1 // Copyright 2006-2008 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
4 // met:
5 //
6 // * Redistributions of source code must retain the above copyright
7 // notice, this list of conditions and the following disclaimer.
8 // * Redistributions in binary form must reproduce the above
9 // copyright notice, this list of conditions and the following
10 // disclaimer in the documentation and/or other materials provided
11 // with the distribution.
12 // * Neither the name of Google Inc. nor the names of its
13 // contributors may be used to endorse or promote products derived
14 // from this software without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 //
28
29 #ifndef V8_HANDLES_INL_H_
30 #define V8_HANDLES_INL_H_
31
32 #include "api.h"
33 #include "apiutils.h"
34 #include "handles.h"
35 #include "isolate.h"
36
37 namespace v8 {
38 namespace internal {
39
GetIsolateForHandle(Object * obj)40 inline Isolate* GetIsolateForHandle(Object* obj) {
41 return Isolate::Current();
42 }
43
GetIsolateForHandle(HeapObject * obj)44 inline Isolate* GetIsolateForHandle(HeapObject* obj) {
45 return obj->GetIsolate();
46 }
47
48 template<typename T>
Handle(T * obj)49 Handle<T>::Handle(T* obj) {
50 ASSERT(!obj->IsFailure());
51 location_ = HandleScope::CreateHandle(obj, GetIsolateForHandle(obj));
52 }
53
54
55 template<typename T>
Handle(T * obj,Isolate * isolate)56 Handle<T>::Handle(T* obj, Isolate* isolate) {
57 ASSERT(!obj->IsFailure());
58 location_ = HandleScope::CreateHandle(obj, isolate);
59 }
60
61
62 template <typename T>
63 inline T* Handle<T>::operator*() const {
64 ASSERT(location_ != NULL);
65 ASSERT(reinterpret_cast<Address>(*location_) != kHandleZapValue);
66 return *BitCast<T**>(location_);
67 }
68
69
HandleScope()70 HandleScope::HandleScope() {
71 Isolate* isolate = Isolate::Current();
72 v8::ImplementationUtilities::HandleScopeData* current =
73 isolate->handle_scope_data();
74 isolate_ = isolate;
75 prev_next_ = current->next;
76 prev_limit_ = current->limit;
77 current->level++;
78 }
79
80
HandleScope(Isolate * isolate)81 HandleScope::HandleScope(Isolate* isolate) {
82 ASSERT(isolate == Isolate::Current());
83 v8::ImplementationUtilities::HandleScopeData* current =
84 isolate->handle_scope_data();
85 isolate_ = isolate;
86 prev_next_ = current->next;
87 prev_limit_ = current->limit;
88 current->level++;
89 }
90
91
~HandleScope()92 HandleScope::~HandleScope() {
93 CloseScope();
94 }
95
CloseScope()96 void HandleScope::CloseScope() {
97 ASSERT(isolate_ == Isolate::Current());
98 v8::ImplementationUtilities::HandleScopeData* current =
99 isolate_->handle_scope_data();
100 current->next = prev_next_;
101 current->level--;
102 if (current->limit != prev_limit_) {
103 current->limit = prev_limit_;
104 DeleteExtensions(isolate_);
105 }
106 #ifdef DEBUG
107 ZapRange(prev_next_, prev_limit_);
108 #endif
109 }
110
111
112 template <typename T>
CloseAndEscape(Handle<T> handle_value)113 Handle<T> HandleScope::CloseAndEscape(Handle<T> handle_value) {
114 T* value = *handle_value;
115 // Throw away all handles in the current scope.
116 CloseScope();
117 v8::ImplementationUtilities::HandleScopeData* current =
118 isolate_->handle_scope_data();
119 // Allocate one handle in the parent scope.
120 ASSERT(current->level > 0);
121 Handle<T> result(CreateHandle<T>(value, isolate_));
122 // Reinitialize the current scope (so that it's ready
123 // to be used or closed again).
124 prev_next_ = current->next;
125 prev_limit_ = current->limit;
126 current->level++;
127 return result;
128 }
129
130
131 template <typename T>
CreateHandle(T * value,Isolate * isolate)132 T** HandleScope::CreateHandle(T* value, Isolate* isolate) {
133 ASSERT(isolate == Isolate::Current());
134 v8::ImplementationUtilities::HandleScopeData* current =
135 isolate->handle_scope_data();
136
137 internal::Object** cur = current->next;
138 if (cur == current->limit) cur = Extend();
139 // Update the current next field, set the value in the created
140 // handle, and return the result.
141 ASSERT(cur < current->limit);
142 current->next = cur + 1;
143
144 T** result = reinterpret_cast<T**>(cur);
145 *result = value;
146 return result;
147 }
148
149
150 #ifdef DEBUG
NoHandleAllocation()151 inline NoHandleAllocation::NoHandleAllocation() {
152 v8::ImplementationUtilities::HandleScopeData* current =
153 Isolate::Current()->handle_scope_data();
154
155 // Shrink the current handle scope to make it impossible to do
156 // handle allocations without an explicit handle scope.
157 current->limit = current->next;
158
159 level_ = current->level;
160 current->level = 0;
161 }
162
163
~NoHandleAllocation()164 inline NoHandleAllocation::~NoHandleAllocation() {
165 // Restore state in current handle scope to re-enable handle
166 // allocations.
167 v8::ImplementationUtilities::HandleScopeData* data =
168 Isolate::Current()->handle_scope_data();
169 ASSERT_EQ(0, data->level);
170 data->level = level_;
171 }
172 #endif
173
174
175 } } // namespace v8::internal
176
177 #endif // V8_HANDLES_INL_H_
178