1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/MasterLoop.c	Sat May 22 19:37:58 2010 -0700
     1.3 @@ -0,0 +1,113 @@
     1.4 +/*
     1.5 + * Copyright 2010  OpenSourceCodeStewardshipFoundation
     1.6 + *
     1.7 + * Licensed under BSD
     1.8 + */
     1.9 +
    1.10 +
    1.11 +
    1.12 +#include <stdio.h>
    1.13 +#include <malloc.h>
    1.14 +
    1.15 +#include "VMS.h"
    1.16 +
    1.17 +
    1.18 +
    1.19 +/*This code is animated by the virtual Master processor.
    1.20 + *Note, it is animated on a different level in virtual processor hierarchy
    1.21 + * than the CoreLoop -- this is the code pointed to in a work-unit that the
    1.22 + * coreLoop jumps to
    1.23 + *
    1.24 + *Polls each virtual slave exactly once, hands any requests made by the slave
    1.25 + * to the "request handler" plug-in function
    1.26 + *
    1.27 + *Any slaves that have no work-unit assigned are given to the "schedule"
    1.28 + * plug-in function, which tries to assign a work-unit to it.
    1.29 + *
    1.30 + *When all slaves that need work-units have been given to the schedule plug-in,
    1.31 + * half of the ones that were successfully scheduled are put into the work
    1.32 + * queue, then a continuation of this function is put in, then the rest of the
    1.33 + * slaves that were successfully scheduled.
    1.34 + *
    1.35 + *The first thing this function does is busy-wait until the previous work-unit
    1.36 + * running this function is done.  This ensures it doesn't overlap with
    1.37 + * tail-end of previous -- IE, continuation may sneak through queue before
    1.38 + * previous done putting second half of scheduled slaves in.  This is the only
    1.39 + * race condition.
    1.40 + *
    1.41 + */
    1.42 +
    1.43 +void masterLoop( void *data )
    1.44 + { bool8 success;
    1.45 +   int slaveIdx, numScheduled, numInFirstHalf, schedSlaveIdx;
    1.46 +   VMSProcr        currSlave, *virtSlaves;
    1.47 +   MasterEnv      *masterEnv;
    1.48 +   SlaveScheduler  slaveScheduler;
    1.49 +   RequestHandler  requestHandler;
    1.50 +
    1.51 +
    1.52 +   masterEnv = (MasterEnv *)data;
    1.53 +
    1.54 +   requestHandler   = masterEnv->requestHandler;
    1.55 +   slaveScheduler   = masterEnv->slaveScheduler;
    1.56 +   virtSlaves       = masterEnv->virtSlaves;
    1.57 +   
    1.58 +      //if another continuation of Master still running, busy-wait
    1.59 +   while( masterEnv->stillRunning ) /*busy wait*/ ;
    1.60 +
    1.61 +      //this is the only master running now, set flag again
    1.62 +   masterEnv->stillRunning = 1;
    1.63 +
    1.64 +      //prepare for scheduling
    1.65 +   masterEnv->numScheduled = 0;
    1.66 +
    1.67 +      //Poll each slave structure's Done flag
    1.68 +   for( slaveIdx = 0; slaveIdx < NUM_SLAVES; slaveIdx++)
    1.69 +    {
    1.70 +      currSlave = virtSlaves[ slaveIdx ];
    1.71 +
    1.72 +      if( currSlave->workIsDone )
    1.73 +       {
    1.74 +         currSlave->workIsDone        = FALSE;
    1.75 +         currSlave->needsWorkAssigned = TRUE;
    1.76 +
    1.77 +            //process requests from slave to master
    1.78 +         (*requestHandler)( currSlave );
    1.79 +       }
    1.80 +      if( currSlave->needsWorkAssigned )
    1.81 +       {    //give slave a new work-unit
    1.82 +         success =
    1.83 +         (*slaveScheduler)( currSlave, masterEnv );
    1.84 +         
    1.85 +         if( success )
    1.86 +          { addToVect( currSlave, &(masterEnv->scheduledSlaves),
    1.87 +                                  &(masterEnv->numScheduled) );
    1.88 +            currSlave->needsWorkAssigned = FALSE;
    1.89 +          }
    1.90 +       }
    1.91 +    }
    1.92 +
    1.93 +      //put half scheduled slaves in, then continuation, then other half
    1.94 +   VMSProcr **scheduledSlaves;
    1.95 +   numInFirstHalf = masterEnv->numScheduled / 2;
    1.96 +   scheduledSlaves = masterEnv->scheduledSlaves;
    1.97 +   for( schedSlaveIdx = 0; schedSlaveIdx < numInFirstHalf; schedSlaveIdx++)
    1.98 +    {
    1.99 +      writeQ( scheduledSlaves[ schedSlaveIdx ], workQ );
   1.100 +    }
   1.101 +
   1.102 +      //enqueue continuation of this loop
   1.103 +      // note that After this enqueue, continuation might sneak through
   1.104 +   writeQ( masterEnv->masterWorkUnit, workQ );
   1.105 +   for( schedSlaveIdx = numInFirstHalf; 
   1.106 +        schedSlaveIdx < numScheduled;
   1.107 +        schedSlaveIdx++)
   1.108 +    {
   1.109 +      writeQ( scheduledSlaves[ schedSlaveIdx ]->workUnitToDo, workQ );
   1.110 +    }
   1.111 +
   1.112 +      //all done, so okay for continuation to proceed
   1.113 +   masterEnv->stillRunning = 0;
   1.114 + }
   1.115 +
   1.116 +