1 // Copyright 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 #ifndef V8_ALLOCATION_H_
29 #define V8_ALLOCATION_H_
30
31 namespace v8 {
32 namespace internal {
33
34
35 // A class that controls whether allocation is allowed. This is for
36 // the C++ heap only!
37 class NativeAllocationChecker {
38 public:
39 typedef enum { ALLOW, DISALLOW } NativeAllocationAllowed;
NativeAllocationChecker(NativeAllocationAllowed allowed)40 explicit inline NativeAllocationChecker(NativeAllocationAllowed allowed)
41 : allowed_(allowed) {
42 #ifdef DEBUG
43 if (allowed == DISALLOW) {
44 allocation_disallowed_++;
45 }
46 #endif
47 }
~NativeAllocationChecker()48 ~NativeAllocationChecker() {
49 #ifdef DEBUG
50 if (allowed_ == DISALLOW) {
51 allocation_disallowed_--;
52 }
53 #endif
54 ASSERT(allocation_disallowed_ >= 0);
55 }
allocation_allowed()56 static inline bool allocation_allowed() {
57 return allocation_disallowed_ == 0;
58 }
59 private:
60 // This static counter ensures that NativeAllocationCheckers can be nested.
61 static int allocation_disallowed_;
62 // This flag applies to this particular instance.
63 NativeAllocationAllowed allowed_;
64 };
65
66
67 // Superclass for classes managed with new & delete.
68 class Malloced {
69 public:
new(size_t size)70 void* operator new(size_t size) { return New(size); }
delete(void * p)71 void operator delete(void* p) { Delete(p); }
72
73 static void FatalProcessOutOfMemory();
74 static void* New(size_t size);
75 static void Delete(void* p);
76 };
77
78
79 // A macro is used for defining the base class used for embedded instances.
80 // The reason is some compilers allocate a minimum of one word for the
81 // superclass. The macro prevents the use of new & delete in debug mode.
82 // In release mode we are not willing to pay this overhead.
83
84 #ifdef DEBUG
85 // Superclass for classes with instances allocated inside stack
86 // activations or inside other objects.
87 class Embedded {
88 public:
89 void* operator new(size_t size);
90 void operator delete(void* p);
91 };
92 #define BASE_EMBEDDED : public Embedded
93 #else
94 #define BASE_EMBEDDED
95 #endif
96
97
98 // Superclass for classes only using statics.
99 class AllStatic {
100 #ifdef DEBUG
101 public:
102 void* operator new(size_t size);
103 void operator delete(void* p);
104 #endif
105 };
106
107
108 template <typename T>
NewArray(int size)109 static T* NewArray(int size) {
110 ASSERT(NativeAllocationChecker::allocation_allowed());
111 T* result = new T[size];
112 if (result == NULL) Malloced::FatalProcessOutOfMemory();
113 return result;
114 }
115
116
117 template <typename T>
DeleteArray(T * array)118 static void DeleteArray(T* array) {
119 delete[] array;
120 }
121
122
123 // The normal strdup functions use malloc. These versions of StrDup
124 // and StrNDup uses new and calls the FatalProcessOutOfMemory handler
125 // if allocation fails.
126 char* StrDup(const char* str);
127 char* StrNDup(const char* str, size_t n);
128
129
130 // Allocation policy for allocating in the C free store using malloc
131 // and free. Used as the default policy for lists.
132 class FreeStoreAllocationPolicy {
133 public:
INLINE(static void * New (size_t size))134 INLINE(static void* New(size_t size)) { return Malloced::New(size); }
INLINE(static void Delete (void * p))135 INLINE(static void Delete(void* p)) { Malloced::Delete(p); }
136 };
137
138
139 // Allocation policy for allocating in preallocated space.
140 // Used as an allocation policy for ScopeInfo when generating
141 // stack traces.
142 class PreallocatedStorage : public AllStatic {
143 public:
144 explicit PreallocatedStorage(size_t size);
size()145 size_t size() { return size_; }
146 static void* New(size_t size);
147 static void Delete(void* p);
148
149 // Preallocate a set number of bytes.
150 static void Init(size_t size);
151
152 private:
153 size_t size_;
154 PreallocatedStorage* previous_;
155 PreallocatedStorage* next_;
156 static bool preallocated_;
157
158 static PreallocatedStorage in_use_list_;
159 static PreallocatedStorage free_list_;
160
161 void LinkTo(PreallocatedStorage* other);
162 void Unlink();
163 DISALLOW_IMPLICIT_CONSTRUCTORS(PreallocatedStorage);
164 };
165
166
167 } } // namespace v8::internal
168
169 #endif // V8_ALLOCATION_H_
170