X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=rts%2Fsm%2FGCUtils.c;h=8b63674c77932ad6970cfa82a70542444a84ff66;hb=bef3da1e26639303fccbf26c312d2833eedb486e;hp=6e1fb302d8c60048d3c857d4565110819c42e50b;hpb=ab0e778ccfde61aed4c22679b24d175fc6cc9bf3;p=ghc-hetmet.git

diff --git a/rts/sm/GCUtils.c b/rts/sm/GCUtils.c
index 6e1fb30..8b63674 100644
--- a/rts/sm/GCUtils.c
+++ b/rts/sm/GCUtils.c
@@ -1,79 +1,310 @@
 /* -----------------------------------------------------------------------------
  *
- * (c) The GHC Team 1998-2006
+ * (c) The GHC Team 1998-2008
  *
  * Generational garbage collector: utilities
  *
+ * Documentation on the architecture of the Garbage Collector can be
+ * found in the online commentary:
+ * 
+ *   http://hackage.haskell.org/trac/ghc/wiki/Commentary/Rts/Storage/GC
+ *
  * ---------------------------------------------------------------------------*/
 
+#include "PosixSource.h"
 #include "Rts.h"
+
+#include "BlockAlloc.h"
 #include "Storage.h"
 #include "GC.h"
+#include "GCThread.h"
 #include "GCUtils.h"
+#include "Printer.h"
+#include "Trace.h"
+#ifdef THREADED_RTS
+#include "WSDeque.h"
+#endif
+
+#ifdef THREADED_RTS
+SpinLock gc_alloc_block_sync;
+#endif
+
+bdescr *
+allocBlock_sync(void)
+{
+    bdescr *bd;
+    ACQUIRE_SPIN_LOCK(&gc_alloc_block_sync);
+    bd = allocBlock();
+    RELEASE_SPIN_LOCK(&gc_alloc_block_sync);
+    return bd;
+}
+
+static bdescr *
+allocGroup_sync(nat n)
+{
+    bdescr *bd;
+    ACQUIRE_SPIN_LOCK(&gc_alloc_block_sync);
+    bd = allocGroup(n);
+    RELEASE_SPIN_LOCK(&gc_alloc_block_sync);
+    return bd;
+}
+
+
+#if 0
+static void
+allocBlocks_sync(nat n, bdescr **hd, bdescr **tl, 
+                 nat gen_no, step *stp,
+                 StgWord32 flags)
+{
+    bdescr *bd;
+    nat i;
+    ACQUIRE_SPIN_LOCK(&gc_alloc_block_sync);
+    bd = allocGroup(n);
+    for (i = 0; i < n; i++) {
+        bd[i].blocks = 1;
+        bd[i].gen_no = gen_no;
+        bd[i].step = stp;
+        bd[i].flags = flags;
+        bd[i].link = &bd[i+1];
+        bd[i].u.scan = bd[i].free = bd[i].start;
+    }
+    *hd = bd;
+    *tl = &bd[n-1];
+    RELEASE_SPIN_LOCK(&gc_alloc_block_sync);
+}
+#endif
+
+void
+freeChain_sync(bdescr *bd)
+{
+    ACQUIRE_SPIN_LOCK(&gc_alloc_block_sync);
+    freeChain(bd);
+    RELEASE_SPIN_LOCK(&gc_alloc_block_sync);
+}
 
 /* -----------------------------------------------------------------------------
-   Allocate a new to-space block in the given step.
+   Workspace utilities
    -------------------------------------------------------------------------- */
 
 bdescr *
-gc_alloc_block(step *stp)
+grab_local_todo_block (gen_workspace *ws)
 {
-    bdescr *bd = allocBlock();
-    bd->gen_no = stp->gen_no;
-    bd->step = stp;
-    bd->link = NULL;
+    bdescr *bd;
+    generation *gen;
+
+    gen = ws->gen;
 
-    // blocks in to-space in generations up to and including N
-    // get the BF_EVACUATED flag.
-    if (stp->gen_no <= N) {
-	bd->flags = BF_EVACUATED;
-    } else {
-	bd->flags = 0;
+    bd = ws->todo_overflow;
+    if (bd != NULL)
+    {
+        ws->todo_overflow = bd->link;
+        bd->link = NULL;
+        ws->n_todo_overflow--;
+	return bd;
     }
 
-    // Start a new to-space block, chain it on after the previous one.
-    if (stp->hp_bd != NULL) {
-	stp->hp_bd->free = stp->hp;
-	stp->hp_bd->link = bd;
+    bd = popWSDeque(ws->todo_q);
+    if (bd != NULL)
+    {
+	ASSERT(bd->link == NULL);
+	return bd;
     }
 
-    stp->hp_bd = bd;
-    stp->hp    = bd->start;
-    stp->hpLim = stp->hp + BLOCK_SIZE_W;
+    return NULL;
+}
 
-    stp->n_blocks++;
-    new_blocks++;
+#if defined(THREADED_RTS)
+bdescr *
+steal_todo_block (nat g)
+{
+    nat n;
+    bdescr *bd;
 
-    return bd;
+    // look for work to steal
+    for (n = 0; n < n_gc_threads; n++) {
+        if (n == gct->thread_index) continue;
+        bd = stealWSDeque(gc_threads[n]->gens[g].todo_q);
+        if (bd) {
+            return bd;
+        }
+    }
+    return NULL;
 }
+#endif
 
-bdescr *
-gc_alloc_scavd_block(step *stp)
+void
+push_scanned_block (bdescr *bd, gen_workspace *ws)
 {
-    bdescr *bd = allocBlock();
-    bd->gen_no = stp->gen_no;
-    bd->step = stp;
-
-    // blocks in to-space in generations up to and including N
-    // get the BF_EVACUATED flag.
-    if (stp->gen_no <= N) {
-	bd->flags = BF_EVACUATED;
-    } else {
-	bd->flags = 0;
+    ASSERT(bd != NULL);
+    ASSERT(bd->link == NULL);
+    ASSERT(bd->gen == ws->gen);
+    ASSERT(bd->u.scan == bd->free);
+
+    if (bd->start + bd->blocks * BLOCK_SIZE_W - bd->free > WORK_UNIT_WORDS)
+    {
+        // a partially full block: put it on the part_list list.
+        bd->link = ws->part_list;
+        ws->part_list = bd;
+        ws->n_part_blocks += bd->blocks;
+        IF_DEBUG(sanity, 
+                 ASSERT(countBlocks(ws->part_list) == ws->n_part_blocks));
+    }
+    else
+    {
+        // put the scan block on the ws->scavd_list.
+        bd->link = ws->scavd_list;
+        ws->scavd_list = bd;
+        ws->n_scavd_blocks += bd->blocks;
+        IF_DEBUG(sanity, 
+                 ASSERT(countBlocks(ws->scavd_list) == ws->n_scavd_blocks));
     }
+}
 
-    bd->link = stp->blocks;
-    stp->blocks = bd;
+StgPtr
+todo_block_full (nat size, gen_workspace *ws)
+{
+    StgPtr p;
+    bdescr *bd;
+
+    // todo_free has been pre-incremented by Evac.c:alloc_for_copy().  We
+    // are expected to leave it bumped when we've finished here.
+    ws->todo_free -= size;
+
+    bd = ws->todo_bd;
+
+    ASSERT(bd != NULL);
+    ASSERT(bd->link == NULL);
+    ASSERT(bd->gen == ws->gen);
 
-    if (stp->scavd_hp != NULL) {
-	Bdescr(stp->scavd_hp)->free = stp->scavd_hp;
+    // If the global list is not empty, or there's not much work in
+    // this block to push, and there's enough room in
+    // this block to evacuate the current object, then just increase
+    // the limit.
+    if (!looksEmptyWSDeque(ws->todo_q) || 
+        (ws->todo_free - bd->u.scan < WORK_UNIT_WORDS / 2)) {
+        if (ws->todo_free + size < bd->start + bd->blocks * BLOCK_SIZE_W) {
+            ws->todo_lim = stg_min(bd->start + bd->blocks * BLOCK_SIZE_W,
+                                   ws->todo_lim + stg_max(WORK_UNIT_WORDS,size));
+            debugTrace(DEBUG_gc, "increasing limit for %p to %p", bd->start, ws->todo_lim);
+            p = ws->todo_free;
+            ws->todo_free += size;
+            return p;
+        }
     }
-    stp->scavd_hp    = bd->start;
-    stp->scavd_hpLim = stp->scavd_hp + BLOCK_SIZE_W;
+    
+    gct->copied += ws->todo_free - bd->free;
+    bd->free = ws->todo_free;
 
-    stp->n_blocks++;
-    new_scavd_blocks++;
+    ASSERT(bd->u.scan >= bd->start && bd->u.scan <= bd->free);
 
-    return bd;
+    // If this block is not the scan block, we want to push it out and
+    // make room for a new todo block.
+    if (bd != gct->scan_bd)
+    {
+        // If this block does not have enough space to allocate the
+        // current object, but it also doesn't have any work to push, then 
+        // push it on to the scanned list.  It cannot be empty, because
+        // then there would be enough room to copy the current object.
+        if (bd->u.scan == bd->free)
+        {
+            ASSERT(bd->free != bd->start);
+            push_scanned_block(bd, ws);
+        }
+        // Otherwise, push this block out to the global list.
+        else 
+        {
+            generation *gen;
+            gen = ws->gen;
+            debugTrace(DEBUG_gc, "push todo block %p (%ld words), step %d, todo_q: %ld", 
+                  bd->start, (unsigned long)(bd->free - bd->u.scan),
+                  gen->no, dequeElements(ws->todo_q));
+
+            if (!pushWSDeque(ws->todo_q, bd)) {
+                bd->link = ws->todo_overflow;
+                ws->todo_overflow = bd;
+                ws->n_todo_overflow++;
+            }
+        }
+    }
+
+    ws->todo_bd   = NULL;
+    ws->todo_free = NULL;
+    ws->todo_lim  = NULL;
+
+    alloc_todo_block(ws, size);
+
+    p = ws->todo_free;
+    ws->todo_free += size;
+    return p;
+}
+
+StgPtr
+alloc_todo_block (gen_workspace *ws, nat size)
+{
+    bdescr *bd/*, *hd, *tl */;
+
+    // Grab a part block if we have one, and it has enough room
+    bd = ws->part_list;
+    if (bd != NULL &&
+        bd->start + bd->blocks * BLOCK_SIZE_W - bd->free > (int)size)
+    {
+        ws->part_list = bd->link;
+        ws->n_part_blocks -= bd->blocks;
+    }
+    else
+    {
+        // blocks in to-space get the BF_EVACUATED flag.
+
+//        allocBlocks_sync(16, &hd, &tl, 
+//                         ws->step->gen_no, ws->step, BF_EVACUATED);
+//
+//        tl->link = ws->part_list;
+//        ws->part_list = hd->link;
+//        ws->n_part_blocks += 15;
+//
+//        bd = hd;
+
+        if (size > BLOCK_SIZE_W) {
+            bd = allocGroup_sync((lnat)BLOCK_ROUND_UP(size*sizeof(W_))
+                                 / BLOCK_SIZE);
+        } else {
+            bd = allocBlock_sync();
+        }
+        initBdescr(bd, ws->gen, ws->gen->to);
+        bd->flags = BF_EVACUATED;
+        bd->u.scan = bd->free = bd->start;
+    }
+
+    bd->link = NULL;
+
+    ws->todo_bd = bd;
+    ws->todo_free = bd->free;
+    ws->todo_lim  = stg_min(bd->start + bd->blocks * BLOCK_SIZE_W,
+                            bd->free + stg_max(WORK_UNIT_WORDS,size));
+
+    debugTrace(DEBUG_gc, "alloc new todo block %p for gen  %d", 
+               bd->free, ws->gen->no);
+
+    return ws->todo_free;
 }
 
+/* -----------------------------------------------------------------------------
+ * Debugging
+ * -------------------------------------------------------------------------- */
+
+#if DEBUG
+void
+printMutableList(bdescr *bd)
+{
+    StgPtr p;
+
+    debugBelch("mutable list %p: ", bd);
+
+    for (; bd != NULL; bd = bd->link) {
+	for (p = bd->start; p < bd->free; p++) {
+	    debugBelch("%p (%s), ", (void *)*p, info_type((StgClosure *)*p));
+	}
+    }
+    debugBelch("\n");
+}
+#endif /* DEBUG */