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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
// Copyright 2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * 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.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "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 THE COPYRIGHT
// OWNER 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 "v8.h"
#include "compilation-cache.h"
namespace v8 { namespace internal {
enum {
NUMBER_OF_ENTRY_KINDS = CompilationCache::LAST_ENTRY + 1
};
// Keep separate tables for the different entry kinds.
static Object* tables[NUMBER_OF_ENTRY_KINDS] = { 0, };
static Handle<CompilationCacheTable> AllocateTable(int size) {
CALL_HEAP_FUNCTION(CompilationCacheTable::Allocate(size),
CompilationCacheTable);
}
static Handle<CompilationCacheTable> GetTable(CompilationCache::Entry entry) {
Handle<CompilationCacheTable> result;
if (tables[entry]->IsUndefined()) {
static const int kInitialCacheSize = 64;
result = AllocateTable(kInitialCacheSize);
tables[entry] = *result;
} else {
CompilationCacheTable* table = CompilationCacheTable::cast(tables[entry]);
result = Handle<CompilationCacheTable>(table);
}
return result;
}
static Handle<JSFunction> Lookup(Handle<String> source,
Handle<Context> context,
CompilationCache::Entry entry) {
// Make sure not to leak the table into the surrounding handle
// scope. Otherwise, we risk keeping old tables around even after
// having cleared the cache.
Object* result;
{ HandleScope scope;
Handle<CompilationCacheTable> table = GetTable(entry);
result = table->LookupEval(*source, *context);
}
if (result->IsJSFunction()) {
return Handle<JSFunction>(JSFunction::cast(result));
} else {
return Handle<JSFunction>::null();
}
}
static Handle<FixedArray> Lookup(Handle<String> source,
JSRegExp::Flags flags) {
// Make sure not to leak the table into the surrounding handle
// scope. Otherwise, we risk keeping old tables around even after
// having cleared the cache.
Object* result;
{ HandleScope scope;
Handle<CompilationCacheTable> table = GetTable(CompilationCache::REGEXP);
result = table->LookupRegExp(*source, flags);
}
if (result->IsFixedArray()) {
return Handle<FixedArray>(FixedArray::cast(result));
} else {
return Handle<FixedArray>::null();
}
}
// We only re-use a cached function for some script source code if the
// script originates from the same place. This is to avoid issues
// when reporting errors, etc.
static bool HasOrigin(Handle<JSFunction> boilerplate,
Handle<Object> name,
int line_offset,
int column_offset) {
Handle<Script> script =
Handle<Script>(Script::cast(boilerplate->shared()->script()));
// If the script name isn't set, the boilerplate script should have
// an undefined name to have the same origin.
if (name.is_null()) {
return script->name()->IsUndefined();
}
// Do the fast bailout checks first.
if (line_offset != script->line_offset()->value()) return false;
if (column_offset != script->column_offset()->value()) return false;
// Check that both names are strings. If not, no match.
if (!name->IsString() || !script->name()->IsString()) return false;
// Compare the two name strings for equality.
return String::cast(*name)->Equals(String::cast(script->name()));
}
static Handle<JSFunction> Lookup(Handle<String> source,
CompilationCache::Entry entry) {
// Make sure not to leak the table into the surrounding handle
// scope. Otherwise, we risk keeping old tables around even after
// having cleared the cache.
Object* result;
{ HandleScope scope;
Handle<CompilationCacheTable> table = GetTable(entry);
result = table->Lookup(*source);
}
if (result->IsJSFunction()) {
return Handle<JSFunction>(JSFunction::cast(result));
} else {
return Handle<JSFunction>::null();
}
}
// TODO(245): Need to allow identical code from different contexts to be
// cached. Currently the first use will be cached, but subsequent code
// from different source / line won't.
Handle<JSFunction> CompilationCache::LookupScript(Handle<String> source,
Handle<Object> name,
int line_offset,
int column_offset) {
Handle<JSFunction> result = Lookup(source, SCRIPT);
if (result.is_null()) {
Counters::compilation_cache_misses.Increment();
} else if (HasOrigin(result, name, line_offset, column_offset)) {
Counters::compilation_cache_hits.Increment();
} else {
result = Handle<JSFunction>::null();
Counters::compilation_cache_misses.Increment();
}
return result;
}
Handle<JSFunction> CompilationCache::LookupEval(Handle<String> source,
Handle<Context> context,
Entry entry) {
ASSERT(entry == EVAL_GLOBAL || entry == EVAL_CONTEXTUAL);
Handle<JSFunction> result = Lookup(source, context, entry);
if (result.is_null()) {
Counters::compilation_cache_misses.Increment();
} else {
Counters::compilation_cache_hits.Increment();
}
return result;
}
Handle<FixedArray> CompilationCache::LookupRegExp(Handle<String> source,
JSRegExp::Flags flags) {
Handle<FixedArray> result = Lookup(source, flags);
if (result.is_null()) {
Counters::compilation_cache_misses.Increment();
} else {
Counters::compilation_cache_hits.Increment();
}
return result;
}
void CompilationCache::PutScript(Handle<String> source,
Handle<JSFunction> boilerplate) {
HandleScope scope;
ASSERT(boilerplate->IsBoilerplate());
Handle<CompilationCacheTable> table = GetTable(SCRIPT);
CALL_HEAP_FUNCTION_VOID(table->Put(*source, *boilerplate));
}
void CompilationCache::PutEval(Handle<String> source,
Handle<Context> context,
Entry entry,
Handle<JSFunction> boilerplate) {
HandleScope scope;
ASSERT(boilerplate->IsBoilerplate());
Handle<CompilationCacheTable> table = GetTable(entry);
CALL_HEAP_FUNCTION_VOID(table->PutEval(*source, *context, *boilerplate));
}
void CompilationCache::PutRegExp(Handle<String> source,
JSRegExp::Flags flags,
Handle<FixedArray> data) {
HandleScope scope;
Handle<CompilationCacheTable> table = GetTable(REGEXP);
CALL_HEAP_FUNCTION_VOID(table->PutRegExp(*source, flags, *data));
}
void CompilationCache::Clear() {
for (int i = 0; i < NUMBER_OF_ENTRY_KINDS; i++) {
tables[i] = Heap::undefined_value();
}
}
void CompilationCache::Iterate(ObjectVisitor* v) {
v->VisitPointers(&tables[0], &tables[NUMBER_OF_ENTRY_KINDS]);
}
} } // namespace v8::internal
|
