Revert "Revert "JVMTI Exception and ExceptionCatch events""

Fixed error where we were incorrectly not updating a ShadowFrame
dex_pc causing deoptimization errors.

Bug: 62821960
Bug: 65049545

Test: ./test.py --host -j50
Test: ./art/tools/run-libcore-tests.sh \
            --mode=host --variant-X32 --debug

This reverts commit 959742483885779f106e000df6dd422fc8657931.

Change-Id: I91ab2bc3e645ddf0359c189b19a59a3ecf0d8921
diff --git a/test/1929-exception-catch-exception/src/Main.java b/test/1929-exception-catch-exception/src/Main.java
new file mode 100644
index 0000000..4651bac
--- /dev/null
+++ b/test/1929-exception-catch-exception/src/Main.java
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+public class Main {
+  public static void main(String[] args) throws Exception {
+    art.Test1929.run();
+  }
+}
diff --git a/test/1929-exception-catch-exception/src/art/Breakpoint.java b/test/1929-exception-catch-exception/src/art/Breakpoint.java
new file mode 100644
index 0000000..bbb89f7
--- /dev/null
+++ b/test/1929-exception-catch-exception/src/art/Breakpoint.java
@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package art;
+
+import java.lang.reflect.Executable;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.Objects;
+
+public class Breakpoint {
+  public static class Manager {
+    public static class BP {
+      public final Executable method;
+      public final long location;
+
+      public BP(Executable method) {
+        this(method, getStartLocation(method));
+      }
+
+      public BP(Executable method, long location) {
+        this.method = method;
+        this.location = location;
+      }
+
+      @Override
+      public boolean equals(Object other) {
+        return (other instanceof BP) &&
+            method.equals(((BP)other).method) &&
+            location == ((BP)other).location;
+      }
+
+      @Override
+      public String toString() {
+        return method.toString() + " @ " + getLine();
+      }
+
+      @Override
+      public int hashCode() {
+        return Objects.hash(method, location);
+      }
+
+      public int getLine() {
+        try {
+          LineNumber[] lines = getLineNumberTable(method);
+          int best = -1;
+          for (LineNumber l : lines) {
+            if (l.location > location) {
+              break;
+            } else {
+              best = l.line;
+            }
+          }
+          return best;
+        } catch (Exception e) {
+          return -1;
+        }
+      }
+    }
+
+    private Set<BP> breaks = new HashSet<>();
+
+    public void setBreakpoints(BP... bs) {
+      for (BP b : bs) {
+        if (breaks.add(b)) {
+          Breakpoint.setBreakpoint(b.method, b.location);
+        }
+      }
+    }
+    public void setBreakpoint(Executable method, long location) {
+      setBreakpoints(new BP(method, location));
+    }
+
+    public void clearBreakpoints(BP... bs) {
+      for (BP b : bs) {
+        if (breaks.remove(b)) {
+          Breakpoint.clearBreakpoint(b.method, b.location);
+        }
+      }
+    }
+    public void clearBreakpoint(Executable method, long location) {
+      clearBreakpoints(new BP(method, location));
+    }
+
+    public void clearAllBreakpoints() {
+      clearBreakpoints(breaks.toArray(new BP[0]));
+    }
+  }
+
+  public static void startBreakpointWatch(Class<?> methodClass,
+                                          Executable breakpointReached,
+                                          Thread thr) {
+    startBreakpointWatch(methodClass, breakpointReached, false, thr);
+  }
+
+  /**
+   * Enables the trapping of breakpoint events.
+   *
+   * If allowRecursive == true then breakpoints will be sent even if one is currently being handled.
+   */
+  public static native void startBreakpointWatch(Class<?> methodClass,
+                                                 Executable breakpointReached,
+                                                 boolean allowRecursive,
+                                                 Thread thr);
+  public static native void stopBreakpointWatch(Thread thr);
+
+  public static final class LineNumber implements Comparable<LineNumber> {
+    public final long location;
+    public final int line;
+
+    private LineNumber(long loc, int line) {
+      this.location = loc;
+      this.line = line;
+    }
+
+    public boolean equals(Object other) {
+      return other instanceof LineNumber && ((LineNumber)other).line == line &&
+          ((LineNumber)other).location == location;
+    }
+
+    public int compareTo(LineNumber other) {
+      int v = Integer.valueOf(line).compareTo(Integer.valueOf(other.line));
+      if (v != 0) {
+        return v;
+      } else {
+        return Long.valueOf(location).compareTo(Long.valueOf(other.location));
+      }
+    }
+  }
+
+  public static native void setBreakpoint(Executable m, long loc);
+  public static void setBreakpoint(Executable m, LineNumber l) {
+    setBreakpoint(m, l.location);
+  }
+
+  public static native void clearBreakpoint(Executable m, long loc);
+  public static void clearBreakpoint(Executable m, LineNumber l) {
+    clearBreakpoint(m, l.location);
+  }
+
+  private static native Object[] getLineNumberTableNative(Executable m);
+  public static LineNumber[] getLineNumberTable(Executable m) {
+    Object[] nativeTable = getLineNumberTableNative(m);
+    long[] location = (long[])(nativeTable[0]);
+    int[] lines = (int[])(nativeTable[1]);
+    if (lines.length != location.length) {
+      throw new Error("Lines and locations have different lengths!");
+    }
+    LineNumber[] out = new LineNumber[lines.length];
+    for (int i = 0; i < lines.length; i++) {
+      out[i] = new LineNumber(location[i], lines[i]);
+    }
+    return out;
+  }
+
+  public static native long getStartLocation(Executable m);
+
+  public static int locationToLine(Executable m, long location) {
+    try {
+      Breakpoint.LineNumber[] lines = Breakpoint.getLineNumberTable(m);
+      int best = -1;
+      for (Breakpoint.LineNumber l : lines) {
+        if (l.location > location) {
+          break;
+        } else {
+          best = l.line;
+        }
+      }
+      return best;
+    } catch (Exception e) {
+      return -1;
+    }
+  }
+
+  public static long lineToLocation(Executable m, int line) throws Exception {
+    try {
+      Breakpoint.LineNumber[] lines = Breakpoint.getLineNumberTable(m);
+      for (Breakpoint.LineNumber l : lines) {
+        if (l.line == line) {
+          return l.location;
+        }
+      }
+      throw new Exception("Unable to find line " + line + " in " + m);
+    } catch (Exception e) {
+      throw new Exception("Unable to get line number info for " + m, e);
+    }
+  }
+}
+
diff --git a/test/1929-exception-catch-exception/src/art/Exceptions.java b/test/1929-exception-catch-exception/src/art/Exceptions.java
new file mode 100644
index 0000000..2c959ec
--- /dev/null
+++ b/test/1929-exception-catch-exception/src/art/Exceptions.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package art;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
+public class Exceptions {
+  public static native void setupExceptionTracing(
+      Class<?> methodClass,
+      Class<?> exceptionClass,
+      Method exceptionEventMethod,
+      Method exceptionCaughtEventMethod);
+
+  public static native void enableExceptionCatchEvent(Thread thr);
+  public static native void enableExceptionEvent(Thread thr);
+  public static native void disableExceptionCatchEvent(Thread thr);
+  public static native void disableExceptionEvent(Thread thr);
+}
diff --git a/test/1929-exception-catch-exception/src/art/StackTrace.java b/test/1929-exception-catch-exception/src/art/StackTrace.java
new file mode 100644
index 0000000..b12c3df
--- /dev/null
+++ b/test/1929-exception-catch-exception/src/art/StackTrace.java
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package art;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Executable;
+
+public class StackTrace {
+  public static class StackFrameData {
+    public final Thread thr;
+    public final Executable method;
+    public final long current_location;
+    public final int depth;
+
+    public StackFrameData(Thread thr, Executable e, long loc, int depth) {
+      this.thr = thr;
+      this.method = e;
+      this.current_location = loc;
+      this.depth = depth;
+    }
+    @Override
+    public String toString() {
+      return String.format(
+          "StackFrameData { thr: '%s', method: '%s', loc: %d, depth: %d }",
+          this.thr,
+          this.method,
+          this.current_location,
+          this.depth);
+    }
+  }
+
+  public static native int GetStackDepth(Thread thr);
+
+  private static native StackFrameData[] nativeGetStackTrace(Thread thr);
+
+  public static StackFrameData[] GetStackTrace(Thread thr) {
+    // The RI seems to give inconsistent (and sometimes nonsensical) results if the thread is not
+    // suspended. The spec says that not being suspended is fine but since we want this to be
+    // consistent we will suspend for the RI.
+    boolean suspend_thread =
+        !System.getProperty("java.vm.name").equals("Dalvik") &&
+        !thr.equals(Thread.currentThread());
+    if (suspend_thread) {
+      Suspension.suspend(thr);
+    }
+    StackFrameData[] out = nativeGetStackTrace(thr);
+    if (suspend_thread) {
+      Suspension.resume(thr);
+    }
+    return out;
+  }
+}
+
diff --git a/test/1929-exception-catch-exception/src/art/Suspension.java b/test/1929-exception-catch-exception/src/art/Suspension.java
new file mode 100644
index 0000000..16e62cc
--- /dev/null
+++ b/test/1929-exception-catch-exception/src/art/Suspension.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package art;
+
+public class Suspension {
+  // Suspends a thread using jvmti.
+  public native static void suspend(Thread thr);
+
+  // Resumes a thread using jvmti.
+  public native static void resume(Thread thr);
+
+  public native static boolean isSuspended(Thread thr);
+
+  public native static int[] suspendList(Thread... threads);
+  public native static int[] resumeList(Thread... threads);
+}
diff --git a/test/1929-exception-catch-exception/src/art/Test1929.java b/test/1929-exception-catch-exception/src/art/Test1929.java
new file mode 100644
index 0000000..07d2087
--- /dev/null
+++ b/test/1929-exception-catch-exception/src/art/Test1929.java
@@ -0,0 +1,300 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package art;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Objects;
+import java.lang.reflect.Executable;
+import java.lang.reflect.Method;
+
+public class Test1929 {
+  public static boolean PRINT_FULL_EXCEPTION = false;
+  public static ExceptionHandler HANDLER = null;
+  public static Collection<Executable> TEST_METHODS;
+
+  public static void doNothing() {};
+  static {
+    try {
+      TEST_METHODS = Arrays.asList(
+        Test1929.class.getDeclaredMethod("doThrow"),
+        Test1929.class.getDeclaredMethod("throwCatchBaseTestException"),
+        Test1929.class.getDeclaredMethod("throwCatchBaseTestExceptionTwice"),
+        Test1929.class.getDeclaredMethod("throwCatchTestException"),
+        Test1929.class.getDeclaredMethod("throwCatchTestExceptionTwice"),
+        Test1929.class.getDeclaredMethod("throwCatchTestExceptionNoRethrow"));
+    } catch (Exception e) {
+      throw new Error("Unable to list test methods!", e);
+    }
+  }
+
+  public static interface ExceptionHandler {
+    public void exceptionOccurred(
+        Executable m, long loc, Throwable exception);
+  }
+
+  private static void PrintStack() {
+    System.out.println("\tCurrent Stack:");
+    for (StackTrace.StackFrameData e : StackTrace.GetStackTrace(Thread.currentThread())) {
+      if (Objects.equals(e.method.getDeclaringClass().getPackage(), Test1929.class.getPackage())) {
+        System.out.println("\t\t" + e.method + " @ line = " +
+            Breakpoint.locationToLine(e.method, e.current_location));
+      }
+    }
+  }
+
+  public static void ExceptionCatchEvent(
+      Thread thr, Executable method, long location, Throwable exception) {
+    System.out.println(thr.getName() + ": " + method + " @ line = " +
+        Breakpoint.locationToLine(method, location) + " caught " +
+        exception.getClass() + ": " + exception.getMessage());
+    PrintStack();
+    if (PRINT_FULL_EXCEPTION) {
+      System.out.print("exception is: ");
+      exception.printStackTrace(System.out);
+    }
+    if (HANDLER != null && TEST_METHODS.contains(method)) {
+      HANDLER.exceptionOccurred(method, location, exception);
+    }
+  }
+
+  public static class BaseTestException extends Error {
+    public BaseTestException(String e) { super(e); }
+    public BaseTestException(String e, Throwable t) { super(e, t); }
+  }
+  public static class TestException extends BaseTestException {
+    public TestException(String e) { super(e); }
+    public TestException(String e, Throwable t) { super(e, t); }
+  }
+
+  public static class TestExceptionNoRethrow extends TestException {
+    public TestExceptionNoRethrow(String e) { super(e); }
+    public TestExceptionNoRethrow(String e, Throwable t) { super(e, t); }
+  }
+
+  public static class DoNothingHandler implements ExceptionHandler {
+    public void exceptionOccurred(Executable m, long loc, Throwable exception) {
+      System.out.println("\tDoing nothing!");
+      return;
+    }
+  }
+
+  public static class ThrowCatchBase implements ExceptionHandler {
+    public void exceptionOccurred(Executable m, long loc, Throwable exception) {
+      System.out.println("\tThrowing BaseTestException and catching it!");
+      try {
+        throw new BaseTestException("ThrowBaseHandler during throw from " + m + " @ line = " +
+            Breakpoint.locationToLine(m, loc), exception);
+      } catch (BaseTestException t) {
+        System.out.println("Caught " + t.getClass().getName() + ": \"" + t.getMessage() + "\"");
+        if (PRINT_FULL_EXCEPTION) {
+          t.printStackTrace(System.out);
+        }
+      }
+    }
+  }
+  public static class ThrowBaseTestExceptionHandler implements ExceptionHandler {
+    public void exceptionOccurred(Executable m, long loc, Throwable exception) {
+      System.out.println("\tThrowing BaseTestException!");
+      throw new BaseTestException("ThrowBaseHandler during throw from " + m + " @ line = " +
+          Breakpoint.locationToLine(m, loc), exception);
+    }
+  }
+
+  public static class ThrowTestExceptionNoRethrowHandler implements ExceptionHandler {
+    public void exceptionOccurred(Executable m, long loc, Throwable exception) {
+      if (exception instanceof TestExceptionNoRethrow) {
+        System.out.println("\tInstance of TestExceptionNoRethrow was thrown. Not throwing again.");
+      } else {
+        System.out.println("\tThrowing TestExceptionNoRethrow!");
+        throw new TestExceptionNoRethrow("ThrowTestExceptionNoRethrowHandler during throw from " +
+            m + " @ line = " + Breakpoint.locationToLine(m, loc), exception);
+      }
+    }
+  }
+  public static void doThrow() {
+    throw new TestException("doThrow");
+  }
+
+  public static class DoThrowClass implements Runnable {
+    public void run() { doThrow(); }
+  }
+
+  public static void throwCatchBaseTestException() {
+    try {
+      throw new TestException("throwCatchBaseTestException");
+    } catch (BaseTestException t) {
+      System.out.println("Caught " + t.getClass().getName() + ": \"" + t.getMessage() + "\"");
+      if (PRINT_FULL_EXCEPTION) {
+        t.printStackTrace(System.out);
+      }
+    }
+  }
+
+  public static class DoThrowCatchBaseTestException implements Runnable {
+    public void run() { throwCatchBaseTestException(); }
+  }
+
+  // dx/d8/jack all do an optimization around catch blocks that (while legal) breaks assumptions
+  // this test relies on so we have the actual implementation be corrected smali. This does work
+  // for RI however.
+  public static final class Impl {
+    private Impl() {}
+    public static void throwCatchBaseTestExceptionTwiceImpl() {
+      try {
+        try {
+          throw new TestException("throwCatchBaseTestExceptionTwice");
+        } catch (BaseTestException t) {
+          System.out.println("Caught " + t.getClass().getName() + ": \"" + t.getMessage() + "\"");
+          if (PRINT_FULL_EXCEPTION) {
+            t.printStackTrace(System.out);
+          }
+        }
+      } catch (BaseTestException t) {
+        System.out.println("2nd Caught " + t.getClass().getName() + ": \"" + t.getMessage() + "\"");
+        if (PRINT_FULL_EXCEPTION) {
+          t.printStackTrace(System.out);
+        }
+      }
+    }
+
+    public static void throwCatchTestExceptionTwiceImpl() {
+      try {
+        try {
+          throw new TestException("throwCatchTestExceptionTwice");
+        } catch (TestException t) {
+          System.out.println("Caught " + t.getClass().getName() + ": \"" + t.getMessage() + "\"");
+          if (PRINT_FULL_EXCEPTION) {
+            t.printStackTrace(System.out);
+          }
+        }
+      } catch (TestException t) {
+        System.out.println("2nd Caught " + t.getClass().getName() + ": \"" + t.getMessage() + "\"");
+        if (PRINT_FULL_EXCEPTION) {
+          t.printStackTrace(System.out);
+        }
+      }
+    }
+  }
+
+  public static void throwCatchBaseTestExceptionTwice() {
+    // The implementation of this has to change depending upon the runtime slightly due to compiler
+    // optimizations present in DX/D8/Jack.
+    Impl.throwCatchBaseTestExceptionTwiceImpl();
+  }
+
+  public static class DoThrowCatchBaseTestExceptionTwice implements Runnable {
+    public void run() { throwCatchBaseTestExceptionTwice(); }
+  }
+
+  public static void throwCatchTestException() {
+    try {
+      throw new TestException("throwCatchTestException");
+    } catch (TestException t) {
+      System.out.println("Caught " + t.getClass().getName() + ": \"" + t.getMessage() + "\"");
+      if (PRINT_FULL_EXCEPTION) {
+        t.printStackTrace(System.out);
+      }
+    }
+  }
+
+  public static class DoThrowCatchTestException implements Runnable {
+    public void run() { throwCatchTestException(); }
+  }
+
+  public static void throwCatchTestExceptionTwice() {
+    // The implementation of this has to change depending upon the runtime slightly due to compiler
+    // optimizations present in DX/D8/Jack.
+    Impl.throwCatchTestExceptionTwiceImpl();
+  }
+
+  public static class DoThrowCatchTestExceptionTwice implements Runnable {
+    public void run() { throwCatchTestExceptionTwice(); }
+  }
+
+  public static void throwCatchTestExceptionNoRethrow() {
+    try {
+      throw new TestException("throwCatchTestExceptionNoRethrow");
+    } catch (TestExceptionNoRethrow t) {
+      System.out.println("Caught " + t.getClass().getName() + ": \"" + t.getMessage() + "\"");
+      if (PRINT_FULL_EXCEPTION) {
+        t.printStackTrace(System.out);
+      }
+    }
+  }
+
+  public static class DoThrowCatchTestExceptionNoRethrow implements Runnable {
+    public void run() { throwCatchTestExceptionNoRethrow(); }
+  }
+
+  public static void run() throws Exception {
+    // Set up breakpoints
+    Exceptions.setupExceptionTracing(
+        Test1929.class,
+        TestException.class,
+        null,
+        Test1929.class.getDeclaredMethod(
+            "ExceptionCatchEvent",
+            Thread.class,
+            Executable.class,
+            Long.TYPE,
+            Throwable.class));
+    Exceptions.enableExceptionCatchEvent(Thread.currentThread());
+
+    ExceptionHandler[] handlers = new ExceptionHandler[] {
+      new DoNothingHandler(),
+      new ThrowCatchBase(),
+      new ThrowBaseTestExceptionHandler(),
+      new ThrowTestExceptionNoRethrowHandler(),
+    };
+
+    Runnable[] tests = new Runnable[] {
+      new DoThrowClass(),
+      new DoThrowCatchBaseTestException(),
+      new DoThrowCatchBaseTestExceptionTwice(),
+      new DoThrowCatchTestException(),
+      new DoThrowCatchTestExceptionTwice(),
+      new DoThrowCatchTestExceptionNoRethrow(),
+    };
+
+    for (ExceptionHandler handler : handlers) {
+      for (Runnable test : tests) {
+        try {
+          HANDLER = handler;
+          System.out.printf("Test \"%s\": Running breakpoint with handler \"%s\"\n",
+              test.getClass().getName(), handler.getClass().getName());
+          test.run();
+          System.out.printf("Test \"%s\": No error caught with handler \"%s\"\n",
+              test.getClass().getName(), handler.getClass().getName());
+        } catch (Throwable e) {
+          System.out.printf("Test \"%s\": Caught error %s:\"%s\" with handler \"%s\"\n",
+              test.getClass().getName(),
+              e.getClass().getName(),
+              e.getMessage(),
+              handler.getClass().getName());
+          if (PRINT_FULL_EXCEPTION) {
+            e.printStackTrace(System.out);
+          }
+        }
+        System.out.printf("Test \"%s\": Finished running with handler \"%s\"\n",
+            test.getClass().getName(), handler.getClass().getName());
+        HANDLER = null;
+      }
+    }
+    Exceptions.disableExceptionCatchEvent(Thread.currentThread());
+  }
+}