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Diffstat (limited to 'src/runtime/mheap.c')
| -rw-r--r-- | src/runtime/mheap.c | 889 |
1 files changed, 0 insertions, 889 deletions
diff --git a/src/runtime/mheap.c b/src/runtime/mheap.c deleted file mode 100644 index bb203d5ce..000000000 --- a/src/runtime/mheap.c +++ /dev/null @@ -1,889 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// Page heap. -// -// See malloc.h for overview. -// -// When a MSpan is in the heap free list, state == MSpanFree -// and heapmap(s->start) == span, heapmap(s->start+s->npages-1) == span. -// -// When a MSpan is allocated, state == MSpanInUse or MSpanStack -// and heapmap(i) == span for all s->start <= i < s->start+s->npages. - -#include "runtime.h" -#include "arch_GOARCH.h" -#include "malloc.h" - -static MSpan *MHeap_AllocSpanLocked(MHeap*, uintptr); -static void MHeap_FreeSpanLocked(MHeap*, MSpan*, bool, bool); -static bool MHeap_Grow(MHeap*, uintptr); -static MSpan *MHeap_AllocLarge(MHeap*, uintptr); -static MSpan *BestFit(MSpan*, uintptr, MSpan*); - -static void -RecordSpan(void *vh, byte *p) -{ - MHeap *h; - MSpan *s; - MSpan **all; - uint32 cap; - - h = vh; - s = (MSpan*)p; - if(h->nspan >= h->nspancap) { - cap = 64*1024/sizeof(all[0]); - if(cap < h->nspancap*3/2) - cap = h->nspancap*3/2; - all = (MSpan**)runtime·sysAlloc(cap*sizeof(all[0]), &mstats.other_sys); - if(all == nil) - runtime·throw("runtime: cannot allocate memory"); - if(h->allspans) { - runtime·memmove(all, h->allspans, h->nspancap*sizeof(all[0])); - // Don't free the old array if it's referenced by sweep. - // See the comment in mgc0.c. - if(h->allspans != runtime·mheap.gcspans) - runtime·SysFree(h->allspans, h->nspancap*sizeof(all[0]), &mstats.other_sys); - } - h->allspans = all; - h->nspancap = cap; - } - h->allspans[h->nspan++] = s; -} - -// Initialize the heap; fetch memory using alloc. -void -runtime·MHeap_Init(MHeap *h) -{ - uint32 i; - - runtime·FixAlloc_Init(&h->spanalloc, sizeof(MSpan), RecordSpan, h, &mstats.mspan_sys); - runtime·FixAlloc_Init(&h->cachealloc, sizeof(MCache), nil, nil, &mstats.mcache_sys); - runtime·FixAlloc_Init(&h->specialfinalizeralloc, sizeof(SpecialFinalizer), nil, nil, &mstats.other_sys); - runtime·FixAlloc_Init(&h->specialprofilealloc, sizeof(SpecialProfile), nil, nil, &mstats.other_sys); - // h->mapcache needs no init - for(i=0; i<nelem(h->free); i++) { - runtime·MSpanList_Init(&h->free[i]); - runtime·MSpanList_Init(&h->busy[i]); - } - runtime·MSpanList_Init(&h->freelarge); - runtime·MSpanList_Init(&h->busylarge); - for(i=0; i<nelem(h->central); i++) - runtime·MCentral_Init(&h->central[i].mcentral, i); -} - -void -runtime·MHeap_MapSpans(MHeap *h) -{ - uintptr n; - - // Map spans array, PageSize at a time. - n = (uintptr)h->arena_used; - n -= (uintptr)h->arena_start; - n = n / PageSize * sizeof(h->spans[0]); - n = ROUND(n, PhysPageSize); - if(h->spans_mapped >= n) - return; - runtime·SysMap((byte*)h->spans + h->spans_mapped, n - h->spans_mapped, h->arena_reserved, &mstats.other_sys); - h->spans_mapped = n; -} - -// Sweeps spans in list until reclaims at least npages into heap. -// Returns the actual number of pages reclaimed. -static uintptr -MHeap_ReclaimList(MHeap *h, MSpan *list, uintptr npages) -{ - MSpan *s; - uintptr n; - uint32 sg; - - n = 0; - sg = runtime·mheap.sweepgen; -retry: - for(s = list->next; s != list; s = s->next) { - if(s->sweepgen == sg-2 && runtime·cas(&s->sweepgen, sg-2, sg-1)) { - runtime·MSpanList_Remove(s); - // swept spans are at the end of the list - runtime·MSpanList_InsertBack(list, s); - runtime·unlock(&h->lock); - n += runtime·MSpan_Sweep(s, false); - runtime·lock(&h->lock); - if(n >= npages) - return n; - // the span could have been moved elsewhere - goto retry; - } - if(s->sweepgen == sg-1) { - // the span is being sweept by background sweeper, skip - continue; - } - // already swept empty span, - // all subsequent ones must also be either swept or in process of sweeping - break; - } - return n; -} - -// Sweeps and reclaims at least npage pages into heap. -// Called before allocating npage pages. -static void -MHeap_Reclaim(MHeap *h, uintptr npage) -{ - uintptr reclaimed, n; - - // First try to sweep busy spans with large objects of size >= npage, - // this has good chances of reclaiming the necessary space. - for(n=npage; n < nelem(h->busy); n++) { - if(MHeap_ReclaimList(h, &h->busy[n], npage)) - return; // Bingo! - } - - // Then -- even larger objects. - if(MHeap_ReclaimList(h, &h->busylarge, npage)) - return; // Bingo! - - // Now try smaller objects. - // One such object is not enough, so we need to reclaim several of them. - reclaimed = 0; - for(n=0; n < npage && n < nelem(h->busy); n++) { - reclaimed += MHeap_ReclaimList(h, &h->busy[n], npage-reclaimed); - if(reclaimed >= npage) - return; - } - - // Now sweep everything that is not yet swept. - runtime·unlock(&h->lock); - for(;;) { - n = runtime·sweepone(); - if(n == -1) // all spans are swept - break; - reclaimed += n; - if(reclaimed >= npage) - break; - } - runtime·lock(&h->lock); -} - -// Allocate a new span of npage pages from the heap for GC'd memory -// and record its size class in the HeapMap and HeapMapCache. -static MSpan* -mheap_alloc(MHeap *h, uintptr npage, int32 sizeclass, bool large) -{ - MSpan *s; - - if(g != g->m->g0) - runtime·throw("mheap_alloc not on M stack"); - runtime·lock(&h->lock); - - // To prevent excessive heap growth, before allocating n pages - // we need to sweep and reclaim at least n pages. - if(!h->sweepdone) - MHeap_Reclaim(h, npage); - - // transfer stats from cache to global - mstats.heap_alloc += g->m->mcache->local_cachealloc; - g->m->mcache->local_cachealloc = 0; - mstats.tinyallocs += g->m->mcache->local_tinyallocs; - g->m->mcache->local_tinyallocs = 0; - - s = MHeap_AllocSpanLocked(h, npage); - if(s != nil) { - // Record span info, because gc needs to be - // able to map interior pointer to containing span. - runtime·atomicstore(&s->sweepgen, h->sweepgen); - s->state = MSpanInUse; - s->freelist = nil; - s->ref = 0; - s->sizeclass = sizeclass; - s->elemsize = (sizeclass==0 ? s->npages<<PageShift : runtime·class_to_size[sizeclass]); - - // update stats, sweep lists - if(large) { - mstats.heap_objects++; - mstats.heap_alloc += npage<<PageShift; - // Swept spans are at the end of lists. - if(s->npages < nelem(h->free)) - runtime·MSpanList_InsertBack(&h->busy[s->npages], s); - else - runtime·MSpanList_InsertBack(&h->busylarge, s); - } - } - runtime·unlock(&h->lock); - return s; -} - -static void -mheap_alloc_m(G *gp) -{ - MHeap *h; - MSpan *s; - - h = g->m->ptrarg[0]; - g->m->ptrarg[0] = nil; - s = mheap_alloc(h, g->m->scalararg[0], g->m->scalararg[1], g->m->scalararg[2]); - g->m->ptrarg[0] = s; - - runtime·gogo(&gp->sched); -} - -MSpan* -runtime·MHeap_Alloc(MHeap *h, uintptr npage, int32 sizeclass, bool large, bool needzero) -{ - MSpan *s; - void (*fn)(G*); - - // Don't do any operations that lock the heap on the G stack. - // It might trigger stack growth, and the stack growth code needs - // to be able to allocate heap. - if(g == g->m->g0) { - s = mheap_alloc(h, npage, sizeclass, large); - } else { - g->m->ptrarg[0] = h; - g->m->scalararg[0] = npage; - g->m->scalararg[1] = sizeclass; - g->m->scalararg[2] = large; - fn = mheap_alloc_m; - runtime·mcall(&fn); - s = g->m->ptrarg[0]; - g->m->ptrarg[0] = nil; - } - if(s != nil) { - if(needzero && s->needzero) - runtime·memclr((byte*)(s->start<<PageShift), s->npages<<PageShift); - s->needzero = 0; - } - return s; -} - -MSpan* -runtime·MHeap_AllocStack(MHeap *h, uintptr npage) -{ - MSpan *s; - - if(g != g->m->g0) - runtime·throw("mheap_allocstack not on M stack"); - runtime·lock(&h->lock); - s = MHeap_AllocSpanLocked(h, npage); - if(s != nil) { - s->state = MSpanStack; - s->freelist = nil; - s->ref = 0; - mstats.stacks_inuse += s->npages<<PageShift; - } - runtime·unlock(&h->lock); - return s; -} - -// Allocates a span of the given size. h must be locked. -// The returned span has been removed from the -// free list, but its state is still MSpanFree. -static MSpan* -MHeap_AllocSpanLocked(MHeap *h, uintptr npage) -{ - uintptr n; - MSpan *s, *t; - pageID p; - - // Try in fixed-size lists up to max. - for(n=npage; n < nelem(h->free); n++) { - if(!runtime·MSpanList_IsEmpty(&h->free[n])) { - s = h->free[n].next; - goto HaveSpan; - } - } - - // Best fit in list of large spans. - if((s = MHeap_AllocLarge(h, npage)) == nil) { - if(!MHeap_Grow(h, npage)) - return nil; - if((s = MHeap_AllocLarge(h, npage)) == nil) - return nil; - } - -HaveSpan: - // Mark span in use. - if(s->state != MSpanFree) - runtime·throw("MHeap_AllocLocked - MSpan not free"); - if(s->npages < npage) - runtime·throw("MHeap_AllocLocked - bad npages"); - runtime·MSpanList_Remove(s); - if(s->next != nil || s->prev != nil) - runtime·throw("still in list"); - if(s->npreleased > 0) { - runtime·SysUsed((void*)(s->start<<PageShift), s->npages<<PageShift); - mstats.heap_released -= s->npreleased<<PageShift; - s->npreleased = 0; - } - - if(s->npages > npage) { - // Trim extra and put it back in the heap. - t = runtime·FixAlloc_Alloc(&h->spanalloc); - runtime·MSpan_Init(t, s->start + npage, s->npages - npage); - s->npages = npage; - p = t->start; - p -= ((uintptr)h->arena_start>>PageShift); - if(p > 0) - h->spans[p-1] = s; - h->spans[p] = t; - h->spans[p+t->npages-1] = t; - t->needzero = s->needzero; - s->state = MSpanStack; // prevent coalescing with s - t->state = MSpanStack; - MHeap_FreeSpanLocked(h, t, false, false); - t->unusedsince = s->unusedsince; // preserve age (TODO: wrong: t is possibly merged and/or deallocated at this point) - s->state = MSpanFree; - } - s->unusedsince = 0; - - p = s->start; - p -= ((uintptr)h->arena_start>>PageShift); - for(n=0; n<npage; n++) - h->spans[p+n] = s; - - mstats.heap_inuse += npage<<PageShift; - mstats.heap_idle -= npage<<PageShift; - - //runtime·printf("spanalloc %p\n", s->start << PageShift); - if(s->next != nil || s->prev != nil) - runtime·throw("still in list"); - return s; -} - -// Allocate a span of exactly npage pages from the list of large spans. -static MSpan* -MHeap_AllocLarge(MHeap *h, uintptr npage) -{ - return BestFit(&h->freelarge, npage, nil); -} - -// Search list for smallest span with >= npage pages. -// If there are multiple smallest spans, take the one -// with the earliest starting address. -static MSpan* -BestFit(MSpan *list, uintptr npage, MSpan *best) -{ - MSpan *s; - - for(s=list->next; s != list; s=s->next) { - if(s->npages < npage) - continue; - if(best == nil - || s->npages < best->npages - || (s->npages == best->npages && s->start < best->start)) - best = s; - } - return best; -} - -// Try to add at least npage pages of memory to the heap, -// returning whether it worked. -static bool -MHeap_Grow(MHeap *h, uintptr npage) -{ - uintptr ask; - void *v; - MSpan *s; - pageID p; - - // Ask for a big chunk, to reduce the number of mappings - // the operating system needs to track; also amortizes - // the overhead of an operating system mapping. - // Allocate a multiple of 64kB. - npage = ROUND(npage, (64<<10)/PageSize); - ask = npage<<PageShift; - if(ask < HeapAllocChunk) - ask = HeapAllocChunk; - - v = runtime·MHeap_SysAlloc(h, ask); - if(v == nil) { - if(ask > (npage<<PageShift)) { - ask = npage<<PageShift; - v = runtime·MHeap_SysAlloc(h, ask); - } - if(v == nil) { - runtime·printf("runtime: out of memory: cannot allocate %D-byte block (%D in use)\n", (uint64)ask, mstats.heap_sys); - return false; - } - } - - // Create a fake "in use" span and free it, so that the - // right coalescing happens. - s = runtime·FixAlloc_Alloc(&h->spanalloc); - runtime·MSpan_Init(s, (uintptr)v>>PageShift, ask>>PageShift); - p = s->start; - p -= ((uintptr)h->arena_start>>PageShift); - h->spans[p] = s; - h->spans[p + s->npages - 1] = s; - runtime·atomicstore(&s->sweepgen, h->sweepgen); - s->state = MSpanInUse; - MHeap_FreeSpanLocked(h, s, false, true); - return true; -} - -// Look up the span at the given address. -// Address is guaranteed to be in map -// and is guaranteed to be start or end of span. -MSpan* -runtime·MHeap_Lookup(MHeap *h, void *v) -{ - uintptr p; - - p = (uintptr)v; - p -= (uintptr)h->arena_start; - return h->spans[p >> PageShift]; -} - -// Look up the span at the given address. -// Address is *not* guaranteed to be in map -// and may be anywhere in the span. -// Map entries for the middle of a span are only -// valid for allocated spans. Free spans may have -// other garbage in their middles, so we have to -// check for that. -MSpan* -runtime·MHeap_LookupMaybe(MHeap *h, void *v) -{ - MSpan *s; - pageID p, q; - - if((byte*)v < h->arena_start || (byte*)v >= h->arena_used) - return nil; - p = (uintptr)v>>PageShift; - q = p; - q -= (uintptr)h->arena_start >> PageShift; - s = h->spans[q]; - if(s == nil || p < s->start || v >= s->limit || s->state != MSpanInUse) - return nil; - return s; -} - -// Free the span back into the heap. -static void -mheap_free(MHeap *h, MSpan *s, int32 acct) -{ - if(g != g->m->g0) - runtime·throw("mheap_free not on M stack"); - runtime·lock(&h->lock); - mstats.heap_alloc += g->m->mcache->local_cachealloc; - g->m->mcache->local_cachealloc = 0; - mstats.tinyallocs += g->m->mcache->local_tinyallocs; - g->m->mcache->local_tinyallocs = 0; - if(acct) { - mstats.heap_alloc -= s->npages<<PageShift; - mstats.heap_objects--; - } - MHeap_FreeSpanLocked(h, s, true, true); - runtime·unlock(&h->lock); -} - -static void -mheap_free_m(G *gp) -{ - MHeap *h; - MSpan *s; - - h = g->m->ptrarg[0]; - s = g->m->ptrarg[1]; - g->m->ptrarg[0] = nil; - g->m->ptrarg[1] = nil; - mheap_free(h, s, g->m->scalararg[0]); - runtime·gogo(&gp->sched); -} - -void -runtime·MHeap_Free(MHeap *h, MSpan *s, int32 acct) -{ - void (*fn)(G*); - - if(g == g->m->g0) { - mheap_free(h, s, acct); - } else { - g->m->ptrarg[0] = h; - g->m->ptrarg[1] = s; - g->m->scalararg[0] = acct; - fn = mheap_free_m; - runtime·mcall(&fn); - } -} - -void -runtime·MHeap_FreeStack(MHeap *h, MSpan *s) -{ - if(g != g->m->g0) - runtime·throw("mheap_freestack not on M stack"); - s->needzero = 1; - runtime·lock(&h->lock); - mstats.stacks_inuse -= s->npages<<PageShift; - MHeap_FreeSpanLocked(h, s, true, true); - runtime·unlock(&h->lock); -} - -static void -MHeap_FreeSpanLocked(MHeap *h, MSpan *s, bool acctinuse, bool acctidle) -{ - MSpan *t; - pageID p; - - switch(s->state) { - case MSpanStack: - if(s->ref != 0) - runtime·throw("MHeap_FreeSpanLocked - invalid stack free"); - break; - case MSpanInUse: - if(s->ref != 0 || s->sweepgen != h->sweepgen) { - runtime·printf("MHeap_FreeSpanLocked - span %p ptr %p ref %d sweepgen %d/%d\n", - s, s->start<<PageShift, s->ref, s->sweepgen, h->sweepgen); - runtime·throw("MHeap_FreeSpanLocked - invalid free"); - } - break; - default: - runtime·throw("MHeap_FreeSpanLocked - invalid span state"); - break; - } - if(acctinuse) - mstats.heap_inuse -= s->npages<<PageShift; - if(acctidle) - mstats.heap_idle += s->npages<<PageShift; - s->state = MSpanFree; - runtime·MSpanList_Remove(s); - // Stamp newly unused spans. The scavenger will use that - // info to potentially give back some pages to the OS. - s->unusedsince = runtime·nanotime(); - s->npreleased = 0; - - // Coalesce with earlier, later spans. - p = s->start; - p -= (uintptr)h->arena_start >> PageShift; - if(p > 0 && (t = h->spans[p-1]) != nil && t->state != MSpanInUse && t->state != MSpanStack) { - s->start = t->start; - s->npages += t->npages; - s->npreleased = t->npreleased; // absorb released pages - s->needzero |= t->needzero; - p -= t->npages; - h->spans[p] = s; - runtime·MSpanList_Remove(t); - t->state = MSpanDead; - runtime·FixAlloc_Free(&h->spanalloc, t); - } - if((p+s->npages)*sizeof(h->spans[0]) < h->spans_mapped && (t = h->spans[p+s->npages]) != nil && t->state != MSpanInUse && t->state != MSpanStack) { - s->npages += t->npages; - s->npreleased += t->npreleased; - s->needzero |= t->needzero; - h->spans[p + s->npages - 1] = s; - runtime·MSpanList_Remove(t); - t->state = MSpanDead; - runtime·FixAlloc_Free(&h->spanalloc, t); - } - - // Insert s into appropriate list. - if(s->npages < nelem(h->free)) - runtime·MSpanList_Insert(&h->free[s->npages], s); - else - runtime·MSpanList_Insert(&h->freelarge, s); -} - -static uintptr -scavengelist(MSpan *list, uint64 now, uint64 limit) -{ - uintptr released, sumreleased; - MSpan *s; - - if(runtime·MSpanList_IsEmpty(list)) - return 0; - - sumreleased = 0; - for(s=list->next; s != list; s=s->next) { - if((now - s->unusedsince) > limit && s->npreleased != s->npages) { - released = (s->npages - s->npreleased) << PageShift; - mstats.heap_released += released; - sumreleased += released; - s->npreleased = s->npages; - runtime·SysUnused((void*)(s->start << PageShift), s->npages << PageShift); - } - } - return sumreleased; -} - -void -runtime·MHeap_Scavenge(int32 k, uint64 now, uint64 limit) -{ - uint32 i; - uintptr sumreleased; - MHeap *h; - - h = &runtime·mheap; - runtime·lock(&h->lock); - sumreleased = 0; - for(i=0; i < nelem(h->free); i++) - sumreleased += scavengelist(&h->free[i], now, limit); - sumreleased += scavengelist(&h->freelarge, now, limit); - runtime·unlock(&h->lock); - - if(runtime·debug.gctrace > 0) { - if(sumreleased > 0) - runtime·printf("scvg%d: %D MB released\n", k, (uint64)sumreleased>>20); - // TODO(dvyukov): these stats are incorrect as we don't subtract stack usage from heap. - // But we can't call ReadMemStats on g0 holding locks. - runtime·printf("scvg%d: inuse: %D, idle: %D, sys: %D, released: %D, consumed: %D (MB)\n", - k, mstats.heap_inuse>>20, mstats.heap_idle>>20, mstats.heap_sys>>20, - mstats.heap_released>>20, (mstats.heap_sys - mstats.heap_released)>>20); - } -} - -void -runtime·scavenge_m(void) -{ - runtime·MHeap_Scavenge(-1, ~(uintptr)0, 0); -} - -// Initialize a new span with the given start and npages. -void -runtime·MSpan_Init(MSpan *span, pageID start, uintptr npages) -{ - span->next = nil; - span->prev = nil; - span->start = start; - span->npages = npages; - span->freelist = nil; - span->ref = 0; - span->sizeclass = 0; - span->incache = false; - span->elemsize = 0; - span->state = MSpanDead; - span->unusedsince = 0; - span->npreleased = 0; - span->specialLock.key = 0; - span->specials = nil; - span->needzero = 0; -} - -// Initialize an empty doubly-linked list. -void -runtime·MSpanList_Init(MSpan *list) -{ - list->state = MSpanListHead; - list->next = list; - list->prev = list; -} - -void -runtime·MSpanList_Remove(MSpan *span) -{ - if(span->prev == nil && span->next == nil) - return; - span->prev->next = span->next; - span->next->prev = span->prev; - span->prev = nil; - span->next = nil; -} - -bool -runtime·MSpanList_IsEmpty(MSpan *list) -{ - return list->next == list; -} - -void -runtime·MSpanList_Insert(MSpan *list, MSpan *span) -{ - if(span->next != nil || span->prev != nil) { - runtime·printf("failed MSpanList_Insert %p %p %p\n", span, span->next, span->prev); - runtime·throw("MSpanList_Insert"); - } - span->next = list->next; - span->prev = list; - span->next->prev = span; - span->prev->next = span; -} - -void -runtime·MSpanList_InsertBack(MSpan *list, MSpan *span) -{ - if(span->next != nil || span->prev != nil) { - runtime·printf("failed MSpanList_Insert %p %p %p\n", span, span->next, span->prev); - runtime·throw("MSpanList_Insert"); - } - span->next = list; - span->prev = list->prev; - span->next->prev = span; - span->prev->next = span; -} - -// Adds the special record s to the list of special records for -// the object p. All fields of s should be filled in except for -// offset & next, which this routine will fill in. -// Returns true if the special was successfully added, false otherwise. -// (The add will fail only if a record with the same p and s->kind -// already exists.) -static bool -addspecial(void *p, Special *s) -{ - MSpan *span; - Special **t, *x; - uintptr offset; - byte kind; - - span = runtime·MHeap_LookupMaybe(&runtime·mheap, p); - if(span == nil) - runtime·throw("addspecial on invalid pointer"); - - // Ensure that the span is swept. - // GC accesses specials list w/o locks. And it's just much safer. - g->m->locks++; - runtime·MSpan_EnsureSwept(span); - - offset = (uintptr)p - (span->start << PageShift); - kind = s->kind; - - runtime·lock(&span->specialLock); - - // Find splice point, check for existing record. - t = &span->specials; - while((x = *t) != nil) { - if(offset == x->offset && kind == x->kind) { - runtime·unlock(&span->specialLock); - g->m->locks--; - return false; // already exists - } - if(offset < x->offset || (offset == x->offset && kind < x->kind)) - break; - t = &x->next; - } - // Splice in record, fill in offset. - s->offset = offset; - s->next = x; - *t = s; - runtime·unlock(&span->specialLock); - g->m->locks--; - return true; -} - -// Removes the Special record of the given kind for the object p. -// Returns the record if the record existed, nil otherwise. -// The caller must FixAlloc_Free the result. -static Special* -removespecial(void *p, byte kind) -{ - MSpan *span; - Special *s, **t; - uintptr offset; - - span = runtime·MHeap_LookupMaybe(&runtime·mheap, p); - if(span == nil) - runtime·throw("removespecial on invalid pointer"); - - // Ensure that the span is swept. - // GC accesses specials list w/o locks. And it's just much safer. - g->m->locks++; - runtime·MSpan_EnsureSwept(span); - - offset = (uintptr)p - (span->start << PageShift); - - runtime·lock(&span->specialLock); - t = &span->specials; - while((s = *t) != nil) { - // This function is used for finalizers only, so we don't check for - // "interior" specials (p must be exactly equal to s->offset). - if(offset == s->offset && kind == s->kind) { - *t = s->next; - runtime·unlock(&span->specialLock); - g->m->locks--; - return s; - } - t = &s->next; - } - runtime·unlock(&span->specialLock); - g->m->locks--; - return nil; -} - -// Adds a finalizer to the object p. Returns true if it succeeded. -bool -runtime·addfinalizer(void *p, FuncVal *f, uintptr nret, Type *fint, PtrType *ot) -{ - SpecialFinalizer *s; - - runtime·lock(&runtime·mheap.speciallock); - s = runtime·FixAlloc_Alloc(&runtime·mheap.specialfinalizeralloc); - runtime·unlock(&runtime·mheap.speciallock); - s->special.kind = KindSpecialFinalizer; - s->fn = f; - s->nret = nret; - s->fint = fint; - s->ot = ot; - if(addspecial(p, &s->special)) - return true; - - // There was an old finalizer - runtime·lock(&runtime·mheap.speciallock); - runtime·FixAlloc_Free(&runtime·mheap.specialfinalizeralloc, s); - runtime·unlock(&runtime·mheap.speciallock); - return false; -} - -// Removes the finalizer (if any) from the object p. -void -runtime·removefinalizer(void *p) -{ - SpecialFinalizer *s; - - s = (SpecialFinalizer*)removespecial(p, KindSpecialFinalizer); - if(s == nil) - return; // there wasn't a finalizer to remove - runtime·lock(&runtime·mheap.speciallock); - runtime·FixAlloc_Free(&runtime·mheap.specialfinalizeralloc, s); - runtime·unlock(&runtime·mheap.speciallock); -} - -// Set the heap profile bucket associated with addr to b. -void -runtime·setprofilebucket_m(void) -{ - void *p; - Bucket *b; - SpecialProfile *s; - - p = g->m->ptrarg[0]; - b = g->m->ptrarg[1]; - g->m->ptrarg[0] = nil; - g->m->ptrarg[1] = nil; - - runtime·lock(&runtime·mheap.speciallock); - s = runtime·FixAlloc_Alloc(&runtime·mheap.specialprofilealloc); - runtime·unlock(&runtime·mheap.speciallock); - s->special.kind = KindSpecialProfile; - s->b = b; - if(!addspecial(p, &s->special)) - runtime·throw("setprofilebucket: profile already set"); -} - -// Do whatever cleanup needs to be done to deallocate s. It has -// already been unlinked from the MSpan specials list. -// Returns true if we should keep working on deallocating p. -bool -runtime·freespecial(Special *s, void *p, uintptr size, bool freed) -{ - SpecialFinalizer *sf; - SpecialProfile *sp; - - switch(s->kind) { - case KindSpecialFinalizer: - sf = (SpecialFinalizer*)s; - runtime·queuefinalizer(p, sf->fn, sf->nret, sf->fint, sf->ot); - runtime·lock(&runtime·mheap.speciallock); - runtime·FixAlloc_Free(&runtime·mheap.specialfinalizeralloc, sf); - runtime·unlock(&runtime·mheap.speciallock); - return false; // don't free p until finalizer is done - case KindSpecialProfile: - sp = (SpecialProfile*)s; - runtime·mProf_Free(sp->b, size, freed); - runtime·lock(&runtime·mheap.speciallock); - runtime·FixAlloc_Free(&runtime·mheap.specialprofilealloc, sp); - runtime·unlock(&runtime·mheap.speciallock); - return true; - default: - runtime·throw("bad special kind"); - return true; - } -} |