Hi Levente,

You are right. I removed the test from trunk.

The AbstractSharedQueueTest>>testContention2 test in CollectionsTests-jar.349
is a useful description of the current behavior, so may want to refer
to that if the differences cause problems.

Sorry for the noise.

Dave

On Sat, Feb 13, 2021 at 10:12:39PM +0100, Levente Uzonyi wrote:
> Hi David,
> 
> While these tests pass now and document something about shared queues, I 
> don't think we should have them in the Trunk.
> I prefer the design-by-contract approach for tests where there are 
> actual requirements to be satisfied by the subject of the tests to make 
> them pass.
> These tests do not describe such requirements, so if the implementations 
> change, they'll start failing, which some may interpret wrongly as actual 
> errors.
> Another problem with them is that people may feel like they can relying on 
> the behavior described by these tests since there are tests for them.
> 
> 
> Levente
> 
> On Sat, 13 Feb 2021, commits at source.squeak.org wrote:
> 
> >David T. Lewis uploaded a new version of CollectionsTests to project The 
> >Trunk:
> >http://source.squeak.org/trunk/CollectionsTests-jar.349.mcz
> >
> >==================== Summary ====================
> >
> >Name: CollectionsTests-jar.349
> >Author: jar
> >Time: 8 February 2021, 8:25:19.407373 pm
> >UUID: f484ba2b-2035-b046-9222-c3e4e42a7ad4
> >Ancestors: CollectionsTests-ul.348
> >
> >Test to show differing SharedQueue and SharedQueue2 semantics
> >
> >=============== Diff against CollectionsTests-ul.348 ===============
> >
> >Item was added:
> >+ ----- Method: AbstractSharedQueueTest>>testContention2 (in category 
> >'tests') -----
> >+ testContention2
> >+ 	"and here's a test case that distunguishes SharedQueue from 
> >SharedQueue2 semantics:
> >+ 	SharedQueue2 produces a sequence #(5 10 15) while SharedQueue 
> >produces #(5 15 10)"
> >+ 
> >+ 	| q r1 r2 r3 |
> >+ 	q := self queueClass new.
> >+ 
> >+ 	[ r1 := q next. q nextPut: 15. r3 := q next ] fork.
> >+ 	[ r2 := q next ] fork.
> >+ 
> >+ 	Processor  yield.   "let the above two threads block"
> >+ 
> >+ 	q nextPut: 5.
> >+ 	Processor yield.    "let the first thread above proceed"
> >+ 
> >+ 	q nextPut: 10.
> >+ 	Processor yield.    "let the unfinished thread above finish"
> >+ 
> >+ 	q class = SharedQueue2 ifTrue: [
> >+ 		self assert: 5 equals: r1.
> >+ 		self assert: 10 equals: r2.
> >+ 		self assert: 15 equals: r3.
> >+ 		self assert: nil equals: q nextOrNil ].
> >+ 
> >+ 	q class = SharedQueue ifTrue: [
> >+ 		self assert: 5 equals: r1.
> >+ 		self assert: 15 equals: r2.
> >+ 		self assert: 10 equals: r3.
> >+ 		self assert: nil equals: q nextOrNil ].
> >+ 
> >+ "SharedQueue2 implementation using a Monitor checks the queue for 
> >available data while + the SharedQueue implementation based on a Semaphore 
> >checks for excessSignals > 0, + which results in these two different 
> >outcomes"!
>