# HG changeset patch
# User Chris Seaton <chris.seaton@oracle.com>
# Date 1386950010 0
# Node ID f28ea693056f39037245424d9c5a2a3d331eae36
# Parent  e585ac5a385d9a07722f78e1aa18faf4888ba9b5
New assumption utilities.

diff -r e585ac5a385d -r f28ea693056f graal/com.oracle.truffle.api.test/src/com/oracle/truffle/api/test/utilities/AlwaysValidAssumptionTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api.test/src/com/oracle/truffle/api/test/utilities/AlwaysValidAssumptionTest.java	Fri Dec 13 15:53:30 2013 +0000
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.api.test.utilities;
+
+import static org.junit.Assert.*;
+import org.junit.*;
+
+import com.oracle.truffle.api.nodes.*;
+import com.oracle.truffle.api.utilities.*;
+
+public class AlwaysValidAssumptionTest {
+
+    @Test
+    public void testCheck() throws InvalidAssumptionException {
+        final AlwaysValidAssumption assumption = new AlwaysValidAssumption();
+        assumption.check();
+    }
+
+    @Test
+    public void testIsValid() {
+        final AlwaysValidAssumption assumption = new AlwaysValidAssumption();
+        assertTrue(assumption.isValid());
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void testCannotInvalidate() {
+        final AlwaysValidAssumption assumption = new AlwaysValidAssumption();
+        assumption.invalidate();
+    }
+
+}
diff -r e585ac5a385d -r f28ea693056f graal/com.oracle.truffle.api.test/src/com/oracle/truffle/api/test/utilities/AssumedValueTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api.test/src/com/oracle/truffle/api/test/utilities/AssumedValueTest.java	Fri Dec 13 15:53:30 2013 +0000
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.api.test.utilities;
+
+import static org.junit.Assert.*;
+import org.junit.*;
+
+import com.oracle.truffle.api.utilities.*;
+
+public class AssumedValueTest {
+
+    @Test
+    public void testGet() {
+        final AssumedValue<String> assumedValue = new AssumedValue<>("assumed-value", "1");
+        assertEquals("1", assumedValue.get());
+    }
+
+    @Test
+    public void testSet() {
+        final AssumedValue<String> assumedValue = new AssumedValue<>("assumed-value", "1");
+        assertEquals("1", assumedValue.get());
+        assumedValue.set("2");
+        assertEquals("2", assumedValue.get());
+    }
+
+}
diff -r e585ac5a385d -r f28ea693056f graal/com.oracle.truffle.api.test/src/com/oracle/truffle/api/test/utilities/CyclicAssumptionTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api.test/src/com/oracle/truffle/api/test/utilities/CyclicAssumptionTest.java	Fri Dec 13 15:53:30 2013 +0000
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.api.test.utilities;
+
+import static org.junit.Assert.*;
+
+import org.junit.*;
+
+import com.oracle.truffle.api.*;
+import com.oracle.truffle.api.utilities.*;
+
+public class CyclicAssumptionTest {
+
+    @Test
+    public void testIsValid() {
+        final CyclicAssumption assumption = new CyclicAssumption("cyclic-assumption");
+        assertTrue(assumption.getAssumption().isValid());
+    }
+
+    @Test
+    public void testInvalidate() {
+        final CyclicAssumption cyclicAssumption = new CyclicAssumption("cyclic-assumption");
+
+        final Assumption firstAssumption = cyclicAssumption.getAssumption();
+        assertEquals("cyclic-assumption", firstAssumption.getName());
+        assertTrue(firstAssumption.isValid());
+
+        cyclicAssumption.invalidate();
+
+        assertFalse(firstAssumption.isValid());
+
+        final Assumption secondAssumption = cyclicAssumption.getAssumption();
+        assertEquals("cyclic-assumption", secondAssumption.getName());
+        assertTrue(secondAssumption.isValid());
+
+        cyclicAssumption.invalidate();
+
+        assertFalse(firstAssumption.isValid());
+        assertFalse(secondAssumption.isValid());
+    }
+
+}
diff -r e585ac5a385d -r f28ea693056f graal/com.oracle.truffle.api.test/src/com/oracle/truffle/api/test/utilities/UnionAssumptionTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api.test/src/com/oracle/truffle/api/test/utilities/UnionAssumptionTest.java	Fri Dec 13 15:53:30 2013 +0000
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.api.test.utilities;
+
+import static org.junit.Assert.*;
+
+import org.junit.*;
+
+import com.oracle.truffle.api.*;
+import com.oracle.truffle.api.nodes.*;
+import com.oracle.truffle.api.utilities.*;
+
+public class UnionAssumptionTest {
+
+    @Test
+    public void testIsValid() {
+        final Assumption first = Truffle.getRuntime().createAssumption("first");
+        final Assumption second = Truffle.getRuntime().createAssumption("second");
+        final UnionAssumption union = new UnionAssumption(first, second);
+        assertTrue(union.isValid());
+    }
+
+    @Test
+    public void testCheck() throws InvalidAssumptionException {
+        final Assumption first = Truffle.getRuntime().createAssumption("first");
+        final Assumption second = Truffle.getRuntime().createAssumption("second");
+        final UnionAssumption union = new UnionAssumption(first, second);
+        union.check();
+    }
+
+    @Test
+    public void testFirstInvalidateIsValid() {
+        final Assumption first = Truffle.getRuntime().createAssumption("first");
+        final Assumption second = Truffle.getRuntime().createAssumption("second");
+        final UnionAssumption union = new UnionAssumption(first, second);
+
+        first.invalidate();
+
+        assertFalse(union.isValid());
+    }
+
+    @Test(expected = InvalidAssumptionException.class)
+    public void testFirstInvalidateCheck() throws InvalidAssumptionException {
+        final Assumption first = Truffle.getRuntime().createAssumption("first");
+        final Assumption second = Truffle.getRuntime().createAssumption("second");
+        final UnionAssumption union = new UnionAssumption(first, second);
+
+        first.invalidate();
+
+        union.check();
+    }
+
+    @Test
+    public void testSecondInvalidateIsValid() {
+        final Assumption first = Truffle.getRuntime().createAssumption("first");
+        final Assumption second = Truffle.getRuntime().createAssumption("second");
+        final UnionAssumption union = new UnionAssumption(first, second);
+
+        second.invalidate();
+
+        assertFalse(union.isValid());
+    }
+
+    @Test(expected = InvalidAssumptionException.class)
+    public void testSecondInvalidateCheck() throws InvalidAssumptionException {
+        final Assumption first = Truffle.getRuntime().createAssumption("first");
+        final Assumption second = Truffle.getRuntime().createAssumption("second");
+        final UnionAssumption union = new UnionAssumption(first, second);
+
+        second.invalidate();
+
+        union.check();
+    }
+
+    @Test
+    public void testBothInvalidateIsValid() {
+        final Assumption first = Truffle.getRuntime().createAssumption("first");
+        final Assumption second = Truffle.getRuntime().createAssumption("second");
+        final UnionAssumption union = new UnionAssumption(first, second);
+
+        first.invalidate();
+        second.invalidate();
+
+        assertFalse(union.isValid());
+    }
+
+    @Test(expected = InvalidAssumptionException.class)
+    public void testBothInvalidateCheck() throws InvalidAssumptionException {
+        final Assumption first = Truffle.getRuntime().createAssumption("first");
+        final Assumption second = Truffle.getRuntime().createAssumption("second");
+        final UnionAssumption union = new UnionAssumption(first, second);
+
+        first.invalidate();
+        second.invalidate();
+
+        union.check();
+    }
+
+}
diff -r e585ac5a385d -r f28ea693056f graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/AlwaysValidAssumption.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/AlwaysValidAssumption.java	Fri Dec 13 15:53:30 2013 +0000
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.api.utilities;
+
+import com.oracle.truffle.api.*;
+import com.oracle.truffle.api.nodes.*;
+
+/**
+ * An assumption that is always valid. Used as a placeholder where an assumption is needed but never
+ * invalidated.
+ */
+public class AlwaysValidAssumption implements Assumption {
+
+    public static final AlwaysValidAssumption INSTANCE = new AlwaysValidAssumption();
+
+    @Override
+    public void check() throws InvalidAssumptionException {
+    }
+
+    @Override
+    public void invalidate() {
+        throw new UnsupportedOperationException("Cannot invalidation this assumption - it is always valid");
+    }
+
+    @Override
+    public String getName() {
+        return getClass().getName();
+    }
+
+    @Override
+    public boolean isValid() {
+        return true;
+    }
+
+}
diff -r e585ac5a385d -r f28ea693056f graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/AssumedValue.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/AssumedValue.java	Fri Dec 13 15:53:30 2013 +0000
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.api.utilities;
+
+import com.oracle.truffle.api.*;
+import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
+import com.oracle.truffle.api.nodes.*;
+
+/**
+ * A {@link CompilationFinal} value combined with an {@link Assumption} to notify when it changes.
+ * Note that you should be careful that modifications to this value do not cause deoptimization
+ * loops. This could be by using a value that is monotonic.
+ */
+public class AssumedValue<T> {
+
+    @CompilationFinal private T value;
+    private final CyclicAssumption assumption;
+
+    public AssumedValue(String name, T initialValue) {
+        assumption = new CyclicAssumption(name);
+        value = initialValue;
+    }
+
+    /**
+     * Get the current value, updating it if it has been {@link #set}. The compiler may be able to
+     * make this method return a constant value, but still accommodate mutation.
+     */
+    public T get() {
+        try {
+            assumption.getAssumption().check();
+        } catch (InvalidAssumptionException e) {
+            // No need to rewrite anything - just pick up the new value
+        }
+
+        return value;
+    }
+
+    /**
+     * Set a new value, which will be picked up the next time {@link #get} is called.
+     */
+    public void set(T newValue) {
+        value = newValue;
+        assumption.invalidate();
+    }
+
+}
diff -r e585ac5a385d -r f28ea693056f graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/CyclicAssumption.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/CyclicAssumption.java	Fri Dec 13 15:53:30 2013 +0000
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.api.utilities;
+
+import com.oracle.truffle.api.*;
+
+/**
+ * Holds an {@link Assumption}, and knows how to recreate it with the same properties on
+ * invalidation. Used so that mutability is isolated in this class, and all other classes that need
+ * an assumption that may be recreated can have a final reference to an object of this class. Note
+ * that you should be careful that repeated invalidations do not cause a deoptimization loop in that
+ * same way that you would with any other assumption.
+ */
+public class CyclicAssumption {
+
+    private final String name;
+    private Assumption assumption;
+
+    public CyclicAssumption(String name) {
+        this.name = name;
+        invalidate();
+    }
+
+    public void invalidate() {
+        if (assumption != null) {
+            assumption.invalidate();
+        }
+
+        assumption = Truffle.getRuntime().createAssumption(name);
+    }
+
+    public Assumption getAssumption() {
+        return assumption;
+    }
+
+}
diff -r e585ac5a385d -r f28ea693056f graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/UnionAssumption.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/UnionAssumption.java	Fri Dec 13 15:53:30 2013 +0000
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.api.utilities;
+
+import com.oracle.truffle.api.*;
+import com.oracle.truffle.api.nodes.*;
+
+/**
+ * An assumption that combines two other assumptions. A check on this assumption checks both of the
+ * child assumptions.
+ */
+public class UnionAssumption implements Assumption {
+
+    private final String name;
+    private final Assumption first;
+    private final Assumption second;
+
+    public UnionAssumption(String name, Assumption first, Assumption second) {
+        this.name = name;
+        this.first = first;
+        this.second = second;
+    }
+
+    public UnionAssumption(Assumption first, Assumption second) {
+        this(null, first, second);
+    }
+
+    @Override
+    public void check() throws InvalidAssumptionException {
+        first.check();
+        second.check();
+    }
+
+    @Override
+    public void invalidate() {
+        first.invalidate();
+        second.invalidate();
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public boolean isValid() {
+        return first.isValid() && second.isValid();
+    }
+
+}