hg/stx-libbasic: comparison ProcessorScheduler.st

equal deleted inserted replaced

-:7c7a4e2354b8
+:264d440a67a0
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
 "
+'From Smalltalk/X, Version:2.10.8 on 21-dec-1995 at 16:28:28'                   !
 Object subclass:#ProcessorScheduler
 	instanceVariableNames:'quiescentProcessLists scheduler zombie activeProcess
 		currentPriority readFdArray readSemaphoreArray readCheckArray
 		writeFdArray writeSemaphoreArray timeoutArray timeoutActionArray
 		timeoutProcessArray timeoutSemaphoreArray idleActions anyTimeouts
-		dispatching interruptedProcess useIOInterrupts'
+		dispatching interruptedProcess useIOInterrupts gotIOInterrupt'
 	classVariableNames:'KnownProcesses KnownProcessIds PureEventDriven
 		UserSchedulingPriority UserInterruptPriority TimingPriority
 		HighestPriority SchedulingPriority MaxNumberOfProcesses'
 	poolDictionaries:''
 	category:'Kernel-Processes'
 "
 handle all timeout actions
 "
 anyTimeouts ifTrue:[
-	self evaluateTimeouts
+self evaluateTimeouts
 ].
 "first do a quick check for semaphores using checkActions - this is needed for
 devices like the X-connection, where some events might be in the event
 queue. Without these checks, a select might block even though there is work to do
 "
 any := false.
 nActions := readCheckArray size.
 1 to:nActions do:[:index |
-	|checkBlock sema|
+|checkBlock sema|
-	checkBlock := readCheckArray at:index.
+checkBlock := readCheckArray at:index.
-	(checkBlock notNil and:[checkBlock value]) ifTrue:[
+(checkBlock notNil and:[checkBlock value]) ifTrue:[
-	    sema := readSemaphoreArray at:index.
+sema := readSemaphoreArray at:index.
-	    sema notNil ifTrue:[
+sema notNil ifTrue:[
-		sema signalOnce.
+sema signalOnce.
-	    ].
+].
-	    any := true.
+any := true.
-	]
+]
 ].
 "now, someone might be runnable ..."
 p := self highestPriorityRunnableProcess.
 p isNil ifTrue:[
-	"no one runnable, hard wait for event or timeout"
+"no one runnable, hard wait for event or timeout"
-	self waitForEventOrTimeout.
+self waitForEventOrTimeout.
-	^ self
+^ self
 ].
 pri := p priority.
 "
 (a future version will have a process running to handle a timeout queue)
 "
 "
 pri < TimingPriority ifTrue:[
-	anyTimeouts ifTrue:[
+anyTimeouts ifTrue:[
-	    millis := self timeToNextTimeout.
+millis := self timeToNextTimeout.
-	    millis == 0 ifTrue:[^ self].
+millis == 0 ifTrue:[^ self].
-	]
+]
 ].
 "
 "
 if the process to run has a lower than UserInterruptPriority,
 or by installing a poll-interrupt after 50ms (if the OS does not).
 "
 pri < UserInterruptPriority ifTrue:[
 "comment out this if above is uncommented"
-	anyTimeouts ifTrue:[
+anyTimeouts ifTrue:[
-	    millis := self timeToNextTimeout.
+millis := self timeToNextTimeout.
-	    millis == 0 ifTrue:[^ self].
+millis == 0 ifTrue:[^ self].
-	].
+].
 "---"
-	useIOInterrupts ifTrue:[
+useIOInterrupts ifTrue:[
-	    readFdArray do:[:fd |
+readFdArray do:[:fd |
-		fd notNil ifTrue:[
+fd notNil ifTrue:[
-		    OperatingSystem enableIOInterruptsOn:fd
+OperatingSystem enableIOInterruptsOn:fd
-		].
+].
-	    ].
+].
-	] ifFalse:[
+] ifFalse:[
-	    millis notNil ifTrue:[
+millis notNil ifTrue:[
-		millis := millis min:50
+millis := millis min:50
-	    ] ifFalse:[
+] ifFalse:[
-		millis := 50
+millis := 50
-	    ]
+]
-	]
+]
 ].
 millis notNil ifTrue:[
-	"schedule a clock interrupt after millis milliseconds"
+"schedule a clock interrupt after millis milliseconds"
-	OperatingSystem enableTimer:millis rounded.
+OperatingSystem enableTimer:millis rounded.
 ].
 "
 now let the process run - will come back here by reschedule
 from ioInterrupt or timerInterrupt ... (running at max+1)
 "
 self threadSwitch:p.
-"... when we arrive here, we are back on stage"
+"... when we arrive here, we are back on stage.
+Either by an ALARM or IO signal, or by a suspend of another process
+"
 millis notNil ifTrue:[
-	OperatingSystem disableTimer.
+OperatingSystem disableTimer.
-	useIOInterrupts ifFalse:[
+].
-	    self checkForInputWithTimeout:0.
-	]
+"/ check for new input
+(gotIOInterrupt or:[useIOInterrupts not]) ifTrue:[
+gotIOInterrupt := false.
+self checkForInputWithTimeout:0.
 ]
-"Modified: 14.12.1995 / 14:45:13 / stefan"
+"Modified: 21.12.1995 / 16:21:54 / stefan"
 !
 dispatchLoop
 "central dispatch loop; the scheduler process is always staying in
 this method, looping forever."
 |nPrios "{ Class: SmallInteger }"
 l p|
 KnownProcesses isNil ifTrue:[
-	KnownProcesses := WeakArray new:10.
+KnownProcesses := WeakArray new:10.
-	KnownProcesses watcher:self class.
+KnownProcesses watcher:self class.
-	KnownProcessIds := OrderedCollection new.
+KnownProcessIds := OrderedCollection new.
 ].
 "
 create a collection with process lists; accessed using the priority as key
 "
 nPrios := SchedulingPriority.
 quiescentProcessLists := Array new:nPrios.
 1 to:nPrios do:[:pri |
-	quiescentProcessLists at:pri put:(LinkedList new)
+quiescentProcessLists at:pri put:(LinkedList new)
 ].
 readFdArray := Array with:nil.
 readCheckArray := Array with:nil.
 readSemaphoreArray := Array with:nil.
 timeoutActionArray := Array with:nil.
 timeoutProcessArray := Array with:nil.
 anyTimeouts := false.
 dispatching := false.
 useIOInterrupts := OperatingSystem supportsIOInterrupts.
+gotIOInterrupt := false.
 "
 handcraft the first (dispatcher-) process - this one will never
 block, but go into a select if there is nothing to do.
 Also, it has a prio of max+1 - thus, it comes first when looking
 "
 let me handle IO and timer interrupts
 "
 ObjectMemory ioInterruptHandler:self.
 ObjectMemory timerInterruptHandler:self.
+"Modified: 21.12.1995 / 16:18:36 / stefan"
 !
 reinitialize
 "all previous processes (except those marked as restartable) are made dead
 - each object should reinstall its process(s) upon restart;
 ioInterrupt
 "data arrived while waiting - switch to scheduler process which will decide
 what to do now."
+gotIOInterrupt := true.
 interruptedProcess := activeProcess.
 self threadSwitch:scheduler
+"Modified: 21.12.1995 / 16:17:40 / stefan"
 !
 schedulerInterrupt
 "forced reschedule - switch to scheduler process which will decide
 what to do now."
 ! !
 !ProcessorScheduler class methodsFor:'documentation'!
 version
-^ '$Header: /cvs/stx/stx/libbasic/ProcessorScheduler.st,v 1.59 1995-12-18 14:18:32 cg Exp $'
+^ '$Header: /cvs/stx/stx/libbasic/ProcessorScheduler.st,v 1.60 1995-12-21 16:56:47 stefan Exp $'
 ! !
 ProcessorScheduler initialize!

changeset 804	264d440a67a0
parent 786	789e2f20de44
child 806	409a8c189e01