/* -----------------------------------------------------------------------------
*
- * (c) The GHC Team, 1998-2006
+ * (c) The GHC Team, 1998-2008
*
* Storage manager front end
*
#include "OSMem.h"
#include "Trace.h"
#include "GC.h"
-#include "GCUtils.h"
+#include "Evac.h"
#include <stdlib.h>
#include <string.h>
+#include "ffi.h"
+
/*
* All these globals require sm_mutex to access in THREADED_RTS mode.
*/
nat alloc_blocks; /* number of allocate()d blocks since GC */
nat alloc_blocks_lim; /* approximate limit on alloc_blocks */
+static bdescr *exec_block;
+
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 */
+nat total_steps = 0;
+step *all_steps = NULL; /* single array of steps */
+
ullong total_allocated = 0; /* total memory allocated during run */
nat n_nurseries = 0; /* == RtsFlags.ParFlags.nNodes, convenience */
* simultaneous access by two STG threads.
*/
Mutex sm_mutex;
-/*
- * This mutex is used by atomicModifyMutVar# only
- */
-Mutex atomic_modify_mutvar_mutex;
#endif
initStep (step *stp, int g, int s)
{
stp->no = s;
+ stp->abs_no = RtsFlags.GcFlags.steps * g + s;
stp->blocks = NULL;
stp->n_blocks = 0;
+ stp->n_words = 0;
+ stp->live_estimate = 0;
stp->old_blocks = NULL;
stp->n_old_blocks = 0;
stp->gen = &generations[g];
stp->n_large_blocks = 0;
stp->scavenged_large_objects = NULL;
stp->n_scavenged_large_blocks = 0;
- stp->is_compacted = 0;
+ stp->mark = 0;
+ stp->compact = 0;
stp->bitmap = NULL;
#ifdef THREADED_RTS
- initSpinLock(&stp->sync_todo);
initSpinLock(&stp->sync_large_objects);
#endif
+ stp->threads = END_TSO_QUEUE;
+ stp->old_threads = END_TSO_QUEUE;
}
void
{
nat g, s;
generation *gen;
- step *step_arr;
if (generations != NULL) {
// multi-init protection
* 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(&stg_BLACKHOLE_info));
+ ASSERT(LOOKS_LIKE_INFO_PTR_NOT_NULL((StgWord)&stg_BLACKHOLE_info));
ASSERT(LOOKS_LIKE_CLOSURE_PTR(&stg_dummy_ret_closure));
ASSERT(!HEAP_ALLOCED(&stg_dummy_ret_closure));
#if defined(THREADED_RTS)
initMutex(&sm_mutex);
- initMutex(&atomic_modify_mutvar_mutex);
#endif
ACQUIRE_SM_LOCK;
it this way, because we need the invariant that two step pointers
can be directly compared to see which is the oldest.
Remember that the last generation has only one step. */
- step_arr = stgMallocBytes(sizeof(struct step_)
- * (1 + ((RtsFlags.GcFlags.generations - 1)
- * RtsFlags.GcFlags.steps)),
- "initStorage: steps");
+ total_steps = 1 + (RtsFlags.GcFlags.generations - 1) * RtsFlags.GcFlags.steps;
+ all_steps = stgMallocBytes(total_steps * sizeof(struct step_),
+ "initStorage: steps");
/* Initialise all generations */
for(g = 0; g < RtsFlags.GcFlags.generations; g++) {
gen->no = g;
gen->mut_list = allocBlock();
gen->collections = 0;
+ gen->par_collections = 0;
gen->failed_promotions = 0;
gen->max_blocks = 0;
}
/* Oldest generation: one step */
oldest_gen->n_steps = 1;
- oldest_gen->steps = step_arr + (RtsFlags.GcFlags.generations - 1)
+ oldest_gen->steps = all_steps + (RtsFlags.GcFlags.generations - 1)
* RtsFlags.GcFlags.steps;
/* 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 = step_arr + g * RtsFlags.GcFlags.steps;
+ generations[g].steps = all_steps + g * RtsFlags.GcFlags.steps;
}
} else {
/* single generation, i.e. a two-space collector */
g0->n_steps = 1;
- g0->steps = step_arr;
+ g0->steps = all_steps;
}
#ifdef THREADED_RTS
}
/* The oldest generation has one step. */
- if (RtsFlags.GcFlags.compact) {
+ if (RtsFlags.GcFlags.compact || RtsFlags.GcFlags.sweep) {
if (RtsFlags.GcFlags.generations == 1) {
- errorBelch("WARNING: compaction is incompatible with -G1; disabled");
+ errorBelch("WARNING: compact/sweep is incompatible with -G1; disabled");
} else {
- oldest_gen->steps[0].is_compacted = 1;
+ oldest_gen->steps[0].mark = 1;
+ if (RtsFlags.GcFlags.compact)
+ oldest_gen->steps[0].compact = 1;
}
}
alloc_blocks = 0;
alloc_blocks_lim = RtsFlags.GcFlags.minAllocAreaSize;
+ exec_block = NULL;
+
/* Tell GNU multi-precision pkg about our custom alloc functions */
mp_set_memory_functions(stgAllocForGMP, stgReallocForGMP, stgDeallocForGMP);
#ifdef THREADED_RTS
initSpinLock(&gc_alloc_block_sync);
+ whitehole_spin = 0;
#endif
+ N = 0;
+
+ initGcThreads();
+
IF_DEBUG(gc, statDescribeGens());
RELEASE_SM_LOCK;
freeAllMBlocks();
#if defined(THREADED_RTS)
closeMutex(&sm_mutex);
- closeMutex(&atomic_modify_mutvar_mutex);
#endif
stgFree(nurseries);
}
* any more and can use it as a STATIC_LINK.
*/
((StgIndStatic *)caf)->saved_info = NULL;
- recordMutableGen(caf, oldest_gen);
+ recordMutableGen(caf, oldest_gen->no);
}
RELEASE_SM_LOCK;
resizeNurseriesFixed(blocks / n_nurseries);
}
+
+/* -----------------------------------------------------------------------------
+ move_TSO is called to update the TSO structure after it has been
+ moved from one place to another.
+ -------------------------------------------------------------------------- */
+
+void
+move_TSO (StgTSO *src, StgTSO *dest)
+{
+ ptrdiff_t diff;
+
+ // relocate the stack pointer...
+ diff = (StgPtr)dest - (StgPtr)src; // In *words*
+ dest->sp = (StgPtr)dest->sp + diff;
+}
+
/* -----------------------------------------------------------------------------
The allocate() interface
-------------------------------------------------------------------------- */
StgPtr
-allocateInGen (generation *g, nat n)
+allocateInGen (generation *g, lnat n)
{
step *stp;
bdescr *bd;
if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_))
{
- nat req_blocks = (lnat)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
+ lnat req_blocks = (lnat)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
// Attempting to allocate an object larger than maxHeapSize
// should definitely be disallowed. (bug #1791)
if (RtsFlags.GcFlags.maxHeapSize > 0 &&
req_blocks >= RtsFlags.GcFlags.maxHeapSize) {
heapOverflow();
+ // heapOverflow() doesn't exit (see #2592), but we aren't
+ // in a position to do a clean shutdown here: we
+ // either have to allocate the memory or exit now.
+ // Allocating the memory would be bad, because the user
+ // has requested that we not exceed maxHeapSize, so we
+ // just exit.
+ stg_exit(EXIT_HEAPOVERFLOW);
}
bd = allocGroup(req_blocks);
dbl_link_onto(bd, &stp->large_objects);
stp->n_large_blocks += bd->blocks; // might be larger than req_blocks
+ alloc_blocks += bd->blocks;
bd->gen_no = g->no;
bd->step = stp;
bd->flags = BF_LARGE;
}
StgPtr
-allocate (nat n)
+allocate (lnat n)
{
return allocateInGen(g0,n);
}
return allocated;
}
+// split N blocks off the front of the given bdescr, returning the
+// new block group. We treat the remainder as if it
+// had been freshly allocated in generation 0.
+bdescr *
+splitLargeBlock (bdescr *bd, nat blocks)
+{
+ bdescr *new_bd;
+
+ // subtract the original number of blocks from the counter first
+ bd->step->n_large_blocks -= bd->blocks;
+
+ new_bd = splitBlockGroup (bd, blocks);
+
+ dbl_link_onto(new_bd, &g0s0->large_objects);
+ g0s0->n_large_blocks += new_bd->blocks;
+ new_bd->gen_no = g0s0->no;
+ new_bd->step = g0s0;
+ new_bd->flags = BF_LARGE;
+ new_bd->free = bd->free;
+ ASSERT(new_bd->free <= new_bd->start + new_bd->blocks * BLOCK_SIZE_W);
+
+ // add the new number of blocks to the counter. Due to the gaps
+ // for block descriptor, new_bd->blocks + bd->blocks might not be
+ // equal to the original bd->blocks, which is why we do it this way.
+ bd->step->n_large_blocks += bd->blocks;
+
+ return new_bd;
+}
+
/* -----------------------------------------------------------------------------
allocateLocal()
-------------------------------------------------------------------------- */
StgPtr
-allocateLocal (Capability *cap, nat n)
+allocateLocal (Capability *cap, lnat n)
{
bdescr *bd;
StgPtr p;
bd->flags = 0;
// NO: alloc_blocks++;
// calcAllocated() uses the size of the nursery, and we've
- // already bumpted nursery->n_blocks above.
+ // already bumpted nursery->n_blocks above. We'll GC
+ // pretty quickly now anyway, because MAYBE_GC() will
+ // notice that CurrentNursery->link is NULL.
} else {
// we have a block in the nursery: take it and put
// it at the *front* of the nursery list, and use it
------------------------------------------------------------------------- */
StgPtr
-allocatePinned( nat n )
+allocatePinned( lnat 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);
+ p = allocate(n);
+ Bdescr(p)->flags |= BF_PINNED;
+ return p;
}
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)) {
}
}
+// Setting a TSO's link field with a write barrier.
+// It is *not* necessary to call this function when
+// * setting the link field to END_TSO_QUEUE
+// * putting a TSO on the blackhole_queue
+// * setting the link field of the currently running TSO, as it
+// will already be dirty.
+void
+setTSOLink (Capability *cap, StgTSO *tso, StgTSO *target)
+{
+ bdescr *bd;
+ if ((tso->flags & (TSO_DIRTY|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);
+ }
+ tso->_link = target;
+}
+
+void
+dirty_TSO (Capability *cap, StgTSO *tso)
+{
+ bdescr *bd;
+ if ((tso->flags & (TSO_DIRTY|TSO_LINK_DIRTY)) == 0) {
+ bd = Bdescr((StgPtr)tso);
+ if (bd->gen_no > 0) recordMutableCap((StgClosure*)tso,cap,bd->gen_no);
+ }
+ tso->flags |= TSO_DIRTY;
+}
+
/*
This is the write barrier for MVARs. An MVAR_CLEAN objects is not
on the mutable list; a MVAR_DIRTY is. When written to, a
static void *
stgReallocForGMP (void *ptr, size_t old_size, size_t new_size)
{
+ size_t min_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++) {
+ min_size = old_size < new_size ? old_size : new_size;
+ for (; i < min_size; i++, p++, q++) {
*q = *p;
}
/* Approximate the amount of live data in the heap. To be called just
* after garbage collection (see GarbageCollect()).
*/
-extern lnat
-calcLive(void)
+lnat
+calcLiveBlocks(void)
{
nat g, s;
lnat live = 0;
step *stp;
if (RtsFlags.GcFlags.generations == 1) {
- return (g0s0->n_large_blocks + g0s0->n_blocks) * BLOCK_SIZE_W;
+ return g0s0->n_large_blocks + g0s0->n_blocks;
}
for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
continue;
}
stp = &generations[g].steps[s];
- live += (stp->n_large_blocks + stp->n_blocks) * BLOCK_SIZE_W;
+ live += stp->n_large_blocks + stp->n_blocks;
}
}
return live;
}
+lnat
+countOccupied(bdescr *bd)
+{
+ lnat words;
+
+ words = 0;
+ for (; bd != NULL; bd = bd->link) {
+ ASSERT(bd->free <= bd->start + bd->blocks * BLOCK_SIZE_W);
+ words += bd->free - bd->start;
+ }
+ return words;
+}
+
+// Return an accurate count of the live data in the heap, excluding
+// generation 0.
+lnat
+calcLiveWords(void)
+{
+ nat g, s;
+ lnat live;
+ step *stp;
+
+ if (RtsFlags.GcFlags.generations == 1) {
+ return g0s0->n_words + countOccupied(g0s0->large_objects);
+ }
+
+ live = 0;
+ 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];
+ live += stp->n_words + countOccupied(stp->large_objects);
+ }
+ }
+ return live;
+}
+
/* Approximate the number of blocks that will be needed at the next
* garbage collection.
*
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;
+
+ // we need at least this much space
+ needed += stp->n_blocks + stp->n_large_blocks;
+
+ // any additional space needed to collect this gen next time?
+ if (g == 0 || // always collect gen 0
+ (generations[g].steps[0].n_blocks +
+ generations[g].steps[0].n_large_blocks
+ > generations[g].max_blocks)) {
+ // we will collect this gen next time
+ if (stp->mark) {
+ // bitmap:
+ needed += stp->n_blocks / BITS_IN(W_);
+ // mark stack:
+ needed += stp->n_blocks / 100;
+ }
+ if (stp->compact) {
+ continue; // no additional space needed for compaction
+ } else {
+ needed += stp->n_blocks;
+ }
}
}
}
should be modified to use allocateExec instead of VirtualAlloc.
------------------------------------------------------------------------- */
-static bdescr *exec_block;
+#if defined(linux_HOST_OS)
+
+// On Linux we need to use libffi for allocating executable memory,
+// because it knows how to work around the restrictions put in place
+// by SELinux.
-void *allocateExec (nat bytes)
+void *allocateExec (nat bytes, void **exec_ret)
+{
+ void **ret, **exec;
+ ACQUIRE_SM_LOCK;
+ ret = ffi_closure_alloc (sizeof(void *) + (size_t)bytes, (void**)&exec);
+ RELEASE_SM_LOCK;
+ if (ret == NULL) return ret;
+ *ret = ret; // save the address of the writable mapping, for freeExec().
+ *exec_ret = exec + 1;
+ return (ret + 1);
+}
+
+// freeExec gets passed the executable address, not the writable address.
+void freeExec (void *addr)
+{
+ void *writable;
+ writable = *((void**)addr - 1);
+ ACQUIRE_SM_LOCK;
+ ffi_closure_free (writable);
+ RELEASE_SM_LOCK
+}
+
+#else
+
+void *allocateExec (nat bytes, void **exec_ret)
{
void *ret;
nat n;
exec_block->free += n + 1;
RELEASE_SM_LOCK
+ *exec_ret = ret;
return ret;
}
RELEASE_SM_LOCK
}
+#endif /* mingw32_HOST_OS */
+
/* -----------------------------------------------------------------------------
Debugging
#ifdef DEBUG
+// Useful for finding partially full blocks in gdb
+void findSlop(bdescr *bd);
+void findSlop(bdescr *bd)
+{
+ lnat slop;
+
+ for (; bd != NULL; bd = bd->link) {
+ slop = (bd->blocks * BLOCK_SIZE_W) - (bd->free - bd->start);
+ if (slop > (1024/sizeof(W_))) {
+ debugBelch("block at %p (bdescr %p) has %ldKB slop\n",
+ bd->start, bd, slop / (1024/sizeof(W_)));
+ }
+ }
+}
+
nat
countBlocks(bdescr *bd)
{
countAllocdBlocks(stp->large_objects);
}
+// If memInventory() calculates that we have a memory leak, this
+// function will try to find the block(s) that are leaking by marking
+// all the ones that we know about, and search through memory to find
+// blocks that are not marked. In the debugger this can help to give
+// us a clue about what kind of block leaked. In the future we might
+// annotate blocks with their allocation site to give more helpful
+// info.
+static void
+findMemoryLeak (void)
+{
+ nat g, s, i;
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ for (i = 0; i < n_capabilities; i++) {
+ markBlocks(capabilities[i].mut_lists[g]);
+ }
+ markBlocks(generations[g].mut_list);
+ for (s = 0; s < generations[g].n_steps; s++) {
+ markBlocks(generations[g].steps[s].blocks);
+ markBlocks(generations[g].steps[s].large_objects);
+ }
+ }
+
+ for (i = 0; i < n_nurseries; i++) {
+ markBlocks(nurseries[i].blocks);
+ markBlocks(nurseries[i].large_objects);
+ }
+
+#ifdef PROFILING
+ // TODO:
+ // if (RtsFlags.ProfFlags.doHeapProfile == HEAP_BY_RETAINER) {
+ // markRetainerBlocks();
+ // }
+#endif
+
+ // count the blocks allocated by the arena allocator
+ // TODO:
+ // markArenaBlocks();
+
+ // count the blocks containing executable memory
+ markBlocks(exec_block);
+
+ reportUnmarkedBlocks();
+}
+
+
void
-memInventory(void)
+memInventory (rtsBool show)
{
nat g, s, i;
step *stp;
lnat nursery_blocks, retainer_blocks,
arena_blocks, exec_blocks;
lnat live_blocks = 0, free_blocks = 0;
+ rtsBool leak;
// count the blocks we current have
live_blocks += nursery_blocks +
+ retainer_blocks + arena_blocks + exec_blocks;
- if (live_blocks + free_blocks != mblocks_allocated * BLOCKS_PER_MBLOCK)
+#define MB(n) (((n) * BLOCK_SIZE_W) / ((1024*1024)/sizeof(W_)))
+
+ leak = live_blocks + free_blocks != mblocks_allocated * BLOCKS_PER_MBLOCK;
+
+ if (show || leak)
{
- debugBelch("Memory leak detected\n");
+ if (leak) {
+ debugBelch("Memory leak detected:\n");
+ } else {
+ debugBelch("Memory inventory:\n");
+ }
for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
- debugBelch(" gen %d blocks : %4lu\n", g, gen_blocks[g]);
+ debugBelch(" gen %d blocks : %5lu blocks (%lu MB)\n", g,
+ gen_blocks[g], MB(gen_blocks[g]));
}
- debugBelch(" nursery : %4lu\n", nursery_blocks);
- debugBelch(" retainer : %4lu\n", retainer_blocks);
- debugBelch(" arena blocks : %4lu\n", arena_blocks);
- debugBelch(" exec : %4lu\n", exec_blocks);
- debugBelch(" free : %4lu\n", free_blocks);
- debugBelch(" total : %4lu\n\n", live_blocks + free_blocks);
- debugBelch(" in system : %4lu\n", mblocks_allocated * BLOCKS_PER_MBLOCK);
- ASSERT(0);
+ debugBelch(" nursery : %5lu blocks (%lu MB)\n",
+ nursery_blocks, MB(nursery_blocks));
+ debugBelch(" retainer : %5lu blocks (%lu MB)\n",
+ retainer_blocks, MB(retainer_blocks));
+ debugBelch(" arena blocks : %5lu blocks (%lu MB)\n",
+ arena_blocks, MB(arena_blocks));
+ debugBelch(" exec : %5lu blocks (%lu MB)\n",
+ exec_blocks, MB(exec_blocks));
+ debugBelch(" free : %5lu blocks (%lu MB)\n",
+ free_blocks, MB(free_blocks));
+ debugBelch(" total : %5lu blocks (%lu MB)\n",
+ live_blocks + free_blocks, MB(live_blocks+free_blocks));
+ if (leak) {
+ debugBelch("\n in system : %5lu blocks (%lu MB)\n",
+ mblocks_allocated * BLOCKS_PER_MBLOCK, mblocks_allocated);
+ }
+ }
+
+ if (leak) {
+ debugBelch("\n");
+ findMemoryLeak();
}
+ ASSERT(n_alloc_blocks == live_blocks);
+ ASSERT(!leak);
}
if (RtsFlags.GcFlags.generations == 1) {
checkHeap(g0s0->blocks);
- checkChain(g0s0->large_objects);
+ checkLargeObjects(g0s0->large_objects);
} else {
for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
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);
- }
+ checkLargeObjects(generations[g].steps[s].large_objects);
}
}
checkFreeListSanity();
}
+
+#if defined(THREADED_RTS)
+ // check the stacks too in threaded mode, because we don't do a
+ // full heap sanity check in this case (see checkHeap())
+ checkMutableLists(rtsTrue);
+#else
+ checkMutableLists(rtsFalse);
+#endif
}
/* Nursery sanity check */