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| 1 | +// Copyright 2020 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 | +namespace runtime { |
| 6 | + extern runtime |
| 7 | + ShrinkFinalizationRegistryUnregisterTokenMap(Context, JSFinalizationRegistry): |
| 8 | + void; |
| 9 | +} |
| 10 | + |
| 11 | +namespace weakref { |
| 12 | + extern transitioning macro |
| 13 | + RemoveFinalizationRegistryCellFromUnregisterTokenMap( |
| 14 | + JSFinalizationRegistry, WeakCell): void; |
| 15 | + |
| 16 | + macro SplitOffTail(weakCell: WeakCell): WeakCell|Undefined { |
| 17 | + const weakCellTail = weakCell.next; |
| 18 | + weakCell.next = Undefined; |
| 19 | + typeswitch (weakCellTail) { |
| 20 | + case (Undefined): { |
| 21 | + } |
| 22 | + case (tailIsNowAHead: WeakCell): { |
| 23 | + assert(tailIsNowAHead.prev == weakCell); |
| 24 | + tailIsNowAHead.prev = Undefined; |
| 25 | + } |
| 26 | + } |
| 27 | + return weakCellTail; |
| 28 | + } |
| 29 | + |
| 30 | + transitioning macro |
| 31 | + PopClearedCell(finalizationRegistry: JSFinalizationRegistry): WeakCell |
| 32 | + |Undefined { |
| 33 | + typeswitch (finalizationRegistry.cleared_cells) { |
| 34 | + case (Undefined): { |
| 35 | + return Undefined; |
| 36 | + } |
| 37 | + case (weakCell: WeakCell): { |
| 38 | + assert(weakCell.prev == Undefined); |
| 39 | + finalizationRegistry.cleared_cells = SplitOffTail(weakCell); |
| 40 | + |
| 41 | + // If the WeakCell has an unregister token, remove the cell from the |
| 42 | + // unregister token linked lists and and the unregister token from |
| 43 | + // key_map. This doesn't shrink key_map, which is done manually after |
| 44 | + // the cleanup loop to avoid a runtime call. |
| 45 | + if (weakCell.unregister_token != Undefined) { |
| 46 | + RemoveFinalizationRegistryCellFromUnregisterTokenMap( |
| 47 | + finalizationRegistry, weakCell); |
| 48 | + } |
| 49 | + |
| 50 | + return weakCell; |
| 51 | + } |
| 52 | + } |
| 53 | + } |
| 54 | + |
| 55 | + transitioning macro |
| 56 | + FinalizationRegistryCleanupLoop(implicit context: Context)( |
| 57 | + finalizationRegistry: JSFinalizationRegistry, callback: Callable) { |
| 58 | + while (true) { |
| 59 | + const weakCellHead = PopClearedCell(finalizationRegistry); |
| 60 | + typeswitch (weakCellHead) { |
| 61 | + case (Undefined): { |
| 62 | + break; |
| 63 | + } |
| 64 | + case (weakCell: WeakCell): { |
| 65 | + try { |
| 66 | + Call(context, callback, Undefined, weakCell.holdings); |
| 67 | + } catch (e) { |
| 68 | + runtime::ShrinkFinalizationRegistryUnregisterTokenMap( |
| 69 | + context, finalizationRegistry); |
| 70 | + ReThrow(context, e); |
| 71 | + } |
| 72 | + } |
| 73 | + } |
| 74 | + } |
| 75 | + |
| 76 | + runtime::ShrinkFinalizationRegistryUnregisterTokenMap( |
| 77 | + context, finalizationRegistry); |
| 78 | + } |
| 79 | + |
| 80 | + transitioning javascript builtin |
| 81 | + FinalizationRegistryPrototypeCleanupSome( |
| 82 | + js-implicit context: NativeContext, |
| 83 | + receiver: JSAny)(...arguments): JSAny { |
| 84 | + // 1. Let finalizationRegistry be the this value. |
| 85 | + // |
| 86 | + // 2. Perform ? RequireInternalSlot(finalizationRegistry, [[Cells]]). |
| 87 | + const methodName: constexpr string = |
| 88 | + 'FinalizationRegistry.prototype.cleanupSome'; |
| 89 | + const finalizationRegistry = |
| 90 | + Cast<JSFinalizationRegistry>(receiver) otherwise ThrowTypeError( |
| 91 | + MessageTemplate::kIncompatibleMethodReceiver, methodName, receiver); |
| 92 | + |
| 93 | + let callback: Callable; |
| 94 | + if (arguments[0] != Undefined) { |
| 95 | + // 4. If callback is not undefined and IsCallable(callback) is |
| 96 | + // false, throw a TypeError exception. |
| 97 | + callback = Cast<Callable>(arguments[0]) otherwise ThrowTypeError( |
| 98 | + MessageTemplate::kWeakRefsCleanupMustBeCallable, arguments[0]); |
| 99 | + } else { |
| 100 | + callback = finalizationRegistry.cleanup; |
| 101 | + } |
| 102 | + |
| 103 | + FinalizationRegistryCleanupLoop(finalizationRegistry, callback); |
| 104 | + return Undefined; |
| 105 | + } |
| 106 | +} |
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