[SR-6810] Timer does not fire in Linux, if added into .commonModes

[swift-ci]

Previous ID	SR-6810
Radar	None
Original Reporter	ttflee (JIRA User)
Type	Bug

Attachment: Download

Environment

Ubuntu 14.04, 16.04

Swift 4.0.3

Additional Detail from JIRA

Votes	0
Component/s	Foundation
Labels	Bug, Linux
Assignee	@millenomi
Priority	Medium

md5: 8a1f53554802145e87b26cf3d865b8f8

Issue Description:

Timer added to .commonModes could not be fired in Ubuntu 14.04/Swift 4.0.3 RELEASE. On the contrary, Dispatch Source Timer does work smoothly.

The open sourced implementations of CFRunLoopAddSource(), CFRunLoopAddObserver(), CFRunLoopAddTimer() etc., compare modeName against kCFRunLoopCommonModes using identity (==) rather than equality (CFEqual()). This might be the root cause of the issue and others.

[swift-ci]

Comment by Zhang Chen (JIRA)

`Timer.scheduledTimer(withTimeInterval:repeats:block)` works.

[swift-ci]

Comment by Zhang Chen (JIRA)

The reason seems to be that commonModes is not supported in RunLoop for Linux.

[swift-ci]

Comment by Zhang Chen (JIRA)

The CFRunLoop implementation compares run loop mode name against kCFRunLoopCommonModes using identity of C string, rather than CFEqual().