stream: do not unconditionally call `_read()` on `resume()` #26965

addaleax · 2019-03-28T20:17:19Z

readable.resume() calls .read(0), which in turn previously set
needReadable = true, and so a subsequent .read() call would
call _read() even though enough data was already available.

This can lead to elevated memory usage, because calling _read()
when enough data is in the readable buffer means that backpressure
is not being honoured.

Fixes: #26957

Checklist

make -j4 test (UNIX), or vcbuild test (Windows) passes
tests and/or benchmarks are included
commit message follows commit guidelines

`readable.resume()` calls `.read(0)`, which in turn previously set `needReadable = true`, and so a subsequent `.read()` call would call `_read()` even though enough data was already available. This can lead to elevated memory usage, because calling `_read()` when enough data is in the readable buffer means that backpressure is not being honoured. Fixes: nodejs#26957

nodejs-github-bot · 2019-03-28T20:17:22Z

@addaleax Sadly, an error occurred when I tried to trigger a build. :(

addaleax · 2019-03-28T20:18:25Z

/cc @nodejs/streams PTAL – does this look like the right approach to you? I’m particularly unsure if this bit makes sense in the first place:

node/lib/_stream_readable.js

Lines 440 to 441 in 2c73868

    
           // if we need a readable event, then we need to do some reading. 
        
           var doRead = state.needReadable;

mcollina

LGTM

mcollina · 2019-03-28T20:20:24Z

This makes sense to me. However this is so complex that we might found a bug in 6 months ;).

nodejs-github-bot · 2019-03-28T20:21:35Z

CI: https://ci.nodejs.org/job/node-test-pull-request/21992/

zbjornson · 2019-03-28T22:04:20Z

🙌 this fixes the buffering part of #25057. (I believe it's still technically possible for read() to bite off more from the internal buffer than can be concatenated, but now that buffer shouldn't be >kMaxLength.)

ronag · 2019-03-31T12:02:06Z

May I suggest we fast-track this?

addaleax · 2019-03-31T12:15:23Z

@ronag This is ready to be merged anyway – I’d be careful about backporting a change like this to LTS faster than usual. I understand that this is an important fix, but at the same time we’ve run into issues with streams changes breaking people’s code much more often than we’d like. /cc @nodejs/lts

Landed in 20c3ac2

`readable.resume()` calls `.read(0)`, which in turn previously set `needReadable = true`, and so a subsequent `.read()` call would call `_read()` even though enough data was already available. This can lead to elevated memory usage, because calling `_read()` when enough data is in the readable buffer means that backpressure is not being honoured. Fixes: #26957 PR-URL: #26965 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Luigi Pinca <[email protected]> Reviewed-By: Ruben Bridgewater <[email protected]>

`readable.resume()` calls `.read(0)`, which in turn previously set `needReadable = true`, and so a subsequent `.read()` call would call `_read()` even though enough data was already available. This can lead to elevated memory usage, because calling `_read()` when enough data is in the readable buffer means that backpressure is not being honoured. Fixes: #26957 PR-URL: #26965 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Luigi Pinca <[email protected]> Reviewed-By: Ruben Bridgewater <[email protected]> Signed-off-by: Beth Griggs <[email protected]>

mcollina · 2019-06-03T09:48:40Z

@nodejs/releasers would you mind bacporting this in the next Node 10 release? thanks!

ronag · 2019-07-03T08:49:16Z

@mcollina any news here? This is rather serious for us and we have no LTS to fallback to...

mcollina · 2019-07-03T09:30:00Z

@ronag what's the question? Are you asking for this to be included in the next version of Node v10?

mcollina · 2019-07-03T09:30:47Z

@nodejs/lts would you mind backporting this?

`readable.resume()` calls `.read(0)`, which in turn previously set `needReadable = true`, and so a subsequent `.read()` call would call `_read()` even though enough data was already available. This can lead to elevated memory usage, because calling `_read()` when enough data is in the readable buffer means that backpressure is not being honoured. Fixes: #26957 PR-URL: #26965 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Luigi Pinca <[email protected]> Reviewed-By: Ruben Bridgewater <[email protected]>

Notable changes: - **stream**: do not unconditionally call `\_read()` on `resume()` (Anna Henningsen) [#26965](#26965) - **worker**: fix nullptr deref after MessagePort deser failure (Anna Henningsen) [#25076](#25076)

Notable changes: - **deps**: upgrade openssl sources to 1.1.1c (Sam Roberts) [#28212](#28212) - **stream**: do not unconditionally call `\_read()` on `resume()` (Anna Henningsen) [#26965](#26965) - **worker**: fix nullptr deref after MessagePort deser failure (Anna Henningsen) [#25076](#25076) PR-URL: #28731

addaleax added stream Issues and PRs related to the stream subsystem. lts-watch-v6.x labels Mar 28, 2019

mcollina approved these changes Mar 28, 2019

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lpinca approved these changes Mar 28, 2019

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addaleax mentioned this pull request Mar 28, 2019

http: Memory Leak #26957

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BridgeAR approved these changes Mar 28, 2019

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BridgeAR added the author ready PRs that have at least one approval, no pending requests for changes, and a CI started. label Mar 28, 2019

addaleax mentioned this pull request Mar 28, 2019

Unexpected RangeError [ERR_INVALID_OPT_VALUE] while reading from a HTTP download stream #25057

Closed

addaleax closed this Mar 31, 2019

addaleax deleted the resume-read0 branch March 31, 2019 12:15

BethGriggs mentioned this pull request Apr 9, 2019

v11.14.0 proposal #27163

Merged

BethGriggs added land-on-v10.x and removed lts-watch-v10.x labels Jul 9, 2019

BethGriggs mentioned this pull request Jul 17, 2019

v10.16.1 proposal #28731

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Hakerh400 mentioned this pull request Jul 26, 2019

httpresponse pause()/resume() leads to out-of-memory error when using local server nodejs/help#2074

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BethGriggs removed the lts-watch-v8.x label Sep 19, 2019

zamnuts mentioned this pull request Mar 3, 2020

Node 8 deprecation party 🎉 googleapis/google-cloud-node#2972

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stream: do not unconditionally call `_read()` on `resume()` #26965

stream: do not unconditionally call `_read()` on `resume()` #26965

addaleax commented Mar 28, 2019

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mcollina commented Jul 3, 2019

stream: do not unconditionally call _read() on resume() #26965

stream: do not unconditionally call _read() on resume() #26965

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mcollina commented Jul 3, 2019

stream: do not unconditionally call `_read()` on `resume()` #26965

stream: do not unconditionally call `_read()` on `resume()` #26965