1 files changed, 202 insertions, 0 deletions
diff --git a/includes/Block.h b/includes/Block.h
new file mode 100644
index 0000000000..d1705ad686
--- /dev/null
+++ b/includes/Block.h
@@ -0,0 +1,202 @@
+/* -----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team, 1998-1999
+ *
+ * Block structure for the storage manager
+ *
+ * ---------------------------------------------------------------------------*/
+
+#ifndef BLOCK_H
+#define BLOCK_H
+
+/* The actual block and megablock-size constants are defined in
+ * includes/Constants.h, all constants here are derived from these.
+ */
+
+/* Block related constants (BLOCK_SHIFT is defined in Constants.h) */
+
+#define BLOCK_SIZE   (1<<BLOCK_SHIFT)
+#define BLOCK_SIZE_W (BLOCK_SIZE/sizeof(W_))
+#define BLOCK_MASK   (BLOCK_SIZE-1)
+
+#define BLOCK_ROUND_UP(p)   ((void *) (((W_)(p)+BLOCK_SIZE-1) & ~BLOCK_MASK))
+#define BLOCK_ROUND_DOWN(p) ((void *) ((W_)(p) & ~BLOCK_MASK))
+
+/* Megablock related constants (MBLOCK_SHIFT is defined in Constants.h) */
+
+#define MBLOCK_SIZE    (1<<MBLOCK_SHIFT)
+#define MBLOCK_SIZE_W  (MBLOCK_SIZE/sizeof(W_))
+#define MBLOCK_MASK    (MBLOCK_SIZE-1)
+
+#define MBLOCK_ROUND_UP(p)   ((void *)(((W_)(p)+MBLOCK_SIZE-1) & ~MBLOCK_MASK))
+#define MBLOCK_ROUND_DOWN(p) ((void *)((W_)(p) & ~MBLOCK_MASK ))
+
+/* The largest size an object can be before we give it a block of its
+ * own and treat it as an immovable object during GC, expressed as a
+ * fraction of BLOCK_SIZE.
+ */
+#define LARGE_OBJECT_THRESHOLD ((nat)(BLOCK_SIZE * 8 / 10))
+
+/* -----------------------------------------------------------------------------
+ * Block descriptor.  This structure *must* be the right length, so we
+ * can do pointer arithmetic on pointers to it.
+ */
+
+/* The block descriptor is 64 bytes on a 64-bit machine, and 32-bytes
+ * on a 32-bit machine.
+ */
+
+#ifndef CMINUSMINUS
+typedef struct bdescr_ {
+  StgPtr start;			/* start addr of memory */
+  StgPtr free;			/* first free byte of memory */
+  struct bdescr_ *link;		/* used for chaining blocks together */
+  union { 
+      struct bdescr_ *back;	/* used (occasionally) for doubly-linked lists*/
+      StgWord *bitmap;
+  } u;
+  unsigned int gen_no;		/* generation */
+  struct step_ *step;		/* step */
+  StgWord32 blocks;		/* no. of blocks (if grp head, 0 otherwise) */
+  StgWord32 flags;              /* block is in to-space */
+#if SIZEOF_VOID_P == 8
+  StgWord32 _padding[2];
+#else
+  StgWord32 _padding[0];
+#endif
+} bdescr;
+#endif
+
+#if SIZEOF_VOID_P == 8
+#define BDESCR_SIZE  0x40
+#define BDESCR_MASK  0x3f
+#define BDESCR_SHIFT 6
+#else
+#define BDESCR_SIZE  0x20
+#define BDESCR_MASK  0x1f
+#define BDESCR_SHIFT 5
+#endif
+
+/* Block contains objects evacuated during this GC */
+#define BF_EVACUATED 1
+/* Block is a large object */
+#define BF_LARGE     2
+/* Block is pinned */
+#define BF_PINNED    4
+/* Block is part of a compacted generation */
+#define BF_COMPACTED 8
+/* Block is free, and on the free list */
+#define BF_FREE      16
+
+/* Finding the block descriptor for a given block -------------------------- */
+
+#ifdef CMINUSMINUS
+
+#define Bdescr(p) \
+    ((((p) &  MBLOCK_MASK & ~BLOCK_MASK) >> (BLOCK_SHIFT-BDESCR_SHIFT)) \
+     | ((p) & ~MBLOCK_MASK))
+
+#else
+
+INLINE_HEADER bdescr *Bdescr(StgPtr p)
+{
+  return (bdescr *)
+    ((((W_)p &  MBLOCK_MASK & ~BLOCK_MASK) >> (BLOCK_SHIFT-BDESCR_SHIFT)) 
+     | ((W_)p & ~MBLOCK_MASK)
+     );
+}
+
+#endif
+
+/* Useful Macros ------------------------------------------------------------ */
+
+/* Offset of first real data block in a megablock */
+
+#define FIRST_BLOCK_OFF \
+   ((W_)BLOCK_ROUND_UP(BDESCR_SIZE * (MBLOCK_SIZE / BLOCK_SIZE)))
+
+/* First data block in a given megablock */
+
+#define FIRST_BLOCK(m) ((void *)(FIRST_BLOCK_OFF + (W_)(m)))
+   
+/* Last data block in a given megablock */
+
+#define LAST_BLOCK(m)  ((void *)(MBLOCK_SIZE-BLOCK_SIZE + (W_)(m)))
+
+/* First real block descriptor in a megablock */
+
+#define FIRST_BDESCR(m) \
+   ((bdescr *)((FIRST_BLOCK_OFF>>(BLOCK_SHIFT-BDESCR_SHIFT)) + (W_)(m)))
+
+/* Number of usable blocks in a megablock */
+
+#define BLOCKS_PER_MBLOCK ((MBLOCK_SIZE - FIRST_BLOCK_OFF) / BLOCK_SIZE)
+
+/* How many blocks in this megablock group */
+
+#define MBLOCK_GROUP_BLOCKS(n) \
+   (BLOCKS_PER_MBLOCK + (n-1) * (MBLOCK_SIZE / BLOCK_SIZE))
+
+/* Compute the required size of a megablock group */
+
+#define BLOCKS_TO_MBLOCKS(n) \
+   (1 + (W_)MBLOCK_ROUND_UP((n-BLOCKS_PER_MBLOCK) * BLOCK_SIZE) / MBLOCK_SIZE)
+
+
+#ifndef CMINUSMINUS 
+/* to the end... */
+
+/* Double-linked block lists: --------------------------------------------- */
+
+INLINE_HEADER void
+dbl_link_onto(bdescr *bd, bdescr **list)
+{
+  bd->link = *list;
+  bd->u.back = NULL;
+  if (*list) {
+    (*list)->u.back = bd; /* double-link the list */
+  }
+  *list = bd;
+}
+
+/* Initialisation ---------------------------------------------------------- */
+
+extern void initBlockAllocator(void);
+
+/* Allocation -------------------------------------------------------------- */
+
+bdescr *allocGroup(nat n);
+bdescr *allocBlock(void);
+
+// versions that take the storage manager lock for you:
+bdescr *allocGroup_lock(nat n);
+bdescr *allocBlock_lock(void);
+
+/* De-Allocation ----------------------------------------------------------- */
+
+void freeGroup(bdescr *p);
+void freeChain(bdescr *p);
+
+// versions that take the storage manager lock for you:
+void freeGroup_lock(bdescr *p);
+void freeChain_lock(bdescr *p);
+
+/* Round a value to megablocks --------------------------------------------- */
+
+#define WORDS_PER_MBLOCK  (BLOCKS_PER_MBLOCK * BLOCK_SIZE_W)
+
+INLINE_HEADER nat
+round_to_mblocks(nat words)
+{
+  if (words > WORDS_PER_MBLOCK) {
+    if ((words % WORDS_PER_MBLOCK) < (WORDS_PER_MBLOCK / 2)) {
+      words = (words / WORDS_PER_MBLOCK) * WORDS_PER_MBLOCK;
+    } else {
+      words = ((words / WORDS_PER_MBLOCK) + 1) * WORDS_PER_MBLOCK;
+    }
+  }
+  return words;
+}
+
+#endif /* !CMINUSMINUS */
+#endif /* BLOCK_H */