--- a/RecursionLock.st	Tue Oct 21 00:41:22 2014 +0200
+++ b/RecursionLock.st	Tue Oct 21 21:19:55 2014 +0200
@@ -173,6 +173,22 @@
     ^ process notNil and:[Processor activeProcess ~~ process]
 ! !
 
+!RecursionLock methodsFor:'signaling'!
+
+signal
+    |wasBlocked|
+
+    process ~~ Processor activeProcess ifTrue:[
+        "I have already got the lock"
+        self error:'RecursionLock - signaling process doesn''t own the lock'.
+    ].
+
+    wasBlocked := OperatingSystem blockInterrupts.
+    process := nil.
+    sema signal.
+    wasBlocked ifFalse:[OperatingSystem unblockInterrupts].
+! !
+
 !RecursionLock methodsFor:'waiting'!
 
 critical:aBlock
@@ -297,15 +313,39 @@
     ].
 
     ^ retVal.
+!
+
+wait
+    "wait, but do not block,
+     if this lock is already held by the current process.
+     Answer false, if alread locked, true if lock has been just acquired."
+
+    |active wasBlocked|
+
+    active := Processor activeProcess.
+    process == active ifTrue:[
+        "I have already got the lock"
+        ^ false.
+    ].
+
+    wasBlocked := OperatingSystem blockInterrupts.
+    (process notNil and:[process isDead]) ifTrue:[
+        'RecursionLock [warning]: cleanup lock from dead process' infoPrintCR.
+        process := nil. sema signal.
+    ].
+    sema wait.
+    process := active.
+    wasBlocked ifFalse:[OperatingSystem unblockInterrupts].
+    ^ true.
 ! !
 
 !RecursionLock class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/RecursionLock.st,v 1.40 2014-02-16 12:51:38 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/RecursionLock.st,v 1.41 2014-10-21 19:19:55 stefan Exp $'
 !
 
 version_CVS
-    ^ '$Header: /cvs/stx/stx/libbasic/RecursionLock.st,v 1.40 2014-02-16 12:51:38 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/RecursionLock.st,v 1.41 2014-10-21 19:19:55 stefan Exp $'
 ! !