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