Printer spooler and TransientSemaphore wait
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Printer spooler and TransientSemaphore wait
 
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Ciao, in the application based on Seaside, i manage some printers devices. Every device have a RcQueue where the system add the 'works' to print. Besides there is a topaz script/server, which read the prints jobs and does the printing. Now this script is based spoolSemaphore class variable set to
on TransientSemaphore, who waits for the presence of a new document to be reported, segnaled when one relative entry is added to one RcQueue printer device.
This is the printerSpool script:
If in the whileTrue loop i define the: spoolSemaphore waitForSeconds: 1. the topaz script works, but not waiting as I would like ..... If in the whileTrue loop i define the: spoolSemaphore wait. the topaz script generates the error: ERROR 2366 , a ThreadError occurred (error 2366), reason:rtErrSchedulerDeadlocked, The ProcessorScheduler is deadlocked (ThreadError)
Considerations... ? Thanks, Dario _______________________________________________ Glass mailing list [hidden email] http://lists.gemtalksystems.com/mailman/listinfo/glass |
Re: Printer spooler and TransientSemaphore wait
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Dario,
Are you intending the semaphore to work between gems? If so, then it won’t work. A semaphore is “DbTransient,” meaning that its state is not persistent in the database. A Smalltalk Semaphore works only inside a single virtual machine (Gem). Instead, it should be sufficient for you to use GemStone’s transaction semantics. A “producer” adds and item to an RcQueue and commits, while a “consumer” periodically aborts and looks to see if the queue is non-empty. For simplicity, the consumer should have a delay in its polling loop. James
_______________________________________________ Glass mailing list [hidden email] http://lists.gemtalksystems.com/mailman/listinfo/glass |
Re: Printer spooler and TransientSemaphore wait
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Also the GemStone seaside package 'Seaside-GemStone-ServiceTask' can manage
the polling James is talking about. It checks every 200ms for tasks to do. The tasks are defined in the class side of WAGemStoneServiceVMTask. See #serviceVMTaskServiceExample for an example. Once you add a task of your own you'd need to restart the servicevm gem. The daemontools repo has the code to set up & run the servicevm GLASS mailing list wrote > Dario, > > Are you intending the semaphore to work between gems? If so, then it won’t > work. A semaphore is “DbTransient,” meaning that its state is not > persistent in the database. A Smalltalk Semaphore works only inside a > single virtual machine (Gem). > > Instead, it should be sufficient for you to use GemStone’s transaction > semantics. A “producer” adds and item to an RcQueue and commits, while a > “consumer” periodically aborts and looks to see if the queue is non-empty. > For simplicity, the consumer should have a delay in its polling loop. > > James > >> On Jul 10, 2018, at 8:17 AM, > dario.trussardi@ > via Glass < > glass@.gemtalksystems > > wrote: >> >> Ciao, >> >> in the application based on Seaside, i manage some printers devices. >> >> Every device have a RcQueue where the system add the 'works' to print. >> >> Besides there is a topaz script/server, which read the prints jobs and >> does the printing. >> >> Now this script is based spoolSemaphore class variable set to on >> TransientSemaphore, >> who waits for the presence of a new document to be reported, >> >> segnaled when one relative entry is added to one RcQueue printer device. >> >> >> >> This is the printerSpool script: >> >> startPrinterSpool >> | cllDbSpoolerActive flagLo...................... | >> >> UserGlobals at: #'FlagSpooler' put: true. >> >> spoolSemaphore := TransientSemaphore new. >> >> >> [ UserGlobals at: #'FlagSpooler' ] >> whileTrue: [ >> spoolSemaphore waitForSeconds: 1. >> >> System commit. " Update the session data " >> counterLimit := DTRdbOperatingDevice ticktesForCicle. >> >> .................... >> >> ............. >> If in the whileTrue loop i define the: >> >> spoolSemaphore waitForSeconds: 1. >> >> the topaz script works, but not waiting as I would like ..... >> >> If in the whileTrue loop i define the: >> >> spoolSemaphore wait. >> >> the topaz script generates the error: >> >> ERROR 2366 , a ThreadError occurred (error 2366), >> reason:rtErrSchedulerDeadlocked, The ProcessorScheduler is deadlocked >> (ThreadError) >> >> >> Considerations... ? >> >> Thanks, >> >> Dario >> >> _______________________________________________ >> Glass mailing list >> > Glass@.gemtalksystems >> http://lists.gemtalksystems.com/mailman/listinfo/glass > > > _______________________________________________ > Glass mailing list > Glass@.gemtalksystems > http://lists.gemtalksystems.com/mailman/listinfo/glass -- Sent from: http://forum.world.st/GLASS-f1460844.html _______________________________________________ Glass mailing list [hidden email] http://lists.gemtalksystems.com/mailman/listinfo/glass |
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