envoyproxy/envoy

bug: lambda captures destruction order not determined.

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#7,184 opened on Jun 5, 2019

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Description

Title: [BUG] lambda captures destruction order not determined in http ConnectionManagerImpl factory callback.

Description:

In envoy/source/extensions/filters/network/http_connection_manager/config.cc when return the ConnectionManagerImpl factory callback, the created HttpConnectionManagerConfig instance "filter_config" takes reference of objects held by shared_ptr route_config_provider_manager and date_provider etc.

Per https://en.cppreference.com/w/cpp/language/lambda the order of captures construction(so destruction as well) is not determined. This may cause issue during destruction of the "filter_config" object.

Repro steps:

It's kinda hard to reproduce as it's compiler dependent. but a easy fix is to fix the order by capturing them in a temp struct or something similar before diving into the lambda.

Note: N/A

Admin and Stats Output: N/A Config: N/A

Logs:N/A Call Stack:N/A

Contributor guide

Research direction
Create a temporary struct to hold the captured references in a defined order to ensure proper destruction sequence.
Tech stack
cpp
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Mostly clear
Prerequisites
C++
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60