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-rw-r--r--src/runtime/heapdump.go752
1 files changed, 752 insertions, 0 deletions
diff --git a/src/runtime/heapdump.go b/src/runtime/heapdump.go
new file mode 100644
index 0000000..c7f2b7a
--- /dev/null
+++ b/src/runtime/heapdump.go
@@ -0,0 +1,752 @@
+// Copyright 2014 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.
+
+// Implementation of runtime/debug.WriteHeapDump. Writes all
+// objects in the heap plus additional info (roots, threads,
+// finalizers, etc.) to a file.
+
+// The format of the dumped file is described at
+// https://golang.org/s/go15heapdump.
+
+package runtime
+
+import (
+ "internal/goarch"
+ "unsafe"
+)
+
+//go:linkname runtime_debug_WriteHeapDump runtime/debug.WriteHeapDump
+func runtime_debug_WriteHeapDump(fd uintptr) {
+ stopTheWorld("write heap dump")
+
+ // Keep m on this G's stack instead of the system stack.
+ // Both readmemstats_m and writeheapdump_m have pretty large
+ // peak stack depths and we risk blowing the system stack.
+ // This is safe because the world is stopped, so we don't
+ // need to worry about anyone shrinking and therefore moving
+ // our stack.
+ var m MemStats
+ systemstack(func() {
+ // Call readmemstats_m here instead of deeper in
+ // writeheapdump_m because we might blow the system stack
+ // otherwise.
+ readmemstats_m(&m)
+ writeheapdump_m(fd, &m)
+ })
+
+ startTheWorld()
+}
+
+const (
+ fieldKindEol = 0
+ fieldKindPtr = 1
+ fieldKindIface = 2
+ fieldKindEface = 3
+ tagEOF = 0
+ tagObject = 1
+ tagOtherRoot = 2
+ tagType = 3
+ tagGoroutine = 4
+ tagStackFrame = 5
+ tagParams = 6
+ tagFinalizer = 7
+ tagItab = 8
+ tagOSThread = 9
+ tagMemStats = 10
+ tagQueuedFinalizer = 11
+ tagData = 12
+ tagBSS = 13
+ tagDefer = 14
+ tagPanic = 15
+ tagMemProf = 16
+ tagAllocSample = 17
+)
+
+var dumpfd uintptr // fd to write the dump to.
+var tmpbuf []byte
+
+// buffer of pending write data
+const (
+ bufSize = 4096
+)
+
+var buf [bufSize]byte
+var nbuf uintptr
+
+func dwrite(data unsafe.Pointer, len uintptr) {
+ if len == 0 {
+ return
+ }
+ if nbuf+len <= bufSize {
+ copy(buf[nbuf:], (*[bufSize]byte)(data)[:len])
+ nbuf += len
+ return
+ }
+
+ write(dumpfd, unsafe.Pointer(&buf), int32(nbuf))
+ if len >= bufSize {
+ write(dumpfd, data, int32(len))
+ nbuf = 0
+ } else {
+ copy(buf[:], (*[bufSize]byte)(data)[:len])
+ nbuf = len
+ }
+}
+
+func dwritebyte(b byte) {
+ dwrite(unsafe.Pointer(&b), 1)
+}
+
+func flush() {
+ write(dumpfd, unsafe.Pointer(&buf), int32(nbuf))
+ nbuf = 0
+}
+
+// Cache of types that have been serialized already.
+// We use a type's hash field to pick a bucket.
+// Inside a bucket, we keep a list of types that
+// have been serialized so far, most recently used first.
+// Note: when a bucket overflows we may end up
+// serializing a type more than once. That's ok.
+const (
+ typeCacheBuckets = 256
+ typeCacheAssoc = 4
+)
+
+type typeCacheBucket struct {
+ t [typeCacheAssoc]*_type
+}
+
+var typecache [typeCacheBuckets]typeCacheBucket
+
+// dump a uint64 in a varint format parseable by encoding/binary
+func dumpint(v uint64) {
+ var buf [10]byte
+ var n int
+ for v >= 0x80 {
+ buf[n] = byte(v | 0x80)
+ n++
+ v >>= 7
+ }
+ buf[n] = byte(v)
+ n++
+ dwrite(unsafe.Pointer(&buf), uintptr(n))
+}
+
+func dumpbool(b bool) {
+ if b {
+ dumpint(1)
+ } else {
+ dumpint(0)
+ }
+}
+
+// dump varint uint64 length followed by memory contents
+func dumpmemrange(data unsafe.Pointer, len uintptr) {
+ dumpint(uint64(len))
+ dwrite(data, len)
+}
+
+func dumpslice(b []byte) {
+ dumpint(uint64(len(b)))
+ if len(b) > 0 {
+ dwrite(unsafe.Pointer(&b[0]), uintptr(len(b)))
+ }
+}
+
+func dumpstr(s string) {
+ sp := stringStructOf(&s)
+ dumpmemrange(sp.str, uintptr(sp.len))
+}
+
+// dump information for a type
+func dumptype(t *_type) {
+ if t == nil {
+ return
+ }
+
+ // If we've definitely serialized the type before,
+ // no need to do it again.
+ b := &typecache[t.hash&(typeCacheBuckets-1)]
+ if t == b.t[0] {
+ return
+ }
+ for i := 1; i < typeCacheAssoc; i++ {
+ if t == b.t[i] {
+ // Move-to-front
+ for j := i; j > 0; j-- {
+ b.t[j] = b.t[j-1]
+ }
+ b.t[0] = t
+ return
+ }
+ }
+
+ // Might not have been dumped yet. Dump it and
+ // remember we did so.
+ for j := typeCacheAssoc - 1; j > 0; j-- {
+ b.t[j] = b.t[j-1]
+ }
+ b.t[0] = t
+
+ // dump the type
+ dumpint(tagType)
+ dumpint(uint64(uintptr(unsafe.Pointer(t))))
+ dumpint(uint64(t.size))
+ if x := t.uncommon(); x == nil || t.nameOff(x.pkgpath).name() == "" {
+ dumpstr(t.string())
+ } else {
+ pkgpathstr := t.nameOff(x.pkgpath).name()
+ pkgpath := stringStructOf(&pkgpathstr)
+ namestr := t.name()
+ name := stringStructOf(&namestr)
+ dumpint(uint64(uintptr(pkgpath.len) + 1 + uintptr(name.len)))
+ dwrite(pkgpath.str, uintptr(pkgpath.len))
+ dwritebyte('.')
+ dwrite(name.str, uintptr(name.len))
+ }
+ dumpbool(t.kind&kindDirectIface == 0 || t.ptrdata != 0)
+}
+
+// dump an object
+func dumpobj(obj unsafe.Pointer, size uintptr, bv bitvector) {
+ dumpint(tagObject)
+ dumpint(uint64(uintptr(obj)))
+ dumpmemrange(obj, size)
+ dumpfields(bv)
+}
+
+func dumpotherroot(description string, to unsafe.Pointer) {
+ dumpint(tagOtherRoot)
+ dumpstr(description)
+ dumpint(uint64(uintptr(to)))
+}
+
+func dumpfinalizer(obj unsafe.Pointer, fn *funcval, fint *_type, ot *ptrtype) {
+ dumpint(tagFinalizer)
+ dumpint(uint64(uintptr(obj)))
+ dumpint(uint64(uintptr(unsafe.Pointer(fn))))
+ dumpint(uint64(uintptr(unsafe.Pointer(fn.fn))))
+ dumpint(uint64(uintptr(unsafe.Pointer(fint))))
+ dumpint(uint64(uintptr(unsafe.Pointer(ot))))
+}
+
+type childInfo struct {
+ // Information passed up from the callee frame about
+ // the layout of the outargs region.
+ argoff uintptr // where the arguments start in the frame
+ arglen uintptr // size of args region
+ args bitvector // if args.n >= 0, pointer map of args region
+ sp *uint8 // callee sp
+ depth uintptr // depth in call stack (0 == most recent)
+}
+
+// dump kinds & offsets of interesting fields in bv
+func dumpbv(cbv *bitvector, offset uintptr) {
+ for i := uintptr(0); i < uintptr(cbv.n); i++ {
+ if cbv.ptrbit(i) == 1 {
+ dumpint(fieldKindPtr)
+ dumpint(uint64(offset + i*goarch.PtrSize))
+ }
+ }
+}
+
+func dumpframe(s *stkframe, arg unsafe.Pointer) bool {
+ child := (*childInfo)(arg)
+ f := s.fn
+
+ // Figure out what we can about our stack map
+ pc := s.pc
+ pcdata := int32(-1) // Use the entry map at function entry
+ if pc != f.entry() {
+ pc--
+ pcdata = pcdatavalue(f, _PCDATA_StackMapIndex, pc, nil)
+ }
+ if pcdata == -1 {
+ // We do not have a valid pcdata value but there might be a
+ // stackmap for this function. It is likely that we are looking
+ // at the function prologue, assume so and hope for the best.
+ pcdata = 0
+ }
+ stkmap := (*stackmap)(funcdata(f, _FUNCDATA_LocalsPointerMaps))
+
+ var bv bitvector
+ if stkmap != nil && stkmap.n > 0 {
+ bv = stackmapdata(stkmap, pcdata)
+ } else {
+ bv.n = -1
+ }
+
+ // Dump main body of stack frame.
+ dumpint(tagStackFrame)
+ dumpint(uint64(s.sp)) // lowest address in frame
+ dumpint(uint64(child.depth)) // # of frames deep on the stack
+ dumpint(uint64(uintptr(unsafe.Pointer(child.sp)))) // sp of child, or 0 if bottom of stack
+ dumpmemrange(unsafe.Pointer(s.sp), s.fp-s.sp) // frame contents
+ dumpint(uint64(f.entry()))
+ dumpint(uint64(s.pc))
+ dumpint(uint64(s.continpc))
+ name := funcname(f)
+ if name == "" {
+ name = "unknown function"
+ }
+ dumpstr(name)
+
+ // Dump fields in the outargs section
+ if child.args.n >= 0 {
+ dumpbv(&child.args, child.argoff)
+ } else {
+ // conservative - everything might be a pointer
+ for off := child.argoff; off < child.argoff+child.arglen; off += goarch.PtrSize {
+ dumpint(fieldKindPtr)
+ dumpint(uint64(off))
+ }
+ }
+
+ // Dump fields in the local vars section
+ if stkmap == nil {
+ // No locals information, dump everything.
+ for off := child.arglen; off < s.varp-s.sp; off += goarch.PtrSize {
+ dumpint(fieldKindPtr)
+ dumpint(uint64(off))
+ }
+ } else if stkmap.n < 0 {
+ // Locals size information, dump just the locals.
+ size := uintptr(-stkmap.n)
+ for off := s.varp - size - s.sp; off < s.varp-s.sp; off += goarch.PtrSize {
+ dumpint(fieldKindPtr)
+ dumpint(uint64(off))
+ }
+ } else if stkmap.n > 0 {
+ // Locals bitmap information, scan just the pointers in
+ // locals.
+ dumpbv(&bv, s.varp-uintptr(bv.n)*goarch.PtrSize-s.sp)
+ }
+ dumpint(fieldKindEol)
+
+ // Record arg info for parent.
+ child.argoff = s.argp - s.fp
+ child.arglen = s.arglen
+ child.sp = (*uint8)(unsafe.Pointer(s.sp))
+ child.depth++
+ stkmap = (*stackmap)(funcdata(f, _FUNCDATA_ArgsPointerMaps))
+ if stkmap != nil {
+ child.args = stackmapdata(stkmap, pcdata)
+ } else {
+ child.args.n = -1
+ }
+ return true
+}
+
+func dumpgoroutine(gp *g) {
+ var sp, pc, lr uintptr
+ if gp.syscallsp != 0 {
+ sp = gp.syscallsp
+ pc = gp.syscallpc
+ lr = 0
+ } else {
+ sp = gp.sched.sp
+ pc = gp.sched.pc
+ lr = gp.sched.lr
+ }
+
+ dumpint(tagGoroutine)
+ dumpint(uint64(uintptr(unsafe.Pointer(gp))))
+ dumpint(uint64(sp))
+ dumpint(uint64(gp.goid))
+ dumpint(uint64(gp.gopc))
+ dumpint(uint64(readgstatus(gp)))
+ dumpbool(isSystemGoroutine(gp, false))
+ dumpbool(false) // isbackground
+ dumpint(uint64(gp.waitsince))
+ dumpstr(gp.waitreason.String())
+ dumpint(uint64(uintptr(gp.sched.ctxt)))
+ dumpint(uint64(uintptr(unsafe.Pointer(gp.m))))
+ dumpint(uint64(uintptr(unsafe.Pointer(gp._defer))))
+ dumpint(uint64(uintptr(unsafe.Pointer(gp._panic))))
+
+ // dump stack
+ var child childInfo
+ child.args.n = -1
+ child.arglen = 0
+ child.sp = nil
+ child.depth = 0
+ gentraceback(pc, sp, lr, gp, 0, nil, 0x7fffffff, dumpframe, noescape(unsafe.Pointer(&child)), 0)
+
+ // dump defer & panic records
+ for d := gp._defer; d != nil; d = d.link {
+ dumpint(tagDefer)
+ dumpint(uint64(uintptr(unsafe.Pointer(d))))
+ dumpint(uint64(uintptr(unsafe.Pointer(gp))))
+ dumpint(uint64(d.sp))
+ dumpint(uint64(d.pc))
+ fn := *(**funcval)(unsafe.Pointer(&d.fn))
+ dumpint(uint64(uintptr(unsafe.Pointer(fn))))
+ if d.fn == nil {
+ // d.fn can be nil for open-coded defers
+ dumpint(uint64(0))
+ } else {
+ dumpint(uint64(uintptr(unsafe.Pointer(fn.fn))))
+ }
+ dumpint(uint64(uintptr(unsafe.Pointer(d.link))))
+ }
+ for p := gp._panic; p != nil; p = p.link {
+ dumpint(tagPanic)
+ dumpint(uint64(uintptr(unsafe.Pointer(p))))
+ dumpint(uint64(uintptr(unsafe.Pointer(gp))))
+ eface := efaceOf(&p.arg)
+ dumpint(uint64(uintptr(unsafe.Pointer(eface._type))))
+ dumpint(uint64(uintptr(unsafe.Pointer(eface.data))))
+ dumpint(0) // was p->defer, no longer recorded
+ dumpint(uint64(uintptr(unsafe.Pointer(p.link))))
+ }
+}
+
+func dumpgs() {
+ assertWorldStopped()
+
+ // goroutines & stacks
+ forEachG(func(gp *g) {
+ status := readgstatus(gp) // The world is stopped so gp will not be in a scan state.
+ switch status {
+ default:
+ print("runtime: unexpected G.status ", hex(status), "\n")
+ throw("dumpgs in STW - bad status")
+ case _Gdead:
+ // ok
+ case _Grunnable,
+ _Gsyscall,
+ _Gwaiting:
+ dumpgoroutine(gp)
+ }
+ })
+}
+
+func finq_callback(fn *funcval, obj unsafe.Pointer, nret uintptr, fint *_type, ot *ptrtype) {
+ dumpint(tagQueuedFinalizer)
+ dumpint(uint64(uintptr(obj)))
+ dumpint(uint64(uintptr(unsafe.Pointer(fn))))
+ dumpint(uint64(uintptr(unsafe.Pointer(fn.fn))))
+ dumpint(uint64(uintptr(unsafe.Pointer(fint))))
+ dumpint(uint64(uintptr(unsafe.Pointer(ot))))
+}
+
+func dumproots() {
+ // To protect mheap_.allspans.
+ assertWorldStopped()
+
+ // TODO(mwhudson): dump datamask etc from all objects
+ // data segment
+ dumpint(tagData)
+ dumpint(uint64(firstmoduledata.data))
+ dumpmemrange(unsafe.Pointer(firstmoduledata.data), firstmoduledata.edata-firstmoduledata.data)
+ dumpfields(firstmoduledata.gcdatamask)
+
+ // bss segment
+ dumpint(tagBSS)
+ dumpint(uint64(firstmoduledata.bss))
+ dumpmemrange(unsafe.Pointer(firstmoduledata.bss), firstmoduledata.ebss-firstmoduledata.bss)
+ dumpfields(firstmoduledata.gcbssmask)
+
+ // mspan.types
+ for _, s := range mheap_.allspans {
+ if s.state.get() == mSpanInUse {
+ // Finalizers
+ for sp := s.specials; sp != nil; sp = sp.next {
+ if sp.kind != _KindSpecialFinalizer {
+ continue
+ }
+ spf := (*specialfinalizer)(unsafe.Pointer(sp))
+ p := unsafe.Pointer(s.base() + uintptr(spf.special.offset))
+ dumpfinalizer(p, spf.fn, spf.fint, spf.ot)
+ }
+ }
+ }
+
+ // Finalizer queue
+ iterate_finq(finq_callback)
+}
+
+// Bit vector of free marks.
+// Needs to be as big as the largest number of objects per span.
+var freemark [_PageSize / 8]bool
+
+func dumpobjs() {
+ // To protect mheap_.allspans.
+ assertWorldStopped()
+
+ for _, s := range mheap_.allspans {
+ if s.state.get() != mSpanInUse {
+ continue
+ }
+ p := s.base()
+ size := s.elemsize
+ n := (s.npages << _PageShift) / size
+ if n > uintptr(len(freemark)) {
+ throw("freemark array doesn't have enough entries")
+ }
+
+ for freeIndex := uintptr(0); freeIndex < s.nelems; freeIndex++ {
+ if s.isFree(freeIndex) {
+ freemark[freeIndex] = true
+ }
+ }
+
+ for j := uintptr(0); j < n; j, p = j+1, p+size {
+ if freemark[j] {
+ freemark[j] = false
+ continue
+ }
+ dumpobj(unsafe.Pointer(p), size, makeheapobjbv(p, size))
+ }
+ }
+}
+
+func dumpparams() {
+ dumpint(tagParams)
+ x := uintptr(1)
+ if *(*byte)(unsafe.Pointer(&x)) == 1 {
+ dumpbool(false) // little-endian ptrs
+ } else {
+ dumpbool(true) // big-endian ptrs
+ }
+ dumpint(goarch.PtrSize)
+ var arenaStart, arenaEnd uintptr
+ for i1 := range mheap_.arenas {
+ if mheap_.arenas[i1] == nil {
+ continue
+ }
+ for i, ha := range mheap_.arenas[i1] {
+ if ha == nil {
+ continue
+ }
+ base := arenaBase(arenaIdx(i1)<<arenaL1Shift | arenaIdx(i))
+ if arenaStart == 0 || base < arenaStart {
+ arenaStart = base
+ }
+ if base+heapArenaBytes > arenaEnd {
+ arenaEnd = base + heapArenaBytes
+ }
+ }
+ }
+ dumpint(uint64(arenaStart))
+ dumpint(uint64(arenaEnd))
+ dumpstr(goarch.GOARCH)
+ dumpstr(buildVersion)
+ dumpint(uint64(ncpu))
+}
+
+func itab_callback(tab *itab) {
+ t := tab._type
+ dumptype(t)
+ dumpint(tagItab)
+ dumpint(uint64(uintptr(unsafe.Pointer(tab))))
+ dumpint(uint64(uintptr(unsafe.Pointer(t))))
+}
+
+func dumpitabs() {
+ iterate_itabs(itab_callback)
+}
+
+func dumpms() {
+ for mp := allm; mp != nil; mp = mp.alllink {
+ dumpint(tagOSThread)
+ dumpint(uint64(uintptr(unsafe.Pointer(mp))))
+ dumpint(uint64(mp.id))
+ dumpint(mp.procid)
+ }
+}
+
+//go:systemstack
+func dumpmemstats(m *MemStats) {
+ assertWorldStopped()
+
+ // These ints should be identical to the exported
+ // MemStats structure and should be ordered the same
+ // way too.
+ dumpint(tagMemStats)
+ dumpint(m.Alloc)
+ dumpint(m.TotalAlloc)
+ dumpint(m.Sys)
+ dumpint(m.Lookups)
+ dumpint(m.Mallocs)
+ dumpint(m.Frees)
+ dumpint(m.HeapAlloc)
+ dumpint(m.HeapSys)
+ dumpint(m.HeapIdle)
+ dumpint(m.HeapInuse)
+ dumpint(m.HeapReleased)
+ dumpint(m.HeapObjects)
+ dumpint(m.StackInuse)
+ dumpint(m.StackSys)
+ dumpint(m.MSpanInuse)
+ dumpint(m.MSpanSys)
+ dumpint(m.MCacheInuse)
+ dumpint(m.MCacheSys)
+ dumpint(m.BuckHashSys)
+ dumpint(m.GCSys)
+ dumpint(m.OtherSys)
+ dumpint(m.NextGC)
+ dumpint(m.LastGC)
+ dumpint(m.PauseTotalNs)
+ for i := 0; i < 256; i++ {
+ dumpint(m.PauseNs[i])
+ }
+ dumpint(uint64(m.NumGC))
+}
+
+func dumpmemprof_callback(b *bucket, nstk uintptr, pstk *uintptr, size, allocs, frees uintptr) {
+ stk := (*[100000]uintptr)(unsafe.Pointer(pstk))
+ dumpint(tagMemProf)
+ dumpint(uint64(uintptr(unsafe.Pointer(b))))
+ dumpint(uint64(size))
+ dumpint(uint64(nstk))
+ for i := uintptr(0); i < nstk; i++ {
+ pc := stk[i]
+ f := findfunc(pc)
+ if !f.valid() {
+ var buf [64]byte
+ n := len(buf)
+ n--
+ buf[n] = ')'
+ if pc == 0 {
+ n--
+ buf[n] = '0'
+ } else {
+ for pc > 0 {
+ n--
+ buf[n] = "0123456789abcdef"[pc&15]
+ pc >>= 4
+ }
+ }
+ n--
+ buf[n] = 'x'
+ n--
+ buf[n] = '0'
+ n--
+ buf[n] = '('
+ dumpslice(buf[n:])
+ dumpstr("?")
+ dumpint(0)
+ } else {
+ dumpstr(funcname(f))
+ if i > 0 && pc > f.entry() {
+ pc--
+ }
+ file, line := funcline(f, pc)
+ dumpstr(file)
+ dumpint(uint64(line))
+ }
+ }
+ dumpint(uint64(allocs))
+ dumpint(uint64(frees))
+}
+
+func dumpmemprof() {
+ // To protect mheap_.allspans.
+ assertWorldStopped()
+
+ iterate_memprof(dumpmemprof_callback)
+ for _, s := range mheap_.allspans {
+ if s.state.get() != mSpanInUse {
+ continue
+ }
+ for sp := s.specials; sp != nil; sp = sp.next {
+ if sp.kind != _KindSpecialProfile {
+ continue
+ }
+ spp := (*specialprofile)(unsafe.Pointer(sp))
+ p := s.base() + uintptr(spp.special.offset)
+ dumpint(tagAllocSample)
+ dumpint(uint64(p))
+ dumpint(uint64(uintptr(unsafe.Pointer(spp.b))))
+ }
+ }
+}
+
+var dumphdr = []byte("go1.7 heap dump\n")
+
+func mdump(m *MemStats) {
+ assertWorldStopped()
+
+ // make sure we're done sweeping
+ for _, s := range mheap_.allspans {
+ if s.state.get() == mSpanInUse {
+ s.ensureSwept()
+ }
+ }
+ memclrNoHeapPointers(unsafe.Pointer(&typecache), unsafe.Sizeof(typecache))
+ dwrite(unsafe.Pointer(&dumphdr[0]), uintptr(len(dumphdr)))
+ dumpparams()
+ dumpitabs()
+ dumpobjs()
+ dumpgs()
+ dumpms()
+ dumproots()
+ dumpmemstats(m)
+ dumpmemprof()
+ dumpint(tagEOF)
+ flush()
+}
+
+func writeheapdump_m(fd uintptr, m *MemStats) {
+ assertWorldStopped()
+
+ _g_ := getg()
+ casgstatus(_g_.m.curg, _Grunning, _Gwaiting)
+ _g_.waitreason = waitReasonDumpingHeap
+
+ // Set dump file.
+ dumpfd = fd
+
+ // Call dump routine.
+ mdump(m)
+
+ // Reset dump file.
+ dumpfd = 0
+ if tmpbuf != nil {
+ sysFree(unsafe.Pointer(&tmpbuf[0]), uintptr(len(tmpbuf)), &memstats.other_sys)
+ tmpbuf = nil
+ }
+
+ casgstatus(_g_.m.curg, _Gwaiting, _Grunning)
+}
+
+// dumpint() the kind & offset of each field in an object.
+func dumpfields(bv bitvector) {
+ dumpbv(&bv, 0)
+ dumpint(fieldKindEol)
+}
+
+func makeheapobjbv(p uintptr, size uintptr) bitvector {
+ // Extend the temp buffer if necessary.
+ nptr := size / goarch.PtrSize
+ if uintptr(len(tmpbuf)) < nptr/8+1 {
+ if tmpbuf != nil {
+ sysFree(unsafe.Pointer(&tmpbuf[0]), uintptr(len(tmpbuf)), &memstats.other_sys)
+ }
+ n := nptr/8 + 1
+ p := sysAlloc(n, &memstats.other_sys)
+ if p == nil {
+ throw("heapdump: out of memory")
+ }
+ tmpbuf = (*[1 << 30]byte)(p)[:n]
+ }
+ // Convert heap bitmap to pointer bitmap.
+ for i := uintptr(0); i < nptr/8+1; i++ {
+ tmpbuf[i] = 0
+ }
+ i := uintptr(0)
+ hbits := heapBitsForAddr(p)
+ for ; i < nptr; i++ {
+ if !hbits.morePointers() {
+ break // end of object
+ }
+ if hbits.isPointer() {
+ tmpbuf[i/8] |= 1 << (i % 8)
+ }
+ hbits = hbits.next()
+ }
+ return bitvector{int32(i), &tmpbuf[0]}
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-19 11:21:41 +0000