X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FBlockAlloc.c;h=ae87fcca6b1609a8f08e12d0872baf3ef83bbcf8;hb=0a565be58ffcde267b09f8c1820a61428afce1c7;hp=e0ded8e2525551fe06e268c7a3a99b6bab6aeb67;hpb=438596897ebbe25a07e1c82085cfbc5bdb00f09e;p=ghc-hetmet.git diff --git a/ghc/rts/BlockAlloc.c b/ghc/rts/BlockAlloc.c index e0ded8e..ae87fcc 100644 --- a/ghc/rts/BlockAlloc.c +++ b/ghc/rts/BlockAlloc.c @@ -1,6 +1,7 @@ /* ----------------------------------------------------------------------------- - * $Id: BlockAlloc.c,v 1.2 1998/12/02 13:28:12 simonm Exp $ * + * (c) The GHC Team 1998-2000 + * * The block allocator and free list manager. * * This is the architecture independent part of the block allocator. @@ -14,17 +15,20 @@ * * ---------------------------------------------------------------------------*/ +#include "PosixSource.h" #include "Rts.h" #include "RtsFlags.h" #include "RtsUtils.h" #include "BlockAlloc.h" #include "MBlock.h" +#include + static void initMBlock(void *mblock); static bdescr *allocMegaGroup(nat mblocks); static void freeMegaGroup(bdescr *bd); -static bdescr *free_list; +static bdescr *free_list = NULL; /* ----------------------------------------------------------------------------- Initialisation @@ -32,14 +36,14 @@ static bdescr *free_list; void initBlockAllocator(void) { - free_list = NULL; + // The free list starts off NULL } /* ----------------------------------------------------------------------------- Allocation -------------------------------------------------------------------------- */ -static inline void +STATIC_INLINE void initGroup(nat n, bdescr *head) { bdescr *bd; @@ -50,6 +54,7 @@ initGroup(nat n, bdescr *head) head->free = head->start; for (i=1, bd = head+1; i < n; i++, bd++) { bd->free = 0; + bd->blocks = 0; bd->link = head; } } @@ -61,6 +66,8 @@ allocGroup(nat n) void *mblock; bdescr *bd, **last; + ASSERT(n != 0); + if (n > BLOCKS_PER_MBLOCK) { return allocMegaGroup(BLOCKS_TO_MBLOCKS(n)); } @@ -71,6 +78,9 @@ allocGroup(nat n) *last = bd->link; /* no initialisation necessary - this is already a * self-contained block group. */ +#ifdef DEBUG + bd->free = bd->start; /* block isn't free now */ +#endif return bd; } if (bd->blocks > n) { /* block too big... */ @@ -86,8 +96,10 @@ allocGroup(nat n) initMBlock(mblock); /* initialise the start fields */ bd = FIRST_BDESCR(mblock); initGroup(n,bd); /* we know the group will fit */ - initGroup(BLOCKS_PER_MBLOCK-n, bd+n); - freeGroup(bd+n); /* add the rest on to the free list */ + if (n < BLOCKS_PER_MBLOCK) { + initGroup(BLOCKS_PER_MBLOCK-n, bd+n); + freeGroup(bd+n); /* add the rest on to the free list */ + } return bd; } @@ -124,7 +136,9 @@ allocMegaGroup(nat n) if (bd->blocks == BLOCKS_PER_MBLOCK) { /* whole megablock found */ - if (grp_start == NULL) { /* is it the first one we've found? */ + /* is it the first one we've found or a non-contiguous megablock? */ + if (grp_start == NULL || + bd->start != last->start + MBLOCK_SIZE/sizeof(W_)) { grp_start = bd; grp_prev = last; mbs_found = 1; @@ -179,19 +193,21 @@ allocMegaGroup(nat n) * pointer to the newly enlarged group p. */ -static inline bdescr * +STATIC_INLINE bdescr * coalesce(bdescr *p) { bdescr *bd, *q; - nat i; + nat i, blocks; q = p->link; if (q != NULL && p->start + p->blocks * BLOCK_SIZE_W == q->start) { /* can coalesce */ p->blocks += q->blocks; p->link = q->link; - for (i = 0, bd = q; i < q->blocks; bd++, i++) { + blocks = q->blocks; + for (i = 0, bd = q; i < blocks; bd++, i++) { bd->free = 0; + bd->blocks = 0; bd->link = p; } return p; @@ -210,6 +226,14 @@ freeGroup(bdescr *p) return; } +#ifdef DEBUG + p->free = (void *)-1; /* indicates that this block is free */ + p->step = NULL; + p->gen_no = 0; + /* fill the block group with garbage if sanity checking is on */ + IF_DEBUG(sanity,memset(p->start, 0xaa, p->blocks * BLOCK_SIZE)); +#endif + /* find correct place in free list to place new group */ last = NULL; for (bd = free_list; bd != NULL && bd->start < p->start; @@ -237,12 +261,13 @@ static void freeMegaGroup(bdescr *p) { nat n; + void *q = p; - n = p->blocks * BLOCK_SIZE / MBLOCK_SIZE + 1; - for (; n > 0; (W_)p += MBLOCK_SIZE, n--) { - initMBlock((void *)((W_)p & ~MBLOCK_MASK)); - initGroup(BLOCKS_PER_MBLOCK, p); - freeGroup(p); + n = ((bdescr *)q)->blocks * BLOCK_SIZE / MBLOCK_SIZE + 1; + for (; n > 0; q += MBLOCK_SIZE, n--) { + initMBlock(MBLOCK_ROUND_DOWN(q)); + initGroup(BLOCKS_PER_MBLOCK, (bdescr *)q); + freeGroup((bdescr *)q); } } @@ -252,9 +277,6 @@ freeChain(bdescr *bd) bdescr *next_bd; while (bd != NULL) { next_bd = bd->link; -#ifdef DEBUG - bd->free = (void *)-1; /* indicates that this block is free */ -#endif freeGroup(bd); bd = next_bd; } @@ -274,7 +296,7 @@ initMBlock(void *mblock) /* Initialise the start field of each block descriptor */ - for (; block <= LAST_BLOCK(mblock); bd += 1, (lnat)block += BLOCK_SIZE) { + for (; block <= LAST_BLOCK(mblock); bd += 1, block += BLOCK_SIZE) { bd->start = block; } } @@ -284,6 +306,18 @@ initMBlock(void *mblock) -------------------------------------------------------------------------- */ #ifdef DEBUG +static void +checkWellFormedGroup( bdescr *bd ) +{ + nat i; + + for (i = 1; i < bd->blocks; i++) { + ASSERT(bd[i].blocks == 0); + ASSERT(bd[i].free == 0); + ASSERT(bd[i].link == bd); + } +} + void checkFreeListSanity(void) { @@ -291,9 +325,10 @@ checkFreeListSanity(void) for (bd = free_list; bd != NULL; bd = bd->link) { IF_DEBUG(block_alloc, - fprintf(stderr,"group at 0x%x, length %d blocks\n", - (nat)bd->start, bd->blocks)); + debugBelch("group at 0x%x, length %d blocks\n", + (nat)bd->start, bd->blocks)); ASSERT(bd->blocks > 0); + checkWellFormedGroup(bd); if (bd->link != NULL) { /* make sure we're fully coalesced */ ASSERT(bd->start + bd->blocks * BLOCK_SIZE_W != bd->link->start); @@ -301,4 +336,16 @@ checkFreeListSanity(void) } } } + +nat /* BLOCKS */ +countFreeList(void) +{ + bdescr *bd; + lnat total_blocks = 0; + + for (bd = free_list; bd != NULL; bd = bd->link) { + total_blocks += bd->blocks; + } + return total_blocks; +} #endif