (commandLine.hasOption("port")) {
             try {
                 devServer.setPort(Integer.parseInt(commandLine.getOptionValue("port")));
diff --git a/tools/core/src/main/java/org/teavm/tooling/util/FileSystemWatcher.java b/tools/core/src/main/java/org/teavm/tooling/util/FileSystemWatcher.java
index d37482961..6676206f8 100644
--- a/tools/core/src/main/java/org/teavm/tooling/util/FileSystemWatcher.java
+++ b/tools/core/src/main/java/org/teavm/tooling/util/FileSystemWatcher.java
@@ -43,6 +43,7 @@ public class FileSystemWatcher {
     private WatchService watchService;
     private Map<WatchKey, Path> keysToPath = new HashMap<>();
     private Map<Path, WatchKey> pathsToKey = new HashMap<>();
+    private Map<Path, Integer> refCount = new HashMap<>();
     private Set<File> changedFiles = new LinkedHashSet<>();
 
     public FileSystemWatcher(String[] classPath) throws IOException {
@@ -51,9 +52,7 @@ public class FileSystemWatcher {
             Path path = Paths.get(entry);
             File file = path.toFile();
             if (file.exists()) {
-                if (!file.isDirectory()) {
-                    registerSingle(path.getParent());
-                } else {
+                if (file.isDirectory()) {
                     register(path);
                 }
             }
@@ -74,6 +73,13 @@ public class FileSystemWatcher {
                         .collect(Collectors.toList()));
                 return FileVisitResult.CONTINUE;
             }
+
+            @Override
+            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
+                Path parent = file.getParent();
+                refCount.put(parent, refCount.getOrDefault(parent, 0) + 1);
+                return FileVisitResult.CONTINUE;
+            }
         });
         return files;
     }
@@ -83,6 +89,9 @@ public class FileSystemWatcher {
                 StandardWatchEventKinds.ENTRY_DELETE, StandardWatchEventKinds.ENTRY_MODIFY);
         keysToPath.put(key, path);
         pathsToKey.put(path, key);
+        refCount.put(path, refCount.getOrDefault(path, 0) + 1);
+        Path parent = path.getParent();
+        refCount.put(parent, refCount.getOrDefault(parent, 0) + 1);
     }
 
     public boolean hasChanges() throws IOException {
@@ -159,9 +168,6 @@ public class FileSystemWatcher {
             return Collections.emptyList();
         }
         Path basePath = keysToPath.get(baseKey);
-        if (basePath == null) {
-            return Collections.emptyList();
-        }
         Path path = basePath.resolve((Path) event.context());
         WatchKey key = pathsToKey.get(path);
 
@@ -170,9 +176,8 @@ public class FileSystemWatcher {
 
         if (event.kind() == StandardWatchEventKinds.ENTRY_DELETE) {
             if (key != null) {
-                pathsToKey.remove(path);
-                keysToPath.remove(key);
                 key.cancel();
+                releasePath(path);
             }
         } else if (event.kind() == StandardWatchEventKinds.ENTRY_CREATE) {
             if (Files.isDirectory(path)) {
@@ -181,4 +186,18 @@ public class FileSystemWatcher {
         }
         return result;
     }
+
+    private void releasePath(Path path) {
+        refCount.put(path, refCount.getOrDefault(path, 0) - 1);
+        while (refCount.getOrDefault(path, 0) <= 0) {
+            WatchKey key = pathsToKey.get(path);
+            if (key == null) {
+                break;
+            }
+            pathsToKey.remove(path);
+            keysToPath.remove(key);
+            path = path.getParent();
+            refCount.put(path, refCount.getOrDefault(path, 0) - 1);
+        }
+    }
 }
diff --git a/tools/devserver/src/main/java/org/teavm/devserver/CodeServlet.java b/tools/devserver/src/main/java/org/teavm/devserver/CodeServlet.java
index 37530efcc..1d0e1d026 100644
--- a/tools/devserver/src/main/java/org/teavm/devserver/CodeServlet.java
+++ b/tools/devserver/src/main/java/org/teavm/devserver/CodeServlet.java
@@ -32,8 +32,10 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.function.Supplier;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
@@ -92,7 +94,10 @@ public class CodeServlet extends HttpServlet {
     private final Map<String, byte[]> content = new HashMap<>();
     private MemoryBuildTarget buildTarget = new MemoryBuildTarget();
 
-    private CodeWsEndpoint wsEndpoint;
+    private final Set<CodeWsEndpoint> wsEndpoints = new LinkedHashSet<>();
+    private final Object statusLock = new Object();
+    private boolean compiling;
+    private double progress;
 
     public CodeServlet(String mainClass, String[] classPath) {
         this.mainClass = mainClass;
@@ -129,14 +134,32 @@ public class CodeServlet extends HttpServlet {
         this.port = port;
     }
 
-    public void setWsEndpoint(CodeWsEndpoint wsEndpoint) {
-        this.wsEndpoint = wsEndpoint;
-    }
-
     public void setAutomaticallyReloaded(boolean automaticallyReloaded) {
         this.automaticallyReloaded = automaticallyReloaded;
     }
 
+    public void addWsEndpoint(CodeWsEndpoint endpoint) {
+        synchronized (wsEndpoints) {
+            wsEndpoints.add(endpoint);
+        }
+
+        double progress;
+        synchronized (statusLock) {
+            if (!compiling) {
+                return;
+            }
+            progress = this.progress;
+        }
+
+        endpoint.progress(progress);
+    }
+
+    public void removeWsEndpoint(CodeWsEndpoint endpoint) {
+        synchronized (wsEndpoints) {
+            wsEndpoints.remove(endpoint);
+        }
+    }
+
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
         String path = req.getPathInfo();
@@ -289,8 +312,17 @@ public class CodeServlet extends HttpServlet {
                     break;
                 }
                 log.info("Changes detected. Recompiling.");
+
                 List<String> staleClasses = getChangedClasses(watcher.grabChangedFiles());
-                log.debug("Following classes changed: " + staleClasses);
+                if (staleClasses.size() > 15) {
+                    List<String> displayedStaleClasses = staleClasses.subList(0, 10);
+                    log.debug("Following classes changed (" + staleClasses.size() + "): "
+                            + String.join(", ", displayedStaleClasses) + " and more...");
+                } else {
+                    log.debug("Following classes changed (" + staleClasses.size() + "): "
+                            + String.join(", ", staleClasses));
+                }
+
                 classSource.evict(staleClasses);
             }
         } catch (Throwable e) {
@@ -358,9 +390,7 @@ public class CodeServlet extends HttpServlet {
         log.info("Starting build");
         progressListener.last = 0;
         progressListener.lastTime = System.currentTimeMillis();
-        if (wsEndpoint != null) {
-            wsEndpoint.progress(0);
-        }
+        reportProgress(0);
         vm.build(buildTarget, fileName);
         addIndicator();
         generateDebug(debugInformationBuilder);
@@ -419,19 +449,18 @@ public class CodeServlet extends HttpServlet {
 
     private void postBuild(TeaVM vm, long startTime) {
         if (!vm.wasCancelled()) {
+            log.info("Recompiled stale methods: " + programCache.getPendingItemsCount());
             if (vm.getProblemProvider().getSevereProblems().isEmpty()) {
                 log.info("Build complete successfully");
                 saveNewResult();
                 lastReachedClasses = vm.getDependencyInfo().getReachableClasses().size();
                 classSource.commit();
-                if (wsEndpoint != null) {
-                    wsEndpoint.complete(true);
-                }
+                programCache.commit();
+                astCache.commit();
+                reportCompilationComplete(true);
             } else {
                 log.info("Build complete with errors");
-                if (wsEndpoint != null) {
-                    wsEndpoint.complete(false);
-                }
+                reportCompilationComplete(false);
             }
             printStats(vm, startTime);
             TeaVMProblemRenderer.describeProblems(vm, log);
@@ -439,6 +468,8 @@ public class CodeServlet extends HttpServlet {
             log.info("Build cancelled");
         }
 
+        astCache.discard();
+        programCache.discard();
         buildTarget.clear();
     }
 
@@ -505,6 +536,43 @@ public class CodeServlet extends HttpServlet {
         return new URLClassLoader(urls, CodeServlet.class.getClassLoader());
     }
 
+    private void reportProgress(double progress) {
+        synchronized (statusLock) {
+            if (compiling && this.progress == progress) {
+                return;
+            }
+            compiling = true;
+            this.progress = progress;
+        }
+
+        CodeWsEndpoint[] endpoints;
+        synchronized (wsEndpoints) {
+            endpoints = wsEndpoints.toArray(new CodeWsEndpoint[0]);
+        }
+
+        for (CodeWsEndpoint endpoint : endpoints) {
+            endpoint.progress(progress);
+        }
+    }
+
+    private void reportCompilationComplete(boolean success) {
+        synchronized (statusLock) {
+            if (!compiling) {
+                return;
+            }
+            compiling = false;
+        }
+
+        CodeWsEndpoint[] endpoints;
+        synchronized (wsEndpoints) {
+            endpoints = wsEndpoints.toArray(new CodeWsEndpoint[0]);
+        }
+
+        for (CodeWsEndpoint endpoint : endpoints) {
+            endpoint.complete(success);
+        }
+    }
+
     private final ProgressListenerImpl progressListener = new ProgressListenerImpl();
 
     class ProgressListenerImpl implements TeaVMProgressListener {
@@ -540,13 +608,13 @@ public class CodeServlet extends HttpServlet {
 
         @Override
         public TeaVMProgressFeedback progressReached(int progress) {
-            if (wsEndpoint != null && indicator) {
+            if (indicator) {
                 int current = start + Math.min(progress, phaseLimit) * (end - start) / phaseLimit;
                 if (current != last) {
                     if (current - last > 10 || System.currentTimeMillis() - lastTime > 100) {
                         lastTime = System.currentTimeMillis();
                         last = current;
-                        wsEndpoint.progress(current / 10.0);
+                        reportProgress(current / 10.0);
                     }
                 }
             }
diff --git a/tools/devserver/src/main/java/org/teavm/devserver/CodeWsEndpoint.java b/tools/devserver/src/main/java/org/teavm/devserver/CodeWsEndpoint.java
index 76bc95151..278cad802 100644
--- a/tools/devserver/src/main/java/org/teavm/devserver/CodeWsEndpoint.java
+++ b/tools/devserver/src/main/java/org/teavm/devserver/CodeWsEndpoint.java
@@ -15,7 +15,7 @@
  */
 package org.teavm.devserver;
 
-import java.util.function.Consumer;
+import javax.websocket.OnClose;
 import javax.websocket.OnOpen;
 import javax.websocket.Session;
 import javax.websocket.server.ServerEndpoint;
@@ -23,38 +23,35 @@ import javax.websocket.server.ServerEndpoint;
 @ServerEndpoint("/")
 public class CodeWsEndpoint {
     private Session session;
-    private boolean compiling;
-    private double progress;
+    private CodeServlet servlet;
 
     @OnOpen
     public void open(Session session) {
         this.session = session;
-        @SuppressWarnings("unchecked")
-        Consumer<CodeWsEndpoint> consumer = (Consumer<CodeWsEndpoint>) session.getUserProperties().get("ws.consumer");
-        if (consumer != null) {
-            consumer.accept(this);
+        servlet = (CodeServlet) session.getUserProperties().get("teavm.servlet");
+        if (servlet != null) {
+            servlet.addWsEndpoint(this);
         }
-        if (compiling) {
-            sendProgress(progress);
+    }
+
+    @OnClose
+    public void close() {
+        if (servlet != null) {
+            servlet.removeWsEndpoint(this);
         }
+        servlet = null;
+        session = null;
     }
 
     public void progress(double value) {
         if (session != null) {
-            sendProgress(value);
+            session.getAsyncRemote().sendText("{ \"command\": \"compiling\", \"progress\": " + value + " }");
         }
-        compiling = true;
-        progress = value;
     }
 
     public void complete(boolean success) {
         if (session != null) {
             session.getAsyncRemote().sendText("{ \"command\": \"complete\", \"success\": " + success + " }");
         }
-        compiling = false;
-    }
-
-    private void sendProgress(double value) {
-        session.getAsyncRemote().sendText("{ \"command\": \"compiling\", \"progress\": " + value + " }");
     }
 }
diff --git a/tools/devserver/src/main/java/org/teavm/devserver/DevServer.java b/tools/devserver/src/main/java/org/teavm/devserver/DevServer.java
index 8aa43a639..675e7c1dd 100644
--- a/tools/devserver/src/main/java/org/teavm/devserver/DevServer.java
+++ b/tools/devserver/src/main/java/org/teavm/devserver/DevServer.java
@@ -20,7 +20,6 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.function.Consumer;
 import javax.websocket.Decoder;
 import javax.websocket.Encoder;
 import javax.websocket.Extension;
@@ -42,7 +41,8 @@ public class DevServer {
     private List<String> sourcePath = new ArrayList<>();
     private boolean indicator;
     private boolean reloadedAutomatically;
-    private TeaVMToolLog log = new ConsoleTeaVMToolLog(false);
+    private boolean verbose;
+    private TeaVMToolLog log;
 
     private Server server;
     private int port = 9090;
@@ -85,11 +85,16 @@ public class DevServer {
         this.reloadedAutomatically = reloadedAutomatically;
     }
 
+    public void setVerbose(boolean verbose) {
+        this.verbose = verbose;
+    }
+
     public List<String> getSourcePath() {
         return sourcePath;
     }
 
     public void start() {
+        log = new ConsoleTeaVMToolLog(verbose);
         server = new Server();
         ServerConnector connector = new ServerConnector(server);
         connector.setPort(port);
@@ -110,7 +115,7 @@ public class DevServer {
 
         try {
             ServerContainer wscontainer = WebSocketServerContainerInitializer.configureContext(context);
-            wscontainer.addEndpoint(new DevServerEndpointConfig(servlet::setWsEndpoint));
+            wscontainer.addEndpoint(new DevServerEndpointConfig(servlet));
             server.start();
             server.join();
         } catch (Exception e) {
@@ -129,8 +134,8 @@ public class DevServer {
     private class DevServerEndpointConfig implements ServerEndpointConfig {
         private Map<String, Object> userProperties = new HashMap<>();
 
-        public DevServerEndpointConfig(Consumer<CodeWsEndpoint> consumer) {
-            userProperties.put("ws.consumer", consumer);
+        public DevServerEndpointConfig(CodeServlet servlet) {
+            userProperties.put("teavm.servlet", servlet);
         }
 
         @Override