ghc/rts/gum/FetchMe.c

   1 /* -----------------------------------------------------------------------------
   2  * $Id: FetchMe.c,v 1.2 1998/12/02 13:29:03 simonm Exp $
   3  *
   4  * Entry code for a FETCH_ME closure
   5  *
   6  * ---------------------------------------------------------------------------*/
   7
   8 #ifdef PAR /* all of it */
   9
  10 #include "Rts.h"
  11 #include "FetchMe.h"
  12 #include "HLC.h"
  13
  14 /* -----------------------------------------------------------------------------
  15    FETCH_ME closures.
  16
  17    A FETCH_ME closure represents data that currently resides on
  18    another PE.  We issue a fetch message, and wait for the data to be
  19    retrieved.
  20    -------------------------------------------------------------------------- */
  21
  22 INFO_TABLE(FETCH_ME_info, FETCH_ME_entry, 0,2, FETCH_ME, const, EF_,0,0);
  23
  24 STGFUN(FETCH_ME_entry)
  25 {
  26     globalAddr *rGA;
  27     globalAddr *lGA;
  28     globalAddr fmbqGA;
  29
  30 # if defined(GRAN)
  31     STGCALL0(void,(),GranSimBlock);     /* Do this before losing its TSO_LINK */
  32 # endif
  33
  34     rGA = FETCHME_GA(R1);
  35     ASSERT(rGA->loc.gc.gtid != mytid);
  36
  37     /* Turn the FETCH_ME into a FETCH_ME_BQ, and place the current thread
  38      * on the blocking queue.
  39      */
  40     R1.cl->header.info = FETCH_ME_BQ_info;
  41     CurrentTSO->link = END_TSO_QUEUE;
  42     ((StgBlackHole *)R1.cl)->blocking_queue = CurrentTSO;
  43
  44 #ifdef 0 /* unknown junk... needed? --SDM */
  45     if (DO_QP_PROF) {
  46         QP_Event1("GR", CurrentTSO);
  47     }
  48
  49     if (RTSflags.ParFlags.granSimStats) {
  50         /* Note that CURRENT_TIME may perform an unsafe call */
  51         TIME now = CURRENT_TIME;
  52         TSO_EXECTIME(CurrentTSO) += now - TSO_BLOCKEDAT(CurrentTSO);
  53         TSO_FETCHCOUNT(CurrentTSO)++;
  54         TSO_QUEUE(CurrentTSO) = Q_FETCHING;
  55         TSO_BLOCKEDAT(CurrentTSO) = now;
  56         /* DumpGranEventAndNode(GR_FETCH, CurrentTSO, (SAVE_R1).p,
  57            taskIDtoPE(rGA->loc.gc.gtid)); */
  58         DumpRawGranEvent(CURRENT_PROC,taskIDtoPE(rGA->loc.gc.gtid),GR_FETCH,
  59                          CurrentTSO,(SAVE_R1).p,0);
  60     }
  61
  62     /* Phil T. claims that this was a workaround for a hard-to-find
  63      * bug, hence I'm leaving it out for now --SDM
  64      */
  65     /* Assign a brand-new global address to the newly created FMBQ */
  66     lGA = MakeGlobal((SAVE_R1).p, rtsFalse);
  67     splitWeight(&fmbqGA, lGA);
  68     ASSERT(fmbqGA.weight == 1L << (BITS_IN(unsigned) - 1));
  69 #endif
  70
  71     /* I *hope* it's ok to call this from STG land. --SDM */
  72     STGCALL3(sendFetch, rGA, &fmbqGA, 0/*load*/);
  73
  74     BLOCK_NP(1); /* back to the scheduler */
  75
  76     FE_
  77 }
  78
  79 /* -----------------------------------------------------------------------------
  80    FETCH_ME_BQ
  81
  82    On the first entry of a FETCH_ME closure, we turn the closure into
  83    a FETCH_ME_BQ, which behaves just like a black hole.  Any thread
  84    entering the FETCH_ME_BQ will be placed in the blocking queue.
  85    When the data arrives from the remote PE, all waiting threads are
  86    woken up and the FETCH_ME_BQ is overwritten with the fetched data.
  87    -------------------------------------------------------------------------- */
  88
  89 INFO_TABLE(FETCH_ME_BQ_info, BLACKHOLE_entry,0,2,BLACKHOLE,const,EF_,0,0);
  90
  91 #endif /* PAR */