--- /dev/null
+/* -----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team, 1998-2004
+ *
+ * Storage manager front end
+ *
+ * ---------------------------------------------------------------------------*/
+
+#include "PosixSource.h"
+#include "Rts.h"
+#include "RtsUtils.h"
+#include "RtsFlags.h"
+#include "Stats.h"
+#include "Hooks.h"
+#include "BlockAlloc.h"
+#include "MBlock.h"
+#include "Weak.h"
+#include "Sanity.h"
+#include "Arena.h"
+#include "OSThreads.h"
+#include "Capability.h"
+#include "Storage.h"
+#include "Schedule.h"
+#include "RetainerProfile.h" // for counting memory blocks (memInventory)
+
+#include <stdlib.h>
+#include <string.h>
+
+/*
+ * All these globals require sm_mutex to access in THREADED_RTS mode.
+ */
+StgClosure *caf_list = NULL;
+StgClosure *revertible_caf_list = NULL;
+rtsBool keepCAFs;
+
+bdescr *small_alloc_list; /* allocate()d small objects */
+bdescr *pinned_object_block; /* allocate pinned objects into this block */
+nat alloc_blocks; /* number of allocate()d blocks since GC */
+nat alloc_blocks_lim; /* approximate limit on alloc_blocks */
+
+StgPtr alloc_Hp = NULL; /* next free byte in small_alloc_list */
+StgPtr alloc_HpLim = NULL; /* end of block at small_alloc_list */
+
+generation *generations = NULL; /* all the generations */
+generation *g0 = NULL; /* generation 0, for convenience */
+generation *oldest_gen = NULL; /* oldest generation, for convenience */
+step *g0s0 = NULL; /* generation 0, step 0, for convenience */
+
+ullong total_allocated = 0; /* total memory allocated during run */
+
+nat n_nurseries = 0; /* == RtsFlags.ParFlags.nNodes, convenience */
+step *nurseries = NULL; /* array of nurseries, >1 only if THREADED_RTS */
+
+#ifdef THREADED_RTS
+/*
+ * Storage manager mutex: protects all the above state from
+ * simultaneous access by two STG threads.
+ */
+Mutex sm_mutex;
+/*
+ * This mutex is used by atomicModifyMutVar# only
+ */
+Mutex atomic_modify_mutvar_mutex;
+#endif
+
+
+/*
+ * Forward references
+ */
+static void *stgAllocForGMP (size_t size_in_bytes);
+static void *stgReallocForGMP (void *ptr, size_t old_size, size_t new_size);
+static void stgDeallocForGMP (void *ptr, size_t size);
+
+static void
+initStep (step *stp, int g, int s)
+{
+ stp->no = s;
+ stp->blocks = NULL;
+ stp->n_blocks = 0;
+ stp->old_blocks = NULL;
+ stp->n_old_blocks = 0;
+ stp->gen = &generations[g];
+ stp->gen_no = g;
+ stp->hp = NULL;
+ stp->hpLim = NULL;
+ stp->hp_bd = NULL;
+ stp->scavd_hp = NULL;
+ stp->scavd_hpLim = NULL;
+ stp->scan = NULL;
+ stp->scan_bd = NULL;
+ stp->large_objects = NULL;
+ stp->n_large_blocks = 0;
+ stp->new_large_objects = NULL;
+ stp->scavenged_large_objects = NULL;
+ stp->n_scavenged_large_blocks = 0;
+ stp->is_compacted = 0;
+ stp->bitmap = NULL;
+}
+
+void
+initStorage( void )
+{
+ nat g, s;
+ generation *gen;
+
+ if (generations != NULL) {
+ // multi-init protection
+ return;
+ }
+
+ /* Sanity check to make sure the LOOKS_LIKE_ macros appear to be
+ * doing something reasonable.
+ */
+ ASSERT(LOOKS_LIKE_INFO_PTR(&stg_BLACKHOLE_info));
+ ASSERT(LOOKS_LIKE_CLOSURE_PTR(&stg_dummy_ret_closure));
+ ASSERT(!HEAP_ALLOCED(&stg_dummy_ret_closure));
+
+ if (RtsFlags.GcFlags.maxHeapSize != 0 &&
+ RtsFlags.GcFlags.heapSizeSuggestion >
+ RtsFlags.GcFlags.maxHeapSize) {
+ RtsFlags.GcFlags.maxHeapSize = RtsFlags.GcFlags.heapSizeSuggestion;
+ }
+
+ if (RtsFlags.GcFlags.maxHeapSize != 0 &&
+ RtsFlags.GcFlags.minAllocAreaSize >
+ RtsFlags.GcFlags.maxHeapSize) {
+ errorBelch("maximum heap size (-M) is smaller than minimum alloc area size (-A)");
+ exit(1);
+ }
+
+ initBlockAllocator();
+
+#if defined(THREADED_RTS)
+ initMutex(&sm_mutex);
+ initMutex(&atomic_modify_mutvar_mutex);
+#endif
+
+ ACQUIRE_SM_LOCK;
+
+ /* allocate generation info array */
+ generations = (generation *)stgMallocBytes(RtsFlags.GcFlags.generations
+ * sizeof(struct generation_),
+ "initStorage: gens");
+
+ /* Initialise all generations */
+ for(g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ gen = &generations[g];
+ gen->no = g;
+ gen->mut_list = allocBlock();
+ gen->collections = 0;
+ gen->failed_promotions = 0;
+ gen->max_blocks = 0;
+ }
+
+ /* A couple of convenience pointers */
+ g0 = &generations[0];
+ oldest_gen = &generations[RtsFlags.GcFlags.generations-1];
+
+ /* Allocate step structures in each generation */
+ if (RtsFlags.GcFlags.generations > 1) {
+ /* Only for multiple-generations */
+
+ /* Oldest generation: one step */
+ oldest_gen->n_steps = 1;
+ oldest_gen->steps =
+ stgMallocBytes(1 * sizeof(struct step_), "initStorage: last step");
+
+ /* set up all except the oldest generation with 2 steps */
+ for(g = 0; g < RtsFlags.GcFlags.generations-1; g++) {
+ generations[g].n_steps = RtsFlags.GcFlags.steps;
+ generations[g].steps =
+ stgMallocBytes (RtsFlags.GcFlags.steps * sizeof(struct step_),
+ "initStorage: steps");
+ }
+
+ } else {
+ /* single generation, i.e. a two-space collector */
+ g0->n_steps = 1;
+ g0->steps = stgMallocBytes (sizeof(struct step_), "initStorage: steps");
+ }
+
+#ifdef THREADED_RTS
+ n_nurseries = n_capabilities;
+ nurseries = stgMallocBytes (n_nurseries * sizeof(struct step_),
+ "initStorage: nurseries");
+#else
+ n_nurseries = 1;
+ nurseries = g0->steps; // just share nurseries[0] with g0s0
+#endif
+
+ /* Initialise all steps */
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ for (s = 0; s < generations[g].n_steps; s++) {
+ initStep(&generations[g].steps[s], g, s);
+ }
+ }
+
+#ifdef THREADED_RTS
+ for (s = 0; s < n_nurseries; s++) {
+ initStep(&nurseries[s], 0, s);
+ }
+#endif
+
+ /* Set up the destination pointers in each younger gen. step */
+ for (g = 0; g < RtsFlags.GcFlags.generations-1; g++) {
+ for (s = 0; s < generations[g].n_steps-1; s++) {
+ generations[g].steps[s].to = &generations[g].steps[s+1];
+ }
+ generations[g].steps[s].to = &generations[g+1].steps[0];
+ }
+ oldest_gen->steps[0].to = &oldest_gen->steps[0];
+
+#ifdef THREADED_RTS
+ for (s = 0; s < n_nurseries; s++) {
+ nurseries[s].to = generations[0].steps[0].to;
+ }
+#endif
+
+ /* The oldest generation has one step. */
+ if (RtsFlags.GcFlags.compact) {
+ if (RtsFlags.GcFlags.generations == 1) {
+ errorBelch("WARNING: compaction is incompatible with -G1; disabled");
+ } else {
+ oldest_gen->steps[0].is_compacted = 1;
+ }
+ }
+
+#ifdef THREADED_RTS
+ if (RtsFlags.GcFlags.generations == 1) {
+ errorBelch("-G1 is incompatible with -threaded");
+ stg_exit(EXIT_FAILURE);
+ }
+#endif
+
+ /* generation 0 is special: that's the nursery */
+ generations[0].max_blocks = 0;
+
+ /* G0S0: the allocation area. Policy: keep the allocation area
+ * small to begin with, even if we have a large suggested heap
+ * size. Reason: we're going to do a major collection first, and we
+ * don't want it to be a big one. This vague idea is borne out by
+ * rigorous experimental evidence.
+ */
+ g0s0 = &generations[0].steps[0];
+
+ allocNurseries();
+
+ weak_ptr_list = NULL;
+ caf_list = NULL;
+ revertible_caf_list = NULL;
+
+ /* initialise the allocate() interface */
+ small_alloc_list = NULL;
+ alloc_blocks = 0;
+ alloc_blocks_lim = RtsFlags.GcFlags.minAllocAreaSize;
+
+ /* Tell GNU multi-precision pkg about our custom alloc functions */
+ mp_set_memory_functions(stgAllocForGMP, stgReallocForGMP, stgDeallocForGMP);
+
+ IF_DEBUG(gc, statDescribeGens());
+
+ RELEASE_SM_LOCK;
+}
+
+void
+exitStorage (void)
+{
+ stat_exit(calcAllocated());
+}
+
+void
+freeStorage (void)
+{
+ freeAllMBlocks();
+}
+
+/* -----------------------------------------------------------------------------
+ CAF management.
+
+ 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
+ - invokes UPD_CAF(), which:
+ - calls newCaf, below
+ - updates the CAF with a static indirection to the CAF_BLACKHOLE
+
+ Why do we build a 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
+ younger generations.
+
+ For GHCI, we have additional requirements when dealing with CAFs:
+
+ - we must *retain* all dynamically-loaded CAFs ever entered,
+ just in case we need them again.
+ - we must be able to *revert* CAFs that have been evaluated, to
+ their pre-evaluated form.
+
+ To do this, we use an additional CAF list. When newCaf() is
+ called on a dynamically-loaded CAF, we add it to the CAF list
+ instead of the old-generation mutable list, and save away its
+ old info pointer (in caf->saved_info) for later reversion.
+
+ To revert all the CAFs, we traverse the CAF list and reset the
+ info pointer to caf->saved_info, then throw away the CAF list.
+ (see GC.c:revertCAFs()).
+
+ -- SDM 29/1/01
+
+ -------------------------------------------------------------------------- */
+
+void
+newCAF(StgClosure* caf)
+{
+ ACQUIRE_SM_LOCK;
+
+ if(keepCAFs)
+ {
+ // HACK:
+ // If we are in GHCi _and_ we are using dynamic libraries,
+ // then we can't redirect newCAF calls to newDynCAF (see below),
+ // so we make newCAF behave almost like newDynCAF.
+ // The dynamic libraries might be used by both the interpreted
+ // program and GHCi itself, so they must not be reverted.
+ // This also means that in GHCi with dynamic libraries, CAFs are not
+ // garbage collected. If this turns out to be a problem, we could
+ // 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;
+ ((StgIndStatic *)caf)->static_link = caf_list;
+ caf_list = caf;
+ }
+ else
+ {
+ /* 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.
+ */
+ ((StgIndStatic *)caf)->saved_info = NULL;
+ recordMutableGen(caf, oldest_gen);
+ }
+
+ RELEASE_SM_LOCK;
+
+#ifdef PAR
+ /* If we are PAR or DIST then we never forget a CAF */
+ { globalAddr *newGA;
+ //debugBelch("<##> Globalising CAF %08x %s",caf,info_type(caf));
+ newGA=makeGlobal(caf,rtsTrue); /*given full weight*/
+ ASSERT(newGA);
+ }
+#endif /* PAR */
+}
+
+// An alternate version of newCaf which is used for dynamically loaded
+// object code in GHCi. In this case we want to retain *all* CAFs in
+// the object code, because they might be demanded at any time from an
+// expression evaluated on the command line.
+// Also, GHCi might want to revert CAFs, so we add these to the
+// revertible_caf_list.
+//
+// The linker hackily arranges that references to newCaf from dynamic
+// code end up pointing to newDynCAF.
+void
+newDynCAF(StgClosure *caf)
+{
+ ACQUIRE_SM_LOCK;
+
+ ((StgIndStatic *)caf)->saved_info = (StgInfoTable *)caf->header.info;
+ ((StgIndStatic *)caf)->static_link = revertible_caf_list;
+ revertible_caf_list = caf;
+
+ RELEASE_SM_LOCK;
+}
+
+/* -----------------------------------------------------------------------------
+ Nursery management.
+ -------------------------------------------------------------------------- */
+
+static bdescr *
+allocNursery (step *stp, bdescr *tail, nat blocks)
+{
+ bdescr *bd;
+ nat i;
+
+ // Allocate a nursery: we allocate fresh blocks one at a time and
+ // cons them on to the front of the list, not forgetting to update
+ // the back pointer on the tail of the list to point to the new block.
+ for (i=0; i < blocks; i++) {
+ // @LDV profiling
+ /*
+ processNursery() in LdvProfile.c assumes that every block group in
+ the nursery contains only a single block. So, if a block group is
+ given multiple blocks, change processNursery() accordingly.
+ */
+ bd = allocBlock();
+ bd->link = tail;
+ // double-link the nursery: we might need to insert blocks
+ if (tail != NULL) {
+ tail->u.back = bd;
+ }
+ bd->step = stp;
+ bd->gen_no = 0;
+ bd->flags = 0;
+ bd->free = bd->start;
+ tail = bd;
+ }
+ tail->u.back = NULL;
+ return tail;
+}
+
+static void
+assignNurseriesToCapabilities (void)
+{
+#ifdef THREADED_RTS
+ nat i;
+
+ for (i = 0; i < n_nurseries; i++) {
+ capabilities[i].r.rNursery = &nurseries[i];
+ capabilities[i].r.rCurrentNursery = nurseries[i].blocks;
+ capabilities[i].r.rCurrentAlloc = NULL;
+ }
+#else /* THREADED_RTS */
+ MainCapability.r.rNursery = &nurseries[0];
+ MainCapability.r.rCurrentNursery = nurseries[0].blocks;
+ MainCapability.r.rCurrentAlloc = NULL;
+#endif
+}
+
+void
+allocNurseries( void )
+{
+ nat i;
+
+ for (i = 0; i < n_nurseries; i++) {
+ nurseries[i].blocks =
+ allocNursery(&nurseries[i], NULL,
+ RtsFlags.GcFlags.minAllocAreaSize);
+ nurseries[i].n_blocks = RtsFlags.GcFlags.minAllocAreaSize;
+ nurseries[i].old_blocks = NULL;
+ nurseries[i].n_old_blocks = 0;
+ /* hp, hpLim, hp_bd, to_space etc. aren't used in the nursery */
+ }
+ assignNurseriesToCapabilities();
+}
+
+void
+resetNurseries( void )
+{
+ nat i;
+ bdescr *bd;
+ step *stp;
+
+ for (i = 0; i < n_nurseries; i++) {
+ stp = &nurseries[i];
+ for (bd = stp->blocks; bd; bd = bd->link) {
+ bd->free = bd->start;
+ ASSERT(bd->gen_no == 0);
+ ASSERT(bd->step == stp);
+ IF_DEBUG(sanity,memset(bd->start, 0xaa, BLOCK_SIZE));
+ }
+ }
+ assignNurseriesToCapabilities();
+}
+
+lnat
+countNurseryBlocks (void)
+{
+ nat i;
+ lnat blocks = 0;
+
+ for (i = 0; i < n_nurseries; i++) {
+ blocks += nurseries[i].n_blocks;
+ }
+ return blocks;
+}
+
+static void
+resizeNursery ( step *stp, nat blocks )
+{
+ bdescr *bd;
+ nat nursery_blocks;
+
+ nursery_blocks = stp->n_blocks;
+ if (nursery_blocks == blocks) return;
+
+ if (nursery_blocks < blocks) {
+ IF_DEBUG(gc, debugBelch("Increasing size of nursery to %d blocks\n",
+ blocks));
+ stp->blocks = allocNursery(stp, stp->blocks, blocks-nursery_blocks);
+ }
+ else {
+ bdescr *next_bd;
+
+ IF_DEBUG(gc, debugBelch("Decreasing size of nursery to %d blocks\n",
+ blocks));
+
+ bd = stp->blocks;
+ while (nursery_blocks > blocks) {
+ next_bd = bd->link;
+ next_bd->u.back = NULL;
+ nursery_blocks -= bd->blocks; // might be a large block
+ freeGroup(bd);
+ bd = next_bd;
+ }
+ stp->blocks = bd;
+ // might have gone just under, by freeing a large block, so make
+ // up the difference.
+ if (nursery_blocks < blocks) {
+ stp->blocks = allocNursery(stp, stp->blocks, blocks-nursery_blocks);
+ }
+ }
+
+ stp->n_blocks = blocks;
+ ASSERT(countBlocks(stp->blocks) == stp->n_blocks);
+}
+
+//
+// Resize each of the nurseries to the specified size.
+//
+void
+resizeNurseriesFixed (nat blocks)
+{
+ nat i;
+ for (i = 0; i < n_nurseries; i++) {
+ resizeNursery(&nurseries[i], blocks);
+ }
+}
+
+//
+// Resize the nurseries to the total specified size.
+//
+void
+resizeNurseries (nat blocks)
+{
+ // If there are multiple nurseries, then we just divide the number
+ // of available blocks between them.
+ resizeNurseriesFixed(blocks / n_nurseries);
+}
+
+/* -----------------------------------------------------------------------------
+ The allocate() interface
+
+ allocate(n) always succeeds, and returns a chunk of memory n words
+ long. n can be larger than the size of a block if necessary, in
+ which case a contiguous block group will be allocated.
+ -------------------------------------------------------------------------- */
+
+StgPtr
+allocate( nat n )
+{
+ bdescr *bd;
+ StgPtr p;
+
+ ACQUIRE_SM_LOCK;
+
+ TICK_ALLOC_HEAP_NOCTR(n);
+ CCS_ALLOC(CCCS,n);
+
+ /* big allocation (>LARGE_OBJECT_THRESHOLD) */
+ /* ToDo: allocate directly into generation 1 */
+ if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
+ nat req_blocks = (lnat)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
+ bd = allocGroup(req_blocks);
+ dbl_link_onto(bd, &g0s0->large_objects);
+ g0s0->n_large_blocks += req_blocks;
+ bd->gen_no = 0;
+ bd->step = g0s0;
+ bd->flags = BF_LARGE;
+ bd->free = bd->start + n;
+ alloc_blocks += req_blocks;
+ RELEASE_SM_LOCK;
+ return bd->start;
+
+ /* small allocation (<LARGE_OBJECT_THRESHOLD) */
+ } else if (small_alloc_list == NULL || alloc_Hp + n > alloc_HpLim) {
+ if (small_alloc_list) {
+ small_alloc_list->free = alloc_Hp;
+ }
+ bd = allocBlock();
+ bd->link = small_alloc_list;
+ small_alloc_list = bd;
+ bd->gen_no = 0;
+ bd->step = g0s0;
+ bd->flags = 0;
+ alloc_Hp = bd->start;
+ alloc_HpLim = bd->start + BLOCK_SIZE_W;
+ alloc_blocks++;
+ }
+
+ p = alloc_Hp;
+ alloc_Hp += n;
+ RELEASE_SM_LOCK;
+ return p;
+}
+
+lnat
+allocated_bytes( void )
+{
+ lnat allocated;
+
+ allocated = alloc_blocks * BLOCK_SIZE_W - (alloc_HpLim - alloc_Hp);
+ if (pinned_object_block != NULL) {
+ allocated -= (pinned_object_block->start + BLOCK_SIZE_W) -
+ pinned_object_block->free;
+ }
+
+ return allocated;
+}
+
+void
+tidyAllocateLists (void)
+{
+ if (small_alloc_list != NULL) {
+ ASSERT(alloc_Hp >= small_alloc_list->start &&
+ alloc_Hp <= small_alloc_list->start + BLOCK_SIZE);
+ small_alloc_list->free = alloc_Hp;
+ }
+}
+
+/* -----------------------------------------------------------------------------
+ allocateLocal()
+
+ This allocates memory in the current thread - it is intended for
+ use primarily from STG-land where we have a Capability. It is
+ better than allocate() because it doesn't require taking the
+ sm_mutex lock in the common case.
+
+ Memory is allocated directly from the nursery if possible (but not
+ from the current nursery block, so as not to interfere with
+ Hp/HpLim).
+ -------------------------------------------------------------------------- */
+
+StgPtr
+allocateLocal (Capability *cap, nat n)
+{
+ bdescr *bd;
+ StgPtr p;
+
+ TICK_ALLOC_HEAP_NOCTR(n);
+ CCS_ALLOC(CCCS,n);
+
+ /* big allocation (>LARGE_OBJECT_THRESHOLD) */
+ /* ToDo: allocate directly into generation 1 */
+ if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
+ nat req_blocks = (lnat)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
+ ACQUIRE_SM_LOCK;
+ bd = allocGroup(req_blocks);
+ dbl_link_onto(bd, &g0s0->large_objects);
+ g0s0->n_large_blocks += req_blocks;
+ bd->gen_no = 0;
+ bd->step = g0s0;
+ bd->flags = BF_LARGE;
+ bd->free = bd->start + n;
+ alloc_blocks += req_blocks;
+ RELEASE_SM_LOCK;
+ return bd->start;
+
+ /* small allocation (<LARGE_OBJECT_THRESHOLD) */
+ } else {
+
+ bd = cap->r.rCurrentAlloc;
+ if (bd == NULL || bd->free + n > bd->start + BLOCK_SIZE_W) {
+
+ // The CurrentAlloc block is full, we need to find another
+ // one. First, we try taking the next block from the
+ // nursery:
+ bd = cap->r.rCurrentNursery->link;
+
+ if (bd == NULL || bd->free + n > bd->start + BLOCK_SIZE_W) {
+ // The nursery is empty, or the next block is already
+ // full: allocate a fresh block (we can't fail here).
+ ACQUIRE_SM_LOCK;
+ bd = allocBlock();
+ cap->r.rNursery->n_blocks++;
+ RELEASE_SM_LOCK;
+ bd->gen_no = 0;
+ bd->step = cap->r.rNursery;
+ bd->flags = 0;
+ } else {
+ // we have a block in the nursery: take it and put
+ // it at the *front* of the nursery list, and use it
+ // to allocate() from.
+ cap->r.rCurrentNursery->link = bd->link;
+ if (bd->link != NULL) {
+ bd->link->u.back = cap->r.rCurrentNursery;
+ }
+ }
+ dbl_link_onto(bd, &cap->r.rNursery->blocks);
+ cap->r.rCurrentAlloc = bd;
+ IF_DEBUG(sanity, checkNurserySanity(cap->r.rNursery));
+ }
+ }
+ p = bd->free;
+ bd->free += n;
+ return p;
+}
+
+/* ---------------------------------------------------------------------------
+ Allocate a fixed/pinned object.
+
+ We allocate small pinned objects into a single block, allocating a
+ new block when the current one overflows. The block is chained
+ onto the large_object_list of generation 0 step 0.
+
+ NOTE: The GC can't in general handle pinned objects. This
+ interface is only safe to use for ByteArrays, which have no
+ pointers and don't require scavenging. It works because the
+ block's descriptor has the BF_LARGE flag set, so the block is
+ treated as a large object and chained onto various lists, rather
+ than the individual objects being copied. However, when it comes
+ to scavenge the block, the GC will only scavenge the first object.
+ The reason is that the GC can't linearly scan a block of pinned
+ objects at the moment (doing so would require using the
+ mostly-copying techniques). But since we're restricting ourselves
+ to pinned ByteArrays, not scavenging is ok.
+
+ This function is called by newPinnedByteArray# which immediately
+ fills the allocated memory with a MutableByteArray#.
+ ------------------------------------------------------------------------- */
+
+StgPtr
+allocatePinned( nat n )
+{
+ StgPtr p;
+ bdescr *bd = pinned_object_block;
+
+ // If the request is for a large object, then allocate()
+ // will give us a pinned object anyway.
+ if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
+ return allocate(n);
+ }
+
+ ACQUIRE_SM_LOCK;
+
+ TICK_ALLOC_HEAP_NOCTR(n);
+ CCS_ALLOC(CCCS,n);
+
+ // we always return 8-byte aligned memory. bd->free must be
+ // 8-byte aligned to begin with, so we just round up n to
+ // the nearest multiple of 8 bytes.
+ if (sizeof(StgWord) == 4) {
+ n = (n+1) & ~1;
+ }
+
+ // If we don't have a block of pinned objects yet, or the current
+ // one isn't large enough to hold the new object, allocate a new one.
+ if (bd == NULL || (bd->free + n) > (bd->start + BLOCK_SIZE_W)) {
+ pinned_object_block = bd = allocBlock();
+ dbl_link_onto(bd, &g0s0->large_objects);
+ bd->gen_no = 0;
+ bd->step = g0s0;
+ bd->flags = BF_PINNED | BF_LARGE;
+ bd->free = bd->start;
+ alloc_blocks++;
+ }
+
+ p = bd->free;
+ bd->free += n;
+ RELEASE_SM_LOCK;
+ return p;
+}
+
+/* -----------------------------------------------------------------------------
+ This is the write barrier for MUT_VARs, a.k.a. IORefs. A
+ MUT_VAR_CLEAN object is not on the mutable list; a MUT_VAR_DIRTY
+ is. When written to, a MUT_VAR_CLEAN turns into a MUT_VAR_DIRTY
+ and is put on the mutable list.
+ -------------------------------------------------------------------------- */
+
+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);
+ }
+}
+
+/* -----------------------------------------------------------------------------
+ Allocation functions for GMP.
+
+ These all use the allocate() interface - we can't have any garbage
+ collection going on during a gmp operation, so we use allocate()
+ which always succeeds. The gmp operations which might need to
+ allocate will ask the storage manager (via doYouWantToGC()) whether
+ a garbage collection is required, in case we get into a loop doing
+ only allocate() style allocation.
+ -------------------------------------------------------------------------- */
+
+static void *
+stgAllocForGMP (size_t size_in_bytes)
+{
+ StgArrWords* arr;
+ nat data_size_in_words, total_size_in_words;
+
+ /* round up to a whole number of words */
+ data_size_in_words = (size_in_bytes + sizeof(W_) + 1) / sizeof(W_);
+ total_size_in_words = sizeofW(StgArrWords) + data_size_in_words;
+
+ /* allocate and fill it in. */
+#if defined(THREADED_RTS)
+ arr = (StgArrWords *)allocateLocal(myTask()->cap, total_size_in_words);
+#else
+ arr = (StgArrWords *)allocateLocal(&MainCapability, total_size_in_words);
+#endif
+ SET_ARR_HDR(arr, &stg_ARR_WORDS_info, CCCS, data_size_in_words);
+
+ /* and return a ptr to the goods inside the array */
+ return arr->payload;
+}
+
+static void *
+stgReallocForGMP (void *ptr, size_t old_size, size_t new_size)
+{
+ void *new_stuff_ptr = stgAllocForGMP(new_size);
+ nat i = 0;
+ char *p = (char *) ptr;
+ char *q = (char *) new_stuff_ptr;
+
+ for (; i < old_size; i++, p++, q++) {
+ *q = *p;
+ }
+
+ return(new_stuff_ptr);
+}
+
+static void
+stgDeallocForGMP (void *ptr STG_UNUSED,
+ size_t size STG_UNUSED)
+{
+ /* easy for us: the garbage collector does the dealloc'n */
+}
+
+/* -----------------------------------------------------------------------------
+ * Stats and stuff
+ * -------------------------------------------------------------------------- */
+
+/* -----------------------------------------------------------------------------
+ * calcAllocated()
+ *
+ * Approximate how much we've allocated: number of blocks in the
+ * nursery + blocks allocated via allocate() - unused nusery blocks.
+ * This leaves a little slop at the end of each block, and doesn't
+ * take into account large objects (ToDo).
+ * -------------------------------------------------------------------------- */
+
+lnat
+calcAllocated( void )
+{
+ nat allocated;
+ bdescr *bd;
+
+ allocated = allocated_bytes();
+ allocated += countNurseryBlocks() * BLOCK_SIZE_W;
+
+ {
+#ifdef THREADED_RTS
+ nat i;
+ for (i = 0; i < n_nurseries; i++) {
+ Capability *cap;
+ for ( bd = capabilities[i].r.rCurrentNursery->link;
+ bd != NULL; bd = bd->link ) {
+ allocated -= BLOCK_SIZE_W;
+ }
+ cap = &capabilities[i];
+ if (cap->r.rCurrentNursery->free <
+ cap->r.rCurrentNursery->start + BLOCK_SIZE_W) {
+ allocated -= (cap->r.rCurrentNursery->start + BLOCK_SIZE_W)
+ - cap->r.rCurrentNursery->free;
+ }
+ }
+#else
+ bdescr *current_nursery = MainCapability.r.rCurrentNursery;
+
+ for ( bd = current_nursery->link; bd != NULL; bd = bd->link ) {
+ allocated -= BLOCK_SIZE_W;
+ }
+ if (current_nursery->free < current_nursery->start + BLOCK_SIZE_W) {
+ allocated -= (current_nursery->start + BLOCK_SIZE_W)
+ - current_nursery->free;
+ }
+#endif
+ }
+
+ total_allocated += allocated;
+ return allocated;
+}
+
+/* Approximate the amount of live data in the heap. To be called just
+ * after garbage collection (see GarbageCollect()).
+ */
+extern lnat
+calcLive(void)
+{
+ nat g, s;
+ lnat live = 0;
+ step *stp;
+
+ if (RtsFlags.GcFlags.generations == 1) {
+ live = (g0s0->n_blocks - 1) * BLOCK_SIZE_W +
+ ((lnat)g0s0->hp_bd->free - (lnat)g0s0->hp_bd->start) / sizeof(W_);
+ return live;
+ }
+
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ for (s = 0; s < generations[g].n_steps; s++) {
+ /* approximate amount of live data (doesn't take into account slop
+ * at end of each block).
+ */
+ if (g == 0 && s == 0) {
+ continue;
+ }
+ stp = &generations[g].steps[s];
+ live += (stp->n_large_blocks + stp->n_blocks - 1) * BLOCK_SIZE_W;
+ if (stp->hp_bd != NULL) {
+ live += ((lnat)stp->hp_bd->free - (lnat)stp->hp_bd->start)
+ / sizeof(W_);
+ }
+ if (stp->scavd_hp != NULL) {
+ live -= (P_)(BLOCK_ROUND_UP(stp->scavd_hp)) - stp->scavd_hp;
+ }
+ }
+ }
+ return live;
+}
+
+/* Approximate the number of blocks that will be needed at the next
+ * garbage collection.
+ *
+ * Assume: all data currently live will remain live. Steps that will
+ * be collected next time will therefore need twice as many blocks
+ * since all the data will be copied.
+ */
+extern lnat
+calcNeeded(void)
+{
+ lnat needed = 0;
+ nat g, s;
+ step *stp;
+
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ for (s = 0; s < generations[g].n_steps; s++) {
+ if (g == 0 && s == 0) { continue; }
+ stp = &generations[g].steps[s];
+ if (generations[g].steps[0].n_blocks +
+ generations[g].steps[0].n_large_blocks
+ > generations[g].max_blocks
+ && stp->is_compacted == 0) {
+ needed += 2 * stp->n_blocks;
+ } else {
+ needed += stp->n_blocks;
+ }
+ }
+ }
+ return needed;
+}
+
+/* -----------------------------------------------------------------------------
+ Debugging
+
+ memInventory() checks for memory leaks by counting up all the
+ blocks we know about and comparing that to the number of blocks
+ allegedly floating around in the system.
+ -------------------------------------------------------------------------- */
+
+#ifdef DEBUG
+
+static lnat
+stepBlocks (step *stp)
+{
+ lnat total_blocks;
+ bdescr *bd;
+
+ total_blocks = stp->n_blocks;
+ total_blocks += stp->n_old_blocks;
+ for (bd = stp->large_objects; bd; bd = bd->link) {
+ total_blocks += bd->blocks;
+ /* hack for megablock groups: they have an extra block or two in
+ the second and subsequent megablocks where the block
+ descriptors would normally go.
+ */
+ if (bd->blocks > BLOCKS_PER_MBLOCK) {
+ total_blocks -= (MBLOCK_SIZE / BLOCK_SIZE - BLOCKS_PER_MBLOCK)
+ * (bd->blocks/(MBLOCK_SIZE/BLOCK_SIZE));
+ }
+ }
+ return total_blocks;
+}
+
+void
+memInventory(void)
+{
+ nat g, s, i;
+ step *stp;
+ bdescr *bd;
+ lnat total_blocks = 0, free_blocks = 0;
+
+ /* count the blocks we current have */
+
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ for (i = 0; i < n_capabilities; i++) {
+ for (bd = capabilities[i].mut_lists[g]; bd != NULL; bd = bd->link) {
+ total_blocks += bd->blocks;
+ }
+ }
+ for (bd = generations[g].mut_list; bd != NULL; bd = bd->link) {
+ total_blocks += bd->blocks;
+ }
+ for (s = 0; s < generations[g].n_steps; s++) {
+ if (g==0 && s==0) continue;
+ stp = &generations[g].steps[s];
+ total_blocks += stepBlocks(stp);
+ }
+ }
+
+ for (i = 0; i < n_nurseries; i++) {
+ total_blocks += stepBlocks(&nurseries[i]);
+ }
+#ifdef THREADED_RTS
+ // We put pinned object blocks in g0s0, so better count blocks there too.
+ total_blocks += stepBlocks(g0s0);
+#endif
+
+ /* any blocks held by allocate() */
+ for (bd = small_alloc_list; bd; bd = bd->link) {
+ total_blocks += bd->blocks;
+ }
+
+#ifdef PROFILING
+ if (RtsFlags.ProfFlags.doHeapProfile == HEAP_BY_RETAINER) {
+ total_blocks += retainerStackBlocks();
+ }
+#endif
+
+ // count the blocks allocated by the arena allocator
+ total_blocks += arenaBlocks();
+
+ /* count the blocks on the free list */
+ free_blocks = countFreeList();
+
+ if (total_blocks + free_blocks != mblocks_allocated *
+ BLOCKS_PER_MBLOCK) {
+ debugBelch("Blocks: %ld live + %ld free = %ld total (%ld around)\n",
+ total_blocks, free_blocks, total_blocks + free_blocks,
+ mblocks_allocated * BLOCKS_PER_MBLOCK);
+ }
+
+ ASSERT(total_blocks + free_blocks == mblocks_allocated * BLOCKS_PER_MBLOCK);
+}
+
+
+nat
+countBlocks(bdescr *bd)
+{
+ nat n;
+ for (n=0; bd != NULL; bd=bd->link) {
+ n += bd->blocks;
+ }
+ return n;
+}
+
+/* Full heap sanity check. */
+void
+checkSanity( void )
+{
+ nat g, s;
+
+ if (RtsFlags.GcFlags.generations == 1) {
+ checkHeap(g0s0->blocks);
+ checkChain(g0s0->large_objects);
+ } else {
+
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ for (s = 0; s < generations[g].n_steps; s++) {
+ if (g == 0 && s == 0) { continue; }
+ ASSERT(countBlocks(generations[g].steps[s].blocks)
+ == generations[g].steps[s].n_blocks);
+ ASSERT(countBlocks(generations[g].steps[s].large_objects)
+ == generations[g].steps[s].n_large_blocks);
+ checkHeap(generations[g].steps[s].blocks);
+ checkChain(generations[g].steps[s].large_objects);
+ if (g > 0) {
+ checkMutableList(generations[g].mut_list, g);
+ }
+ }
+ }
+
+ for (s = 0; s < n_nurseries; s++) {
+ ASSERT(countBlocks(nurseries[s].blocks)
+ == nurseries[s].n_blocks);
+ ASSERT(countBlocks(nurseries[s].large_objects)
+ == nurseries[s].n_large_blocks);
+ }
+
+ checkFreeListSanity();
+ }
+}
+
+/* Nursery sanity check */
+void
+checkNurserySanity( step *stp )
+{
+ bdescr *bd, *prev;
+ nat blocks = 0;
+
+ prev = NULL;
+ for (bd = stp->blocks; bd != NULL; bd = bd->link) {
+ ASSERT(bd->u.back == prev);
+ prev = bd;
+ blocks += bd->blocks;
+ }
+ ASSERT(blocks == stp->n_blocks);
+}
+
+// handy function for use in gdb, because Bdescr() is inlined.
+extern bdescr *_bdescr( StgPtr p );
+
+bdescr *
+_bdescr( StgPtr p )
+{
+ return Bdescr(p);
+}
+
+#endif
projects / ghc-hetmet.git / blobdiff