748 ! !

   749 

   750 !ProcessorScheduler methodsFor:'initializing'!

   751 

   752 initialize

   753     "initialize the one-and-only ProcessorScheduler"

   754 

   755     |nPrios "{ Class: SmallInteger }"

   756      p l|

   757 

   758     KnownProcesses isNil ifTrue:[

   759 	KnownProcesses := WeakArray new:30.

   760 	KnownProcesses addDependent:self class.

   761 	KnownProcessIds := OrderedCollection new.

   762     ].

   763 

   764     "

   765      create a collection with process lists; accessed using the priority as key

   766     "

   767     nPrios := SchedulingPriority.

   768     quiescentProcessLists := Array new:nPrios.

   769 "/    1 to:nPrios do:[:pri |

   770 "/        quiescentProcessLists at:pri put:(LinkedList new)

   771 "/    ].

   772 

   773     readFdArray := Array with:nil.

   774     readCheckArray := Array with:nil.

   775     readSemaphoreArray := Array with:nil.

   776     writeFdArray := Array with:nil.

   777     writeSemaphoreArray := Array with:nil.

   778     timeoutArray := Array with:nil.

   779     timeoutSemaphoreArray := Array with:nil.

   780     timeoutActionArray := Array with:nil.

   781     timeoutProcessArray := Array with:nil.

   782     anyTimeouts := false.

   783     dispatching := false.

   784     exitWhenNoMoreUserProcesses := false. "/ mhmh - how about true ?

   785     useIOInterrupts := OperatingSystem supportsIOInterrupts.

   786     gotIOInterrupt := false.

   787     osChildExitActions := Dictionary new.

   788     gotChildSignalInterrupt := false.

   789 

   790     "

   791      handcraft the first (dispatcher-) process - this one will never

   792      block, but go into a select if there is nothing to do.

   793      Also, it has a prio of max+1 - thus, it comes first when looking

   794      for a runnable process.

   795     "

   796     currentPriority := SchedulingPriority.

   797     p := Process basicNew.

   798     p setId:0 state:#run.

   799     p setPriority:currentPriority.

   800     p name:'scheduler'.

   801 

   802     scheduler := activeProcess := p.

   803     activeProcessId := 0.

   804 

   805     quiescentProcessLists at:currentPriority put:(l := LinkedList new).

   806     l add:p.

   807 

   808     "

   809      let me handle IO and timer interrupts

   810     "

   811     ObjectMemory ioInterruptHandler:self.

   812     ObjectMemory timerInterruptHandler:self.

   813     ObjectMemory childSignalInterruptHandler:self.

   814 

   815     "Modified: 29.7.1996 / 12:10:59 / cg"

   816     "Modified: 7.1.1997 / 16:48:26 / stefan"

   817 !

   818 

   819 reinitialize

   820     "all previous processes (except those marked as restartable) are made dead 

   821      - each object should reinstall its process(s) upon restart;

   822      especially, windowgroups have to.

   823      In contrast to ST-80, restartable processes are restarted at the beginning

   824      NOT continued where left. This is a consequence of the portable implementation

   825      of ST/X, since in order to continue a process, we needed to know the

   826      internals of the machines (and C-compilers) stack layout.

   827      This was not done, favouring portability for process continuation.

   828      In praxis, this is not much of a problem, since in almost every case,

   829      the computation state can be saved in some object, and processing be 

   830      restarted from scratch, reinitializing things from this saved state."

   831 

   832     "

   833      lay all processes to rest, collect restartable ones

   834     "

   835     processesToRestart := OrderedCollection new.

   836     KnownProcesses do:[:p |

   837         (p notNil and:[p ~~ 0]) ifTrue:[

   838             "how, exactly should this be done ?"

   839 

   840             p isRestartable == true ifTrue:[

   841                 p nextLink:nil.

   842                 processesToRestart add:p

   843             ] ifFalse:[

   844                 p setId:nil state:#dead

   845             ]

   846         ].

   847     ].

   848     scheduler setId:nil state:#dead. 

   849 

   850     "

   851      now, start from scratch

   852     "

   853     KnownProcesses := nil.

   854     self initialize.

   855 

   856     "Modified: / 7.6.1998 / 02:05:47 / cg"

   857 !

   858 

   859 restartRestartableProcesses

   860     "restart those that can be.

   861      This must be done as a second step, to make certain that all

   862      of the GUI classes are intitialized first (and, especially the

   863      event dispatching mechanism is running)"

   864 

   865     |procs|

   866 

   867     procs := processesToRestart.

   868     procs notNil ifTrue:[

   869         processesToRestart := nil.

   870 

   871         procs do:[:p |

   872             p imageRestart

   873         ]

   874     ]

   875 

   876     "Created: / 7.6.1998 / 02:06:52 / cg"

   877     "Modified: / 7.6.1998 / 02:07:59 / cg"