"
 COPYRIGHT (c) 1996-2011 by Claus Gittinger

 New code and modifications 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

 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 contains a signature
     of one of the above copright owners. For exact set of such code,
     see the differences between this version and version stx:libjava
     as of 1.9.2010
"
"{ Package: 'stx:libjava' }"

Object subclass:#JavaMonitor
	instanceVariableNames:'owningProcess processesEntered monitorSema count waitingSema
		processesWaiting waitEnabled ownerPrintString'
	classVariableNames:'instVarAccess'
	poolDictionaries:''
	category:'Languages-Java-Support'
!

!JavaMonitor class methodsFor:'documentation'!

copyright
"
 COPYRIGHT (c) 1996-2011 by Claus Gittinger

 New code and modifications 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

 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 contains a signature
     of one of the above copright owners. For exact set of such code,
     see the differences between this version and version stx:libjava
     as of 1.9.2010

"
! !

!JavaMonitor class methodsFor:'initialization'!

initialize
instVarAccess := RecursionLock forMutualExclusion.

    "Created: / 29-11-2011 / 11:23:56 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
! !

!JavaMonitor class methodsFor:'instance creation'!

for: owningObject
    ^ self basicNew initializeFor: owningObject.

    "Created: / 30-11-2011 / 20:39:55 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!

for: owningObject thread: threadOrNil nestedLockCount: count
    ^ self basicNew initializeFor: owningObject thread: threadOrNil nestedLockCount: count

    "Created: / 26-08-2012 / 17:01:43 / Jan Vrany <jan.vrany@fit.cvut.cz>"
! !

!JavaMonitor methodsFor:'accessing'!

activeProcess
    ^ Processor activeProcess
!

copyProcessesEntered
    ^ processesEntered copy.

    "Created: / 20-11-2011 / 14:45:24 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!

count
    ^ count
!

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 
    instVarAccess critical: [ processesEntered add: aProcess ].

    "Created: / 20-11-2011 / 20:30:07 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!

clearOwningProcess
    instVarAccess 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"
    
    instVarAccess critical: [ count := count - 1 ].

    "Created: / 22-11-2011 / 10:49:33 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!

disableWait
    Logger log: ('Waiting is disabled on monitor for %1' bindWith: ownerPrintString) severity:#debug facility:#JVM.
    instVarAccess critical: [ waitEnabled := false ].

    "Created: / 30-11-2011 / 20:34:40 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
    "Modified: / 10-05-2012 / 00:24:05 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

enableWait
instVarAccess critical: [waitEnabled := true].

    "Created: / 30-11-2011 / 20:34:31 / 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"
    
    instVarAccess critical: [ count := count + 1 ].

    "Created: / 22-11-2011 / 10:49:07 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
    "Modified: / 27-08-2012 / 10:42:11 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

owningProcess: aProcess 
    instVarAccess critical: [ owningProcess := aProcess ].

    "Created: / 20-11-2011 / 20:32:26 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!

processesWaitingAdd: aProcess 
    instVarAccess 
        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 
    instVarAccess 
        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"
    
    instVarAccess critical: [ count := 1 ].

    "Created: / 22-11-2011 / 10:51:09 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!

reinitCounter: newCount 
    instVarAccess critical: [ count := newCount ].

    "Created: / 22-11-2011 / 13:00:51 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!

removeProcess: aProcess 
    instVarAccess 
        critical: [
            self assert: processesEntered last == aProcess.
            processesEntered remove: aProcess
        ].

    "Created: / 20-11-2011 / 20:28:37 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!

waitEnabled
    instVarAccess critical: [ ^ waitEnabled].

    "Created: / 30-11-2011 / 20:34:56 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
! !

!JavaMonitor methodsFor:'initialization'!

initialize
    owningProcess := nil.
    processesEntered := OrderedCollection new.
    monitorSema := Semaphore new: 1.
    processesWaiting := Dictionary new.
    waitingSema := Semaphore new: 0.
    waitEnabled.

    "Created: / 20-11-2011 / 13:28:28 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!

initializeFor: owningObject
    self initializeFor: owningObject thread: 0 nestedLockCount: 0.

    "Created: / 30-11-2011 / 20:39:31 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
    "Modified: / 26-08-2012 / 17:25:55 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

initializeFor:owningObject thread:threadId nestedLockCount:cnt 

"/    self assert: (owningObject isJavaObject or:[owningObject isJavaClass]).

    processesEntered := OrderedCollection new.
    waitEnabled := true.
    processesWaiting := Dictionary new.
    waitingSema := Semaphore new:0.
    ownerPrintString := owningObject class name , '@' , owningObject identityHash printString.

    "/Not locked...    
    threadId == 0 ifTrue:[
        monitorSema := Semaphore new:1.
        count := 0.
        ^self.
    ] ifFalse: [
        "threadId is not zero (zero is threadId of scheduler process, which will never try to acquire the monitor)"
        "so it means it is possible that the thin lock is already locked for other thread, we must be careful " 

        owningProcess := Process findProcessWithId:threadId.
        self assert: owningProcess notNil.
        processesEntered add: owningProcess.  
        cnt timesRepeat:[
"/            JavaVM enteredMonitorsOf:  owningProcess add: owningObject.
"/            JavaVM acquiredMonitorsOf: owningProcess add: owningObject.
        ].
        monitorSema := Semaphore new: 0.
        count := cnt.
    ].

    "Created: / 26-08-2012 / 17:02:29 / Jan Vrany <jan.vrany@fit.cvut.cz>"
! !

!JavaMonitor methodsFor:'public'!

acquire
    | thisProcess |
    thisProcess := self activeProcess.
    (self isOwnedBy: thisProcess) ifTrue: [
        self increment.
        ^ self
    ].
    monitorSema wait.
    self owningProcess: thisProcess.
    count := 1.

    "Created: / 20-11-2011 / 13:21:46 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
    "Modified: / 27-08-2012 / 11:45:46 / Jan Vrany <jan.vrany@fit.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 ifAbsent: nil.

    "Created: / 20-11-2011 / 13:21:54 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
    "Modified: / 26-08-2012 / 19:54:14 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

notify
    "wakeup one waiting process"
    
    | thisProcess |
    thisProcess := Processor activeProcess.
    self assert: (self isOwnedBy: thisProcess).
    Logger 
        log: ('%1: notifying %2 processes' bindWith: thisProcess printString
                with: processesWaiting size)
        severity: #debug
        facility: #JVM.
    waitingSema signal.
    Processor yield.

    "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).
    Logger 
        log: ('%1: notifying all %2 processes' bindWith: thisProcess printString
                with: processesWaiting size)
        severity: #debug
        facility: #JVM.
    waitingSema signalForAll.
    Processor yield.

    "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.
        count := 0.
        monitorSema signal.
    ] ifFalse: [
        self decrement.       
    ]

    "Created: / 20-11-2011 / 13:21:52 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
    "Modified: / 27-08-2012 / 11:44:59 / Jan Vrany <jan.vrany@fit.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 waitEnabled ifFalse: [
        Logger 
            log: ('%1 wanted to go to sleep, but it cant, this monitor is for %2 which is already dead' 
                    bindWith: thisProcess printString
                    with: ownerPrintString)
            severity: #debug
            facility: #JVM.
        ^ self.
    ].
    Logger 
        log: ('%1 is going to wait on %3 for timeout: %2' 
                bindWith: thisProcess printString
                with: timeOut
                with: ownerPrintString printString)
        severity: #debug
        facility: #JVM.
    self processesWaitingAdd: thisProcess.
    self releaseAll.
     "JV@2011-11-25: zero timeout means wait without timeout!!!!!!"
    timeOut == 0 ifTrue: [ waitingSema wait ] ifFalse: [
        waitingSema waitWithTimeoutMs: timeOut
    ].
    Logger 
        log: ('%1 has been notified and is trying to acquire monitor for %2 which is owned by %3' 
                bindWith: thisProcess printString with: ownerPrintString printString with: owningProcess printString)
        severity: #debug
        facility: #JVM.
    self acquire.
    self processesWaitingRestore: thisProcess.

    "Created: / 22-11-2011 / 12:52:45 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
    "Modified: / 01-12-2011 / 10:57:52 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
    "Modified: / 10-05-2012 / 00:24:10 / Jan Vrany <jan.vrany@fit.cvut.cz>"
! !

!JavaMonitor methodsFor:'queries'!

isAcquired
    ^ instVarAccess critical: [ owningProcess notNil ].

    "Created: / 20-11-2011 / 13:22:26 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
!

isOwnedBy: aProcess 
    ^ instVarAccess critical: [ owningProcess == aProcess ].

    "Created: / 20-11-2011 / 13:23:14 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"
! !

!JavaMonitor class methodsFor:'documentation'!

version_SVN
    ^ '$Id$'
! !

JavaMonitor initialize!