"
COPYRIGHT (c) 1996-2011 by Claus Gittinger
New code and modification done at SWING Research Group [1]:
COPYRIGHT (c) 2010-2011 by Jan Vrany, Jan Kurs and Marcel Hlopko
SWING Research Group, Czech Technical University in Prague
Parts of the code written by Claus Gittinger are under following
license:
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
[1] Code written at SWING Research Group contain a signature
of one of the above copright owners. For exact set of such code
see the differences between this version and version stx:lib
as of 1.9.2010
"
"{ Package: 'stx:libjava' }"
Object subclass:#JavaMonitor
instanceVariableNames:'owningProcess processesEntered monitorSema processesEnteredAccess
owningProcessAccess count countAccess waitingSema
processesWaitingAccess processesWaiting'
classVariableNames:''
poolDictionaries:''
category:'Languages-Java-Support'
!
!JavaMonitor class methodsFor:'documentation'!
copyright
"
COPYRIGHT (c) 1996-2011 by Claus Gittinger
New code and modification done at SWING Research Group [1]:
COPYRIGHT (c) 2010-2011 by Jan Vrany, Jan Kurs and Marcel Hlopko
SWING Research Group, Czech Technical University in Prague
Parts of the code written by Claus Gittinger are under following
license:
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
[1] Code written at SWING Research Group contain a signature
of one of the above copright owners. For exact set of such code
see the differences between this version and version stx:lib
as of 1.9.2010
"
! !
!JavaMonitor class methodsFor:'instance creation'!
new
^self basicNew initialize.
"Created: / 20-11-2011 / 14:30:36 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
! !
!JavaMonitor methodsFor:'accessing'!
activeProcess
^ Processor activeProcess
!
copyProcessesEntered
^ processesEntered copy.
"Created: / 20-11-2011 / 14:45:24 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
processesEntered
"dont do anything to me, access needs to be sync'd"
^ processesEntered.
"Created: / 20-11-2011 / 13:22:15 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
! !
!JavaMonitor methodsFor:'atomic'!
addProcess: aProcess
processesEnteredAccess critical: [processesEntered add: aProcess].
"Created: / 20-11-2011 / 20:30:07 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
clearOwningProcess
owningProcessAccess critical: [ owningProcess := nil ].
"Created: / 20-11-2011 / 20:34:27 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
decrement
"owning process released monitor, lets lower our counter so we know how many times
do we have to release it"
countAccess critical: [ count := count - 1 ].
"Created: / 22-11-2011 / 10:49:33 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
increment
"owning process entered monitor again (recursion ...), lets raise our counter so we know how many times
do we have to release it"
countAccess critical: [ count := count + 1 ].
"Created: / 22-11-2011 / 10:49:07 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
owningProcess: aProcess
owningProcessAccess critical: [owningProcess := aProcess].
"Created: / 20-11-2011 / 20:32:26 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
processesWaitingAdd: aProcess
processesWaitingAccess
critical: [ self assert: (processesWaiting includesKey: aProcess) not.processesWaiting at: aProcess put: count ].
"Created: / 22-11-2011 / 11:57:50 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
processesWaitingRestore: aProcess
processesWaitingAccess
critical: [
self assert: (processesWaiting includesKey: aProcess).
self reinitCounter: (processesWaiting at: aProcess).
processesWaiting removeKey: aProcess
].
"Created: / 22-11-2011 / 12:59:14 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
reinitCounter
"owning process is different from previous, lets start counting from beginning"
countAccess critical: [ count := 1 ].
"Created: / 22-11-2011 / 10:51:09 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
reinitCounter: newCount
countAccess critical: [ count := newCount ].
"Created: / 22-11-2011 / 13:00:51 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
removeProcess: aProcess
processesEnteredAccess
critical: [
self assert: processesEntered last == aProcess.
processesEntered remove: aProcess
].
"Created: / 20-11-2011 / 20:28:37 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
! !
!JavaMonitor methodsFor:'initialization'!
initialize
owningProcess := nil.
owningProcessAccess := Semaphore forMutualExclusion.
processesEntered := OrderedCollection new.
processesEnteredAccess := Semaphore forMutualExclusion.
monitorSema := Semaphore new: 1.
countAccess := Semaphore forMutualExclusion.
processesWaiting := Dictionary new.
processesWaitingAccess := Semaphore forMutualExclusion.
waitingSema := Semaphore new: 0.
"Created: / 20-11-2011 / 13:28:28 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
! !
!JavaMonitor methodsFor:'public'!
acquire
| thisProcess |
thisProcess := self activeProcess.
(self isOwnedBy: thisProcess) ifTrue: [
self increment.
^ self
].
monitorSema wait.
self owningProcess: thisProcess.
self reinitCounter.
"Created: / 20-11-2011 / 13:21:46 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
enter
| thisProcess |
thisProcess := self activeProcess.
self addProcess: thisProcess.
self acquire.
"Created: / 20-11-2011 / 13:21:42 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
exit
| thisProcess |
thisProcess := self activeProcess.
(self isOwnedBy: thisProcess) ifTrue: [ self release. ].
processesEntered remove: thisProcess.
"Created: / 20-11-2011 / 13:21:54 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
notify
"wakeup one waiting process"
| thisProcess |
thisProcess := Processor activeProcess.
self assert: (self isOwnedBy: thisProcess).
waitingSema signal.
"Created: / 22-11-2011 / 12:14:23 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
notifyAll
"wakeup one waiting process"
| thisProcess |
thisProcess := Processor activeProcess.
self assert: (self isOwnedBy: thisProcess).
waitingSema signalForAll.
"Created: / 22-11-2011 / 12:14:36 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
release
| thisProcess |
thisProcess := self activeProcess.
self assert: (self isOwnedBy: owningProcess).
count == 1 ifTrue: [
self clearOwningProcess.
monitorSema signal.
] ifFalse: [
self decrement.
]
"Created: / 20-11-2011 / 13:21:52 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
releaseAll
count timesRepeat: [self release].
"Created: / 22-11-2011 / 13:05:20 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
wait
"make owning process to go to wait"
self waitForMilliseconds: nil.
"Created: / 22-11-2011 / 11:57:56 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
waitForMilliseconds: timeOut
"make owning process to go to wait, but not longer than timeout"
| thisProcess |
thisProcess := Processor activeProcess.
self assert: (self isOwnedBy: thisProcess).
self processesWaitingAdd: thisProcess.
self releaseAll.
waitingSema waitWithTimeoutMs: timeOut.
self acquire.
self processesWaitingRestore: thisProcess.
"Created: / 22-11-2011 / 12:52:45 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
! !
!JavaMonitor methodsFor:'queries'!
isAcquired
^ owningProcessAccess critical: [owningProcess notNil].
"Created: / 20-11-2011 / 13:22:26 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!
isOwnedBy: aProcess
^ owningProcessAccess critical: [ owningProcess == aProcess ].
"Created: / 20-11-2011 / 13:23:14 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
! !
!JavaMonitor class methodsFor:'documentation'!
version_SVN
^ '$Id$'
! !