"

 COPYRIGHT (c) 1996-2015 by Claus Gittinger

 New code and modifications done at SWING Research Group [1]:

 COPYRIGHT (c) 2010-2015 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' }"

"{ NameSpace: Smalltalk }"

Object subclass:#JavaMonitor

	classVariableNames:''

	poolDictionaries:''

	category:'Languages-Java-Support'

!

!JavaMonitor class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1996-2015 by Claus Gittinger

 New code and modifications done at SWING Research Group [1]:

 COPYRIGHT (c) 2010-2015 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:'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'!

count

    ^ count

!

owningProcess

    "Return the process that has acquired (entered) the receiver or

     nil if no process currently has the monitor."

    "Created: / 12-08-2017 / 23:11:44 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

processesEntered

    "Return a alist of processes that entered the monitor. For testing / debugging purposes only!!"

        ifTrue:[ #() ]

    "Created: / 20-11-2011 / 13:22:15 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"

    "Modified (format): / 03-06-2017 / 23:10:31 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!JavaMonitor methodsFor:'atomic'!

disableWait

    JavaVM monitorTrace ifTrue:[

        Logger log: ('Waiting is disabled on monitor for %1' bindWith: ownerPrintString) severity:Logger severityDEBUG facility:#JVM.

    ].

    "/ critical region not needed here

    "/ self instVarAccessCritical: [ waitEnabled := false ].

    waitEnabled := false.

    "Created: / 30-11-2011 / 20:34:40 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"

    "Modified: / 02-03-2015 / 14:06:51 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

enableWait

    "/ critical region not needed here

    "/ self instVarAccessCritical: [waitEnabled := true].

    waitEnabled := true

    "Created: / 30-11-2011 / 20:34:31 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"

    "Modified (format): / 11-10-2013 / 11:17:58 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

waitEnabled

    "/ critical region not needed here

    "/ self instVarAccessCritical: [ ^ waitEnabled].

    ^ waitEnabled.

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

! !

!JavaMonitor methodsFor:'initialization'!

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>"

!

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

    waitEnabled := true.

    waitingSema := Semaphore new:0.

    ownerPrintString := owningObject class name , '@' , owningObject identityHash printString.

    threadId == 0 ifTrue:[

        count := 0.

        ^self.

    ] ifFalse: [

        "threadId is not zero (zero is threadId of scheduler process, which will never try to acquire the monitor)"

        cnt timesRepeat:[

"/            JavaVM enteredMonitorsOf:  owningProcess add: owningObject.

"/            JavaVM acquiredMonitorsOf: owningProcess add: owningObject.

        ].

        count := cnt.

    ].

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

    "Modified: / 03-06-2017 / 23:10:47 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!JavaMonitor methodsFor:'public'!

acquire

    "Acquire (enter) the monitor and return `true`.

     See JVM spec, section 4.5, MONITORENTER.

    "

        "/ Process already ackquired the monitor, increase the

        "/ count and continue...

        count := count + 1.

    ].

    wasBlocked := OperatingSystem blockInterrupts.

            "/ Process that acquired the monitor died without releasing it.

            "/ This should not happen.

            self assert: false description: 'Process that acquired the monitor died without releasing it'.

            count := 0.

        ].

        "/ We need to know that we already waited on and got semaphore

        "/ in case the Semaphore >> #wait is prematurely terminated.

        "/ Q: Can this actually happen? If so, how?

        count := 1.

        wasBlocked ifFalse:[OperatingSystem unblockInterrupts].

    ] ifCurtailed:[

            OperatingSystem blockInterrupts.

            count := 0.

        ].

    "Created: / 20-11-2011 / 13:21:46 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"

    "Modified: / 11-08-2017 / 22:08:16 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified (comment): / 14-08-2017 / 09:34:16 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

enter

    <resource: #obsolete>

    ^ self acquire.

    "Created: / 20-11-2011 / 13:21:42 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"

    "Modified: / 14-08-2017 / 10:20:31 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

exit

    <resource: #obsolete>

    ^ self release.

    "Created: / 20-11-2011 / 13:21:54 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"

    "Modified: / 14-08-2017 / 10:20:43 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

notify

    <resource: #obsolete>

    self obsoleteMethodWarning: 'Use `notify: false` instead'.

    ^ self notify: false.

    "Created: / 22-11-2011 / 12:14:23 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"

    "Modified: / 14-08-2017 / 10:19:59 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

notify: all

    "

    An implementation of java.lang.Object#notify() and #notifyAll(). If `all` is

    `true` then all waiting threads are notified (see #norifyAll()) otherwise only

    been notified or `false` if calling thread does not own the monitor.

    See Java API documentation for java.lang.Object#notify() and #notifyAll().

        https://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#notify()

        https://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#notifyAll()

    "

        "/ Oops,  calling thread does not own the monitor. return false

        "/ immediately. The caller is responsible for throwing

        "/ IllegalMonitorStateException...

        ^ false.

    ].

    JavaVM monitorTrace ifTrue:[

                    with: (all ifTrue:[ 'all ' ] ifFalse:[ '' ])

                    with: waitingSema waitingProcesses size)

            severity: Logger severityDEBUG

            facility: #JVM.

    ].

    all ifTrue:[ waitingSema signalForAll ] ifFalse:[ waitingSema signal ].

    Processor yield.

    ^ true

    "Created: / 14-08-2017 / 10:17:20 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

notifyAll

    <resource: #obsolete>

    self obsoleteMethodWarning: 'Use `notify: true` instead'.

    ^ self notify: true.

    "Created: / 22-11-2011 / 12:14:36 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"

    "Modified: / 14-08-2017 / 10:19:47 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

release

    "Release (leave) the monitor and return `true` if

     monitor was release, `false` if monitor has not

     been released (because calling thread does not own it).

    "

        "/ Oops,  calling thread does not own the monitor. return false

        "/ immediately. The caller is responsible for throwing

        "/ IllegalMonitorStateException...

        ^ false.

    ].

    wasBlocked := OperatingSystem blockInterrupts.

        count := 0.

        count := count - 1.

    ].

    wasBlocked ifFalse:[ OperatingSystem unblockInterrupts ].

    ^ true

    "Created: / 20-11-2011 / 13:21:52 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"

    "Modified: / 12-08-2017 / 21:28:38 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified (comment): / 14-08-2017 / 09:35:36 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

wait

    ^ self waitForMilliseconds: nil.

    "Created: / 22-11-2011 / 11:57:56 / Marcel Hlopko <hlopkmar@fel.cvut.cz>"

    "Modified: / 14-08-2017 / 09:37:18 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

    "

    An implementation of java.lang.Object#wait(long). Returns `true`

    after waiting or `false` immediately (i.e., won't block) if calling

    thread does not own the monitor.

    See Java API documentation for java.lang.Object#wait(long):

        https://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#wait(long)

    "

        "/ Oops,  calling thread does not own the monitor. return false

        "/ immediately. The caller is responsible for throwing

        "/ IllegalMonitorStateException...

        ^ false.

    ].

    self waitEnabled ifFalse: [

        JavaVM monitorTrace ifTrue:[

                        with: ownerPrintString)

                severity: Logger severityDEBUG

                facility: #JVM.

        ].

        ^ true.

    ].

    JavaVM monitorTrace ifTrue:[

                    with: timeOut

                    with: ownerPrintString printString)

            severity: #debug

            facility: #JVM.

    ].

    countBeforeWait := count.

    "/ Release the monitor so other thread can acquire it

    "/ and call #notify or #notifyAll

    count := 1. "/ note that at this point we still own the monitor

    self release.

    "/ Monitor released, wait...

     "JV@2011-11-25: zero timeout means wait without timeout!!!!!!"

    timeOut == 0 ifTrue: [ waitingSema wait ] ifFalse: [

        waitingSema waitWithTimeoutMs: timeOut

    ].

            severity: #debug

            facility: #JVM.

    ].

    "/ We have been notified, re-acquire the monitor

    self acquire.

    count := countBeforeWait. "/ note that at this point we already own the monitor.

    ^ true.

    "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 (comment): / 14-08-2017 / 09:52:06 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!JavaMonitor methodsFor:'queries'!

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

    "Modified: / 12-08-2017 / 21:24:35 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!JavaMonitor class methodsFor:'documentation'!

version_CVS

    ^ '$Header$'

!

version_HG

    ^ '$Changeset: <not expanded> $'

!

version_SVN

    ^ '$Id$'

! !