1 // Copyright 2011 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "src/heap/store-buffer.h" 6 7 #include <algorithm> 8 9 #include "src/counters.h" 10 #include "src/heap/incremental-marking.h" 11 #include "src/isolate.h" 12 #include "src/objects-inl.h" 13 #include "src/v8.h" 14 15 namespace v8 { 16 namespace internal { 17 18 StoreBuffer::StoreBuffer(Heap* heap) 19 : heap_(heap), 20 top_(nullptr), 21 start_(nullptr), 22 limit_(nullptr), 23 virtual_memory_(nullptr) {} 24 25 void StoreBuffer::SetUp() { 26 // Allocate 3x the buffer size, so that we can start the new store buffer 27 // aligned to 2x the size. This lets us use a bit test to detect the end of 28 // the area. 29 virtual_memory_ = new base::VirtualMemory(kStoreBufferSize * 2); 30 uintptr_t start_as_int = 31 reinterpret_cast<uintptr_t>(virtual_memory_->address()); 32 start_ = reinterpret_cast<Address*>(RoundUp(start_as_int, kStoreBufferSize)); 33 limit_ = start_ + (kStoreBufferSize / kPointerSize); 34 35 DCHECK(reinterpret_cast<Address>(start_) >= virtual_memory_->address()); 36 DCHECK(reinterpret_cast<Address>(limit_) >= virtual_memory_->address()); 37 Address* vm_limit = reinterpret_cast<Address*>( 38 reinterpret_cast<char*>(virtual_memory_->address()) + 39 virtual_memory_->size()); 40 DCHECK(start_ <= vm_limit); 41 DCHECK(limit_ <= vm_limit); 42 USE(vm_limit); 43 DCHECK((reinterpret_cast<uintptr_t>(limit_) & kStoreBufferMask) == 0); 44 45 if (!virtual_memory_->Commit(reinterpret_cast<Address>(start_), 46 kStoreBufferSize, 47 false)) { // Not executable. 48 V8::FatalProcessOutOfMemory("StoreBuffer::SetUp"); 49 } 50 top_ = start_; 51 } 52 53 54 void StoreBuffer::TearDown() { 55 delete virtual_memory_; 56 top_ = start_ = limit_ = nullptr; 57 } 58 59 60 void StoreBuffer::StoreBufferOverflow(Isolate* isolate) { 61 isolate->heap()->store_buffer()->MoveEntriesToRememberedSet(); 62 isolate->counters()->store_buffer_overflows()->Increment(); 63 } 64 65 void StoreBuffer::MoveEntriesToRememberedSet() { 66 if (top_ == start_) return; 67 DCHECK(top_ <= limit_); 68 for (Address* current = start_; current < top_; current++) { 69 DCHECK(!heap_->code_space()->Contains(*current)); 70 Address addr = *current; 71 Page* page = Page::FromAnyPointerAddress(heap_, addr); 72 RememberedSet<OLD_TO_NEW>::Insert(page, addr); 73 } 74 top_ = start_; 75 } 76 77 } // namespace internal 78 } // namespace v8 79
