1/*
2 * Copyright (C) 2017 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include <wtf/PrintStream.h>
29
30namespace JSC {
31
32enum class ConstraintVolatility : uint8_t {
33 // The constraint needs to be validated, but it is unlikely to ever produce information.
34 // It's best to run it at the bitter end.
35 SeldomGreyed,
36
37 // FIXME: We could introduce a new kind of volatility called GreyedByResumption, which
38 // would mean running all of the times that GreyedByExecution runs except as a root in a
39 // full GC.
40 // https://bugs.webkit.org/show_bug.cgi?id=166830
41
42 // The constraint needs to be reevaluated anytime the mutator runs: so at GC start and
43 // whenever the GC resuspends after a resumption. This is almost always something that
44 // you'd call a "root" in a traditional GC.
45 GreyedByExecution,
46
47 // The constraint needs to be reevaluated any time any object is marked and anytime the
48 // mutator resumes.
49 GreyedByMarking
50};
51
52} // namespace JSC
53
54namespace WTF {
55
56inline void printInternal(PrintStream& out, JSC::ConstraintVolatility volatility)
57{
58 switch (volatility) {
59 case JSC::ConstraintVolatility::SeldomGreyed:
60 out.print("SeldomGreyed");
61 return;
62 case JSC::ConstraintVolatility::GreyedByExecution:
63 out.print("GreyedByExecuction");
64 return;
65 case JSC::ConstraintVolatility::GreyedByMarking:
66 out.print("GreyedByMarking");
67 return;
68 }
69 RELEASE_ASSERT_NOT_REACHED();
70}
71
72} // namespace WTF
73
74