New implementation of BLACKHOLEs

[ghc-hetmet.git] / rts / sm / Storage.c

diff --git a/rts/sm/Storage.c b/rts/sm/Storage.c
index 781234a..0234400 100644 (file)
--- a/rts/sm/Storage.c
+++ b/rts/sm/Storage.c
@@ -94,7 +94,7 @@ initGeneration (generation *gen, int g)
 void
 initStorage( void )
 {
-  nat g;
+    nat g, n;
 
   if (generations != NULL) {
       // multi-init protection
@@ -107,7 +107,7 @@ initStorage( void )
    * doing something reasonable.
    */
   /* We use the NOT_NULL variant or gcc warns that the test is always true */
-  ASSERT(LOOKS_LIKE_INFO_PTR_NOT_NULL((StgWord)&stg_BLACKHOLE_info));
+  ASSERT(LOOKS_LIKE_INFO_PTR_NOT_NULL((StgWord)&stg_BLOCKING_QUEUE_CLEAN_info));
   ASSERT(LOOKS_LIKE_CLOSURE_PTR(&stg_dummy_ret_closure));
   ASSERT(!HEAP_ALLOCED(&stg_dummy_ret_closure));
   
@@ -192,6 +192,13 @@ initStorage( void )
 
   N = 0;
 
+  // allocate a block for each mut list
+  for (n = 0; n < n_capabilities; n++) {
+      for (g = 1; g < RtsFlags.GcFlags.generations; g++) {
+          capabilities[n].mut_lists[g] = allocBlock();
+      }
+  }
+
   initGcThreads();
 
   IF_DEBUG(gc, statDescribeGens());
@@ -222,20 +229,20 @@ freeStorage (void)
 
    The entry code for every CAF does the following:
      
-      - builds a CAF_BLACKHOLE in the heap
-      - pushes an update frame pointing to the CAF_BLACKHOLE
+      - builds a BLACKHOLE in the heap
+      - pushes an update frame pointing to the BLACKHOLE
       - invokes UPD_CAF(), which:
           - calls newCaf, below
-         - updates the CAF with a static indirection to the CAF_BLACKHOLE
+         - updates the CAF with a static indirection to the BLACKHOLE
       
-   Why do we build a BLACKHOLE in the heap rather than just updating
+   Why do we build an BLACKHOLE in the heap rather than just updating
    the thunk directly?  It's so that we only need one kind of update
    frame - otherwise we'd need a static version of the update frame too.
 
    newCaf() does the following:
        
-      - it puts the CAF on the oldest generation's mut-once list.
-        This is so that we can treat the CAF as a root when collecting
+      - it puts the CAF on the oldest generation's mutable list.
+        This is so that we treat the CAF as a root when collecting
        younger generations.
 
    For GHCI, we have additional requirements when dealing with CAFs:
@@ -259,11 +266,8 @@ freeStorage (void)
    -------------------------------------------------------------------------- */
 
 void
-newCAF(StgClosure* caf)
+newCAF(StgRegTable *reg, StgClosure* caf)
 {
-  ACQUIRE_SM_LOCK;
-
-#ifdef DYNAMIC
   if(keepCAFs)
   {
     // HACK:
@@ -277,24 +281,25 @@ newCAF(StgClosure* caf)
     // do another hack here and do an address range test on caf to figure
     // out whether it is from a dynamic library.
     ((StgIndStatic *)caf)->saved_info  = (StgInfoTable *)caf->header.info;
+
+    ACQUIRE_SM_LOCK; // caf_list is global, locked by sm_mutex
     ((StgIndStatic *)caf)->static_link = caf_list;
     caf_list = caf;
+    RELEASE_SM_LOCK;
   }
   else
-#endif
   {
-    /* Put this CAF on the mutable list for the old generation.
-    * This is a HACK - the IND_STATIC closure doesn't really have
-    * a mut_link field, but we pretend it has - in fact we re-use
-    * the STATIC_LINK field for the time being, because when we
-    * come to do a major GC we won't need the mut_link field
-    * any more and can use it as a STATIC_LINK.
-    */
+    // Put this CAF on the mutable list for the old generation.
     ((StgIndStatic *)caf)->saved_info = NULL;
-    recordMutableGen(caf, oldest_gen->no);
+    recordMutableCap(caf, regTableToCapability(reg), oldest_gen->no);
   }
-  
-  RELEASE_SM_LOCK;
+}
+
+// External API for setting the keepCAFs flag. see #3900.
+void
+setKeepCAFs (void)
+{
+    keepCAFs = 1;
 }
 
 // An alternate version of newCaf which is used for dynamically loaded
@@ -307,7 +312,7 @@ newCAF(StgClosure* caf)
 // The linker hackily arranges that references to newCaf from dynamic
 // code end up pointing to newDynCAF.
 void
-newDynCAF(StgClosure *caf)
+newDynCAF (StgRegTable *reg STG_UNUSED, StgClosure *caf)
 {
     ACQUIRE_SM_LOCK;
 
@@ -614,6 +619,8 @@ allocate (Capability *cap, lnat n)
     }
     p = bd->free;
     bd->free += n;
+
+    IF_DEBUG(sanity, ASSERT(*((StgWord8*)p) == 0xaa));
     return p;
 }
 
@@ -692,11 +699,9 @@ void
 dirty_MUT_VAR(StgRegTable *reg, StgClosure *p)
 {
     Capability *cap = regTableToCapability(reg);
-    bdescr *bd;
     if (p->header.info == &stg_MUT_VAR_CLEAN_info) {
        p->header.info = &stg_MUT_VAR_DIRTY_info;
-       bd = Bdescr((StgPtr)p);
-       if (bd->gen_no > 0) recordMutableCap(p,cap,bd->gen_no);
+        recordClosureMutated(cap,p);
     }
 }
 
@@ -709,11 +714,9 @@ dirty_MUT_VAR(StgRegTable *reg, StgClosure *p)
 void
 setTSOLink (Capability *cap, StgTSO *tso, StgTSO *target)
 {
-    bdescr *bd;
     if (tso->dirty == 0 && (tso->flags & TSO_LINK_DIRTY) == 0) {
         tso->flags |= TSO_LINK_DIRTY;
-       bd = Bdescr((StgPtr)tso);
-       if (bd->gen_no > 0) recordMutableCap((StgClosure*)tso,cap,bd->gen_no);
+        recordClosureMutated(cap,(StgClosure*)tso);
     }
     tso->_link = target;
 }
@@ -721,10 +724,8 @@ setTSOLink (Capability *cap, StgTSO *tso, StgTSO *target)
 void
 dirty_TSO (Capability *cap, StgTSO *tso)
 {
-    bdescr *bd;
     if (tso->dirty == 0 && (tso->flags & TSO_LINK_DIRTY) == 0) {
-       bd = Bdescr((StgPtr)tso);
-       if (bd->gen_no > 0) recordMutableCap((StgClosure*)tso,cap,bd->gen_no);
+        recordClosureMutated(cap,(StgClosure*)tso);
     }
     tso->dirty = 1;
 }
@@ -740,10 +741,7 @@ dirty_TSO (Capability *cap, StgTSO *tso)
 void
 dirty_MVAR(StgRegTable *reg, StgClosure *p)
 {
-    Capability *cap = regTableToCapability(reg);
-    bdescr *bd;
-    bd = Bdescr((StgPtr)p);
-    if (bd->gen_no > 0) recordMutableCap(p,cap,bd->gen_no);
+    recordClosureMutated(regTableToCapability(reg),p);
 }
 
 /* -----------------------------------------------------------------------------