Move V8 to external/v8
Change-Id: If68025d67453785a651c5dfb34fad298c16676a4
diff --git a/src/zone.h b/src/zone.h
new file mode 100644
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--- /dev/null
+++ b/src/zone.h
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+// Copyright 2006-2008 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following
+// disclaimer in the documentation and/or other materials provided
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_ZONE_H_
+#define V8_ZONE_H_
+
+namespace v8 {
+namespace internal {
+
+
+// Zone scopes are in one of two modes. Either they delete the zone
+// on exit or they do not.
+enum ZoneScopeMode {
+ DELETE_ON_EXIT,
+ DONT_DELETE_ON_EXIT
+};
+
+
+// The Zone supports very fast allocation of small chunks of
+// memory. The chunks cannot be deallocated individually, but instead
+// the Zone supports deallocating all chunks in one fast
+// operation. The Zone is used to hold temporary data structures like
+// the abstract syntax tree, which is deallocated after compilation.
+
+// Note: There is no need to initialize the Zone; the first time an
+// allocation is attempted, a segment of memory will be requested
+// through a call to malloc().
+
+// Note: The implementation is inherently not thread safe. Do not use
+// from multi-threaded code.
+
+class Zone {
+ public:
+ // Allocate 'size' bytes of memory in the Zone; expands the Zone by
+ // allocating new segments of memory on demand using malloc().
+ static inline void* New(int size);
+
+ template <typename T>
+ static inline T* NewArray(int length);
+
+ // Delete all objects and free all memory allocated in the Zone.
+ static void DeleteAll();
+
+ // Returns true if more memory has been allocated in zones than
+ // the limit allows.
+ static inline bool excess_allocation();
+
+ static inline void adjust_segment_bytes_allocated(int delta);
+
+ private:
+
+ // All pointers returned from New() have this alignment.
+ static const int kAlignment = kPointerSize;
+
+ // Never allocate segments smaller than this size in bytes.
+ static const int kMinimumSegmentSize = 8 * KB;
+
+ // Never allocate segments larger than this size in bytes.
+ static const int kMaximumSegmentSize = 1 * MB;
+
+ // Never keep segments larger than this size in bytes around.
+ static const int kMaximumKeptSegmentSize = 64 * KB;
+
+ // Report zone excess when allocation exceeds this limit.
+ static int zone_excess_limit_;
+
+ // The number of bytes allocated in segments. Note that this number
+ // includes memory allocated from the OS but not yet allocated from
+ // the zone.
+ static int segment_bytes_allocated_;
+
+ // The Zone is intentionally a singleton; you should not try to
+ // allocate instances of the class.
+ Zone() { UNREACHABLE(); }
+
+
+ // Expand the Zone to hold at least 'size' more bytes and allocate
+ // the bytes. Returns the address of the newly allocated chunk of
+ // memory in the Zone. Should only be called if there isn't enough
+ // room in the Zone already.
+ static Address NewExpand(int size);
+
+
+ // The free region in the current (front) segment is represented as
+ // the half-open interval [position, limit). The 'position' variable
+ // is guaranteed to be aligned as dictated by kAlignment.
+ static Address position_;
+ static Address limit_;
+};
+
+
+// ZoneObject is an abstraction that helps define classes of objects
+// allocated in the Zone. Use it as a base class; see ast.h.
+class ZoneObject {
+ public:
+ // Allocate a new ZoneObject of 'size' bytes in the Zone.
+ void* operator new(size_t size) { return Zone::New(size); }
+
+ // Ideally, the delete operator should be private instead of
+ // public, but unfortunately the compiler sometimes synthesizes
+ // (unused) destructors for classes derived from ZoneObject, which
+ // require the operator to be visible. MSVC requires the delete
+ // operator to be public.
+
+ // ZoneObjects should never be deleted individually; use
+ // Zone::DeleteAll() to delete all zone objects in one go.
+ void operator delete(void*, size_t) { UNREACHABLE(); }
+};
+
+
+class AssertNoZoneAllocation {
+ public:
+ AssertNoZoneAllocation() : prev_(allow_allocation_) {
+ allow_allocation_ = false;
+ }
+ ~AssertNoZoneAllocation() { allow_allocation_ = prev_; }
+ static bool allow_allocation() { return allow_allocation_; }
+ private:
+ bool prev_;
+ static bool allow_allocation_;
+};
+
+
+// The ZoneListAllocationPolicy is used to specialize the GenericList
+// implementation to allocate ZoneLists and their elements in the
+// Zone.
+class ZoneListAllocationPolicy {
+ public:
+ // Allocate 'size' bytes of memory in the zone.
+ static void* New(int size) { return Zone::New(size); }
+
+ // De-allocation attempts are silently ignored.
+ static void Delete(void* p) { }
+};
+
+
+// ZoneLists are growable lists with constant-time access to the
+// elements. The list itself and all its elements are allocated in the
+// Zone. ZoneLists cannot be deleted individually; you can delete all
+// objects in the Zone by calling Zone::DeleteAll().
+template<typename T>
+class ZoneList: public List<T, ZoneListAllocationPolicy> {
+ public:
+ // Construct a new ZoneList with the given capacity; the length is
+ // always zero. The capacity must be non-negative.
+ explicit ZoneList(int capacity)
+ : List<T, ZoneListAllocationPolicy>(capacity) { }
+};
+
+
+// ZoneScopes keep track of the current parsing and compilation
+// nesting and cleans up generated ASTs in the Zone when exiting the
+// outer-most scope.
+class ZoneScope BASE_EMBEDDED {
+ public:
+ explicit ZoneScope(ZoneScopeMode mode) : mode_(mode) {
+ nesting_++;
+ }
+
+ virtual ~ZoneScope() {
+ if (ShouldDeleteOnExit()) Zone::DeleteAll();
+ --nesting_;
+ }
+
+ bool ShouldDeleteOnExit() {
+ return nesting_ == 1 && mode_ == DELETE_ON_EXIT;
+ }
+
+ // For ZoneScopes that do not delete on exit by default, call this
+ // method to request deletion on exit.
+ void DeleteOnExit() {
+ mode_ = DELETE_ON_EXIT;
+ }
+
+ static int nesting() { return nesting_; }
+
+ private:
+ ZoneScopeMode mode_;
+ static int nesting_;
+};
+
+
+// A zone splay tree. The config type parameter encapsulates the
+// different configurations of a concrete splay tree:
+//
+// typedef Key: the key type
+// typedef Value: the value type
+// static const kNoKey: the dummy key used when no key is set
+// static const kNoValue: the dummy value used to initialize nodes
+// int (Compare)(Key& a, Key& b) -> {-1, 0, 1}: comparison function
+//
+template <typename Config>
+class ZoneSplayTree : public ZoneObject {
+ public:
+ typedef typename Config::Key Key;
+ typedef typename Config::Value Value;
+
+ class Locator;
+
+ ZoneSplayTree() : root_(NULL) { }
+
+ // Inserts the given key in this tree with the given value. Returns
+ // true if a node was inserted, otherwise false. If found the locator
+ // is enabled and provides access to the mapping for the key.
+ bool Insert(const Key& key, Locator* locator);
+
+ // Looks up the key in this tree and returns true if it was found,
+ // otherwise false. If the node is found the locator is enabled and
+ // provides access to the mapping for the key.
+ bool Find(const Key& key, Locator* locator);
+
+ // Finds the mapping with the greatest key less than or equal to the
+ // given key.
+ bool FindGreatestLessThan(const Key& key, Locator* locator);
+
+ // Find the mapping with the greatest key in this tree.
+ bool FindGreatest(Locator* locator);
+
+ // Finds the mapping with the least key greater than or equal to the
+ // given key.
+ bool FindLeastGreaterThan(const Key& key, Locator* locator);
+
+ // Find the mapping with the least key in this tree.
+ bool FindLeast(Locator* locator);
+
+ // Remove the node with the given key from the tree.
+ bool Remove(const Key& key);
+
+ bool is_empty() { return root_ == NULL; }
+
+ // Perform the splay operation for the given key. Moves the node with
+ // the given key to the top of the tree. If no node has the given
+ // key, the last node on the search path is moved to the top of the
+ // tree.
+ void Splay(const Key& key);
+
+ class Node : public ZoneObject {
+ public:
+ Node(const Key& key, const Value& value)
+ : key_(key),
+ value_(value),
+ left_(NULL),
+ right_(NULL) { }
+ Key key() { return key_; }
+ Value value() { return value_; }
+ Node* left() { return left_; }
+ Node* right() { return right_; }
+ private:
+ friend class ZoneSplayTree;
+ friend class Locator;
+ Key key_;
+ Value value_;
+ Node* left_;
+ Node* right_;
+ };
+
+ // A locator provides access to a node in the tree without actually
+ // exposing the node.
+ class Locator {
+ public:
+ explicit Locator(Node* node) : node_(node) { }
+ Locator() : node_(NULL) { }
+ const Key& key() { return node_->key_; }
+ Value& value() { return node_->value_; }
+ void set_value(const Value& value) { node_->value_ = value; }
+ inline void bind(Node* node) { node_ = node; }
+ private:
+ Node* node_;
+ };
+
+ template <class Callback>
+ void ForEach(Callback* callback);
+
+ private:
+ Node* root_;
+};
+
+
+} } // namespace v8::internal
+
+#endif // V8_ZONE_H_