Attach a configurable timeout to expression evaluation

EngineHub · Nov 2, 2017 · 56c8399 · 56c8399
1 parent b951ba7
commit 56c8399
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Showing 7 changed files with 54 additions and 3 deletions.
diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/LocalConfiguration.java b/worldedit-core/src/main/java/com/sk89q/worldedit/LocalConfiguration.java
@@ -104,6 +104,7 @@ public abstract class LocalConfiguration {
     public int navigationWand = ItemID.COMPASS;
     public int navigationWandMaxDistance = 50;
     public int scriptTimeout = 3000;
+    public int calculationTimeout = 100;
     public Set<Integer> allowedDataCycleBlocks = new HashSet<Integer>();
     public String saveDir = "schematics";
     public String scriptsDir = "craftscripts";

diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/Expression.java b/worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/Expression.java
@@ -19,6 +19,8 @@
 
 package com.sk89q.worldedit.internal.expression;
 
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import com.sk89q.worldedit.WorldEdit;
 import com.sk89q.worldedit.internal.expression.lexer.Lexer;
 import com.sk89q.worldedit.internal.expression.lexer.tokens.Token;
 import com.sk89q.worldedit.internal.expression.parser.Parser;
@@ -34,6 +36,13 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Stack;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 
 /**
  * Compiles and evaluates expressions.
@@ -69,6 +78,11 @@
 public class Expression {
 
     private static final ThreadLocal<Stack<Expression>> instance = new ThreadLocal<Stack<Expression>>();
+    private static final ExecutorService evalThread = Executors.newCachedThreadPool(
+            new ThreadFactoryBuilder()
+                    .setDaemon(true)
+                    .setNameFormat("worldedit-expression-eval-%d")
+                    .build());
 
     private final Map<String, RValue> variables = new HashMap<String, RValue>();
     private final String[] variableNames;
@@ -115,9 +129,30 @@ public double evaluate(double... values) throws EvaluationException {
 
         pushInstance();
         try {
-            return root.getValue();
-        } catch (ReturnException e) {
-            return e.getValue();
+            Future<Double> result = evalThread.submit(new Callable<Double>() {
+                @Override
+                public Double call() throws Exception {
+                    return root.getValue();
+                }
+            });
+            try {
+                return result.get(WorldEdit.getInstance().getConfiguration().calculationTimeout, TimeUnit.MILLISECONDS);
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                throw new RuntimeException(e);
+            } catch (ExecutionException e) {
+                Throwable cause = e.getCause();
+                if (cause instanceof ReturnException) {
+                    return ((ReturnException) cause).getValue();
+                }
+                if (cause instanceof RuntimeException) {
+                    throw (RuntimeException) cause;
+                }
+                throw new RuntimeException(cause);
+            } catch (TimeoutException e) {
+                result.cancel(true);
+                throw new EvaluationException(-1, "Calculations exceeded time limit.");
+            }
         } finally {
             popInstance();
         }

diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/runtime/For.java b/worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/runtime/For.java
@@ -50,6 +50,9 @@ public double getValue() throws EvaluationException {
             if (iterations > 256) {
                 throw new EvaluationException(getPosition(), "Loop exceeded 256 iterations.");
             }
+            if (Thread.interrupted()) {
+                throw new EvaluationException(getPosition(), "Calculations exceeded time limit.");
+            }
             ++iterations;
 
             try {

diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/runtime/SimpleFor.java b/worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/runtime/SimpleFor.java
@@ -53,6 +53,9 @@ public double getValue() throws EvaluationException {
             if (iterations > 256) {
                 throw new EvaluationException(getPosition(), "Loop exceeded 256 iterations.");
             }
+            if (Thread.interrupted()) {
+                throw new EvaluationException(getPosition(), "Calculations exceeded time limit.");
+            }
             ++iterations;
 
             try {

diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/runtime/While.java b/worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/runtime/While.java
@@ -49,6 +49,9 @@ public double getValue() throws EvaluationException {
                 if (iterations > 256) {
                     throw new EvaluationException(getPosition(), "Loop exceeded 256 iterations.");
                 }
+                if (Thread.interrupted()) {
+                    throw new EvaluationException(getPosition(), "Calculations exceeded time limit.");
+                }
                 ++iterations;
 
                 try {
@@ -66,6 +69,9 @@ public double getValue() throws EvaluationException {
                 if (iterations > 256) {
                     throw new EvaluationException(getPosition(), "Loop exceeded 256 iterations.");
                 }
+                if (Thread.interrupted()) {
+                    throw new EvaluationException(getPosition(), "Calculations exceeded time limit.");
+                }
                 ++iterations;
 
                 try {

diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/util/PropertiesConfiguration.java b/worldedit-core/src/main/java/com/sk89q/worldedit/util/PropertiesConfiguration.java
@@ -107,6 +107,7 @@ public void load() {
         navigationWandMaxDistance = getInt("nav-wand-distance", navigationWandMaxDistance);
         navigationUseGlass = getBool("nav-use-glass", navigationUseGlass);
         scriptTimeout = getInt("scripting-timeout", scriptTimeout);
+        calculationTimeout = getInt("calculation-timeout", calculationTimeout);
         saveDir = getString("schematic-save-dir", saveDir);
         scriptsDir = getString("craftscript-dir", scriptsDir);
         butcherDefaultRadius = getInt("butcher-default-radius", butcherDefaultRadius);

diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/util/YAMLConfiguration.java b/worldedit-core/src/main/java/com/sk89q/worldedit/util/YAMLConfiguration.java
@@ -103,6 +103,8 @@ public void load() {
         scriptTimeout = config.getInt("scripting.timeout", scriptTimeout);
         scriptsDir = config.getString("scripting.dir", scriptsDir);
 
+        calculationTimeout = config.getInt("calculation.timeout", calculationTimeout);
+
         saveDir = config.getString("saving.dir", saveDir);
 
         allowSymlinks = config.getBoolean("files.allow-symbolic-links", false);