1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
/*
* Copyright (C) 2012-2015 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "Watchpoint.h"
#include <wtf/CompilationThread.h>
#include <wtf/PassRefPtr.h>
namespace JSC {
void StringFireDetail::dump(PrintStream& out) const
{
out.print(m_string);
}
Watchpoint::~Watchpoint()
{
if (isOnList()) {
// This will happen if we get destroyed before the set fires. That's totally a valid
// possibility. For example:
//
// CodeBlock has a Watchpoint on transition from structure S1. The transition never
// happens, but the CodeBlock gets destroyed because of GC.
remove();
}
}
void Watchpoint::fire(const FireDetail& detail)
{
RELEASE_ASSERT(!isOnList());
fireInternal(detail);
}
WatchpointSet::WatchpointSet(WatchpointState state)
: m_state(state)
, m_setIsNotEmpty(false)
{
}
WatchpointSet::~WatchpointSet()
{
// Remove all watchpoints, so that they don't try to remove themselves. Note that we
// don't fire watchpoints on deletion. We assume that any code that is interested in
// watchpoints already also separately has a mechanism to make sure that the code is
// either keeping the watchpoint set's owner alive, or does some weak reference thing.
while (!m_set.isEmpty())
m_set.begin()->remove();
}
void WatchpointSet::add(Watchpoint* watchpoint)
{
ASSERT(!isCompilationThread());
ASSERT(state() != IsInvalidated);
if (!watchpoint)
return;
m_set.push(watchpoint);
m_setIsNotEmpty = true;
m_state = IsWatched;
}
void WatchpointSet::fireAllSlow(const FireDetail& detail)
{
ASSERT(state() == IsWatched);
WTF::storeStoreFence();
m_state = IsInvalidated; // Do this first. Needed for adaptive watchpoints.
fireAllWatchpoints(detail);
WTF::storeStoreFence();
}
void WatchpointSet::fireAllSlow(const char* reason)
{
fireAllSlow(StringFireDetail(reason));
}
void WatchpointSet::fireAllWatchpoints(const FireDetail& detail)
{
// In case there are any adaptive watchpoints, we need to make sure that they see that this
// watchpoint has been already invalidated.
RELEASE_ASSERT(hasBeenInvalidated());
while (!m_set.isEmpty()) {
Watchpoint* watchpoint = m_set.begin();
ASSERT(watchpoint->isOnList());
// Removing the Watchpoint before firing it makes it possible to implement watchpoints
// that add themselves to a different set when they fire. This kind of "adaptive"
// watchpoint can be used to track some semantic property that is more fine-graiend than
// what the set can convey. For example, we might care if a singleton object ever has a
// property called "foo". We can watch for this by checking if its Structure has "foo" and
// then watching its transitions. But then the watchpoint fires if any property is added.
// So, before the watchpoint decides to invalidate any code, it can check if it is
// possible to add itself to the transition watchpoint set of the singleton object's new
// Structure.
watchpoint->remove();
ASSERT(m_set.begin() != watchpoint);
ASSERT(!watchpoint->isOnList());
watchpoint->fire(detail);
// After we fire the watchpoint, the watchpoint pointer may be a dangling pointer. That's
// fine, because we have no use for the pointer anymore.
}
}
void InlineWatchpointSet::add(Watchpoint* watchpoint)
{
inflate()->add(watchpoint);
}
void InlineWatchpointSet::fireAll(const char* reason)
{
fireAll(StringFireDetail(reason));
}
WatchpointSet* InlineWatchpointSet::inflateSlow()
{
ASSERT(isThin());
ASSERT(!isCompilationThread());
WatchpointSet* fat = adoptRef(new WatchpointSet(decodeState(m_data))).leakRef();
WTF::storeStoreFence();
m_data = bitwise_cast<uintptr_t>(fat);
return fat;
}
void InlineWatchpointSet::freeFat()
{
ASSERT(isFat());
fat()->deref();
}
} // namespace JSC
|
