mark-compact.h revision 3fb3ca8c7ca439d408449a395897395c0faae8d1
1a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// Copyright 2006-2008 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_MARK_COMPACT_H_ 29a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#define V8_MARK_COMPACT_H_ 30a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 3144f0eee88ff00398ff7f715fab053374d808c90dSteve Block#include "spaces.h" 3244f0eee88ff00398ff7f715fab053374d808c90dSteve Block 33a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blocknamespace v8 { 34a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blocknamespace internal { 35a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 36a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// Callback function, returns whether an object is alive. The heap size 37a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// of the object is returned in size. It optionally updates the offset 38a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// to the first live object in the page (only used for old and map objects). 39a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blocktypedef bool (*IsAliveFunction)(HeapObject* obj, int* size, int* offset); 40a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 41a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// Forward declarations. 4244f0eee88ff00398ff7f715fab053374d808c90dSteve Blockclass CodeFlusher; 4344f0eee88ff00398ff7f715fab053374d808c90dSteve Blockclass GCTracer; 44a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blockclass MarkingVisitor; 4544f0eee88ff00398ff7f715fab053374d808c90dSteve Blockclass RootMarkingVisitor; 4644f0eee88ff00398ff7f715fab053374d808c90dSteve Block 4744f0eee88ff00398ff7f715fab053374d808c90dSteve Block 4844f0eee88ff00398ff7f715fab053374d808c90dSteve Block// ---------------------------------------------------------------------------- 4944f0eee88ff00398ff7f715fab053374d808c90dSteve Block// Marking stack for tracing live objects. 5044f0eee88ff00398ff7f715fab053374d808c90dSteve Block 5144f0eee88ff00398ff7f715fab053374d808c90dSteve Blockclass MarkingStack { 5244f0eee88ff00398ff7f715fab053374d808c90dSteve Block public: 5344f0eee88ff00398ff7f715fab053374d808c90dSteve Block MarkingStack() : low_(NULL), top_(NULL), high_(NULL), overflowed_(false) { } 5444f0eee88ff00398ff7f715fab053374d808c90dSteve Block 5544f0eee88ff00398ff7f715fab053374d808c90dSteve Block void Initialize(Address low, Address high) { 5644f0eee88ff00398ff7f715fab053374d808c90dSteve Block top_ = low_ = reinterpret_cast<HeapObject**>(low); 5744f0eee88ff00398ff7f715fab053374d808c90dSteve Block high_ = reinterpret_cast<HeapObject**>(high); 5844f0eee88ff00398ff7f715fab053374d808c90dSteve Block overflowed_ = false; 5944f0eee88ff00398ff7f715fab053374d808c90dSteve Block } 6044f0eee88ff00398ff7f715fab053374d808c90dSteve Block 6144f0eee88ff00398ff7f715fab053374d808c90dSteve Block bool is_full() const { return top_ >= high_; } 6244f0eee88ff00398ff7f715fab053374d808c90dSteve Block 6344f0eee88ff00398ff7f715fab053374d808c90dSteve Block bool is_empty() const { return top_ <= low_; } 6444f0eee88ff00398ff7f715fab053374d808c90dSteve Block 6544f0eee88ff00398ff7f715fab053374d808c90dSteve Block bool overflowed() const { return overflowed_; } 6644f0eee88ff00398ff7f715fab053374d808c90dSteve Block 6744f0eee88ff00398ff7f715fab053374d808c90dSteve Block void clear_overflowed() { overflowed_ = false; } 6844f0eee88ff00398ff7f715fab053374d808c90dSteve Block 6944f0eee88ff00398ff7f715fab053374d808c90dSteve Block // Push the (marked) object on the marking stack if there is room, 7044f0eee88ff00398ff7f715fab053374d808c90dSteve Block // otherwise mark the object as overflowed and wait for a rescan of the 7144f0eee88ff00398ff7f715fab053374d808c90dSteve Block // heap. 7244f0eee88ff00398ff7f715fab053374d808c90dSteve Block void Push(HeapObject* object) { 7344f0eee88ff00398ff7f715fab053374d808c90dSteve Block CHECK(object->IsHeapObject()); 7444f0eee88ff00398ff7f715fab053374d808c90dSteve Block if (is_full()) { 7544f0eee88ff00398ff7f715fab053374d808c90dSteve Block object->SetOverflow(); 7644f0eee88ff00398ff7f715fab053374d808c90dSteve Block overflowed_ = true; 7744f0eee88ff00398ff7f715fab053374d808c90dSteve Block } else { 7844f0eee88ff00398ff7f715fab053374d808c90dSteve Block *(top_++) = object; 7944f0eee88ff00398ff7f715fab053374d808c90dSteve Block } 8044f0eee88ff00398ff7f715fab053374d808c90dSteve Block } 8144f0eee88ff00398ff7f715fab053374d808c90dSteve Block 8244f0eee88ff00398ff7f715fab053374d808c90dSteve Block HeapObject* Pop() { 8344f0eee88ff00398ff7f715fab053374d808c90dSteve Block ASSERT(!is_empty()); 8444f0eee88ff00398ff7f715fab053374d808c90dSteve Block HeapObject* object = *(--top_); 8544f0eee88ff00398ff7f715fab053374d808c90dSteve Block CHECK(object->IsHeapObject()); 8644f0eee88ff00398ff7f715fab053374d808c90dSteve Block return object; 8744f0eee88ff00398ff7f715fab053374d808c90dSteve Block } 8844f0eee88ff00398ff7f715fab053374d808c90dSteve Block 8944f0eee88ff00398ff7f715fab053374d808c90dSteve Block private: 9044f0eee88ff00398ff7f715fab053374d808c90dSteve Block HeapObject** low_; 9144f0eee88ff00398ff7f715fab053374d808c90dSteve Block HeapObject** top_; 9244f0eee88ff00398ff7f715fab053374d808c90dSteve Block HeapObject** high_; 9344f0eee88ff00398ff7f715fab053374d808c90dSteve Block bool overflowed_; 9444f0eee88ff00398ff7f715fab053374d808c90dSteve Block 9544f0eee88ff00398ff7f715fab053374d808c90dSteve Block DISALLOW_COPY_AND_ASSIGN(MarkingStack); 9644f0eee88ff00398ff7f715fab053374d808c90dSteve Block}; 97a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 98a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 99a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// ------------------------------------------------------------------------- 100a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// Mark-Compact collector 101a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 10244f0eee88ff00398ff7f715fab053374d808c90dSteve Blockclass OverflowedObjectsScanner; 10344f0eee88ff00398ff7f715fab053374d808c90dSteve Block 10444f0eee88ff00398ff7f715fab053374d808c90dSteve Blockclass MarkCompactCollector { 105a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block public: 106a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Type of functions to compute forwarding addresses of objects in 107a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // compacted spaces. Given an object and its size, return a (non-failure) 108a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Object* that will be the object after forwarding. There is a separate 109a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // allocation function for each (compactable) space based on the location 110a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // of the object before compaction. 11144f0eee88ff00398ff7f715fab053374d808c90dSteve Block typedef MaybeObject* (*AllocationFunction)(Heap* heap, 11244f0eee88ff00398ff7f715fab053374d808c90dSteve Block HeapObject* object, 1135913587db4c6bab03d97bfe44b06289fd6d7270dJohn Reck int object_size); 114a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 115a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Type of functions to encode the forwarding address for an object. 116a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Given the object, its size, and the new (non-failure) object it will be 117a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // forwarded to, encode the forwarding address. For paged spaces, the 118a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 'offset' input/output parameter contains the offset of the forwarded 119a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // object from the forwarding address of the previous live object in the 120a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // page as input, and is updated to contain the offset to be used for the 121a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // next live object in the same page. For spaces using a different 122a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // encoding (ie, contiguous spaces), the offset parameter is ignored. 12344f0eee88ff00398ff7f715fab053374d808c90dSteve Block typedef void (*EncodingFunction)(Heap* heap, 12444f0eee88ff00398ff7f715fab053374d808c90dSteve Block HeapObject* old_object, 125a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int object_size, 126a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block Object* new_object, 127a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int* offset); 128a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 129a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Type of functions to process non-live objects. 1308b112d2025046f85ef7f6be087c6129c872ebad2Ben Murdoch typedef void (*ProcessNonLiveFunction)(HeapObject* object, Isolate* isolate); 131a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 13244f0eee88ff00398ff7f715fab053374d808c90dSteve Block // Pointer to member function, used in IterateLiveObjects. 13344f0eee88ff00398ff7f715fab053374d808c90dSteve Block typedef int (MarkCompactCollector::*LiveObjectCallback)(HeapObject* obj); 13444f0eee88ff00398ff7f715fab053374d808c90dSteve Block 135a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Set the global force_compaction flag, it must be called before Prepare 136a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // to take effect. 13744f0eee88ff00398ff7f715fab053374d808c90dSteve Block void SetForceCompaction(bool value) { 138a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block force_compaction_ = value; 139a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 140a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 141756813857a4c2a4d8ad2e805969d5768d3cf43a0Iain Merrick 142756813857a4c2a4d8ad2e805969d5768d3cf43a0Iain Merrick static void Initialize(); 143756813857a4c2a4d8ad2e805969d5768d3cf43a0Iain Merrick 144a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Prepares for GC by resetting relocation info in old and map spaces and 145a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // choosing spaces to compact. 14644f0eee88ff00398ff7f715fab053374d808c90dSteve Block void Prepare(GCTracer* tracer); 147a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 148a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Performs a global garbage collection. 14944f0eee88ff00398ff7f715fab053374d808c90dSteve Block void CollectGarbage(); 150a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 151a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // True if the last full GC performed heap compaction. 15244f0eee88ff00398ff7f715fab053374d808c90dSteve Block bool HasCompacted() { return compacting_collection_; } 153a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 154a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // True after the Prepare phase if the compaction is taking place. 15544f0eee88ff00398ff7f715fab053374d808c90dSteve Block bool IsCompacting() { 156e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke#ifdef DEBUG 157e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke // For the purposes of asserts we don't want this to keep returning true 158e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke // after the collection is completed. 159e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke return state_ != IDLE && compacting_collection_; 160e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke#else 161e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke return compacting_collection_; 162e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke#endif 163e46be819fca9468a0cd4e74859ce0f778eb8ca60Leon Clarke } 164a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 165a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // The count of the number of objects left marked at the end of the last 166a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // completed full GC (expected to be zero). 16744f0eee88ff00398ff7f715fab053374d808c90dSteve Block int previous_marked_count() { return previous_marked_count_; } 168a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 169a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // During a full GC, there is a stack-allocated GCTracer that is used for 170a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // bookkeeping information. Return a pointer to that tracer. 17144f0eee88ff00398ff7f715fab053374d808c90dSteve Block GCTracer* tracer() { return tracer_; } 172a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 173a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#ifdef DEBUG 174a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Checks whether performing mark-compact collection. 17544f0eee88ff00398ff7f715fab053374d808c90dSteve Block bool in_use() { return state_ > PREPARE_GC; } 17644f0eee88ff00398ff7f715fab053374d808c90dSteve Block bool are_map_pointers_encoded() { return state_ == UPDATE_POINTERS; } 177a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#endif 178a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 179d91b9f7d46489a9ee00f9cb415630299c76a502bLeon Clarke // Determine type of object and emit deletion log event. 1808b112d2025046f85ef7f6be087c6129c872ebad2Ben Murdoch static void ReportDeleteIfNeeded(HeapObject* obj, Isolate* isolate); 1818a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang 1828a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang // Returns size of a possibly marked object. 1838a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang static int SizeOfMarkedObject(HeapObject* obj); 184d91b9f7d46489a9ee00f9cb415630299c76a502bLeon Clarke 18580d68eab642096c1a48b6474d6ec33064b0ad1f5Kristian Monsen // Distinguishable invalid map encodings (for single word and multiple words) 18680d68eab642096c1a48b6474d6ec33064b0ad1f5Kristian Monsen // that indicate free regions. 18780d68eab642096c1a48b6474d6ec33064b0ad1f5Kristian Monsen static const uint32_t kSingleFreeEncoding = 0; 18880d68eab642096c1a48b6474d6ec33064b0ad1f5Kristian Monsen static const uint32_t kMultiFreeEncoding = 1; 18980d68eab642096c1a48b6474d6ec33064b0ad1f5Kristian Monsen 19044f0eee88ff00398ff7f715fab053374d808c90dSteve Block inline Heap* heap() const { return heap_; } 19144f0eee88ff00398ff7f715fab053374d808c90dSteve Block 19244f0eee88ff00398ff7f715fab053374d808c90dSteve Block CodeFlusher* code_flusher() { return code_flusher_; } 19344f0eee88ff00398ff7f715fab053374d808c90dSteve Block inline bool is_code_flushing_enabled() const { return code_flusher_ != NULL; } 19444f0eee88ff00398ff7f715fab053374d808c90dSteve Block void EnableCodeFlushing(bool enable); 19544f0eee88ff00398ff7f715fab053374d808c90dSteve Block 196a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block private: 19744f0eee88ff00398ff7f715fab053374d808c90dSteve Block MarkCompactCollector(); 19844f0eee88ff00398ff7f715fab053374d808c90dSteve Block ~MarkCompactCollector(); 19944f0eee88ff00398ff7f715fab053374d808c90dSteve Block 200a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#ifdef DEBUG 201a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block enum CollectorState { 202a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block IDLE, 203a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block PREPARE_GC, 204a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block MARK_LIVE_OBJECTS, 205a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block SWEEP_SPACES, 206a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block ENCODE_FORWARDING_ADDRESSES, 207a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block UPDATE_POINTERS, 2087f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch RELOCATE_OBJECTS 209a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block }; 210a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 211a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // The current stage of the collector. 21244f0eee88ff00398ff7f715fab053374d808c90dSteve Block CollectorState state_; 213a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#endif 214a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 215a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Global flag that forces a compaction. 21644f0eee88ff00398ff7f715fab053374d808c90dSteve Block bool force_compaction_; 217a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 218a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Global flag indicating whether spaces were compacted on the last GC. 21944f0eee88ff00398ff7f715fab053374d808c90dSteve Block bool compacting_collection_; 220a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 221a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Global flag indicating whether spaces will be compacted on the next GC. 22244f0eee88ff00398ff7f715fab053374d808c90dSteve Block bool compact_on_next_gc_; 223a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 224a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // The number of objects left marked at the end of the last completed full 225a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // GC (expected to be zero). 22644f0eee88ff00398ff7f715fab053374d808c90dSteve Block int previous_marked_count_; 227a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 228a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // A pointer to the current stack-allocated GC tracer object during a full 229a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // collection (NULL before and after). 23044f0eee88ff00398ff7f715fab053374d808c90dSteve Block GCTracer* tracer_; 231a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 232a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Finishes GC, performs heap verification if enabled. 23344f0eee88ff00398ff7f715fab053374d808c90dSteve Block void Finish(); 234a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 235a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // ----------------------------------------------------------------------- 236a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Phase 1: Marking live objects. 237a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 238a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Before: The heap has been prepared for garbage collection by 239a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // MarkCompactCollector::Prepare() and is otherwise in its 240a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // normal state. 241a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 242a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // After: Live objects are marked and non-live objects are unmarked. 243a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 244a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 245a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block friend class RootMarkingVisitor; 246a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block friend class MarkingVisitor; 247756813857a4c2a4d8ad2e805969d5768d3cf43a0Iain Merrick friend class StaticMarkingVisitor; 248756813857a4c2a4d8ad2e805969d5768d3cf43a0Iain Merrick friend class CodeMarkingVisitor; 249756813857a4c2a4d8ad2e805969d5768d3cf43a0Iain Merrick friend class SharedFunctionInfoMarkingVisitor; 250756813857a4c2a4d8ad2e805969d5768d3cf43a0Iain Merrick 25144f0eee88ff00398ff7f715fab053374d808c90dSteve Block void PrepareForCodeFlushing(); 252a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 253a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Marking operations for objects reachable from roots. 25444f0eee88ff00398ff7f715fab053374d808c90dSteve Block void MarkLiveObjects(); 255a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 25644f0eee88ff00398ff7f715fab053374d808c90dSteve Block void MarkUnmarkedObject(HeapObject* obj); 257a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 25844f0eee88ff00398ff7f715fab053374d808c90dSteve Block inline void MarkObject(HeapObject* obj) { 259a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (!obj->IsMarked()) MarkUnmarkedObject(obj); 260a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 261a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 26244f0eee88ff00398ff7f715fab053374d808c90dSteve Block inline void SetMark(HeapObject* obj); 263a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 264a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Creates back pointers for all map transitions, stores them in 265a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // the prototype field. The original prototype pointers are restored 266a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // in ClearNonLiveTransitions(). All JSObject maps 267a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // connected by map transitions have the same prototype object, which 268a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // is why we can use this field temporarily for back pointers. 26944f0eee88ff00398ff7f715fab053374d808c90dSteve Block void CreateBackPointers(); 270a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 271a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Mark a Map and its DescriptorArray together, skipping transitions. 27244f0eee88ff00398ff7f715fab053374d808c90dSteve Block void MarkMapContents(Map* map); 27344f0eee88ff00398ff7f715fab053374d808c90dSteve Block void MarkDescriptorArray(DescriptorArray* descriptors); 274a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 275a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Mark the heap roots and all objects reachable from them. 27644f0eee88ff00398ff7f715fab053374d808c90dSteve Block void MarkRoots(RootMarkingVisitor* visitor); 277a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 278a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Mark the symbol table specially. References to symbols from the 279a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // symbol table are weak. 28044f0eee88ff00398ff7f715fab053374d808c90dSteve Block void MarkSymbolTable(); 281a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 282a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Mark objects in object groups that have at least one object in the 283a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // group marked. 28444f0eee88ff00398ff7f715fab053374d808c90dSteve Block void MarkObjectGroups(); 28544f0eee88ff00398ff7f715fab053374d808c90dSteve Block 28644f0eee88ff00398ff7f715fab053374d808c90dSteve Block // Mark objects in implicit references groups if their parent object 28744f0eee88ff00398ff7f715fab053374d808c90dSteve Block // is marked. 28844f0eee88ff00398ff7f715fab053374d808c90dSteve Block void MarkImplicitRefGroups(); 289a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 29044f0eee88ff00398ff7f715fab053374d808c90dSteve Block // Mark all objects which are reachable due to host application 29144f0eee88ff00398ff7f715fab053374d808c90dSteve Block // logic like object groups or implicit references' groups. 29244f0eee88ff00398ff7f715fab053374d808c90dSteve Block void ProcessExternalMarking(); 293a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 294a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Mark objects reachable (transitively) from objects in the marking stack 295a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // or overflowed in the heap. 29644f0eee88ff00398ff7f715fab053374d808c90dSteve Block void ProcessMarkingStack(); 297a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 298a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Mark objects reachable (transitively) from objects in the marking 299a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // stack. This function empties the marking stack, but may leave 300a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // overflowed objects in the heap, in which case the marking stack's 301a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // overflow flag will be set. 30244f0eee88ff00398ff7f715fab053374d808c90dSteve Block void EmptyMarkingStack(); 303a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 304a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Refill the marking stack with overflowed objects from the heap. This 305a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // function either leaves the marking stack full or clears the overflow 306a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // flag on the marking stack. 30744f0eee88ff00398ff7f715fab053374d808c90dSteve Block void RefillMarkingStack(); 308a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 3093fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch // After reachable maps have been marked process per context object 3103fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch // literal map caches removing unmarked entries. 3113fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch void ProcessMapCaches(); 3123fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch 313a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Callback function for telling whether the object *p is an unmarked 314a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // heap object. 315a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block static bool IsUnmarkedHeapObject(Object** p); 316a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 317a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#ifdef DEBUG 31844f0eee88ff00398ff7f715fab053374d808c90dSteve Block void UpdateLiveObjectCount(HeapObject* obj); 319a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#endif 320a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 321a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // We sweep the large object space in the same way whether we are 322a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // compacting or not, because the large object space is never compacted. 32344f0eee88ff00398ff7f715fab053374d808c90dSteve Block void SweepLargeObjectSpace(); 324a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 325a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Test whether a (possibly marked) object is a Map. 326a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block static inline bool SafeIsMap(HeapObject* object); 327a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 328a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Map transitions from a live map to a dead map must be killed. 329a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // We replace them with a null descriptor, with the same key. 33044f0eee88ff00398ff7f715fab053374d808c90dSteve Block void ClearNonLiveTransitions(); 331a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 332a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // ----------------------------------------------------------------------- 333a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Phase 2: Sweeping to clear mark bits and free non-live objects for 334a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // a non-compacting collection, or else computing and encoding 335a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // forwarding addresses for a compacting collection. 336a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 337a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Before: Live objects are marked and non-live objects are unmarked. 338a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 339a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // After: (Non-compacting collection.) Live objects are unmarked, 340a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // non-live regions have been added to their space's free 341a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // list. 342a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 343a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // After: (Compacting collection.) The forwarding address of live 344a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // objects in the paged spaces is encoded in their map word 345a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // along with their (non-forwarded) map pointer. 346a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 347a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // The forwarding address of live objects in the new space is 348a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // written to their map word's offset in the inactive 349a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // semispace. 350a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 3517f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // Bookkeeping data is written to the page header of 352a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // eached paged-space page that contains live objects after 353a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // compaction: 354a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 3557f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // The allocation watermark field is used to track the 3567f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // relocation top address, the address of the first word 3577f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // after the end of the last live object in the page after 3587f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // compaction. 359a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 3607f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // The Page::mc_page_index field contains the zero-based index of the 3617f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // page in its space. This word is only used for map space pages, in 362a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // order to encode the map addresses in 21 bits to free 11 363a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // bits per map word for the forwarding address. 364a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 3657f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // The Page::mc_first_forwarded field contains the (nonencoded) 3667f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // forwarding address of the first live object in the page. 367a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 368a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // In both the new space and the paged spaces, a linked list 369a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // of live regions is constructructed (linked through 370a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // pointers in the non-live region immediately following each 371a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // live region) to speed further passes of the collector. 372a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 373a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Encodes forwarding addresses of objects in compactable parts of the 374a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // heap. 37544f0eee88ff00398ff7f715fab053374d808c90dSteve Block void EncodeForwardingAddresses(); 376a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 377a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Encodes the forwarding addresses of objects in new space. 37844f0eee88ff00398ff7f715fab053374d808c90dSteve Block void EncodeForwardingAddressesInNewSpace(); 379a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 380a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Function template to encode the forwarding addresses of objects in 381a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // paged spaces, parameterized by allocation and non-live processing 382a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // functions. 383a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block template<AllocationFunction Alloc, ProcessNonLiveFunction ProcessNonLive> 38444f0eee88ff00398ff7f715fab053374d808c90dSteve Block void EncodeForwardingAddressesInPagedSpace(PagedSpace* space); 385a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 386a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Iterates live objects in a space, passes live objects 387a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // to a callback function which returns the heap size of the object. 388a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Returns the number of live objects iterated. 38944f0eee88ff00398ff7f715fab053374d808c90dSteve Block int IterateLiveObjects(NewSpace* space, LiveObjectCallback size_f); 39044f0eee88ff00398ff7f715fab053374d808c90dSteve Block int IterateLiveObjects(PagedSpace* space, LiveObjectCallback size_f); 391a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 392a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Iterates the live objects between a range of addresses, returning the 393a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // number of live objects. 39444f0eee88ff00398ff7f715fab053374d808c90dSteve Block int IterateLiveObjectsInRange(Address start, Address end, 39544f0eee88ff00398ff7f715fab053374d808c90dSteve Block LiveObjectCallback size_func); 396a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 397a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // If we are not compacting the heap, we simply sweep the spaces except 398a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // for the large object space, clearing mark bits and adding unmarked 399a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // regions to each space's free list. 40044f0eee88ff00398ff7f715fab053374d808c90dSteve Block void SweepSpaces(); 401a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 402a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // ----------------------------------------------------------------------- 403a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Phase 3: Updating pointers in live objects. 404a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 405a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Before: Same as after phase 2 (compacting collection). 406a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 407a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // After: All pointers in live objects, including encoded map 408a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // pointers, are updated to point to their target's new 4097f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // location. 410a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 411a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block friend class UpdatingVisitor; // helper for updating visited objects 412a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 413a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Updates pointers in all spaces. 41444f0eee88ff00398ff7f715fab053374d808c90dSteve Block void UpdatePointers(); 415a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 416a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Updates pointers in an object in new space. 417a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Returns the heap size of the object. 41844f0eee88ff00398ff7f715fab053374d808c90dSteve Block int UpdatePointersInNewObject(HeapObject* obj); 419a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 420a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Updates pointers in an object in old spaces. 421a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Returns the heap size of the object. 42244f0eee88ff00398ff7f715fab053374d808c90dSteve Block int UpdatePointersInOldObject(HeapObject* obj); 423a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 424a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Calculates the forwarding address of an object in an old space. 425a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block static Address GetForwardingAddressInOldSpace(HeapObject* obj); 426a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 427a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // ----------------------------------------------------------------------- 428a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Phase 4: Relocating objects. 429a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 430a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Before: Pointers to live objects are updated to point to their 4317f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // target's new location. 432a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 4337f4d5bd8c03935e2c0cd412e561b8fc5a6a880aeBen Murdoch // After: Objects have been moved to their new addresses. 434a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 435a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Relocates objects in all spaces. 43644f0eee88ff00398ff7f715fab053374d808c90dSteve Block void RelocateObjects(); 437a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 438a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Converts a code object's inline target to addresses, convention from 439a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // address to target happens in the marking phase. 44044f0eee88ff00398ff7f715fab053374d808c90dSteve Block int ConvertCodeICTargetToAddress(HeapObject* obj); 441a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 442a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Relocate a map object. 44344f0eee88ff00398ff7f715fab053374d808c90dSteve Block int RelocateMapObject(HeapObject* obj); 444a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 445a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Relocates an old object. 44644f0eee88ff00398ff7f715fab053374d808c90dSteve Block int RelocateOldPointerObject(HeapObject* obj); 44744f0eee88ff00398ff7f715fab053374d808c90dSteve Block int RelocateOldDataObject(HeapObject* obj); 448a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 449a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Relocate a property cell object. 45044f0eee88ff00398ff7f715fab053374d808c90dSteve Block int RelocateCellObject(HeapObject* obj); 451a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 452a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Helper function. 45344f0eee88ff00398ff7f715fab053374d808c90dSteve Block inline int RelocateOldNonCodeObject(HeapObject* obj, 45444f0eee88ff00398ff7f715fab053374d808c90dSteve Block PagedSpace* space); 455a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 456a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Relocates an object in the code space. 45744f0eee88ff00398ff7f715fab053374d808c90dSteve Block int RelocateCodeObject(HeapObject* obj); 458a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 459a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Copy a new object. 46044f0eee88ff00398ff7f715fab053374d808c90dSteve Block int RelocateNewObject(HeapObject* obj); 461a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 462a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#ifdef DEBUG 463a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // ----------------------------------------------------------------------- 464a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Debugging variables, functions and classes 465a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Counters used for debugging the marking phase of mark-compact or 466a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // mark-sweep collection. 467a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 4686ded16be15dd865a9b21ea304d5273c8be299c87Steve Block // Size of live objects in Heap::to_space_. 46944f0eee88ff00398ff7f715fab053374d808c90dSteve Block int live_young_objects_size_; 470a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 4716ded16be15dd865a9b21ea304d5273c8be299c87Steve Block // Size of live objects in Heap::old_pointer_space_. 47244f0eee88ff00398ff7f715fab053374d808c90dSteve Block int live_old_pointer_objects_size_; 473a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 4746ded16be15dd865a9b21ea304d5273c8be299c87Steve Block // Size of live objects in Heap::old_data_space_. 47544f0eee88ff00398ff7f715fab053374d808c90dSteve Block int live_old_data_objects_size_; 476a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 4776ded16be15dd865a9b21ea304d5273c8be299c87Steve Block // Size of live objects in Heap::code_space_. 47844f0eee88ff00398ff7f715fab053374d808c90dSteve Block int live_code_objects_size_; 479a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 4806ded16be15dd865a9b21ea304d5273c8be299c87Steve Block // Size of live objects in Heap::map_space_. 48144f0eee88ff00398ff7f715fab053374d808c90dSteve Block int live_map_objects_size_; 482a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 4836ded16be15dd865a9b21ea304d5273c8be299c87Steve Block // Size of live objects in Heap::cell_space_. 48444f0eee88ff00398ff7f715fab053374d808c90dSteve Block int live_cell_objects_size_; 485a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 4866ded16be15dd865a9b21ea304d5273c8be299c87Steve Block // Size of live objects in Heap::lo_space_. 48744f0eee88ff00398ff7f715fab053374d808c90dSteve Block int live_lo_objects_size_; 488a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 489a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Number of live bytes in this collection. 49044f0eee88ff00398ff7f715fab053374d808c90dSteve Block int live_bytes_; 491a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 492a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block friend class MarkObjectVisitor; 493a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block static void VisitObject(HeapObject* obj); 494a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 495a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block friend class UnmarkObjectVisitor; 496a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block static void UnmarkObject(HeapObject* obj); 497a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#endif 49844f0eee88ff00398ff7f715fab053374d808c90dSteve Block 49944f0eee88ff00398ff7f715fab053374d808c90dSteve Block Heap* heap_; 50044f0eee88ff00398ff7f715fab053374d808c90dSteve Block MarkingStack marking_stack_; 50144f0eee88ff00398ff7f715fab053374d808c90dSteve Block CodeFlusher* code_flusher_; 50244f0eee88ff00398ff7f715fab053374d808c90dSteve Block 50344f0eee88ff00398ff7f715fab053374d808c90dSteve Block friend class Heap; 50444f0eee88ff00398ff7f715fab053374d808c90dSteve Block friend class OverflowedObjectsScanner; 505a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block}; 506a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 507a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 508a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block} } // namespace v8::internal 509a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 510a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block#endif // V8_MARK_COMPACT_H_ 511