1a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// Copyright 2009 the V8 project authors. All rights reserved. 2a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// Redistribution and use in source and binary forms, with or without 3a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// modification, are permitted provided that the following conditions are 4a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// met: 5a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// 6a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// * Redistributions of source code must retain the above copyright 7a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// notice, this list of conditions and the following disclaimer. 8a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// * Redistributions in binary form must reproduce the above 9a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// copyright notice, this list of conditions and the following 10a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// disclaimer in the documentation and/or other materials provided 11a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// with the distribution. 12a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// * Neither the name of Google Inc. nor the names of its 13a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// contributors may be used to endorse or promote products derived 14a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// from this software without specific prior written permission. 15a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// 16a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 28a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#ifndef V8_REGEXP_STACK_H_ 29a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#define V8_REGEXP_STACK_H_ 30a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 31a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blocknamespace v8 { 32a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blocknamespace internal { 33a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 3444f0eee88ff00398ff7f715fab053374d808c90dSteve Blockclass RegExpStack; 3544f0eee88ff00398ff7f715fab053374d808c90dSteve Block 36a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// Maintains a per-v8thread stack area that can be used by irregexp 37a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// implementation for its backtracking stack. 38a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// Since there is only one stack area, the Irregexp implementation is not 39a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// re-entrant. I.e., no regular expressions may be executed in the same thread 40a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// during a preempted Irregexp execution. 4144f0eee88ff00398ff7f715fab053374d808c90dSteve Blockclass RegExpStackScope { 4244f0eee88ff00398ff7f715fab053374d808c90dSteve Block public: 4344f0eee88ff00398ff7f715fab053374d808c90dSteve Block // Create and delete an instance to control the life-time of a growing stack. 4444f0eee88ff00398ff7f715fab053374d808c90dSteve Block 4544f0eee88ff00398ff7f715fab053374d808c90dSteve Block // Initializes the stack memory area if necessary. 4644f0eee88ff00398ff7f715fab053374d808c90dSteve Block explicit RegExpStackScope(Isolate* isolate); 4744f0eee88ff00398ff7f715fab053374d808c90dSteve Block ~RegExpStackScope(); // Releases the stack if it has grown. 4844f0eee88ff00398ff7f715fab053374d808c90dSteve Block 4944f0eee88ff00398ff7f715fab053374d808c90dSteve Block RegExpStack* stack() const { return regexp_stack_; } 5044f0eee88ff00398ff7f715fab053374d808c90dSteve Block 5144f0eee88ff00398ff7f715fab053374d808c90dSteve Block private: 5244f0eee88ff00398ff7f715fab053374d808c90dSteve Block RegExpStack* regexp_stack_; 5344f0eee88ff00398ff7f715fab053374d808c90dSteve Block 5444f0eee88ff00398ff7f715fab053374d808c90dSteve Block DISALLOW_COPY_AND_ASSIGN(RegExpStackScope); 5544f0eee88ff00398ff7f715fab053374d808c90dSteve Block}; 5644f0eee88ff00398ff7f715fab053374d808c90dSteve Block 5744f0eee88ff00398ff7f715fab053374d808c90dSteve Block 58a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blockclass RegExpStack { 59a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block public: 60a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Number of allocated locations on the stack below the limit. 61a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // No sequence of pushes must be longer that this without doing a stack-limit 62a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // check. 63a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block static const int kStackLimitSlack = 32; 64a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 65a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Gives the top of the memory used as stack. 6644f0eee88ff00398ff7f715fab053374d808c90dSteve Block Address stack_base() { 67a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block ASSERT(thread_local_.memory_size_ != 0); 68a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block return thread_local_.memory_ + thread_local_.memory_size_; 69a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 70a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 71a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // The total size of the memory allocated for the stack. 7244f0eee88ff00398ff7f715fab053374d808c90dSteve Block size_t stack_capacity() { return thread_local_.memory_size_; } 73a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 74a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // If the stack pointer gets below the limit, we should react and 75a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // either grow the stack or report an out-of-stack exception. 76a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // There is only a limited number of locations below the stack limit, 77a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // so users of the stack should check the stack limit during any 78a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // sequence of pushes longer that this. 7944f0eee88ff00398ff7f715fab053374d808c90dSteve Block Address* limit_address() { return &(thread_local_.limit_); } 80a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 81a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Ensures that there is a memory area with at least the specified size. 82a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // If passing zero, the default/minimum size buffer is allocated. 8344f0eee88ff00398ff7f715fab053374d808c90dSteve Block Address EnsureCapacity(size_t size); 84a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 85a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Thread local archiving. 86d0582a6c46733687d045e4188a1bcd0123c758a1Steve Block static int ArchiveSpacePerThread() { 8744f0eee88ff00398ff7f715fab053374d808c90dSteve Block return static_cast<int>(sizeof(ThreadLocal)); 88d0582a6c46733687d045e4188a1bcd0123c758a1Steve Block } 8944f0eee88ff00398ff7f715fab053374d808c90dSteve Block char* ArchiveStack(char* to); 9044f0eee88ff00398ff7f715fab053374d808c90dSteve Block char* RestoreStack(char* from); 9144f0eee88ff00398ff7f715fab053374d808c90dSteve Block void FreeThreadResources() { thread_local_.Free(); } 92589d6979ff2ef66fca2d8fa51404c369ca5e9250Ben Murdoch 93a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block private: 9444f0eee88ff00398ff7f715fab053374d808c90dSteve Block RegExpStack(); 9544f0eee88ff00398ff7f715fab053374d808c90dSteve Block ~RegExpStack(); 9644f0eee88ff00398ff7f715fab053374d808c90dSteve Block 97a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Artificial limit used when no memory has been allocated. 98a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block static const uintptr_t kMemoryTop = static_cast<uintptr_t>(-1); 99a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 100a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Minimal size of allocated stack area. 101a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block static const size_t kMinimumStackSize = 1 * KB; 102a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 103a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Maximal size of allocated stack area. 104a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block static const size_t kMaximumStackSize = 64 * MB; 105a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 106a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Structure holding the allocated memory, size and limit. 107a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block struct ThreadLocal { 10844f0eee88ff00398ff7f715fab053374d808c90dSteve Block ThreadLocal() { Clear(); } 109a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // If memory_size_ > 0 then memory_ must be non-NULL. 110a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block Address memory_; 111a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block size_t memory_size_; 112a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block Address limit_; 11344f0eee88ff00398ff7f715fab053374d808c90dSteve Block void Clear() { 11444f0eee88ff00398ff7f715fab053374d808c90dSteve Block memory_ = NULL; 11544f0eee88ff00398ff7f715fab053374d808c90dSteve Block memory_size_ = 0; 11644f0eee88ff00398ff7f715fab053374d808c90dSteve Block limit_ = reinterpret_cast<Address>(kMemoryTop); 11744f0eee88ff00398ff7f715fab053374d808c90dSteve Block } 118a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block void Free(); 119a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block }; 120a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 121e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke // Address of allocated memory. 12244f0eee88ff00398ff7f715fab053374d808c90dSteve Block Address memory_address() { 123e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke return reinterpret_cast<Address>(&thread_local_.memory_); 124e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke } 125e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke 126e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke // Address of size of allocated memory. 12744f0eee88ff00398ff7f715fab053374d808c90dSteve Block Address memory_size_address() { 128e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke return reinterpret_cast<Address>(&thread_local_.memory_size_); 129e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke } 130e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke 131a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Resets the buffer if it has grown beyond the default/minimum size. 132a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // After this, the buffer is either the default size, or it is empty, so 133a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // you have to call EnsureCapacity before using it again. 13444f0eee88ff00398ff7f715fab053374d808c90dSteve Block void Reset(); 135a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 13644f0eee88ff00398ff7f715fab053374d808c90dSteve Block ThreadLocal thread_local_; 13744f0eee88ff00398ff7f715fab053374d808c90dSteve Block Isolate* isolate_; 138e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke 139e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke friend class ExternalReference; 14044f0eee88ff00398ff7f715fab053374d808c90dSteve Block friend class Isolate; 14144f0eee88ff00398ff7f715fab053374d808c90dSteve Block friend class RegExpStackScope; 14244f0eee88ff00398ff7f715fab053374d808c90dSteve Block 14344f0eee88ff00398ff7f715fab053374d808c90dSteve Block DISALLOW_COPY_AND_ASSIGN(RegExpStack); 144a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block}; 145a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 146a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block}} // namespace v8::internal 147a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 148a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#endif // V8_REGEXP_STACK_H_ 149