%
% (c) Parade/AQUA Projects, Glasgow University, 1995 
%     Kevin Hammond, February 15th. 1995
%
%     This is for GUM only.
%
%************************************************************************
%*                                                                      *
\section[FetchMe.lhc]{Reading Closures}
%*									*
%************************************************************************

This module defines routines for handling remote pointers (@FetchMe@s)
in GUM.  It is threaded (@.lhc@) because @FetchMe_entry@ will be
called during evaluation.

\begin{code}
#ifdef PAR /* whole file */

#define MAIN_REG_MAP	    /* STG world */
#include "rtsdefs.h"
\end{code}

\begin{code}

EXTDATA_RO(BH_UPD_info);
EXTDATA_RO(FetchMe_info);

EXTFUN(EnterNodeCode);

STGFUN(FetchMe_entry)
{
    globalAddr *rGA;
    globalAddr *lGA;
    globalAddr fmbqGA;

# if defined(GRAN)
    STGCALL0(void,(),GranSimBlock);	/* Do this before losing its TSO_LINK */
# endif

    rGA = FETCHME_GA(Node);
    ASSERT(rGA->loc.gc.gtid != mytid);

    TSO_LINK(CurrentTSO) = Prelude_Z91Z93_closure;
    SET_INFO_PTR(Node, FMBQ_info);
    FMBQ_ENTRIES(Node) = (W_) CurrentTSO;

    LivenessReg = LIVENESS_R1;
    SaveAllStgRegs();
    TSO_PC1(CurrentTSO) = EnterNodeCode;

    /* Calls out are now safe */

    if (DO_QP_PROF) {
    	QP_Event1("GR", CurrentTSO);
    }

    if (RTSflags.ParFlags.granSimStats) {
        /* Note that CURRENT_TIME may perform an unsafe call */
	TIME now = CURRENT_TIME;
        TSO_EXECTIME(CurrentTSO) += now - TSO_BLOCKEDAT(CurrentTSO);
        TSO_FETCHCOUNT(CurrentTSO)++;
	TSO_QUEUE(CurrentTSO) = Q_FETCHING;
        TSO_BLOCKEDAT(CurrentTSO) = now;
        /* DumpGranEventAndNode(GR_FETCH, CurrentTSO, (SAVE_R1).p, 
           taskIDtoPE(rGA->loc.gc.gtid)); */
	DumpRawGranEvent(CURRENT_PROC,taskIDtoPE(rGA->loc.gc.gtid),GR_FETCH,
			 CurrentTSO,(SAVE_R1).p,0);
    }

    /* Assign a brand-new global address to the newly created FMBQ */
    lGA = MakeGlobal((SAVE_R1).p, rtsFalse);
    splitWeight(&fmbqGA, lGA);
    ASSERT(fmbqGA.weight == 1L << (BITS_IN(unsigned) - 1));

    sendFetch(rGA, &fmbqGA, 0/*load*/);

    ReSchedule(0);
    FE_
}

FETCHME_ITBL(FetchMe_info,FetchMe_entry);

\end{code}

And for migrated FetchMes that are now blocked on remote blocking queues...

\begin{code}

STGFUN(BF_entry)
{
    FB_
    /* Don't wrap the calls; we're done with STG land */
    fprintf(stderr, "Panic: Entered a BlockedFetch\n");
    EXIT(EXIT_FAILURE);
    FE_
}

BF_ITBL();

\end{code}

@FMBQ@ nodes are @FetchMe@s with blocking queues attached.  The fetch has
been sent, but no reply has been received yet.

\begin{code}

EXTFUN(EnterNodeCode);

STGFUN(FMBQ_entry)
{   
    FB_

#if defined(GRAN)
    STGCALL0(void,(),GranSimBlock);	/* Before overwriting TSO_LINK */
#endif

    TSO_LINK(CurrentTSO) = (P_) FMBQ_ENTRIES(Node);
    FMBQ_ENTRIES(Node) = (W_) CurrentTSO;

    LivenessReg = LIVENESS_R1;
    SaveAllStgRegs();
    TSO_PC1(CurrentTSO) = EnterNodeCode;

    if (DO_QP_PROF) {
    	QP_Event1("GR", CurrentTSO);
    }

    if (RTSflags.ParFlags.granSimStats) {
        /* Note that CURRENT_TIME may perform an unsafe call */
	TIME now = CURRENT_TIME;
        TSO_EXECTIME(CurrentTSO) += now - TSO_BLOCKEDAT(CurrentTSO);
        TSO_FETCHCOUNT(CurrentTSO)++;
	TSO_QUEUE(CurrentTSO) = Q_FETCHING;
        TSO_BLOCKEDAT(CurrentTSO) = now;
        DumpGranEvent(GR_FETCH, CurrentTSO);
    }

    ReSchedule(0);
    FE_
}

FMBQ_ITBL();

#endif /* PAR -- whole file */
\end{code}