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// Copyright 2010 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.
// Export guts for testing.
package runtime
import (
"internal/goarch"
"internal/goos"
"runtime/internal/atomic"
"runtime/internal/sys"
"unsafe"
)
var Fadd64 = fadd64
var Fsub64 = fsub64
var Fmul64 = fmul64
var Fdiv64 = fdiv64
var F64to32 = f64to32
var F32to64 = f32to64
var Fcmp64 = fcmp64
var Fintto64 = fintto64
var F64toint = f64toint
var Entersyscall = entersyscall
var Exitsyscall = exitsyscall
var LockedOSThread = lockedOSThread
var Xadduintptr = atomic.Xadduintptr
var Fastlog2 = fastlog2
var Atoi = atoi
var Atoi32 = atoi32
var ParseByteCount = parseByteCount
var Nanotime = nanotime
var NetpollBreak = netpollBreak
var Usleep = usleep
var PhysPageSize = physPageSize
var PhysHugePageSize = physHugePageSize
var NetpollGenericInit = netpollGenericInit
var Memmove = memmove
var MemclrNoHeapPointers = memclrNoHeapPointers
var LockPartialOrder = lockPartialOrder
type LockRank lockRank
func (l LockRank) String() string {
return lockRank(l).String()
}
const PreemptMSupported = preemptMSupported
type LFNode struct {
Next uint64
Pushcnt uintptr
}
func LFStackPush(head *uint64, node *LFNode) {
(*lfstack)(head).push((*lfnode)(unsafe.Pointer(node)))
}
func LFStackPop(head *uint64) *LFNode {
return (*LFNode)(unsafe.Pointer((*lfstack)(head).pop()))
}
func LFNodeValidate(node *LFNode) {
lfnodeValidate((*lfnode)(unsafe.Pointer(node)))
}
func Netpoll(delta int64) {
systemstack(func() {
netpoll(delta)
})
}
func GCMask(x any) (ret []byte) {
systemstack(func() {
ret = getgcmask(x)
})
return
}
func RunSchedLocalQueueTest() {
pp := new(p)
gs := make([]g, len(pp.runq))
Escape(gs) // Ensure gs doesn't move, since we use guintptrs
for i := 0; i < len(pp.runq); i++ {
if g, _ := runqget(pp); g != nil {
throw("runq is not empty initially")
}
for j := 0; j < i; j++ {
runqput(pp, &gs[i], false)
}
for j := 0; j < i; j++ {
if g, _ := runqget(pp); g != &gs[i] {
print("bad element at iter ", i, "/", j, "\n")
throw("bad element")
}
}
if g, _ := runqget(pp); g != nil {
throw("runq is not empty afterwards")
}
}
}
func RunSchedLocalQueueStealTest() {
p1 := new(p)
p2 := new(p)
gs := make([]g, len(p1.runq))
Escape(gs) // Ensure gs doesn't move, since we use guintptrs
for i := 0; i < len(p1.runq); i++ {
for j := 0; j < i; j++ {
gs[j].sig = 0
runqput(p1, &gs[j], false)
}
gp := runqsteal(p2, p1, true)
s := 0
if gp != nil {
s++
gp.sig++
}
for {
gp, _ = runqget(p2)
if gp == nil {
break
}
s++
gp.sig++
}
for {
gp, _ = runqget(p1)
if gp == nil {
break
}
gp.sig++
}
for j := 0; j < i; j++ {
if gs[j].sig != 1 {
print("bad element ", j, "(", gs[j].sig, ") at iter ", i, "\n")
throw("bad element")
}
}
if s != i/2 && s != i/2+1 {
print("bad steal ", s, ", want ", i/2, " or ", i/2+1, ", iter ", i, "\n")
throw("bad steal")
}
}
}
func RunSchedLocalQueueEmptyTest(iters int) {
// Test that runq is not spuriously reported as empty.
// Runq emptiness affects scheduling decisions and spurious emptiness
// can lead to underutilization (both runnable Gs and idle Ps coexist
// for arbitrary long time).
done := make(chan bool, 1)
p := new(p)
gs := make([]g, 2)
Escape(gs) // Ensure gs doesn't move, since we use guintptrs
ready := new(uint32)
for i := 0; i < iters; i++ {
*ready = 0
next0 := (i & 1) == 0
next1 := (i & 2) == 0
runqput(p, &gs[0], next0)
go func() {
for atomic.Xadd(ready, 1); atomic.Load(ready) != 2; {
}
if runqempty(p) {
println("next:", next0, next1)
throw("queue is empty")
}
done <- true
}()
for atomic.Xadd(ready, 1); atomic.Load(ready) != 2; {
}
runqput(p, &gs[1], next1)
runqget(p)
<-done
runqget(p)
}
}
var (
StringHash = stringHash
BytesHash = bytesHash
Int32Hash = int32Hash
Int64Hash = int64Hash
MemHash = memhash
MemHash32 = memhash32
MemHash64 = memhash64
EfaceHash = efaceHash
IfaceHash = ifaceHash
)
var UseAeshash = &useAeshash
func MemclrBytes(b []byte) {
s := (*slice)(unsafe.Pointer(&b))
memclrNoHeapPointers(s.array, uintptr(s.len))
}
const HashLoad = hashLoad
// entry point for testing
func GostringW(w []uint16) (s string) {
systemstack(func() {
s = gostringw(&w[0])
})
return
}
var Open = open
var Close = closefd
var Read = read
var Write = write
func Envs() []string { return envs }
func SetEnvs(e []string) { envs = e }
// For benchmarking.
func BenchSetType(n int, x any) {
e := *efaceOf(&x)
t := e._type
var size uintptr
var p unsafe.Pointer
switch t.kind & kindMask {
case kindPtr:
t = (*ptrtype)(unsafe.Pointer(t)).elem
size = t.size
p = e.data
case kindSlice:
slice := *(*struct {
ptr unsafe.Pointer
len, cap uintptr
})(e.data)
t = (*slicetype)(unsafe.Pointer(t)).elem
size = t.size * slice.len
p = slice.ptr
}
allocSize := roundupsize(size)
systemstack(func() {
for i := 0; i < n; i++ {
heapBitsSetType(uintptr(p), allocSize, size, t)
}
})
}
const PtrSize = goarch.PtrSize
var ForceGCPeriod = &forcegcperiod
// SetTracebackEnv is like runtime/debug.SetTraceback, but it raises
// the "environment" traceback level, so later calls to
// debug.SetTraceback (e.g., from testing timeouts) can't lower it.
func SetTracebackEnv(level string) {
setTraceback(level)
traceback_env = traceback_cache
}
var ReadUnaligned32 = readUnaligned32
var ReadUnaligned64 = readUnaligned64
func CountPagesInUse() (pagesInUse, counted uintptr) {
stopTheWorld("CountPagesInUse")
pagesInUse = uintptr(mheap_.pagesInUse.Load())
for _, s := range mheap_.allspans {
if s.state.get() == mSpanInUse {
counted += s.npages
}
}
startTheWorld()
return
}
func Fastrand() uint32 { return fastrand() }
func Fastrand64() uint64 { return fastrand64() }
func Fastrandn(n uint32) uint32 { return fastrandn(n) }
type ProfBuf profBuf
func NewProfBuf(hdrsize, bufwords, tags int) *ProfBuf {
return (*ProfBuf)(newProfBuf(hdrsize, bufwords, tags))
}
func (p *ProfBuf) Write(tag *unsafe.Pointer, now int64, hdr []uint64, stk []uintptr) {
(*profBuf)(p).write(tag, now, hdr, stk)
}
const (
ProfBufBlocking = profBufBlocking
ProfBufNonBlocking = profBufNonBlocking
)
func (p *ProfBuf) Read(mode profBufReadMode) ([]uint64, []unsafe.Pointer, bool) {
return (*profBuf)(p).read(profBufReadMode(mode))
}
func (p *ProfBuf) Close() {
(*profBuf)(p).close()
}
func ReadMetricsSlow(memStats *MemStats, samplesp unsafe.Pointer, len, cap int) {
stopTheWorld("ReadMetricsSlow")
// Initialize the metrics beforehand because this could
// allocate and skew the stats.
metricsLock()
initMetrics()
metricsUnlock()
systemstack(func() {
// Read memstats first. It's going to flush
// the mcaches which readMetrics does not do, so
// going the other way around may result in
// inconsistent statistics.
readmemstats_m(memStats)
})
// Read metrics off the system stack.
//
// The only part of readMetrics that could allocate
// and skew the stats is initMetrics.
readMetrics(samplesp, len, cap)
startTheWorld()
}
// ReadMemStatsSlow returns both the runtime-computed MemStats and
// MemStats accumulated by scanning the heap.
func ReadMemStatsSlow() (base, slow MemStats) {
stopTheWorld("ReadMemStatsSlow")
// Run on the system stack to avoid stack growth allocation.
systemstack(func() {
// Make sure stats don't change.
getg().m.mallocing++
readmemstats_m(&base)
// Initialize slow from base and zero the fields we're
// recomputing.
slow = base
slow.Alloc = 0
slow.TotalAlloc = 0
slow.Mallocs = 0
slow.Frees = 0
slow.HeapReleased = 0
var bySize [_NumSizeClasses]struct {
Mallocs, Frees uint64
}
// Add up current allocations in spans.
for _, s := range mheap_.allspans {
if s.state.get() != mSpanInUse {
continue
}
if s.isUnusedUserArenaChunk() {
continue
}
if sizeclass := s.spanclass.sizeclass(); sizeclass == 0 {
slow.Mallocs++
slow.Alloc += uint64(s.elemsize)
} else {
slow.Mallocs += uint64(s.allocCount)
slow.Alloc += uint64(s.allocCount) * uint64(s.elemsize)
bySize[sizeclass].Mallocs += uint64(s.allocCount)
}
}
// Add in frees by just reading the stats for those directly.
var m heapStatsDelta
memstats.heapStats.unsafeRead(&m)
// Collect per-sizeclass free stats.
var smallFree uint64
for i := 0; i < _NumSizeClasses; i++ {
slow.Frees += uint64(m.smallFreeCount[i])
bySize[i].Frees += uint64(m.smallFreeCount[i])
bySize[i].Mallocs += uint64(m.smallFreeCount[i])
smallFree += uint64(m.smallFreeCount[i]) * uint64(class_to_size[i])
}
slow.Frees += uint64(m.tinyAllocCount) + uint64(m.largeFreeCount)
slow.Mallocs += slow.Frees
slow.TotalAlloc = slow.Alloc + uint64(m.largeFree) + smallFree
for i := range slow.BySize {
slow.BySize[i].Mallocs = bySize[i].Mallocs
slow.BySize[i].Frees = bySize[i].Frees
}
for i := mheap_.pages.start; i < mheap_.pages.end; i++ {
chunk := mheap_.pages.tryChunkOf(i)
if chunk == nil {
continue
}
pg := chunk.scavenged.popcntRange(0, pallocChunkPages)
slow.HeapReleased += uint64(pg) * pageSize
}
for _, p := range allp {
pg := sys.OnesCount64(p.pcache.scav)
slow.HeapReleased += uint64(pg) * pageSize
}
getg().m.mallocing--
})
startTheWorld()
return
}
// BlockOnSystemStack switches to the system stack, prints "x\n" to
// stderr, and blocks in a stack containing
// "runtime.blockOnSystemStackInternal".
func BlockOnSystemStack() {
systemstack(blockOnSystemStackInternal)
}
func blockOnSystemStackInternal() {
print("x\n")
lock(&deadlock)
lock(&deadlock)
}
type RWMutex struct {
rw rwmutex
}
func (rw *RWMutex) RLock() {
rw.rw.rlock()
}
func (rw *RWMutex) RUnlock() {
rw.rw.runlock()
}
func (rw *RWMutex) Lock() {
rw.rw.lock()
}
func (rw *RWMutex) Unlock() {
rw.rw.unlock()
}
const RuntimeHmapSize = unsafe.Sizeof(hmap{})
func MapBucketsCount(m map[int]int) int {
h := *(**hmap)(unsafe.Pointer(&m))
return 1 << h.B
}
func MapBucketsPointerIsNil(m map[int]int) bool {
h := *(**hmap)(unsafe.Pointer(&m))
return h.buckets == nil
}
func LockOSCounts() (external, internal uint32) {
gp := getg()
if gp.m.lockedExt+gp.m.lockedInt == 0 {
if gp.lockedm != 0 {
panic("lockedm on non-locked goroutine")
}
} else {
if gp.lockedm == 0 {
panic("nil lockedm on locked goroutine")
}
}
return gp.m.lockedExt, gp.m.lockedInt
}
//go:noinline
func TracebackSystemstack(stk []uintptr, i int) int {
if i == 0 {
pc, sp := getcallerpc(), getcallersp()
return gentraceback(pc, sp, 0, getg(), 0, &stk[0], len(stk), nil, nil, _TraceJumpStack)
}
n := 0
systemstack(func() {
n = TracebackSystemstack(stk, i-1)
})
return n
}
func KeepNArenaHints(n int) {
hint := mheap_.arenaHints
for i := 1; i < n; i++ {
hint = hint.next
if hint == nil {
return
}
}
hint.next = nil
}
// MapNextArenaHint reserves a page at the next arena growth hint,
// preventing the arena from growing there, and returns the range of
// addresses that are no longer viable.
//
// This may fail to reserve memory. If it fails, it still returns the
// address range it attempted to reserve.
func MapNextArenaHint() (start, end uintptr, ok bool) {
hint := mheap_.arenaHints
addr := hint.addr
if hint.down {
start, end = addr-heapArenaBytes, addr
addr -= physPageSize
} else {
start, end = addr, addr+heapArenaBytes
}
got := sysReserve(unsafe.Pointer(addr), physPageSize)
ok = (addr == uintptr(got))
if !ok {
// We were unable to get the requested reservation.
// Release what we did get and fail.
sysFreeOS(got, physPageSize)
}
return
}
func GetNextArenaHint() uintptr {
return mheap_.arenaHints.addr
}
type G = g
type Sudog = sudog
func Getg() *G {
return getg()
}
func GIsWaitingOnMutex(gp *G) bool {
return readgstatus(gp) == _Gwaiting && gp.waitreason.isMutexWait()
}
var CasGStatusAlwaysTrack = &casgstatusAlwaysTrack
//go:noinline
func PanicForTesting(b []byte, i int) byte {
return unexportedPanicForTesting(b, i)
}
//go:noinline
func unexportedPanicForTesting(b []byte, i int) byte {
return b[i]
}
func G0StackOverflow() {
systemstack(func() {
stackOverflow(nil)
})
}
func stackOverflow(x *byte) {
var buf [256]byte
stackOverflow(&buf[0])
}
func MapTombstoneCheck(m map[int]int) {
// Make sure emptyOne and emptyRest are distributed correctly.
// We should have a series of filled and emptyOne cells, followed by
// a series of emptyRest cells.
h := *(**hmap)(unsafe.Pointer(&m))
i := any(m)
t := *(**maptype)(unsafe.Pointer(&i))
for x := 0; x < 1<<h.B; x++ {
b0 := (*bmap)(add(h.buckets, uintptr(x)*uintptr(t.bucketsize)))
n := 0
for b := b0; b != nil; b = b.overflow(t) {
for i := 0; i < bucketCnt; i++ {
if b.tophash[i] != emptyRest {
n++
}
}
}
k := 0
for b := b0; b != nil; b = b.overflow(t) {
for i := 0; i < bucketCnt; i++ {
if k < n && b.tophash[i] == emptyRest {
panic("early emptyRest")
}
if k >= n && b.tophash[i] != emptyRest {
panic("late non-emptyRest")
}
if k == n-1 && b.tophash[i] == emptyOne {
panic("last non-emptyRest entry is emptyOne")
}
k++
}
}
}
}
func RunGetgThreadSwitchTest() {
// Test that getg works correctly with thread switch.
// With gccgo, if we generate getg inlined, the backend
// may cache the address of the TLS variable, which
// will become invalid after a thread switch. This test
// checks that the bad caching doesn't happen.
ch := make(chan int)
go func(ch chan int) {
ch <- 5
LockOSThread()
}(ch)
g1 := getg()
// Block on a receive. This is likely to get us a thread
// switch. If we yield to the sender goroutine, it will
// lock the thread, forcing us to resume on a different
// thread.
<-ch
g2 := getg()
if g1 != g2 {
panic("g1 != g2")
}
// Also test getg after some control flow, as the
// backend is sensitive to control flow.
g3 := getg()
if g1 != g3 {
panic("g1 != g3")
}
}
const (
PageSize = pageSize
PallocChunkPages = pallocChunkPages
PageAlloc64Bit = pageAlloc64Bit
PallocSumBytes = pallocSumBytes
)
// Expose pallocSum for testing.
type PallocSum pallocSum
func PackPallocSum(start, max, end uint) PallocSum { return PallocSum(packPallocSum(start, max, end)) }
func (m PallocSum) Start() uint { return pallocSum(m).start() }
func (m PallocSum) Max() uint { return pallocSum(m).max() }
func (m PallocSum) End() uint { return pallocSum(m).end() }
// Expose pallocBits for testing.
type PallocBits pallocBits
func (b *PallocBits) Find(npages uintptr, searchIdx uint) (uint, uint) {
return (*pallocBits)(b).find(npages, searchIdx)
}
func (b *PallocBits) AllocRange(i, n uint) { (*pallocBits)(b).allocRange(i, n) }
func (b *PallocBits) Free(i, n uint) { (*pallocBits)(b).free(i, n) }
func (b *PallocBits) Summarize() PallocSum { return PallocSum((*pallocBits)(b).summarize()) }
func (b *PallocBits) PopcntRange(i, n uint) uint { return (*pageBits)(b).popcntRange(i, n) }
// SummarizeSlow is a slow but more obviously correct implementation
// of (*pallocBits).summarize. Used for testing.
func SummarizeSlow(b *PallocBits) PallocSum {
var start, max, end uint
const N = uint(len(b)) * 64
for start < N && (*pageBits)(b).get(start) == 0 {
start++
}
for end < N && (*pageBits)(b).get(N-end-1) == 0 {
end++
}
run := uint(0)
for i := uint(0); i < N; i++ {
if (*pageBits)(b).get(i) == 0 {
run++
} else {
run = 0
}
if run > max {
max = run
}
}
return PackPallocSum(start, max, end)
}
// Expose non-trivial helpers for testing.
func FindBitRange64(c uint64, n uint) uint { return findBitRange64(c, n) }
// Given two PallocBits, returns a set of bit ranges where
// they differ.
func DiffPallocBits(a, b *PallocBits) []BitRange {
ba := (*pageBits)(a)
bb := (*pageBits)(b)
var d []BitRange
base, size := uint(0), uint(0)
for i := uint(0); i < uint(len(ba))*64; i++ {
if ba.get(i) != bb.get(i) {
if size == 0 {
base = i
}
size++
} else {
if size != 0 {
d = append(d, BitRange{base, size})
}
size = 0
}
}
if size != 0 {
d = append(d, BitRange{base, size})
}
return d
}
// StringifyPallocBits gets the bits in the bit range r from b,
// and returns a string containing the bits as ASCII 0 and 1
// characters.
func StringifyPallocBits(b *PallocBits, r BitRange) string {
str := ""
for j := r.I; j < r.I+r.N; j++ {
if (*pageBits)(b).get(j) != 0 {
str += "1"
} else {
str += "0"
}
}
return str
}
// Expose pallocData for testing.
type PallocData pallocData
func (d *PallocData) FindScavengeCandidate(searchIdx uint, min, max uintptr) (uint, uint) {
return (*pallocData)(d).findScavengeCandidate(searchIdx, min, max)
}
func (d *PallocData) AllocRange(i, n uint) { (*pallocData)(d).allocRange(i, n) }
func (d *PallocData) ScavengedSetRange(i, n uint) {
(*pallocData)(d).scavenged.setRange(i, n)
}
func (d *PallocData) PallocBits() *PallocBits {
return (*PallocBits)(&(*pallocData)(d).pallocBits)
}
func (d *PallocData) Scavenged() *PallocBits {
return (*PallocBits)(&(*pallocData)(d).scavenged)
}
// Expose fillAligned for testing.
func FillAligned(x uint64, m uint) uint64 { return fillAligned(x, m) }
// Expose pageCache for testing.
type PageCache pageCache
const PageCachePages = pageCachePages
func NewPageCache(base uintptr, cache, scav uint64) PageCache {
return PageCache(pageCache{base: base, cache: cache, scav: scav})
}
func (c *PageCache) Empty() bool { return (*pageCache)(c).empty() }
func (c *PageCache) Base() uintptr { return (*pageCache)(c).base }
func (c *PageCache) Cache() uint64 { return (*pageCache)(c).cache }
func (c *PageCache) Scav() uint64 { return (*pageCache)(c).scav }
func (c *PageCache) Alloc(npages uintptr) (uintptr, uintptr) {
return (*pageCache)(c).alloc(npages)
}
func (c *PageCache) Flush(s *PageAlloc) {
cp := (*pageCache)(c)
sp := (*pageAlloc)(s)
systemstack(func() {
// None of the tests need any higher-level locking, so we just
// take the lock internally.
lock(sp.mheapLock)
cp.flush(sp)
unlock(sp.mheapLock)
})
}
// Expose chunk index type.
type ChunkIdx chunkIdx
// Expose pageAlloc for testing. Note that because pageAlloc is
// not in the heap, so is PageAlloc.
type PageAlloc pageAlloc
func (p *PageAlloc) Alloc(npages uintptr) (uintptr, uintptr) {
pp := (*pageAlloc)(p)
var addr, scav uintptr
systemstack(func() {
// None of the tests need any higher-level locking, so we just
// take the lock internally.
lock(pp.mheapLock)
addr, scav = pp.alloc(npages)
unlock(pp.mheapLock)
})
return addr, scav
}
func (p *PageAlloc) AllocToCache() PageCache {
pp := (*pageAlloc)(p)
var c PageCache
systemstack(func() {
// None of the tests need any higher-level locking, so we just
// take the lock internally.
lock(pp.mheapLock)
c = PageCache(pp.allocToCache())
unlock(pp.mheapLock)
})
return c
}
func (p *PageAlloc) Free(base, npages uintptr) {
pp := (*pageAlloc)(p)
systemstack(func() {
// None of the tests need any higher-level locking, so we just
// take the lock internally.
lock(pp.mheapLock)
pp.free(base, npages, true)
unlock(pp.mheapLock)
})
}
func (p *PageAlloc) Bounds() (ChunkIdx, ChunkIdx) {
return ChunkIdx((*pageAlloc)(p).start), ChunkIdx((*pageAlloc)(p).end)
}
func (p *PageAlloc) Scavenge(nbytes uintptr) (r uintptr) {
pp := (*pageAlloc)(p)
systemstack(func() {
r = pp.scavenge(nbytes, nil)
})
return
}
func (p *PageAlloc) InUse() []AddrRange {
ranges := make([]AddrRange, 0, len(p.inUse.ranges))
for _, r := range p.inUse.ranges {
ranges = append(ranges, AddrRange{r})
}
return ranges
}
// Returns nil if the PallocData's L2 is missing.
func (p *PageAlloc) PallocData(i ChunkIdx) *PallocData {
ci := chunkIdx(i)
return (*PallocData)((*pageAlloc)(p).tryChunkOf(ci))
}
// AddrRange is a wrapper around addrRange for testing.
type AddrRange struct {
addrRange
}
// MakeAddrRange creates a new address range.
func MakeAddrRange(base, limit uintptr) AddrRange {
return AddrRange{makeAddrRange(base, limit)}
}
// Base returns the virtual base address of the address range.
func (a AddrRange) Base() uintptr {
return a.addrRange.base.addr()
}
// Base returns the virtual address of the limit of the address range.
func (a AddrRange) Limit() uintptr {
return a.addrRange.limit.addr()
}
// Equals returns true if the two address ranges are exactly equal.
func (a AddrRange) Equals(b AddrRange) bool {
return a == b
}
// Size returns the size in bytes of the address range.
func (a AddrRange) Size() uintptr {
return a.addrRange.size()
}
// testSysStat is the sysStat passed to test versions of various
// runtime structures. We do actually have to keep track of this
// because otherwise memstats.mappedReady won't actually line up
// with other stats in the runtime during tests.
var testSysStat = &memstats.other_sys
// AddrRanges is a wrapper around addrRanges for testing.
type AddrRanges struct {
addrRanges
mutable bool
}
// NewAddrRanges creates a new empty addrRanges.
//
// Note that this initializes addrRanges just like in the
// runtime, so its memory is persistentalloc'd. Call this
// function sparingly since the memory it allocates is
// leaked.
//
// This AddrRanges is mutable, so we can test methods like
// Add.
func NewAddrRanges() AddrRanges {
r := addrRanges{}
r.init(testSysStat)
return AddrRanges{r, true}
}
// MakeAddrRanges creates a new addrRanges populated with
// the ranges in a.
//
// The returned AddrRanges is immutable, so methods like
// Add will fail.
func MakeAddrRanges(a ...AddrRange) AddrRanges {
// Methods that manipulate the backing store of addrRanges.ranges should
// not be used on the result from this function (e.g. add) since they may
// trigger reallocation. That would normally be fine, except the new
// backing store won't come from the heap, but from persistentalloc, so
// we'll leak some memory implicitly.
ranges := make([]addrRange, 0, len(a))
total := uintptr(0)
for _, r := range a {
ranges = append(ranges, r.addrRange)
total += r.Size()
}
return AddrRanges{addrRanges{
ranges: ranges,
totalBytes: total,
sysStat: testSysStat,
}, false}
}
// Ranges returns a copy of the ranges described by the
// addrRanges.
func (a *AddrRanges) Ranges() []AddrRange {
result := make([]AddrRange, 0, len(a.addrRanges.ranges))
for _, r := range a.addrRanges.ranges {
result = append(result, AddrRange{r})
}
return result
}
// FindSucc returns the successor to base. See addrRanges.findSucc
// for more details.
func (a *AddrRanges) FindSucc(base uintptr) int {
return a.findSucc(base)
}
// Add adds a new AddrRange to the AddrRanges.
//
// The AddrRange must be mutable (i.e. created by NewAddrRanges),
// otherwise this method will throw.
func (a *AddrRanges) Add(r AddrRange) {
if !a.mutable {
throw("attempt to mutate immutable AddrRanges")
}
a.add(r.addrRange)
}
// TotalBytes returns the totalBytes field of the addrRanges.
func (a *AddrRanges) TotalBytes() uintptr {
return a.addrRanges.totalBytes
}
// BitRange represents a range over a bitmap.
type BitRange struct {
I, N uint // bit index and length in bits
}
// NewPageAlloc creates a new page allocator for testing and
// initializes it with the scav and chunks maps. Each key in these maps
// represents a chunk index and each value is a series of bit ranges to
// set within each bitmap's chunk.
//
// The initialization of the pageAlloc preserves the invariant that if a
// scavenged bit is set the alloc bit is necessarily unset, so some
// of the bits described by scav may be cleared in the final bitmap if
// ranges in chunks overlap with them.
//
// scav is optional, and if nil, the scavenged bitmap will be cleared
// (as opposed to all 1s, which it usually is). Furthermore, every
// chunk index in scav must appear in chunks; ones that do not are
// ignored.
func NewPageAlloc(chunks, scav map[ChunkIdx][]BitRange) *PageAlloc {
p := new(pageAlloc)
// We've got an entry, so initialize the pageAlloc.
p.init(new(mutex), testSysStat)
lockInit(p.mheapLock, lockRankMheap)
p.test = true
for i, init := range chunks {
addr := chunkBase(chunkIdx(i))
// Mark the chunk's existence in the pageAlloc.
systemstack(func() {
lock(p.mheapLock)
p.grow(addr, pallocChunkBytes)
unlock(p.mheapLock)
})
// Initialize the bitmap and update pageAlloc metadata.
chunk := p.chunkOf(chunkIndex(addr))
// Clear all the scavenged bits which grow set.
chunk.scavenged.clearRange(0, pallocChunkPages)
// Apply scavenge state if applicable.
if scav != nil {
if scvg, ok := scav[i]; ok {
for _, s := range scvg {
// Ignore the case of s.N == 0. setRange doesn't handle
// it and it's a no-op anyway.
if s.N != 0 {
chunk.scavenged.setRange(s.I, s.N)
}
}
}
}
// Apply alloc state.
for _, s := range init {
// Ignore the case of s.N == 0. allocRange doesn't handle
// it and it's a no-op anyway.
if s.N != 0 {
chunk.allocRange(s.I, s.N)
}
}
// Make sure the scavenge index is updated.
//
// This is an inefficient way to do it, but it's also the simplest way.
minPages := physPageSize / pageSize
if minPages < 1 {
minPages = 1
}
_, npages := chunk.findScavengeCandidate(pallocChunkPages-1, minPages, minPages)
if npages != 0 {
p.scav.index.mark(addr, addr+pallocChunkBytes)
}
// Update heap metadata for the allocRange calls above.
systemstack(func() {
lock(p.mheapLock)
p.update(addr, pallocChunkPages, false, false)
unlock(p.mheapLock)
})
}
return (*PageAlloc)(p)
}
// FreePageAlloc releases hard OS resources owned by the pageAlloc. Once this
// is called the pageAlloc may no longer be used. The object itself will be
// collected by the garbage collector once it is no longer live.
func FreePageAlloc(pp *PageAlloc) {
p := (*pageAlloc)(pp)
// Free all the mapped space for the summary levels.
if pageAlloc64Bit != 0 {
for l := 0; l < summaryLevels; l++ {
sysFreeOS(unsafe.Pointer(&p.summary[l][0]), uintptr(cap(p.summary[l]))*pallocSumBytes)
}
// Only necessary on 64-bit. This is a global on 32-bit.
sysFreeOS(unsafe.Pointer(&p.scav.index.chunks[0]), uintptr(cap(p.scav.index.chunks)))
} else {
resSize := uintptr(0)
for _, s := range p.summary {
resSize += uintptr(cap(s)) * pallocSumBytes
}
sysFreeOS(unsafe.Pointer(&p.summary[0][0]), alignUp(resSize, physPageSize))
}
// Subtract back out whatever we mapped for the summaries.
// sysUsed adds to p.sysStat and memstats.mappedReady no matter what
// (and in anger should actually be accounted for), and there's no other
// way to figure out how much we actually mapped.
gcController.mappedReady.Add(-int64(p.summaryMappedReady))
testSysStat.add(-int64(p.summaryMappedReady))
// Free the mapped space for chunks.
for i := range p.chunks {
if x := p.chunks[i]; x != nil {
p.chunks[i] = nil
// This memory comes from sysAlloc and will always be page-aligned.
sysFree(unsafe.Pointer(x), unsafe.Sizeof(*p.chunks[0]), testSysStat)
}
}
}
// BaseChunkIdx is a convenient chunkIdx value which works on both
// 64 bit and 32 bit platforms, allowing the tests to share code
// between the two.
//
// This should not be higher than 0x100*pallocChunkBytes to support
// mips and mipsle, which only have 31-bit address spaces.
var BaseChunkIdx = func() ChunkIdx {
var prefix uintptr
if pageAlloc64Bit != 0 {
prefix = 0xc000
} else {
prefix = 0x100
}
baseAddr := prefix * pallocChunkBytes
if goos.IsAix != 0 {
baseAddr += arenaBaseOffset
}
return ChunkIdx(chunkIndex(baseAddr))
}()
// PageBase returns an address given a chunk index and a page index
// relative to that chunk.
func PageBase(c ChunkIdx, pageIdx uint) uintptr {
return chunkBase(chunkIdx(c)) + uintptr(pageIdx)*pageSize
}
type BitsMismatch struct {
Base uintptr
Got, Want uint64
}
func CheckScavengedBitsCleared(mismatches []BitsMismatch) (n int, ok bool) {
ok = true
// Run on the system stack to avoid stack growth allocation.
systemstack(func() {
getg().m.mallocing++
// Lock so that we can safely access the bitmap.
lock(&mheap_.lock)
chunkLoop:
for i := mheap_.pages.start; i < mheap_.pages.end; i++ {
chunk := mheap_.pages.tryChunkOf(i)
if chunk == nil {
continue
}
for j := 0; j < pallocChunkPages/64; j++ {
// Run over each 64-bit bitmap section and ensure
// scavenged is being cleared properly on allocation.
// If a used bit and scavenged bit are both set, that's
// an error, and could indicate a larger problem, or
// an accounting problem.
want := chunk.scavenged[j] &^ chunk.pallocBits[j]
got := chunk.scavenged[j]
if want != got {
ok = false
if n >= len(mismatches) {
break chunkLoop
}
mismatches[n] = BitsMismatch{
Base: chunkBase(i) + uintptr(j)*64*pageSize,
Got: got,
Want: want,
}
n++
}
}
}
unlock(&mheap_.lock)
getg().m.mallocing--
})
return
}
func PageCachePagesLeaked() (leaked uintptr) {
stopTheWorld("PageCachePagesLeaked")
// Walk over destroyed Ps and look for unflushed caches.
deadp := allp[len(allp):cap(allp)]
for _, p := range deadp {
// Since we're going past len(allp) we may see nil Ps.
// Just ignore them.
if p != nil {
leaked += uintptr(sys.OnesCount64(p.pcache.cache))
}
}
startTheWorld()
return
}
var Semacquire = semacquire
var Semrelease1 = semrelease1
func SemNwait(addr *uint32) uint32 {
root := semtable.rootFor(addr)
return root.nwait.Load()
}
const SemTableSize = semTabSize
// SemTable is a wrapper around semTable exported for testing.
type SemTable struct {
semTable
}
// Enqueue simulates enqueuing a waiter for a semaphore (or lock) at addr.
func (t *SemTable) Enqueue(addr *uint32) {
s := acquireSudog()
s.releasetime = 0
s.acquiretime = 0
s.ticket = 0
t.semTable.rootFor(addr).queue(addr, s, false)
}
// Dequeue simulates dequeuing a waiter for a semaphore (or lock) at addr.
//
// Returns true if there actually was a waiter to be dequeued.
func (t *SemTable) Dequeue(addr *uint32) bool {
s, _ := t.semTable.rootFor(addr).dequeue(addr)
if s != nil {
releaseSudog(s)
return true
}
return false
}
// mspan wrapper for testing.
type MSpan mspan
// Allocate an mspan for testing.
func AllocMSpan() *MSpan {
var s *mspan
systemstack(func() {
lock(&mheap_.lock)
s = (*mspan)(mheap_.spanalloc.alloc())
unlock(&mheap_.lock)
})
return (*MSpan)(s)
}
// Free an allocated mspan.
func FreeMSpan(s *MSpan) {
systemstack(func() {
lock(&mheap_.lock)
mheap_.spanalloc.free(unsafe.Pointer(s))
unlock(&mheap_.lock)
})
}
func MSpanCountAlloc(ms *MSpan, bits []byte) int {
s := (*mspan)(ms)
s.nelems = uintptr(len(bits) * 8)
s.gcmarkBits = (*gcBits)(unsafe.Pointer(&bits[0]))
result := s.countAlloc()
s.gcmarkBits = nil
return result
}
const (
TimeHistSubBucketBits = timeHistSubBucketBits
TimeHistNumSubBuckets = timeHistNumSubBuckets
TimeHistNumBuckets = timeHistNumBuckets
TimeHistMinBucketBits = timeHistMinBucketBits
TimeHistMaxBucketBits = timeHistMaxBucketBits
)
type TimeHistogram timeHistogram
// Counts returns the counts for the given bucket, subBucket indices.
// Returns true if the bucket was valid, otherwise returns the counts
// for the overflow bucket if bucket > 0 or the underflow bucket if
// bucket < 0, and false.
func (th *TimeHistogram) Count(bucket, subBucket int) (uint64, bool) {
t := (*timeHistogram)(th)
if bucket < 0 {
return t.underflow.Load(), false
}
i := bucket*TimeHistNumSubBuckets + subBucket
if i >= len(t.counts) {
return t.overflow.Load(), false
}
return t.counts[i].Load(), true
}
func (th *TimeHistogram) Record(duration int64) {
(*timeHistogram)(th).record(duration)
}
var TimeHistogramMetricsBuckets = timeHistogramMetricsBuckets
func SetIntArgRegs(a int) int {
lock(&finlock)
old := intArgRegs
if a >= 0 {
intArgRegs = a
}
unlock(&finlock)
return old
}
func FinalizerGAsleep() bool {
return fingStatus.Load()&fingWait != 0
}
// For GCTestMoveStackOnNextCall, it's important not to introduce an
// extra layer of call, since then there's a return before the "real"
// next call.
var GCTestMoveStackOnNextCall = gcTestMoveStackOnNextCall
// For GCTestIsReachable, it's important that we do this as a call so
// escape analysis can see through it.
func GCTestIsReachable(ptrs ...unsafe.Pointer) (mask uint64) {
return gcTestIsReachable(ptrs...)
}
// For GCTestPointerClass, it's important that we do this as a call so
// escape analysis can see through it.
//
// This is nosplit because gcTestPointerClass is.
//
//go:nosplit
func GCTestPointerClass(p unsafe.Pointer) string {
return gcTestPointerClass(p)
}
const Raceenabled = raceenabled
const (
GCBackgroundUtilization = gcBackgroundUtilization
GCGoalUtilization = gcGoalUtilization
DefaultHeapMinimum = defaultHeapMinimum
MemoryLimitHeapGoalHeadroom = memoryLimitHeapGoalHeadroom
)
type GCController struct {
gcControllerState
}
func NewGCController(gcPercent int, memoryLimit int64) *GCController {
// Force the controller to escape. We're going to
// do 64-bit atomics on it, and if it gets stack-allocated
// on a 32-bit architecture, it may get allocated unaligned
// space.
g := Escape(new(GCController))
g.gcControllerState.test = true // Mark it as a test copy.
g.init(int32(gcPercent), memoryLimit)
return g
}
func (c *GCController) StartCycle(stackSize, globalsSize uint64, scannableFrac float64, gomaxprocs int) {
trigger, _ := c.trigger()
if c.heapMarked > trigger {
trigger = c.heapMarked
}
c.maxStackScan.Store(stackSize)
c.globalsScan.Store(globalsSize)
c.heapLive.Store(trigger)
c.heapScan.Add(int64(float64(trigger-c.heapMarked) * scannableFrac))
c.startCycle(0, gomaxprocs, gcTrigger{kind: gcTriggerHeap})
}
func (c *GCController) AssistWorkPerByte() float64 {
return c.assistWorkPerByte.Load()
}
func (c *GCController) HeapGoal() uint64 {
return c.heapGoal()
}
func (c *GCController) HeapLive() uint64 {
return c.heapLive.Load()
}
func (c *GCController) HeapMarked() uint64 {
return c.heapMarked
}
func (c *GCController) Triggered() uint64 {
return c.triggered
}
type GCControllerReviseDelta struct {
HeapLive int64
HeapScan int64
HeapScanWork int64
StackScanWork int64
GlobalsScanWork int64
}
func (c *GCController) Revise(d GCControllerReviseDelta) {
c.heapLive.Add(d.HeapLive)
c.heapScan.Add(d.HeapScan)
c.heapScanWork.Add(d.HeapScanWork)
c.stackScanWork.Add(d.StackScanWork)
c.globalsScanWork.Add(d.GlobalsScanWork)
c.revise()
}
func (c *GCController) EndCycle(bytesMarked uint64, assistTime, elapsed int64, gomaxprocs int) {
c.assistTime.Store(assistTime)
c.endCycle(elapsed, gomaxprocs, false)
c.resetLive(bytesMarked)
c.commit(false)
}
func (c *GCController) AddIdleMarkWorker() bool {
return c.addIdleMarkWorker()
}
func (c *GCController) NeedIdleMarkWorker() bool {
return c.needIdleMarkWorker()
}
func (c *GCController) RemoveIdleMarkWorker() {
c.removeIdleMarkWorker()
}
func (c *GCController) SetMaxIdleMarkWorkers(max int32) {
c.setMaxIdleMarkWorkers(max)
}
var alwaysFalse bool
var escapeSink any
func Escape[T any](x T) T {
if alwaysFalse {
escapeSink = x
}
return x
}
// Acquirem blocks preemption.
func Acquirem() {
acquirem()
}
func Releasem() {
releasem(getg().m)
}
var Timediv = timediv
type PIController struct {
piController
}
func NewPIController(kp, ti, tt, min, max float64) *PIController {
return &PIController{piController{
kp: kp,
ti: ti,
tt: tt,
min: min,
max: max,
}}
}
func (c *PIController) Next(input, setpoint, period float64) (float64, bool) {
return c.piController.next(input, setpoint, period)
}
const (
CapacityPerProc = capacityPerProc
GCCPULimiterUpdatePeriod = gcCPULimiterUpdatePeriod
)
type GCCPULimiter struct {
limiter gcCPULimiterState
}
func NewGCCPULimiter(now int64, gomaxprocs int32) *GCCPULimiter {
// Force the controller to escape. We're going to
// do 64-bit atomics on it, and if it gets stack-allocated
// on a 32-bit architecture, it may get allocated unaligned
// space.
l := Escape(new(GCCPULimiter))
l.limiter.test = true
l.limiter.resetCapacity(now, gomaxprocs)
return l
}
func (l *GCCPULimiter) Fill() uint64 {
return l.limiter.bucket.fill
}
func (l *GCCPULimiter) Capacity() uint64 {
return l.limiter.bucket.capacity
}
func (l *GCCPULimiter) Overflow() uint64 {
return l.limiter.overflow
}
func (l *GCCPULimiter) Limiting() bool {
return l.limiter.limiting()
}
func (l *GCCPULimiter) NeedUpdate(now int64) bool {
return l.limiter.needUpdate(now)
}
func (l *GCCPULimiter) StartGCTransition(enableGC bool, now int64) {
l.limiter.startGCTransition(enableGC, now)
}
func (l *GCCPULimiter) FinishGCTransition(now int64) {
l.limiter.finishGCTransition(now)
}
func (l *GCCPULimiter) Update(now int64) {
l.limiter.update(now)
}
func (l *GCCPULimiter) AddAssistTime(t int64) {
l.limiter.addAssistTime(t)
}
func (l *GCCPULimiter) ResetCapacity(now int64, nprocs int32) {
l.limiter.resetCapacity(now, nprocs)
}
const ScavengePercent = scavengePercent
type Scavenger struct {
Sleep func(int64) int64
Scavenge func(uintptr) (uintptr, int64)
ShouldStop func() bool
GoMaxProcs func() int32
released atomic.Uintptr
scavenger scavengerState
stop chan<- struct{}
done <-chan struct{}
}
func (s *Scavenger) Start() {
if s.Sleep == nil || s.Scavenge == nil || s.ShouldStop == nil || s.GoMaxProcs == nil {
panic("must populate all stubs")
}
// Install hooks.
s.scavenger.sleepStub = s.Sleep
s.scavenger.scavenge = s.Scavenge
s.scavenger.shouldStop = s.ShouldStop
s.scavenger.gomaxprocs = s.GoMaxProcs
// Start up scavenger goroutine, and wait for it to be ready.
stop := make(chan struct{})
s.stop = stop
done := make(chan struct{})
s.done = done
go func() {
// This should match bgscavenge, loosely.
s.scavenger.init()
s.scavenger.park()
for {
select {
case <-stop:
close(done)
return
default:
}
released, workTime := s.scavenger.run()
if released == 0 {
s.scavenger.park()
continue
}
s.released.Add(released)
s.scavenger.sleep(workTime)
}
}()
if !s.BlockUntilParked(1e9 /* 1 second */) {
panic("timed out waiting for scavenger to get ready")
}
}
// BlockUntilParked blocks until the scavenger parks, or until
// timeout is exceeded. Returns true if the scavenger parked.
//
// Note that in testing, parked means something slightly different.
// In anger, the scavenger parks to sleep, too, but in testing,
// it only parks when it actually has no work to do.
func (s *Scavenger) BlockUntilParked(timeout int64) bool {
// Just spin, waiting for it to park.
//
// The actual parking process is racy with respect to
// wakeups, which is fine, but for testing we need something
// a bit more robust.
start := nanotime()
for nanotime()-start < timeout {
lock(&s.scavenger.lock)
parked := s.scavenger.parked
unlock(&s.scavenger.lock)
if parked {
return true
}
Gosched()
}
return false
}
// Released returns how many bytes the scavenger released.
func (s *Scavenger) Released() uintptr {
return s.released.Load()
}
// Wake wakes up a parked scavenger to keep running.
func (s *Scavenger) Wake() {
s.scavenger.wake()
}
// Stop cleans up the scavenger's resources. The scavenger
// must be parked for this to work.
func (s *Scavenger) Stop() {
lock(&s.scavenger.lock)
parked := s.scavenger.parked
unlock(&s.scavenger.lock)
if !parked {
panic("tried to clean up scavenger that is not parked")
}
close(s.stop)
s.Wake()
<-s.done
}
type ScavengeIndex struct {
i scavengeIndex
}
func NewScavengeIndex(min, max ChunkIdx) *ScavengeIndex {
s := new(ScavengeIndex)
s.i.chunks = make([]atomic.Uint8, uintptr(1<<heapAddrBits/pallocChunkBytes/8))
s.i.min.Store(int32(min / 8))
s.i.max.Store(int32(max / 8))
return s
}
func (s *ScavengeIndex) Find() (ChunkIdx, uint) {
ci, off := s.i.find()
return ChunkIdx(ci), off
}
func (s *ScavengeIndex) Mark(base, limit uintptr) {
s.i.mark(base, limit)
}
func (s *ScavengeIndex) Clear(ci ChunkIdx) {
s.i.clear(chunkIdx(ci))
}
const GTrackingPeriod = gTrackingPeriod
var ZeroBase = unsafe.Pointer(&zerobase)
const UserArenaChunkBytes = userArenaChunkBytes
type UserArena struct {
arena *userArena
}
func NewUserArena() *UserArena {
return &UserArena{newUserArena()}
}
func (a *UserArena) New(out *any) {
i := efaceOf(out)
typ := i._type
if typ.kind&kindMask != kindPtr {
panic("new result of non-ptr type")
}
typ = (*ptrtype)(unsafe.Pointer(typ)).elem
i.data = a.arena.new(typ)
}
func (a *UserArena) Slice(sl any, cap int) {
a.arena.slice(sl, cap)
}
func (a *UserArena) Free() {
a.arena.free()
}
func GlobalWaitingArenaChunks() int {
n := 0
systemstack(func() {
lock(&mheap_.lock)
for s := mheap_.userArena.quarantineList.first; s != nil; s = s.next {
n++
}
unlock(&mheap_.lock)
})
return n
}
func UserArenaClone[T any](s T) T {
return arena_heapify(s).(T)
}
var AlignUp = alignUp
// BlockUntilEmptyFinalizerQueue blocks until either the finalizer
// queue is emptied (and the finalizers have executed) or the timeout
// is reached. Returns true if the finalizer queue was emptied.
func BlockUntilEmptyFinalizerQueue(timeout int64) bool {
start := nanotime()
for nanotime()-start < timeout {
lock(&finlock)
// We know the queue has been drained when both finq is nil
// and the finalizer g has stopped executing.
empty := finq == nil
empty = empty && readgstatus(fing) == _Gwaiting && fing.waitreason == waitReasonFinalizerWait
unlock(&finlock)
if empty {
return true
}
Gosched()
}
return false
}
func FrameStartLine(f *Frame) int {
return f.startLine
}
// PersistentAlloc allocates some memory that lives outside the Go heap.
// This memory will never be freed; use sparingly.
func PersistentAlloc(n uintptr) unsafe.Pointer {
return persistentalloc(n, 0, &memstats.other_sys)
}