[project @ 2005-02-28 17:12:36 by simonmar]
[ghc-hetmet.git] / ghc / includes / Updates.h
index 1cad7b2..0845e20 100644 (file)
@@ -1,9 +1,8 @@
 /* -----------------------------------------------------------------------------
- * $Id: Updates.h,v 1.10 1999/05/11 16:47:42 keithw Exp $
  *
- * (c) The GHC Team, 1998-1999
+ * (c) The GHC Team, 1998-2004
  *
- * Definitions related to updates.
+ * Performing updates.
  *
  * ---------------------------------------------------------------------------*/
 
 #define UPDATES_H
 
 /* -----------------------------------------------------------------------------
-   Update a closure with an indirection.  This may also involve waking
-   up a queue of blocked threads waiting on the result of this
-   computation.
-   -------------------------------------------------------------------------- */
+   Updates
 
-/* ToDo: overwrite slop words with something safe in case sanity checking 
- *       is turned on.  
- *       (I think the fancy version of the GC is supposed to do this too.)
- */
+   We have two layers of update macros.  The top layer, UPD_IND() and
+   friends perform all the work of an update.  In detail:
 
-/* This expands to a fair chunk of code, what with waking up threads 
- * and checking whether we're updating something in a old generation.
- * preferably don't use this macro inline in compiled code.
- */
+      - if the closure being updated is a blocking queue, then all the
+        threads waiting on the blocking queue are updated.
+
+      - then the lower level updateWithIndirection() macro is invoked 
+        to actually replace the closure with an indirection (see below).
+
+   -------------------------------------------------------------------------- */
 
 #ifdef TICKY_TICKY
-# define UPD_IND(updclosure, heapptr) UPD_PERM_IND(updclosure,heapptr)
+# define UPD_IND(updclosure, heapptr) \
+   UPD_PERM_IND(updclosure,heapptr)
+# define UPD_SPEC_IND(updclosure, ind_info, heapptr, and_then) \
+   UPD_PERM_IND(updclosure,heapptr); and_then
+#else
+#  define SEMI ;
+# define UPD_IND(updclosure, heapptr) \
+   UPD_REAL_IND(updclosure,INFO_PTR(stg_IND_info),heapptr,SEMI)
+# define UPD_SPEC_IND(updclosure, ind_info, heapptr, and_then) \
+   UPD_REAL_IND(updclosure,ind_info,heapptr,and_then)
+#endif
+
+/* These macros have to work in both C and C--, so here's the
+ * impedence matching:
+ */
+#ifdef CMINUSMINUS
+#define BLOCK_BEGIN
+#define BLOCK_END
+#define DECLARE_IPTR(info)  W_ info
+#define FCALL               foreign "C"
+#define INFO_PTR(info)      info
+#define ARG_PTR             "ptr"
 #else
-# define UPD_IND(updclosure, heapptr) UPD_REAL_IND(updclosure,heapptr)
+#define BLOCK_BEGIN         {
+#define BLOCK_END           }
+#define DECLARE_IPTR(info)  const StgInfoTable *(info)
+#define FCALL               /* nothing */
+#define INFO_PTR(info)      &info
+#define StgBlockingQueue_blocking_queue(closure) \
+    (((StgBlockingQueue *)closure)->blocking_queue)
+#define ARG_PTR             /* nothing */
 #endif
 
 /* UPD_IND actually does a PERM_IND if TICKY_TICKY is on;
    if you *really* need an IND use UPD_REAL_IND
  */
-#define UPD_REAL_IND(updclosure, heapptr)                       \
-        AWAKEN_BQ(updclosure);                                  \
-       updateWithIndirection((StgClosure *)updclosure,         \
-                             (StgClosure *)heapptr);
+#define UPD_REAL_IND(updclosure, ind_info, heapptr, and_then)  \
+        BLOCK_BEGIN                                            \
+       DECLARE_IPTR(info);                                     \
+       info = GET_INFO(updclosure);                            \
+        AWAKEN_BQ(info,updclosure);                            \
+       updateWithIndirection(GET_INFO(updclosure), ind_info,   \
+                             updclosure,                       \
+                             heapptr,                          \
+                             and_then);                        \
+       BLOCK_END
 
 #if defined(PROFILING) || defined(TICKY_TICKY)
-#define UPD_PERM_IND(updclosure, heapptr)                       \
-        AWAKEN_BQ(updclosure);                                  \
-       updateWithPermIndirection((StgClosure *)updclosure,     \
-                                 (StgClosure *)heapptr);
+#define UPD_PERM_IND(updclosure, heapptr)      \
+        BLOCK_BEGIN                            \
+       DECLARE_IPTR(info);                     \
+       info = GET_INFO(updclosure);            \
+        AWAKEN_BQ(info,updclosure);            \
+       updateWithPermIndirection(info,         \
+                                 updclosure,   \
+                                 heapptr);     \
+       BLOCK_END
+#endif
+
+#if defined(RTS_SUPPORTS_THREADS)
+
+# ifdef TICKY_TICKY
+#  define UPD_IND_NOLOCK(updclosure, heapptr)  \
+        BLOCK_BEGIN                            \
+       DECLARE_IPTR(info);                     \
+       info = GET_INFO(updclosure);            \
+        AWAKEN_BQ_NOLOCK(info,updclosure);     \
+       updateWithPermIndirection(info,         \
+                                 updclosure,   \
+                                 heapptr);     \
+       BLOCK_END
+# else
+#  define UPD_IND_NOLOCK(updclosure, heapptr)                  \
+        BLOCK_BEGIN                                            \
+       DECLARE_IPTR(info);                                     \
+       info = GET_INFO(updclosure);                            \
+        AWAKEN_BQ_NOLOCK(info,updclosure);                     \
+       updateWithIndirection(info, INFO_PTR(stg_IND_info),     \
+                             updclosure,                       \
+                             heapptr,);                        \
+       BLOCK_END
+# endif
+
+#else
+#define UPD_IND_NOLOCK(updclosure,heapptr) UPD_IND(updclosure,heapptr)
 #endif
 
 /* -----------------------------------------------------------------------------
-   Awaken any threads waiting on this computation
+   Awaken any threads waiting on a blocking queue (BLACKHOLE_BQ).
    -------------------------------------------------------------------------- */
 
-extern void awaken_blocked_queue(StgTSO *q);
+#if defined(PAR) 
+
+/* 
+   In a parallel setup several types of closures might have a blocking queue:
+     BLACKHOLE_BQ ... same as in the default concurrent setup; it will be
+                      reawakened via calling UPD_IND on that closure after
+                     having finished the computation of the graph
+     FETCH_ME_BQ  ... a global indirection (FETCH_ME) may be entered by a 
+                      local TSO, turning it into a FETCH_ME_BQ; it will be
+                     reawakened via calling processResume
+     RBH          ... a revertible black hole may be entered by another 
+                      local TSO, putting it onto its blocking queue; since
+                     RBHs only exist while the corresponding closure is in 
+                     transit, they will be reawakened via calling 
+                     convertToFetchMe (upon processing an ACK message)
 
-#define AWAKEN_BQ(closure)                                             \
-       if (closure->header.info == &BLACKHOLE_BQ_info) {               \
-               StgTSO *bq = ((StgBlockingQueue *)closure)->blocking_queue;\
-               if (bq != (StgTSO *)&END_TSO_QUEUE_closure) {           \
-                       STGCALL1(awaken_blocked_queue, bq);             \
-               }                                                       \
+   In a parallel setup a blocking queue may contain 3 types of closures:
+     TSO           ... as in the default concurrent setup
+     BLOCKED_FETCH ... indicating that a TSO on another PE is waiting for
+                       the result of the current computation
+     CONSTR        ... an RBHSave closure (which contains data ripped out of
+                       the closure to make room for a blocking queue; since
+                      it only contains data we use the exisiting type of
+                      a CONSTR closure); this closure is the end of a 
+                      blocking queue for an RBH closure; it only exists in
+                      this kind of blocking queue and must be at the end
+                      of the queue
+*/                   
+extern void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
+#define DO_AWAKEN_BQ(bqe, node)  STGCALL2(awakenBlockedQueue, bqe, node);
+
+#define AWAKEN_BQ(info,closure)                                                \
+       if (info == &stg_BLACKHOLE_BQ_info ||               \
+           info == &stg_FETCH_ME_BQ_info ||                \
+           get_itbl(closure)->type == RBH) {                           \
+               DO_AWAKEN_BQ(((StgBlockingQueue *)closure)->blocking_queue, closure);                           \
        }
 
+#elif defined(GRAN)
 
-/* -----------------------------------------------------------------------------
-   Push an update frame on the stack.
-   -------------------------------------------------------------------------- */
+extern void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
+#define DO_AWAKEN_BQ(bq, node)  STGCALL2(awakenBlockedQueue, bq, node);
 
-#if defined(PROFILING)
-#define PUSH_STD_CCCS(frame) frame->header.prof.ccs = CCCS
-#else
-#define PUSH_STD_CCCS(frame)
-#endif
+/* In GranSim we don't have FETCH_ME or FETCH_ME_BQ closures, so they are
+   not checked. The rest of the code is the same as for GUM.
+*/
+#define AWAKEN_BQ(info,closure)                                                \
+       if (info == &stg_BLACKHOLE_BQ_info ||               \
+           get_itbl(closure)->type == RBH) {                           \
+               DO_AWAKEN_BQ(((StgBlockingQueue *)closure)->blocking_queue, closure);                           \
+       }
+
+
+#else /* !GRAN && !PAR */
 
-extern DLL_IMPORT_DATA const StgPolyInfoTable Upd_frame_info; 
-
-#define PUSH_UPD_FRAME(target, Sp_offset)                      \
-       {                                                       \
-               StgUpdateFrame *__frame;                        \
-               TICK_UPDF_PUSHED(target, GET_INFO((StgClosure*)target));                        \
-               __frame = stgCast(StgUpdateFrame*,Sp + (Sp_offset)) - 1; \
-               SET_INFO(__frame,stgCast(StgInfoTable*,&Upd_frame_info));   \
-               __frame->link = Su;                             \
-               __frame->updatee = (StgClosure *)(target);      \
-               PUSH_STD_CCCS(__frame);                         \
-               Su = __frame;                                   \
+#define DO_AWAKEN_BQ(closure)          \
+        FCALL awakenBlockedQueue(StgBlockingQueue_blocking_queue(closure) ARG_PTR);
+
+#define AWAKEN_BQ(info,closure)                                                \
+       if (info == INFO_PTR(stg_BLACKHOLE_BQ_info)) {                  \
+          DO_AWAKEN_BQ(closure);                                        \
        }
 
-/* -----------------------------------------------------------------------------
-   Entering CAFs
+#define AWAKEN_STATIC_BQ(info,closure)                                 \
+       if (info == INFO_PTR(stg_BLACKHOLE_BQ_STATIC_info)) {           \
+          DO_AWAKEN_BQ(closure);                                        \
+       }
 
-   When a CAF is first entered, it creates a black hole in the heap,
-   and updates itself with an indirection to this new black hole.
+#ifdef RTS_SUPPORTS_THREADS
+#define DO_AWAKEN_BQ_NOLOCK(closure) \
+        FCALL awakenBlockedQueueNoLock(StgBlockingQueue_blocking_queue(closure) ARG_PTR);
 
-   We update the CAF with an indirection to a newly-allocated black
-   hole in the heap.  We also set the blocking queue on the newly
-   allocated black hole to be empty.
+#define AWAKEN_BQ_NOLOCK(info,closure)                                 \
+       if (info == INFO_PTR(stg_BLACKHOLE_BQ_info)) {                  \
+          DO_AWAKEN_BQ_NOLOCK(closure);                                 \
+       }
+#endif
+#endif /* GRAN || PAR */
 
-   Why do we make a black hole in the heap when we enter a CAF?
-      
-       - for a  generational garbage collector, which needs a fast
-         test for whether an updatee is in an old generation or not
+/* -----------------------------------------------------------------------------
+   Updates: lower-level macros which update a closure with an
+   indirection to another closure.
 
-       - for the parallel system, which can implement updates more
-         easily if the updatee is always in the heap. (allegedly).
+   There are several variants of this code.
 
-   When debugging, we maintain a separate CAF list so we can tell when
-   a CAF has been garbage collected.
+       PROFILING:
    -------------------------------------------------------------------------- */
-   
-/* ToDo: only call newCAF when debugging. */
 
-extern void newCAF(StgClosure*);
+/* LDV profiling:
+ * We call LDV_recordDead_FILL_SLOP_DYNAMIC(p1) regardless of the generation in 
+ * which p1 resides.
+ *
+ * Note: 
+ *   After all, we do *NOT* need to call LDV_RECORD_CREATE() for both IND and 
+ *   IND_OLDGEN closures because they are inherently used. But, it corrupts
+ *   the invariants that every closure keeps its creation time in the profiling
+ *  field. So, we call LDV_RECORD_CREATE().
+ */
 
-#define UPD_CAF(cafptr, bhptr)                                 \
-  {                                                            \
-    SET_INFO((StgInd *)cafptr,(const StgInfoTable*)&IND_STATIC_info);          \
-    ((StgInd *)cafptr)->indirectee   = (StgClosure *)(bhptr);  \
-    STGCALL1(newCAF,(StgClosure *)cafptr);                     \
+/* In the DEBUG case, we also zero out the slop of the old closure,
+ * so that the sanity checker can tell where the next closure is.
+ *
+ * Two important invariants: we should never try to update a closure
+ * to point to itself, and the closure being updated should not
+ * already have been updated (the mutable list will get messed up
+ * otherwise).
+ */
+#if !defined(DEBUG)
+
+#define DEBUG_FILL_SLOP(p) /* nothing */
+
+#else  /* DEBUG */
+
+#ifdef CMINUSMINUS
+
+#define DEBUG_FILL_SLOP(p)                     \
+  W_ inf;                                      \
+  W_ np;                                       \
+  W_ nw;                                       \
+  W_ i;                                                \
+  inf = %GET_STD_INFO(p);                      \
+  np = TO_W_(%INFO_PTRS(inf));                 \
+  nw = TO_W_(%INFO_NPTRS(inf));                        \
+  if (%INFO_TYPE(inf) != HALF_W_(THUNK_SELECTOR)) {    \
+    i = 0;                                     \
+    for:                                       \
+      if (i < np + nw) {                       \
+        StgClosure_payload(p,i) = 0;           \
+        i = i + 1;                             \
+        goto for;                              \
+      }                                                \
   }
 
-/* -----------------------------------------------------------------------------
-   Update-related prototypes
-   -------------------------------------------------------------------------- */
 
-DLL_IMPORT_RTS extern STGFUN(Upd_frame_entry);
+#else /* !CMINUSMINUS */
 
-extern DLL_IMPORT_DATA const StgInfoTable PAP_info;
-DLL_IMPORT_RTS STGFUN(PAP_entry);
+INLINE_HEADER void
+DEBUG_FILL_SLOP(StgClosure *p)
+{                                              
+    StgInfoTable *inf = get_itbl(p);           
+    nat np = inf->layout.payload.ptrs,         
+       nw = inf->layout.payload.nptrs, i;
+    if (inf->type != THUNK_SELECTOR) {
+       for (i = 0; i < np + nw; i++) {
+           ((StgClosure *)p)->payload[i] = 0;
+       }
+    }
+}
 
-EXTFUN_RTS(stg_update_PAP);
+#endif /* CMINUSMINUS */
+#endif /* DEBUG */
 
-extern DLL_IMPORT_DATA const StgInfoTable AP_UPD_info;
-DLL_IMPORT_RTS STGFUN(AP_UPD_entry);
+/* We have two versions of this macro (sadly), one for use in C-- code,
+ * and the other for C.
+ *
+ * The and_then argument is a performance hack so that we can paste in
+ * the continuation code directly.  It helps shave a couple of
+ * instructions off the common case in the update code, which is
+ * worthwhile (the update code is often part of the inner loop).
+ * (except that gcc now appears to common up this code again and
+ * invert the optimisation.  Grrrr --SDM).
+ */
+#ifdef CMINUSMINUS
+#define generation(n) (W_[generations] + n*SIZEOF_generation)
+#define updateWithIndirection(info, ind_info, p1, p2, and_then)        \
+    W_ bd;                                                     \
+                                                               \
+/*    ASSERT( p1 != p2 && !closure_IND(p1) );                  \
+ */ LDV_RECORD_DEAD_FILL_SLOP_DYNAMIC(p1);                     \
+    bd = Bdescr(p1);                                           \
+    if (bdescr_gen_no(bd) == 0 :: CInt) {                      \
+      StgInd_indirectee(p1) = p2;                              \
+      SET_INFO(p1, ind_info);                                  \
+      LDV_RECORD_CREATE(p1);                                   \
+      TICK_UPD_NEW_IND();                                      \
+      and_then;                                                        \
+    } else {                                                   \
+      if (info != stg_BLACKHOLE_BQ_info) {                     \
+        DEBUG_FILL_SLOP(p1);                                   \
+        foreign "C" recordMutableGen(p1 "ptr",                         \
+                generation(TO_W_(bdescr_gen_no(bd))) "ptr");   \
+      }                                                                \
+      StgInd_indirectee(p1) = p2;                              \
+      SET_INFO(p1, stg_IND_OLDGEN_info);                       \
+      LDV_RECORD_CREATE(p1);                                   \
+      TICK_UPD_OLD_IND();                                      \
+      and_then;                                                        \
+  }
+#else
+#define updateWithIndirection(_info, ind_info, p1, p2, and_then)       \
+  {                                                                    \
+    bdescr *bd;                                                                \
+                                                                       \
+    ASSERT( (P_)p1 != (P_)p2 && !closure_IND(p1) );                    \
+    LDV_RECORD_DEAD_FILL_SLOP_DYNAMIC(p1);                             \
+    bd = Bdescr((P_)p1);                                               \
+    if (bd->gen_no == 0) {                                             \
+      ((StgInd *)p1)->indirectee = p2;                                 \
+      SET_INFO(p1, ind_info);                                          \
+      LDV_RECORD_CREATE(p1);                                           \
+      TICK_UPD_NEW_IND();                                              \
+      and_then;                                                                \
+    } else {                                                           \
+      if (_info != &stg_BLACKHOLE_BQ_info) {                           \
+        DEBUG_FILL_SLOP(p1);                                           \
+        recordMutableGen(p1, &generations[bd->gen_no]);                        \
+      }                                                                        \
+      ((StgInd *)p1)->indirectee = p2;                                 \
+      SET_INFO(p1, &stg_IND_OLDGEN_info);                              \
+      TICK_UPD_OLD_IND();                                              \
+      and_then;                                                                \
+    }                                                                  \
+  }
+#endif
 
-extern DLL_IMPORT_DATA const StgInfoTable raise_info;
+/* The permanent indirection version isn't performance critical.  We
+ * therefore use an inline C function instead of the C-- macro.
+ */
+#ifndef CMINUSMINUS
+INLINE_HEADER void
+updateWithPermIndirection(const StgInfoTable *info, 
+                         StgClosure *p1,
+                         StgClosure *p2) 
+{
+  bdescr *bd;
+
+  ASSERT( p1 != p2 && !closure_IND(p1) );
+
+  // @LDV profiling
+  // Destroy the old closure.
+  // Nb: LDV_* stuff cannot mix with ticky-ticky
+  LDV_RECORD_DEAD_FILL_SLOP_DYNAMIC(p1);
+
+  bd = Bdescr((P_)p1);
+  if (bd->gen_no == 0) {
+    ((StgInd *)p1)->indirectee = p2;
+    SET_INFO(p1, &stg_IND_PERM_info);
+    // @LDV profiling
+    // We have just created a new closure.
+    LDV_RECORD_CREATE(p1);
+    TICK_UPD_NEW_PERM_IND(p1);
+  } else {
+    if (info != &stg_BLACKHOLE_BQ_info) {
+       recordMutableGen(p1, &generations[bd->gen_no]);
+    }
+    ((StgInd *)p1)->indirectee = p2;
+    SET_INFO(p1, &stg_IND_OLDGEN_PERM_info);
+    // @LDV profiling
+    // We have just created a new closure.
+    LDV_RECORD_CREATE(p1);
+    TICK_UPD_OLD_PERM_IND();
+  }
+}
+#endif
 
 #endif /* UPDATES_H */