1// Copyright 2009 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
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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#include "v8.h"
29#include "regexp-stack.h"
30
31namespace v8 {
32namespace internal {
33
34RegExpStackScope::RegExpStackScope(Isolate* isolate)
35    : regexp_stack_(isolate->regexp_stack()) {
36  // Initialize, if not already initialized.
37  regexp_stack_->EnsureCapacity(0);
38}
39
40
41RegExpStackScope::~RegExpStackScope() {
42  ASSERT(Isolate::Current() == regexp_stack_->isolate_);
43  // Reset the buffer if it has grown.
44  regexp_stack_->Reset();
45}
46
47
48RegExpStack::RegExpStack()
49    : isolate_(NULL) {
50}
51
52
53RegExpStack::~RegExpStack() {
54}
55
56
57char* RegExpStack::ArchiveStack(char* to) {
58  size_t size = sizeof(thread_local_);
59  memcpy(reinterpret_cast<void*>(to),
60         &thread_local_,
61         size);
62  thread_local_ = ThreadLocal();
63  return to + size;
64}
65
66
67char* RegExpStack::RestoreStack(char* from) {
68  size_t size = sizeof(thread_local_);
69  memcpy(&thread_local_, reinterpret_cast<void*>(from), size);
70  return from + size;
71}
72
73
74void RegExpStack::Reset() {
75  if (thread_local_.memory_size_ > kMinimumStackSize) {
76    DeleteArray(thread_local_.memory_);
77    thread_local_ = ThreadLocal();
78  }
79}
80
81
82void RegExpStack::ThreadLocal::Free() {
83  if (memory_size_ > 0) {
84    DeleteArray(memory_);
85    Clear();
86  }
87}
88
89
90Address RegExpStack::EnsureCapacity(size_t size) {
91  if (size > kMaximumStackSize) return NULL;
92  if (size < kMinimumStackSize) size = kMinimumStackSize;
93  if (thread_local_.memory_size_ < size) {
94    Address new_memory = NewArray<byte>(static_cast<int>(size));
95    if (thread_local_.memory_size_ > 0) {
96      // Copy original memory into top of new memory.
97      memcpy(reinterpret_cast<void*>(
98          new_memory + size - thread_local_.memory_size_),
99             reinterpret_cast<void*>(thread_local_.memory_),
100             thread_local_.memory_size_);
101      DeleteArray(thread_local_.memory_);
102    }
103    thread_local_.memory_ = new_memory;
104    thread_local_.memory_size_ = size;
105    thread_local_.limit_ = new_memory + kStackLimitSlack * kPointerSize;
106  }
107  return thread_local_.memory_ + thread_local_.memory_size_;
108}
109
110
111}}  // namespace v8::internal
112