diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Drop.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Drop.java
index 121e5f30a..1f5ebf4df 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Drop.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Drop.java
@@ -6,7 +6,6 @@
 import java.io.File;
 import java.io.PrintStream;
 import java.nio.file.Files;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
  * Created by Дмитрий on 07.10.14.
@@ -24,54 +23,48 @@ public  boolean exec(Welcome dbConnector, String[] args, PrintStream out, PrintS
         }
 
         boolean inProvider = true;
-        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-        lock.readLock().lock();
-        try {
-            StoreableTable map = dbConnector.getActiveTableProvider().getTables().get(args[0]);
-            if (map == null) {
-                map = dbConnector.getTables().get(args[0]);
-                inProvider = false;
+        StoreableTable map = dbConnector.getActiveTableProvider().getTables().get(args[0]);
+        if (map == null) {
+            map = dbConnector.getTables().get(args[0]);
+            inProvider = false;
+        }
+        if (map == null) {
+            err.println(args[0] + " not exists");
+            if (batchModeInInteractive) {
+                return false;
             }
-            if (map == null) {
-                err.println(args[0] + " not exists");
-                if (batchModeInInteractive) {
-                    return false;
-                }
-                if (batchMode) {
-                    System.exit(-1);
-                }
-                return true;
+            if (batchMode) {
+                System.exit(-1);
+            }
+            return true;
+        }
+        if (dbConnector.getActiveTable() == map) {
+            if (inProvider) {
+                dbConnector.getActiveTableProvider().getTables().remove(args[0]);
+            } else {
+                dbConnector.getTables().remove(args[0]);
             }
-            if (dbConnector.getActiveTable() == map) {
+            dbConnector.setActiveTable(null);
+        }
+        try {
+            if (dbConnector != null) {
                 if (inProvider) {
                     dbConnector.getActiveTableProvider().getTables().remove(args[0]);
                 } else {
                     dbConnector.getTables().remove(args[0]);
                 }
-                dbConnector.setActiveTable(null);
             }
-            try {
-                if (dbConnector != null) {
-                    if (inProvider) {
-                        dbConnector.getActiveTableProvider().getTables().remove(args[0]);
-                    } else {
-                        dbConnector.getTables().remove(args[0]);
-                    }
-                }
-                if (dbConnector.getActiveTable() == null) {
-                    map.deleteFiles("", true);
-                    Files.delete(new File(map.dbPath + File.separator + "signature.tsv").toPath());
-                } else {
-                    map.deleteFiles(dbConnector.getActiveTable().getName(), true);
-                }
-                Files.delete(map.dbPath);
-            } catch (Exception e) {
-                err.println("Exception in drop: can't delete " + map.dbPath.toString()
-                        + " because " + e.getLocalizedMessage());
-                System.exit(-1);
+            if (dbConnector.getActiveTable() == null) {
+                map.deleteFiles("", true);
+                Files.delete(new File(map.dbPath + File.separator + "signature.tsv").toPath());
+            } else {
+                map.deleteFiles(dbConnector.getActiveTable().getName(), true);
             }
-        } finally {
-            lock.readLock().unlock();
+            Files.delete(map.dbPath);
+        } catch (Exception e) {
+            err.println("Exception in drop: can't delete " + map.dbPath.toString()
+                    + " because " + e.getLocalizedMessage());
+            System.exit(-1);
         }
         out.println("dropped");
         return true;
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/List.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/List.java
index 819003e19..b6c8b91f0 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/List.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/List.java
@@ -3,6 +3,7 @@
 import ru.fizteh.fivt.students.Kudriavtsev_Dmitry.Proxy.Welcome;
 
 import java.io.PrintStream;
+import java.util.StringJoiner;
 
 /**
  * Created by Дмитрий on 04.10.14.
@@ -26,15 +27,11 @@ public boolean exec(Welcome dbConnector, String[] args, PrintStream out, PrintSt
             return true;
         }
         java.util.List<String> keySet = dbConnector.getActiveTable().list();
-        int count = 0;
+        StringJoiner strJoin = new StringJoiner(" ,");
         for (String key : keySet) {
-            out.print(key);
-            if (count != keySet.size() - 1) {
-                out.print(", ");
-                ++count;
-            }
+            strJoin.add(key);
         }
-        out.println();
+        out.println(strJoin.toString());
         return true;
     }
 }
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Put.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Put.java
index 0749a4b1d..f7deaa296 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Put.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Put.java
@@ -7,7 +7,6 @@
 import java.io.File;
 import java.io.PrintStream;
 import java.text.ParseException;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
  * Created by Дмитрий on 04.10.14.
@@ -41,37 +40,31 @@ public boolean exec(Welcome dbConnector, String[] args, PrintStream out, PrintSt
             return true;
         }
         Storeable value;
-        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-        lock.readLock().lock();
         try {
-            try {
-                value = dbConnector.getActiveTable().put(args[0],
-                        dbConnector.getActiveTableProvider().deserialize(dbConnector.getActiveTable(), args[1]));
-            } catch (ParseException e) {
-                err.println("Parse Exception in deserialize");
-                return !batchModeInInteractive;
-            }
-            if (value != null) {
-                out.println("overwrite");
-                for (Object val : ((CurrentStoreable) value).getValues()) {
-                    out.println(val.toString());
-                }
-            } else {
-                out.println("new");
+            value = dbConnector.getActiveTable().put(args[0],
+                    dbConnector.getActiveTableProvider().deserialize(dbConnector.getActiveTable(), args[1]));
+        } catch (ParseException e) {
+            err.println("Parse Exception in deserialize");
+            return !batchModeInInteractive;
+        }
+        if (value != null) {
+            out.println("overwrite");
+            for (Object val : ((CurrentStoreable) value).getValues()) {
+                out.println(val.toString());
             }
-            String newPath = dbConnector.getActiveTable().whereToSave("", args[0]).getKey();
-            if (new File(newPath).exists() || dbConnector.getActiveTable().getChangedFiles().containsKey(newPath)) {
-                Integer collisionCount = dbConnector.getActiveTable().getChangedFiles().get(newPath);
-                if (collisionCount == null) {
-                    collisionCount = dbConnector.getActiveTable().countOfCollisionsInFile(new File(newPath).toPath());
-                }
-                ++collisionCount;
-                dbConnector.getActiveTable().getChangedFiles().put(newPath, collisionCount);
-            } else {
-                dbConnector.getActiveTable().getChangedFiles().put(newPath, 0);
+        } else {
+            out.println("new");
+        }
+        String newPath = dbConnector.getActiveTable().whereToSave("", args[0]).path;
+        if (new File(newPath).exists() || dbConnector.getActiveTable().getChangedFiles().containsKey(newPath)) {
+            Integer collisionCount = dbConnector.getActiveTable().getChangedFiles().get(newPath);
+            if (collisionCount == null) {
+                collisionCount = dbConnector.getActiveTable().countOfCollisionsInFile(new File(newPath).toPath());
             }
-        } finally {
-            lock.readLock().unlock();
+            ++collisionCount;
+            dbConnector.getActiveTable().getChangedFiles().put(newPath, collisionCount);
+        } else {
+            dbConnector.getActiveTable().getChangedFiles().put(newPath, 0);
         }
         return true;
     }
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Remove.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Remove.java
index 3635e34c6..4438d42bf 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Remove.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Remove.java
@@ -3,7 +3,6 @@
 import ru.fizteh.fivt.students.Kudriavtsev_Dmitry.Proxy.Welcome;
 
 import java.io.PrintStream;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
  * Created by Дмитрий on 04.10.14.
@@ -26,21 +25,15 @@ public boolean exec(Welcome dbConnector, String[] args, PrintStream out, PrintSt
             noTable(err);
             return true;
         }
-        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-        lock.readLock().lock();
-        try {
-            if (dbConnector.getActiveTable().remove(args[0]) != null) {
-                out.println("removed");
-                dbConnector.getActiveTable().getChangedFiles().put(
-                        dbConnector.getActiveTable().whereToSave("", args[0]).getKey(), 0);
-            } else {
-                err.println("not found");
-                if (batchModeInInteractive) {
-                    return false;
-                }
+        if (dbConnector.getActiveTable().remove(args[0]) != null) {
+            out.println("removed");
+            dbConnector.getActiveTable().getChangedFiles().put(
+                    dbConnector.getActiveTable().whereToSave("", args[0]).path, 0);
+        } else {
+            err.println("not found");
+            if (batchModeInInteractive) {
+                return false;
             }
-        } finally {
-            lock.readLock().unlock();
         }
         return true;
     }
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Show.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Show.java
index 2e42272c7..3b79cff70 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Show.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Show.java
@@ -5,7 +5,6 @@
 
 import java.io.PrintStream;
 import java.util.Map;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
  * Created by Дмитрий on 07.10.14.
@@ -38,18 +37,12 @@ public boolean exec(Welcome dbConnector, String[] args, PrintStream out, PrintSt
             return checkForArgs(err);
         }
 
-        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-        lock.readLock().lock();
-        try {
-            if (dbConnector.getTables().isEmpty() && dbConnector.getActiveTableProvider().getTables().isEmpty()) {
-                return true;
-            }
-
-            for (Map.Entry<String, StoreableTable> a : dbConnector.getActiveTableProvider().getTables().entrySet()) {
-                out.println(a.getKey() + " " + a.getValue().size());
-            }
-        } finally {
-            lock.readLock().unlock();
+        if (dbConnector.getTables().isEmpty() && dbConnector.getActiveTableProvider().getTables().isEmpty()) {
+            return true;
+        }
+
+        for (Map.Entry<String, StoreableTable> a : dbConnector.getActiveTableProvider().getTables().entrySet()) {
+            out.println(a.getKey() + " " + a.getValue().size());
         }
         return true;
     }
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Size.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Size.java
index d9f44b566..7e23374d5 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Size.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Size.java
@@ -3,7 +3,6 @@
 import ru.fizteh.fivt.students.Kudriavtsev_Dmitry.Proxy.Welcome;
 
 import java.io.PrintStream;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
  * Created by Дмитрий on 31.10.2014.
@@ -19,17 +18,11 @@ public boolean exec(Welcome dbConnector, String[] args, PrintStream out, PrintSt
             return !batchModeInInteractive;
         }
         int size = 0;
-        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-        lock.readLock().lock();
-        try {
-            for (String s : dbConnector.getTables().keySet()) {
-                size += dbConnector.getTables().get(s).size();
-            }
-            for (String s : dbConnector.getActiveTableProvider().getTables().keySet()) {
-                size += dbConnector.getActiveTableProvider().getTables().get(s).size();
-            }
-        } finally {
-            lock.readLock().unlock();
+        for (String s : dbConnector.getTables().keySet()) {
+            size += dbConnector.getTables().get(s).size();
+        }
+        for (String s : dbConnector.getActiveTableProvider().getTables().keySet()) {
+            size += dbConnector.getActiveTableProvider().getTables().get(s).size();
         }
         out.println(size);
         return true;
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Use.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Use.java
index c8a83740a..749bce4cf 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Use.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Commands/Use.java
@@ -4,7 +4,6 @@
 import ru.fizteh.fivt.students.Kudriavtsev_Dmitry.Proxy.Welcome;
 
 import java.io.PrintStream;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
  * Created by Дмитрий on 07.10.14.
@@ -20,49 +19,43 @@ public boolean exec(Welcome dbConnector, String[] args, PrintStream out, PrintSt
         if (!checkArguments(args.length, err)) {
             return !batchModeInInteractive;
         }
-        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-        lock.readLock().lock();
-        try {
-            if (dbConnector.getActiveTable() != null) {
-                if (!dbConnector.getActiveTable().getRemoved().isEmpty()
-                        || !dbConnector.getActiveTable().getNewKey().isEmpty()) {
-                    int count = 0;
-                    for (String s : dbConnector.getActiveTable().getRemoved().keySet()) {
-                        if (dbConnector.getActiveTable().getActiveTable().containsKey(s)) {
-                            ++count;
-                        }
+        if (dbConnector.getActiveTable() != null) {
+            if (!dbConnector.getActiveTable().getRemoved().isEmpty()
+                    || !dbConnector.getActiveTable().getNewKey().isEmpty()) {
+                int count = 0;
+                for (String s : dbConnector.getActiveTable().getRemoved().keySet()) {
+                    if (dbConnector.getActiveTable().getActiveTable().containsKey(s)) {
+                        ++count;
                     }
-                    count += dbConnector.getActiveTable().getNewKey().size();
-                    out.println(count + " unsaved changes");
-                    return true;
                 }
+                count += dbConnector.getActiveTable().getNewKey().size();
+                out.println(count + " unsaved changes");
+                return true;
             }
-            StoreableTable map = dbConnector.getActiveTableProvider().getTables().get(args[0]);
-            if (map == null) {
-                map = dbConnector.getTables().get(args[0]);
+        }
+        StoreableTable map = dbConnector.getActiveTableProvider().getTables().get(args[0]);
+        if (map == null) {
+            map = dbConnector.getTables().get(args[0]);
+        }
+        if (map == null) {
+            err.println(args[0] + " not exists");
+            if (batchModeInInteractive) {
+                return false;
             }
-            if (map == null) {
-                err.println(args[0] + " not exists");
-                if (batchModeInInteractive) {
-                    return false;
-                }
-                if (batchMode) {
-                    System.exit(-1);
-                }
-                return true;
+            if (batchMode) {
+                System.exit(-1);
             }
-            if (dbConnector.getActiveTable() != null) {
-                dbConnector.getActiveTable().unload(
-                    dbConnector.getActiveTable(), dbConnector.getActiveTable().getName());
-                if (dbConnector.getActiveTable().dbPath.getFileName().toString().equals(args[0])) {
-                    out.println("using " + args[0]);
-                    return true;
-                }
+            return true;
+        }
+        if (dbConnector.getActiveTable() != null) {
+            dbConnector.getActiveTable().unload(
+                dbConnector.getActiveTable(), dbConnector.getActiveTable().getName());
+            if (dbConnector.getActiveTable().dbPath.getFileName().toString().equals(args[0])) {
+                out.println("using " + args[0]);
+                return true;
             }
-            dbConnector.setActiveTable(map);
-        } finally {
-            lock.readLock().unlock();
         }
+        dbConnector.setActiveTable(map);
         out.println("using " + args[0]);
         return true;
     }
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Interpreter.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Interpreter.java
index 3888dede4..877e24789 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Interpreter.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Interpreter.java
@@ -3,6 +3,7 @@
 import java.io.InputStream;
 import java.io.PrintStream;
 import java.util.Scanner;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
  * Created by ВАНЯ on 19.12.2014.
@@ -12,6 +13,7 @@ public class Interpreter {
     private final InputStream in;
     private final PrintStream out;
     private final PrintStream err;
+    private ReentrantReadWriteLock lock;
 
     public Interpreter(Welcome mainClass, InputStream in, PrintStream out, PrintStream err) {
         if (in == null || out == null || err == null) {
@@ -21,6 +23,7 @@ public Interpreter(Welcome mainClass, InputStream in, PrintStream out, PrintStre
         this.in = in;
         this.out = out;
         this.err = err;
+        lock = new ReentrantReadWriteLock();
     }
 
     private boolean exitWarning() {
@@ -140,11 +143,10 @@ public boolean run(String name, String[] args, boolean batchMode, boolean batchM
         Command command = mainClass.commands.get(name);
         command.batchMode = batchMode;
         command.batchModeInInteractive = batchModeInInteractive;
-        if (command != null) {
-            if (!command.exec(mainClass, args, out, err)) {
-                return false;
-            }
-        } else if (!args[0].equals("")) {
+        if (!command.exec(mainClass, args, out, err)) {
+            return false;
+        }
+        else if (!args[0].equals("")) {
             err.println(args[0] + " : command not found");
             return false;
         }
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Main.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Main.java
index 2d1a050cb..a3f4c1c6b 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Main.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Main.java
@@ -7,6 +7,7 @@
 /**
  * Created by ВАНЯ on 19.12.2014.
  */
+
 public class Main {
     public static void main(String[] args) {
         Path dbPath;
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/MyLoggingProxy.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/MyLoggingProxy.java
index 28e615534..198e1407c 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/MyLoggingProxy.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/MyLoggingProxy.java
@@ -95,7 +95,7 @@ private void putReturnValue(JSONObject jsonObj, Method method, Object res)
                 jsonObj.put("returnValue", arr);
             } else {
                 if (res == null) {
-                    jsonObj.put("returnValue", JSONObject.NULL);
+                    jsonObj.put("returnValue", "void");
                 } else {
                     jsonObj.put("returnValue", res);
                 }
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/StoreableTable.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/StoreableTable.java
index b33ed1970..29527b9aa 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/StoreableTable.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/StoreableTable.java
@@ -100,7 +100,12 @@ public StoreableTable(final StoreableTableProvider newProvider, final String dbN
         signature = newSignature;
         provider = newProvider;
         types = provider.getRevClassNames();
-        readDb();
+        lock.readLock().lock();
+        try {
+            readDb();
+        } finally {
+            lock.readLock().unlock();
+        }
     }
 
     public void readDb() {
@@ -292,7 +297,7 @@ public List<String> list() {
     @Override
     public int commit() {
         checkClosed();
-        lock.readLock().lock();
+        lock.writeLock().lock();
         try {
             removed.get().keySet().forEach(activeTable.get()::remove);
             for (Map.Entry<String, Storeable> entry : newKey.get().entrySet()) {
@@ -301,7 +306,7 @@ public int commit() {
             unload(this, getName());
             return remindChanges(true);
         } finally {
-            lock.readLock().unlock();
+            lock.writeLock().unlock();
         }
     }
 
@@ -354,14 +359,11 @@ private Path nameOfPath(String nameOfTable, int directory) {
         return dbPath.resolve(nameOfTable + File.separator + directory + FORMATOFDIRECTORY + File.separator);
     }
 
-    public AbstractMap.SimpleEntry<String, AbstractMap.SimpleEntry<Integer, Integer>>
-                                            whereToSave(final String nameOfTable, final String value) {
+    public Triple<String, Integer, Integer> whereToSave(final String nameOfTable, final String value) {
         int hashCode = value.hashCode();
-        int d = hashCode % DIRECTORIES_COUNT;
-        int f = hashCode / DIRECTORIES_COUNT % FILES_COUNT;
-        return new AbstractMap.SimpleEntry<>(
-                nameOfPath(nameOfTable, d, f).toString(),
-                new AbstractMap.SimpleEntry<>(d, f));
+        int directory = hashCode % DIRECTORIES_COUNT;
+        int file = hashCode / DIRECTORIES_COUNT % FILES_COUNT;
+        return new Triple<>(nameOfPath(nameOfTable, directory, file).toString(), directory, file);
     }
 
     public void deleteFiles(final String nameOfTable, final boolean all)
@@ -400,11 +402,10 @@ public void unload(final StoreableTable currentTable, final String nameOfTable)
                 Files.createDirectory(dbPath);
             }
             for (Map.Entry<String, Storeable> entry :  currentTable.activeTable.get().entrySet()) {
-                AbstractMap.SimpleEntry<String, AbstractMap.SimpleEntry<Integer, Integer>> pathOfFile =
-                        whereToSave("", entry.getKey());
-                if (changedFiles.get().containsKey(pathOfFile.getKey())) {
-                    int d = pathOfFile.getValue().getKey();
-                    int f = pathOfFile.getValue().getValue();
+                Triple<String, Integer, Integer> pathOfFile = whereToSave("", entry.getKey());
+                if (changedFiles.get().containsKey(pathOfFile.path)) {
+                    int d = pathOfFile.directory;
+                    int f = pathOfFile.file;
                     if (streams[d][f] == null) {
                         if (!dir[d]) {
                             if (!Files.exists(nameOfPath("", d))) {
@@ -416,12 +417,12 @@ public void unload(final StoreableTable currentTable, final String nameOfTable)
                                 nameOfPath("", d, f)));
                     }
                     writeToFile(streams[d][f], entry.getKey(), entry.getValue());
-                    Integer collisionCount = changedFiles.get().get(pathOfFile.getKey());
+                    Integer collisionCount = changedFiles.get().get(pathOfFile.path);
                     if (collisionCount > 0) {
                         --collisionCount;
-                        changedFiles.get().put(pathOfFile.getKey(), collisionCount);
+                        changedFiles.get().put(pathOfFile.path, collisionCount);
                     } else {
-                        changedFiles.get().remove(pathOfFile.getKey());
+                        changedFiles.get().remove(pathOfFile.path);
                     }
                 }
             }
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/StoreableTableProvider.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/StoreableTableProvider.java
index 2a6552fef..b92569f12 100644
--- a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/StoreableTableProvider.java
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/StoreableTableProvider.java
@@ -125,7 +125,12 @@ public StoreableTable getTable(final String name)
             throws IllegalArgumentException {
         checkClosed();
         checkTableName(name);
-        return tables.get(name);
+        lock.readLock().lock();
+        try {
+            return tables.get(name);
+        } finally {
+            lock.readLock().unlock();
+        }
     }
 
     @Override
@@ -137,7 +142,7 @@ public StoreableTable createTable(final String name, final List<Class<?>> column
             throw new IllegalArgumentException("Type can't be null");
         }
 
-        lock.readLock().lock();
+        lock.writeLock().lock();
         try {
             try {
                 new CurrentStoreable(columnTypes);
@@ -163,7 +168,7 @@ public StoreableTable createTable(final String name, final List<Class<?>> column
             tables.put(name, table);
             return table;
         } finally {
-            lock.readLock().unlock();
+            lock.writeLock().unlock();
         }
     }
 
@@ -174,7 +179,7 @@ public void removeTable(final String name)
         checkTableName(name);
         String directory = dbDirectory + File.separator + name;
         File tableDirectory = new File(directory);
-        lock.readLock().lock();
+        lock.writeLock().lock();
         try {
             if (!tableDirectory.exists() || !tables.containsKey(name)) {
                 throw new IllegalArgumentException("table doesn't exist");
@@ -182,7 +187,7 @@ public void removeTable(final String name)
             StoreableTable table = tables.remove(name);
             table.deleteFiles(name, true);
         } finally {
-            lock.readLock().unlock();
+            lock.writeLock().unlock();
         }
     }
 
diff --git a/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Triple.java b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Triple.java
new file mode 100644
index 000000000..36fb08abf
--- /dev/null
+++ b/src/ru/fizteh/fivt/students/Kudriavtsev_Dmitry/Proxy/Triple.java
@@ -0,0 +1,15 @@
+package ru.fizteh.fivt.students.Kudriavtsev_Dmitry.Proxy;
+
+/**
+ * Created by Дмитрий on 25.12.2014.
+ */
+public class Triple<T1, T2, T3> {
+    public T1 path;
+    public T2 directory;
+    public T3 file;
+    public Triple(T1 path, T2 directory, T3 file) {
+        this.path = path;
+        this.directory = directory;
+        this.file = file;
+    }
+}