Me@0: /*
Me@0:  * Copyright 2010  OpenSourceCodeStewardshipFoundation
Me@0:  *
Me@0:  * Licensed under BSD
Me@0:  */
Me@0: 
Me@0: 
Me@0: 
Me@0: #include <stdio.h>
Me@0: #include <malloc.h>
Me@0: 
Me@0: #include "VMS.h"
Me@0: 
Me@0: 
Me@0: 
Me@0: /*This code is animated by the virtual Master processor.
Me@0:  *Note, it is animated on a different level in virtual processor hierarchy
Me@0:  * than the CoreLoop -- this is the code pointed to in a work-unit that the
Me@0:  * coreLoop jumps to
Me@0:  *
Me@0:  *Polls each virtual slave exactly once, hands any requests made by the slave
Me@0:  * to the "request handler" plug-in function
Me@0:  *
Me@0:  *Any slaves that have no work-unit assigned are given to the "schedule"
Me@0:  * plug-in function, which tries to assign a work-unit to it.
Me@0:  *
Me@0:  *When all slaves that need work-units have been given to the schedule plug-in,
Me@0:  * half of the ones that were successfully scheduled are put into the work
Me@0:  * queue, then a continuation of this function is put in, then the rest of the
Me@0:  * slaves that were successfully scheduled.
Me@0:  *
Me@0:  *The first thing this function does is busy-wait until the previous work-unit
Me@0:  * running this function is done.  This ensures it doesn't overlap with
Me@0:  * tail-end of previous -- IE, continuation may sneak through queue before
Me@0:  * previous done putting second half of scheduled slaves in.  This is the only
Me@0:  * race condition.
Me@0:  *
Me@0:  */
Me@0: 
Me@0: void masterLoop( void *data )
Me@0:  { bool8 success;
Me@0:    int slaveIdx, numScheduled, numInFirstHalf, schedSlaveIdx;
Me@0:    VMSProcr        currSlave, *virtSlaves;
Me@0:    MasterEnv      *masterEnv;
Me@0:    SlaveScheduler  slaveScheduler;
Me@0:    RequestHandler  requestHandler;
Me@0: 
Me@0: 
Me@0:    masterEnv = (MasterEnv *)data;
Me@0: 
Me@0:    requestHandler   = masterEnv->requestHandler;
Me@0:    slaveScheduler   = masterEnv->slaveScheduler;
Me@0:    virtSlaves       = masterEnv->virtSlaves;
Me@0:    
Me@0:       //if another continuation of Master still running, busy-wait
Me@0:    while( masterEnv->stillRunning ) /*busy wait*/ ;
Me@0: 
Me@0:       //this is the only master running now, set flag again
Me@0:    masterEnv->stillRunning = 1;
Me@0: 
Me@0:       //prepare for scheduling
Me@0:    masterEnv->numScheduled = 0;
Me@0: 
Me@0:       //Poll each slave structure's Done flag
Me@0:    for( slaveIdx = 0; slaveIdx < NUM_SLAVES; slaveIdx++)
Me@0:     {
Me@0:       currSlave = virtSlaves[ slaveIdx ];
Me@0: 
Me@0:       if( currSlave->workIsDone )
Me@0:        {
Me@0:          currSlave->workIsDone        = FALSE;
Me@0:          currSlave->needsWorkAssigned = TRUE;
Me@0: 
Me@0:             //process requests from slave to master
Me@0:          (*requestHandler)( currSlave );
Me@0:        }
Me@0:       if( currSlave->needsWorkAssigned )
Me@0:        {    //give slave a new work-unit
Me@0:          success =
Me@0:          (*slaveScheduler)( currSlave, masterEnv );
Me@0:          
Me@0:          if( success )
Me@0:           { addToVect( currSlave, &(masterEnv->scheduledSlaves),
Me@0:                                   &(masterEnv->numScheduled) );
Me@0:             currSlave->needsWorkAssigned = FALSE;
Me@0:           }
Me@0:        }
Me@0:     }
Me@0: 
Me@0:       //put half scheduled slaves in, then continuation, then other half
Me@0:    VMSProcr **scheduledSlaves;
Me@0:    numInFirstHalf = masterEnv->numScheduled / 2;
Me@0:    scheduledSlaves = masterEnv->scheduledSlaves;
Me@0:    for( schedSlaveIdx = 0; schedSlaveIdx < numInFirstHalf; schedSlaveIdx++)
Me@0:     {
Me@0:       writeQ( scheduledSlaves[ schedSlaveIdx ], workQ );
Me@0:     }
Me@0: 
Me@0:       //enqueue continuation of this loop
Me@0:       // note that After this enqueue, continuation might sneak through
Me@0:    writeQ( masterEnv->masterWorkUnit, workQ );
Me@0:    for( schedSlaveIdx = numInFirstHalf; 
Me@0:         schedSlaveIdx < numScheduled;
Me@0:         schedSlaveIdx++)
Me@0:     {
Me@0:       writeQ( scheduledSlaves[ schedSlaveIdx ]->workUnitToDo, workQ );
Me@0:     }
Me@0: 
Me@0:       //all done, so okay for continuation to proceed
Me@0:    masterEnv->stillRunning = 0;
Me@0:  }
Me@0: 
Me@0: