[SR-6391] Repeated invocation of ProcessInfo.hostname causes unbounded heap growth

[swift-ci]

Previous ID	SR-6391
Radar	None
Original Reporter	swizzlr (JIRA User)
Type	Bug
Status	In Progress
Resolution

Additional Detail from JIRA

Votes	0
Component/s	Foundation
Labels	Bug
Assignee	swizzlr (JIRA)
Priority	Medium

md5: eb2a2f92784172873e4d6e8c88472cf1

Issue Description:

This was a fun bug to track down. `massif` is amazing, tho.

https://github.com/apple/swift-corelibs-foundation/blob/swift-4.0-branch/Foundation/Host.swift#L85 is the line where _addresses is appended to with a string.

_resolveCurrent() is called by _resolve() when `_resolved` is set to false. The bug is here: `_resolved` is, as far as I can tell, never set to `true`.

_resolve() is called in the `names` getter; the `names` getter is called by `name`'s getter, which is called by ProcessInfo.hostname against the `Host.current()` object.

Fix is to set _resolved to `true` after `_resolveCurrent()` succeeds.

Workaround is to cache the hostname elsewhere.

[swift-ci]

Comment by Thomas Catterall (JIRA)

#1320