Ok. I wrote MutextTests which show problems. See in attachment.��

Attached Mutex.st contains fix which suggest Ben for his scenario. But it broke other scenario.��

Mutex>>critical: aBlock

"Evaluate aBlock protected by the receiver."

| activeProcess signalRequired blockValue |

activeProcess := Processor activeProcess.

activeProcess == owner ifTrue:[^aBlock value].

signalRequired := false.

[

signalRequired := true.

semaphore wait.

owner:= activeProcess.

blockValue := aBlock value

] ensure: [signalRequired & (owner == activeProcess) ifTrue: [owner := nil. semaphore signal]].

^blockValue

My idea of ifCurtailed: usage not helps too. But if you change MutexTest to use Semaphore instead of Mutex then all tests will be green.