deps: V8: cherry-pick d3a1a5b6c491

Original commit message:

    [objects] Fix memory leak in PrototypeUsers::Add

    PrototypeUsers::Add now iterates the WeakArrayList to find empty slots
    before growing the array. Not reusing empty slots caused a memory leak.

    It might also be desirable to shrink the WeakArrayList in the future.
    Right now it is only compacted when invoking CreateBlob.

    Also removed unused PrototypeUsers::IsEmptySlot declaration.

    Bug: v8:10031
    Change-Id: I570ec78fca37e8f0c794f1f40846a4daab47c225
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1967317
    Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
    Reviewed-by: Igor Sheludko <ishell@chromium.org>
    Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#65456}

Refs: d3a1a5b6c4
Fixes: https://github.com/nodejs/node/issues/30753

PR-URL: https://github.com/nodejs/node/pull/31005
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Rich Trott <rtrott@gmail.com>
This commit is contained in:
Michaël Zasso
2019-12-17 17:44:07 +01:00
parent 38a593b0f3
commit 05041d3ab1
3 changed files with 18 additions and 2 deletions

View File

@@ -39,7 +39,7 @@
# Reset this number to 0 on major V8 upgrades.
# Increment by one for each non-official patch applied to deps/v8.
'v8_embedder_string': '-node.23',
'v8_embedder_string': '-node.24',
##### V8 defaults for Node.js #####

View File

@@ -4038,6 +4038,13 @@ Handle<WeakArrayList> PrototypeUsers::Add(Isolate* isolate,
// If there are empty slots, use one of them.
int empty_slot = Smi::ToInt(empty_slot_index(*array));
if (empty_slot == kNoEmptySlotsMarker) {
// GCs might have cleared some references, rescan the array for empty slots.
PrototypeUsers::ScanForEmptySlots(*array);
empty_slot = Smi::ToInt(empty_slot_index(*array));
}
if (empty_slot != kNoEmptySlotsMarker) {
DCHECK_GE(empty_slot, kFirstIndex);
CHECK_LT(empty_slot, array->length());
@@ -4060,6 +4067,15 @@ Handle<WeakArrayList> PrototypeUsers::Add(Isolate* isolate,
return array;
}
// static
void PrototypeUsers::ScanForEmptySlots(WeakArrayList array) {
for (int i = kFirstIndex; i < array.length(); i++) {
if (array.Get(i)->IsCleared()) {
PrototypeUsers::MarkSlotEmpty(array, i);
}
}
}
WeakArrayList PrototypeUsers::Compact(Handle<WeakArrayList> array, Heap* heap,
CompactionCallback callback,
AllocationType allocation) {

View File

@@ -99,7 +99,7 @@ class V8_EXPORT_PRIVATE PrototypeUsers : public WeakArrayList {
static inline Smi empty_slot_index(WeakArrayList array);
static inline void set_empty_slot_index(WeakArrayList array, int index);
static void IsSlotEmpty(WeakArrayList array, int index);
static void ScanForEmptySlots(WeakArrayList array);
DISALLOW_IMPLICIT_CONSTRUCTORS(PrototypeUsers);
};