Mercurial > hg > graal-compiler
annotate graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/AssumedValue.java @ 17440:935de03661c1
Truffle: clearer comment in AssumedValue.
author | Chris Seaton <chris.seaton@oracle.com> |
---|---|
date | Tue, 14 Oct 2014 15:10:17 +0100 |
parents | 0e7894989f37 |
children |
rev | line source |
---|---|
13325
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
1 /* |
17056
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
2 * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved. |
13325
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
4 * |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
5 * This code is free software; you can redistribute it and/or modify it |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
6 * under the terms of the GNU General Public License version 2 only, as |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
7 * published by the Free Software Foundation. Oracle designates this |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
8 * particular file as subject to the "Classpath" exception as provided |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
9 * by Oracle in the LICENSE file that accompanied this code. |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
10 * |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
11 * This code is distributed in the hope that it will be useful, but WITHOUT |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
14 * version 2 for more details (a copy is included in the LICENSE file that |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
15 * accompanied this code). |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
16 * |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
17 * You should have received a copy of the GNU General Public License version |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
18 * 2 along with this work; if not, write to the Free Software Foundation, |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
20 * |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
22 * or visit www.oracle.com if you need additional information or have any |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
23 * questions. |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
24 */ |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
25 package com.oracle.truffle.api.utilities; |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
26 |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
27 import com.oracle.truffle.api.*; |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
28 import com.oracle.truffle.api.CompilerDirectives.CompilationFinal; |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
29 import com.oracle.truffle.api.nodes.*; |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
30 |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
31 /** |
17440
935de03661c1
Truffle: clearer comment in AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
17056
diff
changeset
|
32 * A value that the compiler can assume is constant, but can be changed by invalidation. |
935de03661c1
Truffle: clearer comment in AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
17056
diff
changeset
|
33 * <p> |
935de03661c1
Truffle: clearer comment in AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
17056
diff
changeset
|
34 * Compiled code that uses the value will be invalidated each time the value changes, so you should |
935de03661c1
Truffle: clearer comment in AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
17056
diff
changeset
|
35 * take care to only change values infrequently, or to monitor the number of times the value has |
935de03661c1
Truffle: clearer comment in AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
17056
diff
changeset
|
36 * changed and at some point to replace the value with something more generic so that it does not |
935de03661c1
Truffle: clearer comment in AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
17056
diff
changeset
|
37 * have to be changed and code does not have to keep being recompiled. |
13325
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
38 */ |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
39 public class AssumedValue<T> { |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
40 |
17056
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
41 private final String name; |
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
42 |
13325
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
43 @CompilationFinal private T value; |
17056
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
44 @CompilationFinal private Assumption assumption; |
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
45 |
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
46 public AssumedValue(T initialValue) { |
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
47 this(null, initialValue); |
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
48 } |
13325
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
49 |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
50 public AssumedValue(String name, T initialValue) { |
17056
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
51 this.name = name; |
13325
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
52 value = initialValue; |
17056
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
53 assumption = Truffle.getRuntime().createAssumption(name); |
13325
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
54 } |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
55 |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
56 /** |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
57 * Get the current value, updating it if it has been {@link #set}. The compiler may be able to |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
58 * make this method return a constant value, but still accommodate mutation. |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
59 */ |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
60 public T get() { |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
61 try { |
17056
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
62 assumption.check(); |
13325
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
63 } catch (InvalidAssumptionException e) { |
17056
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
64 // No need to rewrite anything - just pick up the new values |
13325
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
65 } |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
66 |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
67 return value; |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
68 } |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
69 |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
70 /** |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
71 * Set a new value, which will be picked up the next time {@link #get} is called. |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
72 */ |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
73 public void set(T newValue) { |
17056
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
74 CompilerDirectives.transferToInterpreter(); |
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
75 |
13325
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
76 value = newValue; |
17056
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
77 final Assumption oldAssumption = assumption; |
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
78 assumption = Truffle.getRuntime().createAssumption(name); |
0e7894989f37
Truffle: fix AssumedValue.
Chris Seaton <chris.seaton@oracle.com>
parents:
13325
diff
changeset
|
79 oldAssumption.invalidate(); |
13325
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
80 } |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
81 |
f28ea693056f
New assumption utilities.
Chris Seaton <chris.seaton@oracle.com>
parents:
diff
changeset
|
82 } |