1 // Copyright 2015 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/array-buffer-tracker.h"
6 #include "src/heap/array-buffer-tracker-inl.h"
7 #include "src/heap/heap.h"
8
9 namespace v8 {
10 namespace internal {
11
~LocalArrayBufferTracker()12 LocalArrayBufferTracker::~LocalArrayBufferTracker() {
13 CHECK(array_buffers_.empty());
14 }
15
16 template <LocalArrayBufferTracker::FreeMode free_mode>
Free()17 void LocalArrayBufferTracker::Free() {
18 size_t freed_memory = 0;
19 for (TrackingData::iterator it = array_buffers_.begin();
20 it != array_buffers_.end();) {
21 JSArrayBuffer* buffer = reinterpret_cast<JSArrayBuffer*>(it->first);
22 if ((free_mode == kFreeAll) ||
23 Marking::IsWhite(ObjectMarking::MarkBitFrom(buffer))) {
24 const size_t len = it->second;
25 heap_->isolate()->array_buffer_allocator()->Free(buffer->backing_store(),
26 len);
27 freed_memory += len;
28 it = array_buffers_.erase(it);
29 } else {
30 ++it;
31 }
32 }
33 if (freed_memory > 0) {
34 heap_->update_external_memory_concurrently_freed(
35 static_cast<intptr_t>(freed_memory));
36 }
37 }
38
39 template <typename Callback>
Process(Callback callback)40 void LocalArrayBufferTracker::Process(Callback callback) {
41 JSArrayBuffer* new_buffer = nullptr;
42 size_t freed_memory = 0;
43 for (TrackingData::iterator it = array_buffers_.begin();
44 it != array_buffers_.end();) {
45 const CallbackResult result = callback(it->first, &new_buffer);
46 if (result == kKeepEntry) {
47 ++it;
48 } else if (result == kUpdateEntry) {
49 DCHECK_NOT_NULL(new_buffer);
50 Page* target_page = Page::FromAddress(new_buffer->address());
51 // We need to lock the target page because we cannot guarantee
52 // exclusive access to new space pages.
53 if (target_page->InNewSpace()) target_page->mutex()->Lock();
54 LocalArrayBufferTracker* tracker = target_page->local_tracker();
55 if (tracker == nullptr) {
56 target_page->AllocateLocalTracker();
57 tracker = target_page->local_tracker();
58 }
59 DCHECK_NOT_NULL(tracker);
60 tracker->Add(new_buffer, it->second);
61 if (target_page->InNewSpace()) target_page->mutex()->Unlock();
62 it = array_buffers_.erase(it);
63 } else if (result == kRemoveEntry) {
64 const size_t len = it->second;
65 heap_->isolate()->array_buffer_allocator()->Free(
66 it->first->backing_store(), len);
67 freed_memory += len;
68 it = array_buffers_.erase(it);
69 } else {
70 UNREACHABLE();
71 }
72 }
73 if (freed_memory > 0) {
74 heap_->update_external_memory_concurrently_freed(
75 static_cast<intptr_t>(freed_memory));
76 }
77 }
78
FreeDeadInNewSpace(Heap * heap)79 void ArrayBufferTracker::FreeDeadInNewSpace(Heap* heap) {
80 DCHECK_EQ(heap->gc_state(), Heap::HeapState::SCAVENGE);
81 for (Page* page : NewSpacePageRange(heap->new_space()->FromSpaceStart(),
82 heap->new_space()->FromSpaceEnd())) {
83 bool empty = ProcessBuffers(page, kUpdateForwardedRemoveOthers);
84 CHECK(empty);
85 }
86 heap->account_external_memory_concurrently_freed();
87 }
88
FreeDead(Page * page)89 void ArrayBufferTracker::FreeDead(Page* page) {
90 // Callers need to ensure having the page lock.
91 LocalArrayBufferTracker* tracker = page->local_tracker();
92 if (tracker == nullptr) return;
93 DCHECK(!page->SweepingDone());
94 tracker->Free<LocalArrayBufferTracker::kFreeDead>();
95 if (tracker->IsEmpty()) {
96 page->ReleaseLocalTracker();
97 }
98 }
99
FreeAll(Page * page)100 void ArrayBufferTracker::FreeAll(Page* page) {
101 LocalArrayBufferTracker* tracker = page->local_tracker();
102 if (tracker == nullptr) return;
103 tracker->Free<LocalArrayBufferTracker::kFreeAll>();
104 if (tracker->IsEmpty()) {
105 page->ReleaseLocalTracker();
106 }
107 }
108
ProcessBuffers(Page * page,ProcessingMode mode)109 bool ArrayBufferTracker::ProcessBuffers(Page* page, ProcessingMode mode) {
110 LocalArrayBufferTracker* tracker = page->local_tracker();
111 if (tracker == nullptr) return true;
112
113 DCHECK(page->SweepingDone());
114 tracker->Process(
115 [mode](JSArrayBuffer* old_buffer, JSArrayBuffer** new_buffer) {
116 MapWord map_word = old_buffer->map_word();
117 if (map_word.IsForwardingAddress()) {
118 *new_buffer = JSArrayBuffer::cast(map_word.ToForwardingAddress());
119 return LocalArrayBufferTracker::kUpdateEntry;
120 }
121 return mode == kUpdateForwardedKeepOthers
122 ? LocalArrayBufferTracker::kKeepEntry
123 : LocalArrayBufferTracker::kRemoveEntry;
124 });
125 return tracker->IsEmpty();
126 }
127
IsTracked(JSArrayBuffer * buffer)128 bool ArrayBufferTracker::IsTracked(JSArrayBuffer* buffer) {
129 Page* page = Page::FromAddress(buffer->address());
130 {
131 base::LockGuard<base::Mutex> guard(page->mutex());
132 LocalArrayBufferTracker* tracker = page->local_tracker();
133 if (tracker == nullptr) return false;
134 return tracker->IsTracked(buffer);
135 }
136 }
137
138 } // namespace internal
139 } // namespace v8
140