Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 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/compilation-dependencies.h" |
| 6 | |
| 7 | #include "src/factory.h" |
| 8 | #include "src/handles-inl.h" |
| 9 | #include "src/isolate.h" |
| 10 | #include "src/objects-inl.h" |
| 11 | #include "src/zone.h" |
| 12 | |
| 13 | namespace v8 { |
| 14 | namespace internal { |
| 15 | |
| 16 | DependentCode* CompilationDependencies::Get(Handle<Object> object) { |
| 17 | if (object->IsMap()) { |
| 18 | return Handle<Map>::cast(object)->dependent_code(); |
| 19 | } else if (object->IsPropertyCell()) { |
| 20 | return Handle<PropertyCell>::cast(object)->dependent_code(); |
| 21 | } else if (object->IsAllocationSite()) { |
| 22 | return Handle<AllocationSite>::cast(object)->dependent_code(); |
| 23 | } |
| 24 | UNREACHABLE(); |
| 25 | return nullptr; |
| 26 | } |
| 27 | |
| 28 | |
| 29 | void CompilationDependencies::Set(Handle<Object> object, |
| 30 | Handle<DependentCode> dep) { |
| 31 | if (object->IsMap()) { |
| 32 | Handle<Map>::cast(object)->set_dependent_code(*dep); |
| 33 | } else if (object->IsPropertyCell()) { |
| 34 | Handle<PropertyCell>::cast(object)->set_dependent_code(*dep); |
| 35 | } else if (object->IsAllocationSite()) { |
| 36 | Handle<AllocationSite>::cast(object)->set_dependent_code(*dep); |
| 37 | } else { |
| 38 | UNREACHABLE(); |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | |
| 43 | void CompilationDependencies::Insert(DependentCode::DependencyGroup group, |
| 44 | Handle<HeapObject> object) { |
| 45 | if (groups_[group] == nullptr) { |
| 46 | groups_[group] = new (zone_) ZoneList<Handle<HeapObject>>(2, zone_); |
| 47 | } |
| 48 | groups_[group]->Add(object, zone_); |
| 49 | |
| 50 | if (object_wrapper_.is_null()) { |
| 51 | // Allocate the wrapper if necessary. |
| 52 | object_wrapper_ = |
| 53 | isolate_->factory()->NewForeign(reinterpret_cast<Address>(this)); |
| 54 | } |
| 55 | |
| 56 | // Get the old dependent code list. |
| 57 | Handle<DependentCode> old_dependent_code = |
| 58 | Handle<DependentCode>(Get(object), isolate_); |
| 59 | Handle<DependentCode> new_dependent_code = |
| 60 | DependentCode::InsertCompilationDependencies(old_dependent_code, group, |
| 61 | object_wrapper_); |
| 62 | |
| 63 | // Set the new dependent code list if the head of the list changed. |
| 64 | if (!new_dependent_code.is_identical_to(old_dependent_code)) { |
| 65 | Set(object, new_dependent_code); |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | |
| 70 | void CompilationDependencies::Commit(Handle<Code> code) { |
| 71 | if (IsEmpty()) return; |
| 72 | |
| 73 | DCHECK(!object_wrapper_.is_null()); |
| 74 | Handle<WeakCell> cell = Code::WeakCellFor(code); |
| 75 | AllowDeferredHandleDereference get_wrapper; |
| 76 | for (int i = 0; i < DependentCode::kGroupCount; i++) { |
| 77 | ZoneList<Handle<HeapObject>>* group_objects = groups_[i]; |
| 78 | if (group_objects == nullptr) continue; |
| 79 | DependentCode::DependencyGroup group = |
| 80 | static_cast<DependentCode::DependencyGroup>(i); |
| 81 | for (int j = 0; j < group_objects->length(); j++) { |
| 82 | DependentCode* dependent_code = Get(group_objects->at(j)); |
| 83 | dependent_code->UpdateToFinishedCode(group, *object_wrapper_, *cell); |
| 84 | } |
| 85 | groups_[i] = nullptr; // Zone-allocated, no need to delete. |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | |
| 90 | void CompilationDependencies::Rollback() { |
| 91 | if (IsEmpty()) return; |
| 92 | |
| 93 | AllowDeferredHandleDereference get_wrapper; |
| 94 | // Unregister from all dependent maps if not yet committed. |
| 95 | for (int i = 0; i < DependentCode::kGroupCount; i++) { |
| 96 | ZoneList<Handle<HeapObject>>* group_objects = groups_[i]; |
| 97 | if (group_objects == nullptr) continue; |
| 98 | DependentCode::DependencyGroup group = |
| 99 | static_cast<DependentCode::DependencyGroup>(i); |
| 100 | for (int j = 0; j < group_objects->length(); j++) { |
| 101 | DependentCode* dependent_code = Get(group_objects->at(j)); |
| 102 | dependent_code->RemoveCompilationDependencies(group, *object_wrapper_); |
| 103 | } |
| 104 | groups_[i] = nullptr; // Zone-allocated, no need to delete. |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | |
| 109 | void CompilationDependencies::AssumeMapNotDeprecated(Handle<Map> map) { |
| 110 | DCHECK(!map->is_deprecated()); |
| 111 | // Do nothing if the map cannot be deprecated. |
| 112 | if (map->CanBeDeprecated()) { |
| 113 | Insert(DependentCode::kTransitionGroup, map); |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | |
| 118 | void CompilationDependencies::AssumeMapStable(Handle<Map> map) { |
| 119 | DCHECK(map->is_stable()); |
| 120 | // Do nothing if the map cannot transition. |
| 121 | if (map->CanTransition()) { |
| 122 | Insert(DependentCode::kPrototypeCheckGroup, map); |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | |
| 127 | void CompilationDependencies::AssumePrototypeMapsStable( |
| 128 | Handle<Map> map, MaybeHandle<JSReceiver> prototype) { |
| 129 | for (PrototypeIterator i(map); !i.IsAtEnd(); i.Advance()) { |
| 130 | Handle<JSReceiver> const current = |
| 131 | PrototypeIterator::GetCurrent<JSReceiver>(i); |
| 132 | AssumeMapStable(handle(current->map())); |
| 133 | Handle<JSReceiver> last; |
| 134 | if (prototype.ToHandle(&last) && last.is_identical_to(current)) { |
| 135 | break; |
| 136 | } |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | |
| 141 | void CompilationDependencies::AssumeTransitionStable( |
| 142 | Handle<AllocationSite> site) { |
| 143 | // Do nothing if the object doesn't have any useful element transitions left. |
| 144 | ElementsKind kind = |
| 145 | site->SitePointsToLiteral() |
| 146 | ? JSObject::cast(site->transition_info())->GetElementsKind() |
| 147 | : site->GetElementsKind(); |
| 148 | if (AllocationSite::GetMode(kind) == TRACK_ALLOCATION_SITE) { |
| 149 | Insert(DependentCode::kAllocationSiteTransitionChangedGroup, site); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | } // namespace internal |
| 154 | } // namespace v8 |