Core dump while adding to Set

[hemanth]

Version

v19.0.0-pre

Platform

Linux codespaces_2ecb6d 5.4.0-1074-azure #77~18.04.1-Ubuntu SMP Wed Mar 30 15:36:02 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

Subsystem

No response

What steps will reproduce the bug?

> all = new Set(require('module').builtinModules)
> all.forEach(k => all.add(`node:${k}`))

<--- Last few GCs --->

[7264:0x5592d00a66e0]   177263 ms: Mark-sweep 1959.9 (2091.2) -> 1958.8 (2091.2) MB, 56.9 / 0.0 ms  (average mu = 0.954, current mu = 0.739) allocation failure; scavenge might not succeed
[7264:0x5592d00a66e0]   177444 ms: Mark-sweep 1974.5 (2091.2) -> 1973.4 (2123.2) MB, 132.8 / 0.0 ms  (average mu = 0.839, current mu = 0.265) allocation failure; scavenge might not succeed


<--- JS stacktrace --->

FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory
 1: 0x5592ca8d4684 node::Abort() [node]
 2: 0x5592ca7c43ea node::FatalError(char const*, char const*) [node]
 3: 0x5592caaeff1a v8::Utils::ReportOOMFailure(v8::internal::Isolate*, char const*, bool) [node]
 4: 0x5592caaf01ff v8::internal::V8::FatalProcessOutOfMemory(v8::internal::Isolate*, char const*, bool) [node]
 5: 0x5592cacfd5e9  [node]
 6: 0x5592cad1124f v8::internal::Heap::CollectGarbage(v8::internal::AllocationSpace, v8::internal::GarbageCollectionReason, v8::GCCallbackFlags) [node]
 7: 0x5592cace7c17 v8::internal::HeapAllocator::AllocateRawWithLightRetrySlowPath(int, v8::internal::AllocationType, v8::internal::AllocationOrigin, v8::internal::AllocationAlignment) [node]
 8: 0x5592cace8f1b v8::internal::HeapAllocator::AllocateRawWithRetryOrFailSlowPath(int, v8::internal::AllocationType, v8::internal::AllocationOrigin, v8::internal::AllocationAlignment) [node]
 9: 0x5592cacc50d6 v8::internal::Factory::AllocateRaw(int, v8::internal::AllocationType, v8::internal::AllocationAlignment) [node]
10: 0x5592cacbcd98 v8::internal::FactoryBase<v8::internal::Factory>::AllocateRawWithImmortalMap(int, v8::internal::AllocationType, v8::internal::Map, v8::internal::AllocationAlignment) [node]
11: 0x5592cacbf22e v8::internal::FactoryBase<v8::internal::Factory>::NewRawOneByteString(int, v8::internal::AllocationType) [node]
12: 0x5592cb00e548 v8::internal::String::SlowFlatten(v8::internal::Isolate*, v8::internal::Handle<v8::internal::ConsString>, v8::internal::AllocationType) [node]
13: 0x5592cb0115f2 v8::internal::String::SlowEquals(v8::internal::Isolate*, v8::internal::Handle<v8::internal::String>, v8::internal::Handle<v8::internal::String>) [node]
14: 0x5592cb13730a v8::internal::Runtime_StringEqual(int, unsigned long*, v8::internal::Isolate*) [node]
15: 0x5592cb5bb0b9  [node]
Aborted (core dumped)

^ In REPL or Just script

How often does it reproduce? Is there a required condition?

Everytime

What is the expected behavior?

We should be able to add them all to the Set.

What do you see instead?

Core dump

Additional information

P.S: Same happen on v17+

[ljharb]

I think this might be because forEach visits newly added items - iow, this should work:

all = new Set(require('module').builtinModules)
[...all].forEach(k => all.add(`node:${k}`))

[hemanth]

Ah, so we live with it?

[ljharb]

Yep, it's the way forEach is supposed to work.