ghc/includes/Updates.h

   1 /* -----------------------------------------------------------------------------
   2  * $Id: Updates.h,v 1.31 2003/04/08 15:32:38 sof Exp $
   3  *
   4  * (c) The GHC Team, 1998-1999
   5  *
   6  * Definitions related to updates.
   7  *
   8  * ---------------------------------------------------------------------------*/
   9
  10 #ifndef UPDATES_H
  11 #define UPDATES_H
  12
  13 /* -----------------------------------------------------------------------------
  14    Update a closure with an indirection.  This may also involve waking
  15    up a queue of blocked threads waiting on the result of this
  16    computation.
  17    -------------------------------------------------------------------------- */
  18
  19 /* ToDo: overwrite slop words with something safe in case sanity checking
  20  *       is turned on.
  21  *       (I think the fancy version of the GC is supposed to do this too.)
  22  */
  23
  24 /* This expands to a fair chunk of code, what with waking up threads
  25  * and checking whether we're updating something in a old generation.
  26  * preferably don't use this macro inline in compiled code.
  27  */
  28
  29 #ifdef TICKY_TICKY
  30 # define UPD_IND(updclosure, heapptr) \
  31    UPD_PERM_IND(updclosure,heapptr)
  32 # define UPD_SPEC_IND(updclosure, ind_info, heapptr, and_then) \
  33    UPD_PERM_IND(updclosure,heapptr); and_then
  34 #else
  35 # define UPD_IND(updclosure, heapptr) \
  36    UPD_REAL_IND(updclosure,&stg_IND_info,heapptr,)
  37 # define UPD_SPEC_IND(updclosure, ind_info, heapptr, and_then) \
  38    UPD_REAL_IND(updclosure,ind_info,heapptr,and_then)
  39 #endif
  40
  41 /* UPD_IND actually does a PERM_IND if TICKY_TICKY is on;
  42    if you *really* need an IND use UPD_REAL_IND
  43  */
  44 #ifdef SMP
  45 #define UPD_REAL_IND(updclosure, ind_info, heapptr, and_then)           \
  46    {                                                                    \
  47         const StgInfoTable *info;                                       \
  48         if (Bdescr((P_)updclosure)->u.back != (bdescr *)BaseReg) {      \
  49                 info = LOCK_CLOSURE(updclosure);                        \
  50         } else {                                                        \
  51                 info = updclosure->header.info;                         \
  52         }                                                               \
  53         AWAKEN_BQ(info,updclosure);                                     \
  54         updateWithIndirection(info, ind_info,                           \
  55                               (StgClosure *)updclosure,                 \
  56                               (StgClosure *)heapptr,                    \
  57                               and_then);                                \
  58    }
  59 #else
  60 #define UPD_REAL_IND(updclosure, ind_info, heapptr, and_then)   \
  61    {                                                    \
  62         const StgInfoTable *info;                       \
  63         info = ((StgClosure *)updclosure)->header.info; \
  64         AWAKEN_BQ(info,updclosure);                     \
  65         updateWithIndirection(((StgClosure *)updclosure)->header.info, ind_info,                \
  66                               (StgClosure *)updclosure, \
  67                               (StgClosure *)heapptr,    \
  68                               and_then);                \
  69    }
  70 #endif
  71
  72 #define UPD_STATIC_IND(updclosure, heapptr)                     \
  73    {                                                            \
  74         const StgInfoTable *info;                               \
  75         info = ((StgClosure *)updclosure)->header.info;         \
  76         AWAKEN_STATIC_BQ(info,updclosure);                      \
  77         updateWithStaticIndirection(info,                       \
  78                                     (StgClosure *)updclosure,   \
  79                                     (StgClosure *)heapptr);     \
  80    }
  81
  82 #if defined(PROFILING) || defined(TICKY_TICKY)
  83 #define UPD_PERM_IND(updclosure, heapptr)                       \
  84    {                                                            \
  85         const StgInfoTable *info;                               \
  86         info = ((StgClosure *)updclosure)->header.info;         \
  87         AWAKEN_BQ(info,updclosure);                             \
  88         updateWithPermIndirection(info,                         \
  89                                   (StgClosure *)updclosure,     \
  90                                   (StgClosure *)heapptr);       \
  91    }
  92 #endif
  93
  94 #ifdef SMP
  95 #define UPD_IND_NOLOCK(updclosure, heapptr)                             \
  96    {                                                                    \
  97         const StgInfoTable *info;                                       \
  98         info = updclosure->header.info;                                 \
  99         AWAKEN_BQ(info,updclosure);                                     \
 100         updateWithIndirection(info,&stg_IND_info,                       \
 101                               (StgClosure *)updclosure,                 \
 102                               (StgClosure *)heapptr,);                  \
 103    }
 104 #elif defined(RTS_SUPPORTS_THREADS)
 105
 106 # ifdef TICKY_TICKY
 107 #  define UPD_IND_NOLOCK(updclosure, heapptr)                   \
 108    {                                                            \
 109         const StgInfoTable *info;                               \
 110         info = ((StgClosure *)updclosure)->header.info;         \
 111         AWAKEN_BQ_NOLOCK(info,updclosure);                      \
 112         updateWithPermIndirection(info,                         \
 113                                   (StgClosure *)updclosure,     \
 114                                   (StgClosure *)heapptr);       \
 115    }
 116 # else
 117 #  define UPD_IND_NOLOCK(updclosure, heapptr)           \
 118    {                                                    \
 119         const StgInfoTable *info;                       \
 120         info = ((StgClosure *)updclosure)->header.info; \
 121         AWAKEN_BQ_NOLOCK(info,updclosure);              \
 122         updateWithIndirection(info,&stg_IND_info,       \
 123                               (StgClosure *)updclosure, \
 124                               (StgClosure *)heapptr,);  \
 125    }
 126 # endif
 127
 128 #else
 129 #define UPD_IND_NOLOCK(updclosure,heapptr) UPD_IND(updclosure,heapptr)
 130 #endif
 131
 132 /* -----------------------------------------------------------------------------
 133    Awaken any threads waiting on this computation
 134    -------------------------------------------------------------------------- */
 135
 136 #if defined(PAR)
 137
 138 /*
 139    In a parallel setup several types of closures might have a blocking queue:
 140      BLACKHOLE_BQ ... same as in the default concurrent setup; it will be
 141                       reawakened via calling UPD_IND on that closure after
 142                       having finished the computation of the graph
 143      FETCH_ME_BQ  ... a global indirection (FETCH_ME) may be entered by a
 144                       local TSO, turning it into a FETCH_ME_BQ; it will be
 145                       reawakened via calling processResume
 146      RBH          ... a revertible black hole may be entered by another
 147                       local TSO, putting it onto its blocking queue; since
 148                       RBHs only exist while the corresponding closure is in
 149                       transit, they will be reawakened via calling
 150                       convertToFetchMe (upon processing an ACK message)
 151
 152    In a parallel setup a blocking queue may contain 3 types of closures:
 153      TSO           ... as in the default concurrent setup
 154      BLOCKED_FETCH ... indicating that a TSO on another PE is waiting for
 155                        the result of the current computation
 156      CONSTR        ... an RBHSave closure (which contains data ripped out of
 157                        the closure to make room for a blocking queue; since
 158                        it only contains data we use the exisiting type of
 159                        a CONSTR closure); this closure is the end of a
 160                        blocking queue for an RBH closure; it only exists in
 161                        this kind of blocking queue and must be at the end
 162                        of the queue
 163 */
 164 extern void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
 165 #define DO_AWAKEN_BQ(bqe, node)  STGCALL2(awakenBlockedQueue, bqe, node);
 166
 167 #define AWAKEN_BQ(info,closure)                                         \
 168         if (info == &stg_BLACKHOLE_BQ_info ||               \
 169             info == &stg_FETCH_ME_BQ_info ||                \
 170             get_itbl(closure)->type == RBH) {                           \
 171                 DO_AWAKEN_BQ(((StgBlockingQueue *)closure)->blocking_queue, closure);                           \
 172         }
 173
 174 #elif defined(GRAN)
 175
 176 extern void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
 177 #define DO_AWAKEN_BQ(bq, node)  STGCALL2(awakenBlockedQueue, bq, node);
 178
 179 /* In GranSim we don't have FETCH_ME or FETCH_ME_BQ closures, so they are
 180    not checked. The rest of the code is the same as for GUM.
 181 */
 182 #define AWAKEN_BQ(info,closure)                                         \
 183         if (info == &stg_BLACKHOLE_BQ_info ||               \
 184             get_itbl(closure)->type == RBH) {                           \
 185                 DO_AWAKEN_BQ(((StgBlockingQueue *)closure)->blocking_queue, closure);                           \
 186         }
 187
 188
 189 #else /* !GRAN && !PAR */
 190
 191 extern void awakenBlockedQueue(StgTSO *q);
 192 #define DO_AWAKEN_BQ(closure)   \
 193         STGCALL1(awakenBlockedQueue,            \
 194                  ((StgBlockingQueue *)closure)->blocking_queue);
 195
 196 #define AWAKEN_BQ(info,closure)                                         \
 197         if (info == &stg_BLACKHOLE_BQ_info) {                           \
 198           DO_AWAKEN_BQ(closure);                                        \
 199         }
 200
 201 #define AWAKEN_STATIC_BQ(info,closure)                                  \
 202         if (info == &stg_BLACKHOLE_BQ_STATIC_info) {                    \
 203           DO_AWAKEN_BQ(closure);                                        \
 204         }
 205
 206 #ifdef RTS_SUPPORTS_THREADS
 207 extern void awakenBlockedQueueNoLock(StgTSO *q);
 208 #define DO_AWAKEN_BQ_NOLOCK(closure)                                    \
 209         STGCALL1(awakenBlockedQueueNoLock,                              \
 210                  ((StgBlockingQueue *)closure)->blocking_queue);
 211
 212 #define AWAKEN_BQ_NOLOCK(info,closure)                                  \
 213         if (info == &stg_BLACKHOLE_BQ_info) {                           \
 214           DO_AWAKEN_BQ_NOLOCK(closure);                                 \
 215         }
 216 #endif
 217 #endif /* GRAN || PAR */
 218
 219 /* -------------------------------------------------------------------------
 220    Push an update frame on the stack.
 221    ------------------------------------------------------------------------- */
 222
 223 #if defined(PROFILING)
 224 // frame->header.prof.hp.rs = NULL (or frame-header.prof.hp.ldvw = 0) is unnecessary
 225 // because it is not used anyhow.
 226 #define PUSH_STD_CCCS(frame) (frame->header.prof.ccs = CCCS)
 227 #else
 228 #define PUSH_STD_CCCS(frame)
 229 #endif
 230
 231 extern DLL_IMPORT_RTS const StgPolyInfoTable stg_upd_frame_info;
 232 extern DLL_IMPORT_RTS const StgPolyInfoTable stg_noupd_frame_info;
 233
 234 #define PUSH_UPD_FRAME(target, Sp_offset)                       \
 235         {                                                       \
 236                 StgUpdateFrame *__frame;                        \
 237                 TICK_UPDF_PUSHED(target, GET_INFO((StgClosure*)target)); \
 238                 __frame = (StgUpdateFrame *)(Sp + (Sp_offset)) - 1; \
 239                 SET_INFO(__frame, (StgInfoTable *)&stg_upd_frame_info);   \
 240                 __frame->updatee = (StgClosure *)(target);      \
 241                 PUSH_STD_CCCS(__frame);                         \
 242         }
 243
 244 /* -----------------------------------------------------------------------------
 245    Entering CAFs
 246
 247    When a CAF is first entered, it creates a black hole in the heap,
 248    and updates itself with an indirection to this new black hole.
 249
 250    We update the CAF with an indirection to a newly-allocated black
 251    hole in the heap.  We also set the blocking queue on the newly
 252    allocated black hole to be empty.
 253
 254    Why do we make a black hole in the heap when we enter a CAF?
 255
 256        - for a  generational garbage collector, which needs a fast
 257          test for whether an updatee is in an old generation or not
 258
 259        - for the parallel system, which can implement updates more
 260          easily if the updatee is always in the heap. (allegedly).
 261
 262    When debugging, we maintain a separate CAF list so we can tell when
 263    a CAF has been garbage collected.
 264    -------------------------------------------------------------------------- */
 265
 266 /* ToDo: only call newCAF when debugging. */
 267
 268 extern void newCAF(StgClosure*);
 269
 270 /* newCAF must be called before the itbl ptr is overwritten, since
 271    newCAF records the old itbl ptr in order to do CAF reverting
 272    (which Hugs needs to do in order that combined mode works right.)
 273 */
 274 #define UPD_CAF(cafptr, bhptr)                                          \
 275   {                                                                     \
 276     LOCK_CLOSURE(cafptr);                                               \
 277     STGCALL1(newCAF,(StgClosure *)cafptr);                              \
 278     ((StgInd *)cafptr)->indirectee   = (StgClosure *)(bhptr);           \
 279     SET_INFO((StgInd *)cafptr,(const StgInfoTable*)&stg_IND_STATIC_info);\
 280   }
 281
 282 /* -----------------------------------------------------------------------------
 283    Update-related prototypes
 284    -------------------------------------------------------------------------- */
 285
 286 #endif /* UPDATES_H */