export_test.go

     1  // Copyright 2010 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Export guts for testing.
     6  
     7  package runtime
     8  
     9  import (
    10  	"internal/abi"
    11  	"internal/goarch"
    12  	"internal/goos"
    13  	"internal/runtime/atomic"
    14  	"internal/runtime/gc"
    15  	"internal/runtime/sys"
    16  	"unsafe"
    17  )
    18  
    19  var Fadd64 = fadd64
    20  var Fsub64 = fsub64
    21  var Fmul64 = fmul64
    22  var Fdiv64 = fdiv64
    23  var F64to32 = f64to32
    24  var F32to64 = f32to64
    25  var Fcmp64 = fcmp64
    26  var Fintto64 = fintto64
    27  var F64toint = f64toint
    28  
    29  var Entersyscall = entersyscall
    30  var Exitsyscall = exitsyscall
    31  var LockedOSThread = lockedOSThread
    32  var Xadduintptr = atomic.Xadduintptr
    33  
    34  var ReadRandomFailed = &readRandomFailed
    35  
    36  var Fastlog2 = fastlog2
    37  
    38  var ParseByteCount = parseByteCount
    39  
    40  var Nanotime = nanotime
    41  var Cputicks = cputicks
    42  var CyclesPerSecond = pprof_cyclesPerSecond
    43  var NetpollBreak = netpollBreak
    44  var Usleep = usleep
    45  
    46  var PhysPageSize = physPageSize
    47  var PhysHugePageSize = physHugePageSize
    48  
    49  var NetpollGenericInit = netpollGenericInit
    50  
    51  var Memmove = memmove
    52  var MemclrNoHeapPointers = memclrNoHeapPointers
    53  
    54  var CgoCheckPointer = cgoCheckPointer
    55  
    56  const CrashStackImplemented = crashStackImplemented
    57  
    58  const TracebackInnerFrames = tracebackInnerFrames
    59  const TracebackOuterFrames = tracebackOuterFrames
    60  
    61  var LockPartialOrder = lockPartialOrder
    62  
    63  type TimeTimer = timeTimer
    64  
    65  type LockRank lockRank
    66  
    67  func (l LockRank) String() string {
    68  	return lockRank(l).String()
    69  }
    70  
    71  const PreemptMSupported = preemptMSupported
    72  
    73  type LFNode struct {
    74  	Next    uint64
    75  	Pushcnt uintptr
    76  }
    77  
    78  func LFStackPush(head *uint64, node *LFNode) {
    79  	(*lfstack)(head).push((*lfnode)(unsafe.Pointer(node)))
    80  }
    81  
    82  func LFStackPop(head *uint64) *LFNode {
    83  	return (*LFNode)((*lfstack)(head).pop())
    84  }
    85  func LFNodeValidate(node *LFNode) {
    86  	lfnodeValidate((*lfnode)(unsafe.Pointer(node)))
    87  }
    88  
    89  func Netpoll(delta int64) {
    90  	systemstack(func() {
    91  		netpoll(delta)
    92  	})
    93  }
    94  
    95  func PointerMask(x any) (ret []byte) {
    96  	systemstack(func() {
    97  		ret = pointerMask(x)
    98  	})
    99  	return
   100  }
   101  
   102  func RunSchedLocalQueueTest() {
   103  	pp := new(p)
   104  	gs := make([]g, len(pp.runq))
   105  	Escape(gs) // Ensure gs doesn't move, since we use guintptrs
   106  	for i := 0; i < len(pp.runq); i++ {
   107  		if g, _ := runqget(pp); g != nil {
   108  			throw("runq is not empty initially")
   109  		}
   110  		for j := 0; j < i; j++ {
   111  			runqput(pp, &gs[i], false)
   112  		}
   113  		for j := 0; j < i; j++ {
   114  			if g, _ := runqget(pp); g != &gs[i] {
   115  				print("bad element at iter ", i, "/", j, "\n")
   116  				throw("bad element")
   117  			}
   118  		}
   119  		if g, _ := runqget(pp); g != nil {
   120  			throw("runq is not empty afterwards")
   121  		}
   122  	}
   123  }
   124  
   125  func RunSchedLocalQueueStealTest() {
   126  	p1 := new(p)
   127  	p2 := new(p)
   128  	gs := make([]g, len(p1.runq))
   129  	Escape(gs) // Ensure gs doesn't move, since we use guintptrs
   130  	for i := 0; i < len(p1.runq); i++ {
   131  		for j := 0; j < i; j++ {
   132  			gs[j].sig = 0
   133  			runqput(p1, &gs[j], false)
   134  		}
   135  		gp := runqsteal(p2, p1, true)
   136  		s := 0
   137  		if gp != nil {
   138  			s++
   139  			gp.sig++
   140  		}
   141  		for {
   142  			gp, _ = runqget(p2)
   143  			if gp == nil {
   144  				break
   145  			}
   146  			s++
   147  			gp.sig++
   148  		}
   149  		for {
   150  			gp, _ = runqget(p1)
   151  			if gp == nil {
   152  				break
   153  			}
   154  			gp.sig++
   155  		}
   156  		for j := 0; j < i; j++ {
   157  			if gs[j].sig != 1 {
   158  				print("bad element ", j, "(", gs[j].sig, ") at iter ", i, "\n")
   159  				throw("bad element")
   160  			}
   161  		}
   162  		if s != i/2 && s != i/2+1 {
   163  			print("bad steal ", s, ", want ", i/2, " or ", i/2+1, ", iter ", i, "\n")
   164  			throw("bad steal")
   165  		}
   166  	}
   167  }
   168  
   169  func RunSchedLocalQueueEmptyTest(iters int) {
   170  	// Test that runq is not spuriously reported as empty.
   171  	// Runq emptiness affects scheduling decisions and spurious emptiness
   172  	// can lead to underutilization (both runnable Gs and idle Ps coexist
   173  	// for arbitrary long time).
   174  	done := make(chan bool, 1)
   175  	p := new(p)
   176  	gs := make([]g, 2)
   177  	Escape(gs) // Ensure gs doesn't move, since we use guintptrs
   178  	ready := new(uint32)
   179  	for i := 0; i < iters; i++ {
   180  		*ready = 0
   181  		next0 := (i & 1) == 0
   182  		next1 := (i & 2) == 0
   183  		runqput(p, &gs[0], next0)
   184  		go func() {
   185  			for atomic.Xadd(ready, 1); atomic.Load(ready) != 2; {
   186  			}
   187  			if runqempty(p) {
   188  				println("next:", next0, next1)
   189  				throw("queue is empty")
   190  			}
   191  			done <- true
   192  		}()
   193  		for atomic.Xadd(ready, 1); atomic.Load(ready) != 2; {
   194  		}
   195  		runqput(p, &gs[1], next1)
   196  		runqget(p)
   197  		<-done
   198  		runqget(p)
   199  	}
   200  }
   201  
   202  var (
   203  	StringHash = stringHash
   204  	BytesHash  = bytesHash
   205  	Int32Hash  = int32Hash
   206  	Int64Hash  = int64Hash
   207  	MemHash    = memhash
   208  	MemHash32  = memhash32
   209  	MemHash64  = memhash64
   210  	EfaceHash  = efaceHash
   211  	IfaceHash  = ifaceHash
   212  )
   213  
   214  var UseAeshash = &useAeshash
   215  
   216  func MemclrBytes(b []byte) {
   217  	s := (*slice)(unsafe.Pointer(&b))
   218  	memclrNoHeapPointers(s.array, uintptr(s.len))
   219  }
   220  
   221  const HashLoad = hashLoad
   222  
   223  // entry point for testing
   224  func GostringW(w []uint16) (s string) {
   225  	systemstack(func() {
   226  		s = gostringw(&w[0])
   227  	})
   228  	return
   229  }
   230  
   231  var Open = open
   232  var Close = closefd
   233  var Read = read
   234  var Write = write
   235  
   236  func Envs() []string     { return envs }
   237  func SetEnvs(e []string) { envs = e }
   238  
   239  const PtrSize = goarch.PtrSize
   240  
   241  const ClobberdeadPtr = clobberdeadPtr
   242  
   243  func Clobberfree() bool {
   244  	return debug.clobberfree != 0
   245  }
   246  
   247  var ForceGCPeriod = &forcegcperiod
   248  
   249  // SetTracebackEnv is like runtime/debug.SetTraceback, but it raises
   250  // the "environment" traceback level, so later calls to
   251  // debug.SetTraceback (e.g., from testing timeouts) can't lower it.
   252  func SetTracebackEnv(level string) {
   253  	setTraceback(level)
   254  	traceback_env = traceback_cache
   255  }
   256  
   257  var ReadUnaligned32 = readUnaligned32
   258  var ReadUnaligned64 = readUnaligned64
   259  
   260  func CountPagesInUse() (pagesInUse, counted uintptr) {
   261  	stw := stopTheWorld(stwForTestCountPagesInUse)
   262  
   263  	pagesInUse = mheap_.pagesInUse.Load()
   264  
   265  	for _, s := range mheap_.allspans {
   266  		if s.state.get() == mSpanInUse {
   267  			counted += s.npages
   268  		}
   269  	}
   270  
   271  	startTheWorld(stw)
   272  
   273  	return
   274  }
   275  
   276  func Fastrand() uint32          { return uint32(rand()) }
   277  func Fastrand64() uint64        { return rand() }
   278  func Fastrandn(n uint32) uint32 { return randn(n) }
   279  
   280  type ProfBuf profBuf
   281  
   282  func NewProfBuf(hdrsize, bufwords, tags int) *ProfBuf {
   283  	return (*ProfBuf)(newProfBuf(hdrsize, bufwords, tags))
   284  }
   285  
   286  func (p *ProfBuf) Write(tag *unsafe.Pointer, now int64, hdr []uint64, stk []uintptr) {
   287  	(*profBuf)(p).write(tag, now, hdr, stk)
   288  }
   289  
   290  const (
   291  	ProfBufBlocking    = profBufBlocking
   292  	ProfBufNonBlocking = profBufNonBlocking
   293  )
   294  
   295  func (p *ProfBuf) Read(mode profBufReadMode) ([]uint64, []unsafe.Pointer, bool) {
   296  	return (*profBuf)(p).read(mode)
   297  }
   298  
   299  func (p *ProfBuf) Close() {
   300  	(*profBuf)(p).close()
   301  }
   302  
   303  type CPUStats = cpuStats
   304  
   305  func ReadCPUStats() CPUStats {
   306  	return work.cpuStats
   307  }
   308  
   309  func ReadMetricsSlow(memStats *MemStats, samplesp unsafe.Pointer, len, cap int) {
   310  	stw := stopTheWorld(stwForTestReadMetricsSlow)
   311  
   312  	// Initialize the metrics beforehand because this could
   313  	// allocate and skew the stats.
   314  	metricsLock()
   315  	initMetrics()
   316  
   317  	systemstack(func() {
   318  		// Donate the racectx to g0. readMetricsLocked calls into the race detector
   319  		// via map access.
   320  		getg().racectx = getg().m.curg.racectx
   321  
   322  		// Read the metrics once before in case it allocates and skews the metrics.
   323  		// readMetricsLocked is designed to only allocate the first time it is called
   324  		// with a given slice of samples. In effect, this extra read tests that this
   325  		// remains true, since otherwise the second readMetricsLocked below could
   326  		// allocate before it returns.
   327  		readMetricsLocked(samplesp, len, cap)
   328  
   329  		// Read memstats first. It's going to flush
   330  		// the mcaches which readMetrics does not do, so
   331  		// going the other way around may result in
   332  		// inconsistent statistics.
   333  		readmemstats_m(memStats)
   334  
   335  		// Read metrics again. We need to be sure we're on the
   336  		// system stack with readmemstats_m so that we don't call into
   337  		// the stack allocator and adjust metrics between there and here.
   338  		readMetricsLocked(samplesp, len, cap)
   339  
   340  		// Undo the donation.
   341  		getg().racectx = 0
   342  	})
   343  	metricsUnlock()
   344  
   345  	startTheWorld(stw)
   346  }
   347  
   348  var DoubleCheckReadMemStats = &doubleCheckReadMemStats
   349  
   350  // ReadMemStatsSlow returns both the runtime-computed MemStats and
   351  // MemStats accumulated by scanning the heap.
   352  func ReadMemStatsSlow() (base, slow MemStats) {
   353  	stw := stopTheWorld(stwForTestReadMemStatsSlow)
   354  
   355  	// Run on the system stack to avoid stack growth allocation.
   356  	systemstack(func() {
   357  		// Make sure stats don't change.
   358  		getg().m.mallocing++
   359  
   360  		readmemstats_m(&base)
   361  
   362  		// Initialize slow from base and zero the fields we're
   363  		// recomputing.
   364  		slow = base
   365  		slow.Alloc = 0
   366  		slow.TotalAlloc = 0
   367  		slow.Mallocs = 0
   368  		slow.Frees = 0
   369  		slow.HeapReleased = 0
   370  		var bySize [gc.NumSizeClasses]struct {
   371  			Mallocs, Frees uint64
   372  		}
   373  
   374  		// Add up current allocations in spans.
   375  		for _, s := range mheap_.allspans {
   376  			if s.state.get() != mSpanInUse {
   377  				continue
   378  			}
   379  			if s.isUnusedUserArenaChunk() {
   380  				continue
   381  			}
   382  			if sizeclass := s.spanclass.sizeclass(); sizeclass == 0 {
   383  				slow.Mallocs++
   384  				slow.Alloc += uint64(s.elemsize)
   385  			} else {
   386  				slow.Mallocs += uint64(s.allocCount)
   387  				slow.Alloc += uint64(s.allocCount) * uint64(s.elemsize)
   388  				bySize[sizeclass].Mallocs += uint64(s.allocCount)
   389  			}
   390  		}
   391  
   392  		// Add in frees by just reading the stats for those directly.
   393  		var m heapStatsDelta
   394  		memstats.heapStats.unsafeRead(&m)
   395  
   396  		// Collect per-sizeclass free stats.
   397  		var smallFree uint64
   398  		for i := 0; i < gc.NumSizeClasses; i++ {
   399  			slow.Frees += m.smallFreeCount[i]
   400  			bySize[i].Frees += m.smallFreeCount[i]
   401  			bySize[i].Mallocs += m.smallFreeCount[i]
   402  			smallFree += m.smallFreeCount[i] * uint64(gc.SizeClassToSize[i])
   403  		}
   404  		slow.Frees += m.tinyAllocCount + m.largeFreeCount
   405  		slow.Mallocs += slow.Frees
   406  
   407  		slow.TotalAlloc = slow.Alloc + m.largeFree + smallFree
   408  
   409  		for i := range slow.BySize {
   410  			slow.BySize[i].Mallocs = bySize[i].Mallocs
   411  			slow.BySize[i].Frees = bySize[i].Frees
   412  		}
   413  
   414  		for i := mheap_.pages.start; i < mheap_.pages.end; i++ {
   415  			chunk := mheap_.pages.tryChunkOf(i)
   416  			if chunk == nil {
   417  				continue
   418  			}
   419  			pg := chunk.scavenged.popcntRange(0, pallocChunkPages)
   420  			slow.HeapReleased += uint64(pg) * pageSize
   421  		}
   422  		for _, p := range allp {
   423  			// Only count scav bits for pages in the cache
   424  			pg := sys.OnesCount64(p.pcache.cache & p.pcache.scav)
   425  			slow.HeapReleased += uint64(pg) * pageSize
   426  		}
   427  
   428  		getg().m.mallocing--
   429  	})
   430  
   431  	startTheWorld(stw)
   432  	return
   433  }
   434  
   435  // ShrinkStackAndVerifyFramePointers attempts to shrink the stack of the current goroutine
   436  // and verifies that unwinding the new stack doesn't crash, even if the old
   437  // stack has been freed or reused (simulated via poisoning).
   438  func ShrinkStackAndVerifyFramePointers() {
   439  	before := stackPoisonCopy
   440  	defer func() { stackPoisonCopy = before }()
   441  	stackPoisonCopy = 1
   442  
   443  	gp := getg()
   444  	systemstack(func() {
   445  		shrinkstack(gp)
   446  	})
   447  	// If our new stack contains frame pointers into the old stack, this will
   448  	// crash because the old stack has been poisoned.
   449  	FPCallers(make([]uintptr, 1024))
   450  }
   451  
   452  type StackPoisonCopyRestore int
   453  
   454  func (s StackPoisonCopyRestore) Restore() { stackPoisonCopy = int(s) }
   455  
   456  func StackPoisonCopy() StackPoisonCopyRestore {
   457  	before := stackPoisonCopy
   458  	stackPoisonCopy = 1
   459  	return StackPoisonCopyRestore(before)
   460  }
   461  
   462  // BlockOnSystemStack switches to the system stack, prints "x\n" to
   463  // stderr, and blocks in a stack containing
   464  // "runtime.blockOnSystemStackInternal".
   465  func BlockOnSystemStack() {
   466  	systemstack(blockOnSystemStackInternal)
   467  }
   468  
   469  func blockOnSystemStackInternal() {
   470  	print("x\n")
   471  	lock(&deadlock)
   472  	lock(&deadlock)
   473  }
   474  
   475  type RWMutex struct {
   476  	rw rwmutex
   477  }
   478  
   479  func (rw *RWMutex) Init() {
   480  	rw.rw.init(lockRankTestR, lockRankTestRInternal, lockRankTestW)
   481  }
   482  
   483  func (rw *RWMutex) RLock() {
   484  	rw.rw.rlock()
   485  }
   486  
   487  func (rw *RWMutex) RUnlock() {
   488  	rw.rw.runlock()
   489  }
   490  
   491  func (rw *RWMutex) Lock() {
   492  	rw.rw.lock()
   493  }
   494  
   495  func (rw *RWMutex) Unlock() {
   496  	rw.rw.unlock()
   497  }
   498  
   499  func LockOSCounts() (external, internal uint32) {
   500  	gp := getg()
   501  	if gp.m.lockedExt+gp.m.lockedInt == 0 {
   502  		if gp.lockedm != 0 {
   503  			panic("lockedm on non-locked goroutine")
   504  		}
   505  	} else {
   506  		if gp.lockedm == 0 {
   507  			panic("nil lockedm on locked goroutine")
   508  		}
   509  	}
   510  	return gp.m.lockedExt, gp.m.lockedInt
   511  }
   512  
   513  //go:noinline
   514  func TracebackSystemstack(stk []uintptr, i int) int {
   515  	if i == 0 {
   516  		pc, sp := sys.GetCallerPC(), sys.GetCallerSP()
   517  		var u unwinder
   518  		u.initAt(pc, sp, 0, getg(), unwindJumpStack) // Don't ignore errors, for testing
   519  		return tracebackPCs(&u, 0, stk)
   520  	}
   521  	n := 0
   522  	systemstack(func() {
   523  		n = TracebackSystemstack(stk, i-1)
   524  	})
   525  	return n
   526  }
   527  
   528  func KeepNArenaHints(n int) {
   529  	hint := mheap_.arenaHints
   530  	for i := 1; i < n; i++ {
   531  		hint = hint.next
   532  		if hint == nil {
   533  			return
   534  		}
   535  	}
   536  	hint.next = nil
   537  }
   538  
   539  // MapNextArenaHint reserves a page at the next arena growth hint,
   540  // preventing the arena from growing there, and returns the range of
   541  // addresses that are no longer viable.
   542  //
   543  // This may fail to reserve memory. If it fails, it still returns the
   544  // address range it attempted to reserve.
   545  func MapNextArenaHint() (start, end uintptr, ok bool) {
   546  	hint := mheap_.arenaHints
   547  	addr := hint.addr
   548  	if hint.down {
   549  		start, end = addr-heapArenaBytes, addr
   550  		addr -= physPageSize
   551  	} else {
   552  		start, end = addr, addr+heapArenaBytes
   553  	}
   554  	got := sysReserve(unsafe.Pointer(addr), physPageSize, "")
   555  	ok = (addr == uintptr(got))
   556  	if !ok {
   557  		// We were unable to get the requested reservation.
   558  		// Release what we did get and fail.
   559  		sysUnreserve(got, physPageSize)
   560  	}
   561  	return
   562  }
   563  
   564  func NextArenaHint() (uintptr, bool) {
   565  	if mheap_.arenaHints == nil {
   566  		return 0, false
   567  	}
   568  	return mheap_.arenaHints.addr, true
   569  }
   570  
   571  type G = g
   572  
   573  type Sudog = sudog
   574  
   575  type XRegPerG = xRegPerG
   576  
   577  func Getg() *G {
   578  	return getg()
   579  }
   580  
   581  func Goid() uint64 {
   582  	return getg().goid
   583  }
   584  
   585  func GIsWaitingOnMutex(gp *G) bool {
   586  	return readgstatus(gp) == _Gwaiting && gp.waitreason.isMutexWait()
   587  }
   588  
   589  var CasGStatusAlwaysTrack = &casgstatusAlwaysTrack
   590  
   591  //go:noinline
   592  func PanicForTesting(b []byte, i int) byte {
   593  	return unexportedPanicForTesting(b, i)
   594  }
   595  
   596  //go:noinline
   597  func unexportedPanicForTesting(b []byte, i int) byte {
   598  	return b[i]
   599  }
   600  
   601  func G0StackOverflow() {
   602  	systemstack(func() {
   603  		g0 := getg()
   604  		sp := sys.GetCallerSP()
   605  		// The stack bounds for g0 stack is not always precise.
   606  		// Use an artificially small stack, to trigger a stack overflow
   607  		// without actually run out of the system stack (which may seg fault).
   608  		g0.stack.lo = sp - 4096 - stackSystem
   609  		g0.stackguard0 = g0.stack.lo + stackGuard
   610  		g0.stackguard1 = g0.stackguard0
   611  
   612  		stackOverflow(nil)
   613  	})
   614  }
   615  
   616  func stackOverflow(x *byte) {
   617  	var buf [256]byte
   618  	stackOverflow(&buf[0])
   619  }
   620  
   621  func RunGetgThreadSwitchTest() {
   622  	// Test that getg works correctly with thread switch.
   623  	// With gccgo, if we generate getg inlined, the backend
   624  	// may cache the address of the TLS variable, which
   625  	// will become invalid after a thread switch. This test
   626  	// checks that the bad caching doesn't happen.
   627  
   628  	ch := make(chan int)
   629  	go func(ch chan int) {
   630  		ch <- 5
   631  		LockOSThread()
   632  	}(ch)
   633  
   634  	g1 := getg()
   635  
   636  	// Block on a receive. This is likely to get us a thread
   637  	// switch. If we yield to the sender goroutine, it will
   638  	// lock the thread, forcing us to resume on a different
   639  	// thread.
   640  	<-ch
   641  
   642  	g2 := getg()
   643  	if g1 != g2 {
   644  		panic("g1 != g2")
   645  	}
   646  
   647  	// Also test getg after some control flow, as the
   648  	// backend is sensitive to control flow.
   649  	g3 := getg()
   650  	if g1 != g3 {
   651  		panic("g1 != g3")
   652  	}
   653  }
   654  
   655  // Expose freegc for testing.
   656  func Freegc(p unsafe.Pointer, size uintptr, noscan bool) {
   657  	freegc(p, size, noscan)
   658  }
   659  
   660  // Expose gcAssistBytes for the current g for testing.
   661  func AssistCredit() int64 {
   662  	assistG := getg()
   663  	if assistG.m.curg != nil {
   664  		assistG = assistG.m.curg
   665  	}
   666  	return assistG.gcAssistBytes
   667  }
   668  
   669  // Expose gcBlackenEnabled for testing.
   670  func GcBlackenEnable() bool {
   671  	// Note we do a non-atomic load here.
   672  	// Some checks against gcBlackenEnabled (e.g., in mallocgc)
   673  	// are currently done via non-atomic load for performance reasons,
   674  	// but other checks are done via atomic load (e.g., in mgcmark.go),
   675  	// so interpreting this value in a test may be subtle.
   676  	return gcBlackenEnabled != 0
   677  }
   678  
   679  const SizeSpecializedMallocEnabled = sizeSpecializedMallocEnabled
   680  
   681  const RuntimeFreegcEnabled = runtimeFreegcEnabled
   682  
   683  const (
   684  	PageSize         = pageSize
   685  	PallocChunkPages = pallocChunkPages
   686  	PageAlloc64Bit   = pageAlloc64Bit
   687  	PallocSumBytes   = pallocSumBytes
   688  )
   689  
   690  // Expose pallocSum for testing.
   691  type PallocSum pallocSum
   692  
   693  func PackPallocSum(start, max, end uint) PallocSum { return PallocSum(packPallocSum(start, max, end)) }
   694  func (m PallocSum) Start() uint                    { return pallocSum(m).start() }
   695  func (m PallocSum) Max() uint                      { return pallocSum(m).max() }
   696  func (m PallocSum) End() uint                      { return pallocSum(m).end() }
   697  
   698  // Expose pallocBits for testing.
   699  type PallocBits pallocBits
   700  
   701  func (b *PallocBits) Find(npages uintptr, searchIdx uint) (uint, uint) {
   702  	return (*pallocBits)(b).find(npages, searchIdx)
   703  }
   704  func (b *PallocBits) AllocRange(i, n uint)       { (*pallocBits)(b).allocRange(i, n) }
   705  func (b *PallocBits) Free(i, n uint)             { (*pallocBits)(b).free(i, n) }
   706  func (b *PallocBits) Summarize() PallocSum       { return PallocSum((*pallocBits)(b).summarize()) }
   707  func (b *PallocBits) PopcntRange(i, n uint) uint { return (*pageBits)(b).popcntRange(i, n) }
   708  
   709  // SummarizeSlow is a slow but more obviously correct implementation
   710  // of (*pallocBits).summarize. Used for testing.
   711  func SummarizeSlow(b *PallocBits) PallocSum {
   712  	var start, most, end uint
   713  
   714  	const N = uint(len(b)) * 64
   715  	for start < N && (*pageBits)(b).get(start) == 0 {
   716  		start++
   717  	}
   718  	for end < N && (*pageBits)(b).get(N-end-1) == 0 {
   719  		end++
   720  	}
   721  	run := uint(0)
   722  	for i := uint(0); i < N; i++ {
   723  		if (*pageBits)(b).get(i) == 0 {
   724  			run++
   725  		} else {
   726  			run = 0
   727  		}
   728  		most = max(most, run)
   729  	}
   730  	return PackPallocSum(start, most, end)
   731  }
   732  
   733  // Expose non-trivial helpers for testing.
   734  func FindBitRange64(c uint64, n uint) uint { return findBitRange64(c, n) }
   735  
   736  // Given two PallocBits, returns a set of bit ranges where
   737  // they differ.
   738  func DiffPallocBits(a, b *PallocBits) []BitRange {
   739  	ba := (*pageBits)(a)
   740  	bb := (*pageBits)(b)
   741  
   742  	var d []BitRange
   743  	base, size := uint(0), uint(0)
   744  	for i := uint(0); i < uint(len(ba))*64; i++ {
   745  		if ba.get(i) != bb.get(i) {
   746  			if size == 0 {
   747  				base = i
   748  			}
   749  			size++
   750  		} else {
   751  			if size != 0 {
   752  				d = append(d, BitRange{base, size})
   753  			}
   754  			size = 0
   755  		}
   756  	}
   757  	if size != 0 {
   758  		d = append(d, BitRange{base, size})
   759  	}
   760  	return d
   761  }
   762  
   763  // StringifyPallocBits gets the bits in the bit range r from b,
   764  // and returns a string containing the bits as ASCII 0 and 1
   765  // characters.
   766  func StringifyPallocBits(b *PallocBits, r BitRange) string {
   767  	str := ""
   768  	for j := r.I; j < r.I+r.N; j++ {
   769  		if (*pageBits)(b).get(j) != 0 {
   770  			str += "1"
   771  		} else {
   772  			str += "0"
   773  		}
   774  	}
   775  	return str
   776  }
   777  
   778  // Expose pallocData for testing.
   779  type PallocData pallocData
   780  
   781  func (d *PallocData) FindScavengeCandidate(searchIdx uint, min, max uintptr) (uint, uint) {
   782  	return (*pallocData)(d).findScavengeCandidate(searchIdx, min, max)
   783  }
   784  func (d *PallocData) AllocRange(i, n uint) { (*pallocData)(d).allocRange(i, n) }
   785  func (d *PallocData) ScavengedSetRange(i, n uint) {
   786  	(*pallocData)(d).scavenged.setRange(i, n)
   787  }
   788  func (d *PallocData) PallocBits() *PallocBits {
   789  	return (*PallocBits)(&(*pallocData)(d).pallocBits)
   790  }
   791  func (d *PallocData) Scavenged() *PallocBits {
   792  	return (*PallocBits)(&(*pallocData)(d).scavenged)
   793  }
   794  
   795  // Expose fillAligned for testing.
   796  func FillAligned(x uint64, m uint) uint64 { return fillAligned(x, m) }
   797  
   798  // Expose pageCache for testing.
   799  type PageCache pageCache
   800  
   801  const PageCachePages = pageCachePages
   802  
   803  func NewPageCache(base uintptr, cache, scav uint64) PageCache {
   804  	return PageCache(pageCache{base: base, cache: cache, scav: scav})
   805  }
   806  func (c *PageCache) Empty() bool   { return (*pageCache)(c).empty() }
   807  func (c *PageCache) Base() uintptr { return (*pageCache)(c).base }
   808  func (c *PageCache) Cache() uint64 { return (*pageCache)(c).cache }
   809  func (c *PageCache) Scav() uint64  { return (*pageCache)(c).scav }
   810  func (c *PageCache) Alloc(npages uintptr) (uintptr, uintptr) {
   811  	return (*pageCache)(c).alloc(npages)
   812  }
   813  func (c *PageCache) Flush(s *PageAlloc) {
   814  	cp := (*pageCache)(c)
   815  	sp := (*pageAlloc)(s)
   816  
   817  	systemstack(func() {
   818  		// None of the tests need any higher-level locking, so we just
   819  		// take the lock internally.
   820  		lock(sp.mheapLock)
   821  		cp.flush(sp)
   822  		unlock(sp.mheapLock)
   823  	})
   824  }
   825  
   826  // Expose chunk index type.
   827  type ChunkIdx chunkIdx
   828  
   829  // Expose pageAlloc for testing. Note that because pageAlloc is
   830  // not in the heap, so is PageAlloc.
   831  type PageAlloc pageAlloc
   832  
   833  func (p *PageAlloc) Alloc(npages uintptr) (uintptr, uintptr) {
   834  	pp := (*pageAlloc)(p)
   835  
   836  	var addr, scav uintptr
   837  	systemstack(func() {
   838  		// None of the tests need any higher-level locking, so we just
   839  		// take the lock internally.
   840  		lock(pp.mheapLock)
   841  		addr, scav = pp.alloc(npages)
   842  		unlock(pp.mheapLock)
   843  	})
   844  	return addr, scav
   845  }
   846  func (p *PageAlloc) AllocToCache() PageCache {
   847  	pp := (*pageAlloc)(p)
   848  
   849  	var c PageCache
   850  	systemstack(func() {
   851  		// None of the tests need any higher-level locking, so we just
   852  		// take the lock internally.
   853  		lock(pp.mheapLock)
   854  		c = PageCache(pp.allocToCache())
   855  		unlock(pp.mheapLock)
   856  	})
   857  	return c
   858  }
   859  func (p *PageAlloc) Free(base, npages uintptr) {
   860  	pp := (*pageAlloc)(p)
   861  
   862  	systemstack(func() {
   863  		// None of the tests need any higher-level locking, so we just
   864  		// take the lock internally.
   865  		lock(pp.mheapLock)
   866  		pp.free(base, npages)
   867  		unlock(pp.mheapLock)
   868  	})
   869  }
   870  func (p *PageAlloc) Bounds() (ChunkIdx, ChunkIdx) {
   871  	return ChunkIdx((*pageAlloc)(p).start), ChunkIdx((*pageAlloc)(p).end)
   872  }
   873  func (p *PageAlloc) Scavenge(nbytes uintptr) (r uintptr) {
   874  	pp := (*pageAlloc)(p)
   875  	systemstack(func() {
   876  		r = pp.scavenge(nbytes, nil, true)
   877  	})
   878  	return
   879  }
   880  func (p *PageAlloc) InUse() []AddrRange {
   881  	ranges := make([]AddrRange, 0, len(p.inUse.ranges))
   882  	for _, r := range p.inUse.ranges {
   883  		ranges = append(ranges, AddrRange{r})
   884  	}
   885  	return ranges
   886  }
   887  
   888  // Returns nil if the PallocData's L2 is missing.
   889  func (p *PageAlloc) PallocData(i ChunkIdx) *PallocData {
   890  	ci := chunkIdx(i)
   891  	return (*PallocData)((*pageAlloc)(p).tryChunkOf(ci))
   892  }
   893  
   894  // AddrRange is a wrapper around addrRange for testing.
   895  type AddrRange struct {
   896  	addrRange
   897  }
   898  
   899  // MakeAddrRange creates a new address range.
   900  func MakeAddrRange(base, limit uintptr) AddrRange {
   901  	return AddrRange{makeAddrRange(base, limit)}
   902  }
   903  
   904  // Base returns the virtual base address of the address range.
   905  func (a AddrRange) Base() uintptr {
   906  	return a.addrRange.base.addr()
   907  }
   908  
   909  // Base returns the virtual address of the limit of the address range.
   910  func (a AddrRange) Limit() uintptr {
   911  	return a.addrRange.limit.addr()
   912  }
   913  
   914  // Equals returns true if the two address ranges are exactly equal.
   915  func (a AddrRange) Equals(b AddrRange) bool {
   916  	return a == b
   917  }
   918  
   919  // Size returns the size in bytes of the address range.
   920  func (a AddrRange) Size() uintptr {
   921  	return a.addrRange.size()
   922  }
   923  
   924  // testSysStat is the sysStat passed to test versions of various
   925  // runtime structures. We do actually have to keep track of this
   926  // because otherwise memstats.mappedReady won't actually line up
   927  // with other stats in the runtime during tests.
   928  var testSysStat = &memstats.other_sys
   929  
   930  // AddrRanges is a wrapper around addrRanges for testing.
   931  type AddrRanges struct {
   932  	addrRanges
   933  	mutable bool
   934  }
   935  
   936  // NewAddrRanges creates a new empty addrRanges.
   937  //
   938  // Note that this initializes addrRanges just like in the
   939  // runtime, so its memory is persistentalloc'd. Call this
   940  // function sparingly since the memory it allocates is
   941  // leaked.
   942  //
   943  // This AddrRanges is mutable, so we can test methods like
   944  // Add.
   945  func NewAddrRanges() AddrRanges {
   946  	r := addrRanges{}
   947  	r.init(testSysStat)
   948  	return AddrRanges{r, true}
   949  }
   950  
   951  // MakeAddrRanges creates a new addrRanges populated with
   952  // the ranges in a.
   953  //
   954  // The returned AddrRanges is immutable, so methods like
   955  // Add will fail.
   956  func MakeAddrRanges(a ...AddrRange) AddrRanges {
   957  	// Methods that manipulate the backing store of addrRanges.ranges should
   958  	// not be used on the result from this function (e.g. add) since they may
   959  	// trigger reallocation. That would normally be fine, except the new
   960  	// backing store won't come from the heap, but from persistentalloc, so
   961  	// we'll leak some memory implicitly.
   962  	ranges := make([]addrRange, 0, len(a))
   963  	total := uintptr(0)
   964  	for _, r := range a {
   965  		ranges = append(ranges, r.addrRange)
   966  		total += r.Size()
   967  	}
   968  	return AddrRanges{addrRanges{
   969  		ranges:     ranges,
   970  		totalBytes: total,
   971  		sysStat:    testSysStat,
   972  	}, false}
   973  }
   974  
   975  // Ranges returns a copy of the ranges described by the
   976  // addrRanges.
   977  func (a *AddrRanges) Ranges() []AddrRange {
   978  	result := make([]AddrRange, 0, len(a.addrRanges.ranges))
   979  	for _, r := range a.addrRanges.ranges {
   980  		result = append(result, AddrRange{r})
   981  	}
   982  	return result
   983  }
   984  
   985  // FindSucc returns the successor to base. See addrRanges.findSucc
   986  // for more details.
   987  func (a *AddrRanges) FindSucc(base uintptr) int {
   988  	return a.findSucc(base)
   989  }
   990  
   991  // Add adds a new AddrRange to the AddrRanges.
   992  //
   993  // The AddrRange must be mutable (i.e. created by NewAddrRanges),
   994  // otherwise this method will throw.
   995  func (a *AddrRanges) Add(r AddrRange) {
   996  	if !a.mutable {
   997  		throw("attempt to mutate immutable AddrRanges")
   998  	}
   999  	a.add(r.addrRange)
  1000  }
  1001  
  1002  // TotalBytes returns the totalBytes field of the addrRanges.
  1003  func (a *AddrRanges) TotalBytes() uintptr {
  1004  	return a.addrRanges.totalBytes
  1005  }
  1006  
  1007  // BitRange represents a range over a bitmap.
  1008  type BitRange struct {
  1009  	I, N uint // bit index and length in bits
  1010  }
  1011  
  1012  // NewPageAlloc creates a new page allocator for testing and
  1013  // initializes it with the scav and chunks maps. Each key in these maps
  1014  // represents a chunk index and each value is a series of bit ranges to
  1015  // set within each bitmap's chunk.
  1016  //
  1017  // The initialization of the pageAlloc preserves the invariant that if a
  1018  // scavenged bit is set the alloc bit is necessarily unset, so some
  1019  // of the bits described by scav may be cleared in the final bitmap if
  1020  // ranges in chunks overlap with them.
  1021  //
  1022  // scav is optional, and if nil, the scavenged bitmap will be cleared
  1023  // (as opposed to all 1s, which it usually is). Furthermore, every
  1024  // chunk index in scav must appear in chunks; ones that do not are
  1025  // ignored.
  1026  func NewPageAlloc(chunks, scav map[ChunkIdx][]BitRange) *PageAlloc {
  1027  	p := new(pageAlloc)
  1028  
  1029  	// We've got an entry, so initialize the pageAlloc.
  1030  	p.init(new(mutex), testSysStat, true)
  1031  	lockInit(p.mheapLock, lockRankMheap)
  1032  	for i, init := range chunks {
  1033  		addr := chunkBase(chunkIdx(i))
  1034  
  1035  		// Mark the chunk's existence in the pageAlloc.
  1036  		systemstack(func() {
  1037  			lock(p.mheapLock)
  1038  			p.grow(addr, pallocChunkBytes)
  1039  			unlock(p.mheapLock)
  1040  		})
  1041  
  1042  		// Initialize the bitmap and update pageAlloc metadata.
  1043  		ci := chunkIndex(addr)
  1044  		chunk := p.chunkOf(ci)
  1045  
  1046  		// Clear all the scavenged bits which grow set.
  1047  		chunk.scavenged.clearRange(0, pallocChunkPages)
  1048  
  1049  		// Simulate the allocation and subsequent free of all pages in
  1050  		// the chunk for the scavenge index. This sets the state equivalent
  1051  		// with all pages within the index being free.
  1052  		p.scav.index.alloc(ci, pallocChunkPages)
  1053  		p.scav.index.free(ci, 0, pallocChunkPages)
  1054  
  1055  		// Apply scavenge state if applicable.
  1056  		if scav != nil {
  1057  			if scvg, ok := scav[i]; ok {
  1058  				for _, s := range scvg {
  1059  					// Ignore the case of s.N == 0. setRange doesn't handle
  1060  					// it and it's a no-op anyway.
  1061  					if s.N != 0 {
  1062  						chunk.scavenged.setRange(s.I, s.N)
  1063  					}
  1064  				}
  1065  			}
  1066  		}
  1067  
  1068  		// Apply alloc state.
  1069  		for _, s := range init {
  1070  			// Ignore the case of s.N == 0. allocRange doesn't handle
  1071  			// it and it's a no-op anyway.
  1072  			if s.N != 0 {
  1073  				chunk.allocRange(s.I, s.N)
  1074  
  1075  				// Make sure the scavenge index is updated.
  1076  				p.scav.index.alloc(ci, s.N)
  1077  			}
  1078  		}
  1079  
  1080  		// Update heap metadata for the allocRange calls above.
  1081  		systemstack(func() {
  1082  			lock(p.mheapLock)
  1083  			p.update(addr, pallocChunkPages, false, false)
  1084  			unlock(p.mheapLock)
  1085  		})
  1086  	}
  1087  
  1088  	return (*PageAlloc)(p)
  1089  }
  1090  
  1091  // FreePageAlloc releases hard OS resources owned by the pageAlloc. Once this
  1092  // is called the pageAlloc may no longer be used. The object itself will be
  1093  // collected by the garbage collector once it is no longer live.
  1094  func FreePageAlloc(pp *PageAlloc) {
  1095  	p := (*pageAlloc)(pp)
  1096  
  1097  	// Free all the mapped space for the summary levels.
  1098  	if pageAlloc64Bit != 0 {
  1099  		for l := 0; l < summaryLevels; l++ {
  1100  			// This isn't quite right, as some of this memory may
  1101  			// be Ready instead of Reserved. The mappedReady and
  1102  			// testSysStat adjustments below correct for the
  1103  			// difference.
  1104  			sysUnreserve(unsafe.Pointer(&p.summary[l][0]), uintptr(cap(p.summary[l]))*pallocSumBytes)
  1105  		}
  1106  	} else {
  1107  		resSize := uintptr(0)
  1108  		for _, s := range p.summary {
  1109  			resSize += uintptr(cap(s)) * pallocSumBytes
  1110  		}
  1111  		// See sysUnreserve comment above.
  1112  		sysUnreserve(unsafe.Pointer(&p.summary[0][0]), alignUp(resSize, physPageSize))
  1113  	}
  1114  
  1115  	// Subtract back out whatever we mapped for the summaries.
  1116  	// sysUsed adds to p.sysStat and memstats.mappedReady no matter what
  1117  	// (and in anger should actually be accounted for), and there's no other
  1118  	// way to figure out how much we actually mapped.
  1119  	gcController.mappedReady.Add(-int64(p.summaryMappedReady))
  1120  	testSysStat.add(-int64(p.summaryMappedReady))
  1121  
  1122  	// Free extra data structures.
  1123  	//
  1124  	// TODO(prattmic): As above, some of this may be Ready, so we should
  1125  	// manually adjust mappedReady and testSysStat?
  1126  	sysUnreserve(unsafe.Pointer(&p.scav.index.chunks[0]), uintptr(cap(p.scav.index.chunks))*unsafe.Sizeof(atomicScavChunkData{}))
  1127  
  1128  	// Free the mapped space for chunks.
  1129  	for i := range p.chunks {
  1130  		if x := p.chunks[i]; x != nil {
  1131  			p.chunks[i] = nil
  1132  			// This memory comes from sysAlloc and will always be page-aligned.
  1133  			sysFree(unsafe.Pointer(x), unsafe.Sizeof(*p.chunks[0]), testSysStat)
  1134  		}
  1135  	}
  1136  }
  1137  
  1138  // BaseChunkIdx is a convenient chunkIdx value which works on both
  1139  // 64 bit and 32 bit platforms, allowing the tests to share code
  1140  // between the two.
  1141  //
  1142  // This should not be higher than 0x100*pallocChunkBytes to support
  1143  // mips and mipsle, which only have 31-bit address spaces.
  1144  var BaseChunkIdx = func() ChunkIdx {
  1145  	var prefix uintptr
  1146  	if pageAlloc64Bit != 0 {
  1147  		prefix = 0xc000
  1148  	} else {
  1149  		prefix = 0x100
  1150  	}
  1151  	baseAddr := prefix * pallocChunkBytes
  1152  	if goos.IsAix != 0 {
  1153  		baseAddr += arenaBaseOffset
  1154  	}
  1155  	return ChunkIdx(chunkIndex(baseAddr))
  1156  }()
  1157  
  1158  // PageBase returns an address given a chunk index and a page index
  1159  // relative to that chunk.
  1160  func PageBase(c ChunkIdx, pageIdx uint) uintptr {
  1161  	return chunkBase(chunkIdx(c)) + uintptr(pageIdx)*pageSize
  1162  }
  1163  
  1164  type BitsMismatch struct {
  1165  	Base      uintptr
  1166  	Got, Want uint64
  1167  }
  1168  
  1169  func CheckScavengedBitsCleared(mismatches []BitsMismatch) (n int, ok bool) {
  1170  	ok = true
  1171  
  1172  	// Run on the system stack to avoid stack growth allocation.
  1173  	systemstack(func() {
  1174  		getg().m.mallocing++
  1175  
  1176  		// Lock so that we can safely access the bitmap.
  1177  		lock(&mheap_.lock)
  1178  
  1179  	chunkLoop:
  1180  		for i := mheap_.pages.start; i < mheap_.pages.end; i++ {
  1181  			chunk := mheap_.pages.tryChunkOf(i)
  1182  			if chunk == nil {
  1183  				continue
  1184  			}
  1185  			cb := chunkBase(i)
  1186  			for j := 0; j < pallocChunkPages/64; j++ {
  1187  				// Run over each 64-bit bitmap section and ensure
  1188  				// scavenged is being cleared properly on allocation.
  1189  				// If a used bit and scavenged bit are both set, that's
  1190  				// an error, and could indicate a larger problem, or
  1191  				// an accounting problem.
  1192  				want := chunk.scavenged[j] &^ chunk.pallocBits[j]
  1193  				got := chunk.scavenged[j]
  1194  				if want != got {
  1195  					ok = false
  1196  					if n >= len(mismatches) {
  1197  						break chunkLoop
  1198  					}
  1199  					mismatches[n] = BitsMismatch{
  1200  						Base: cb + uintptr(j)*64*pageSize,
  1201  						Got:  got,
  1202  						Want: want,
  1203  					}
  1204  					n++
  1205  				}
  1206  			}
  1207  		}
  1208  		unlock(&mheap_.lock)
  1209  
  1210  		getg().m.mallocing--
  1211  	})
  1212  
  1213  	if randomizeHeapBase && len(mismatches) > 0 {
  1214  		// When goexperiment.RandomizedHeapBase64 is set we use a series of
  1215  		// padding pages to generate randomized heap base address which have
  1216  		// both the alloc and scav bits set. Because of this we expect exactly
  1217  		// one arena will have mismatches, so check for that explicitly and
  1218  		// remove the mismatches if that property holds. If we see more than one
  1219  		// arena with this property, that is an indication something has
  1220  		// actually gone wrong, so return the mismatches.
  1221  		//
  1222  		// We do this, instead of ignoring the mismatches in the chunkLoop, because
  1223  		// it's not easy to determine which arena we added the padding pages to
  1224  		// programmatically, without explicitly recording the base address somewhere
  1225  		// in a global variable (which we'd rather not do as the address of that variable
  1226  		// is likely to be somewhat predictable, potentially defeating the purpose
  1227  		// of our randomization).
  1228  		affectedArenas := map[arenaIdx]bool{}
  1229  		for _, mismatch := range mismatches {
  1230  			if mismatch.Base > 0 {
  1231  				affectedArenas[arenaIndex(mismatch.Base)] = true
  1232  			}
  1233  		}
  1234  		if len(affectedArenas) == 1 {
  1235  			ok = true
  1236  			// zero the mismatches
  1237  			for i := range n {
  1238  				mismatches[i] = BitsMismatch{}
  1239  			}
  1240  		}
  1241  	}
  1242  
  1243  	return
  1244  }
  1245  
  1246  func PageCachePagesLeaked() (leaked uintptr) {
  1247  	stw := stopTheWorld(stwForTestPageCachePagesLeaked)
  1248  
  1249  	// Walk over destroyed Ps and look for unflushed caches.
  1250  	deadp := allp[len(allp):cap(allp)]
  1251  	for _, p := range deadp {
  1252  		// Since we're going past len(allp) we may see nil Ps.
  1253  		// Just ignore them.
  1254  		if p != nil {
  1255  			leaked += uintptr(sys.OnesCount64(p.pcache.cache))
  1256  		}
  1257  	}
  1258  
  1259  	startTheWorld(stw)
  1260  	return
  1261  }
  1262  
  1263  var ProcYield = procyield
  1264  var OSYield = osyield
  1265  
  1266  type Mutex = mutex
  1267  
  1268  var Lock = lock
  1269  var Unlock = unlock
  1270  
  1271  var MutexContended = mutexContended
  1272  
  1273  func SemRootLock(addr *uint32) *mutex {
  1274  	root := semtable.rootFor(addr)
  1275  	return &root.lock
  1276  }
  1277  
  1278  var Semacquire = semacquire
  1279  var Semrelease1 = semrelease1
  1280  
  1281  func SemNwait(addr *uint32) uint32 {
  1282  	root := semtable.rootFor(addr)
  1283  	return root.nwait.Load()
  1284  }
  1285  
  1286  const SemTableSize = semTabSize
  1287  
  1288  // SemTable is a wrapper around semTable exported for testing.
  1289  type SemTable struct {
  1290  	semTable
  1291  }
  1292  
  1293  // Enqueue simulates enqueuing a waiter for a semaphore (or lock) at addr.
  1294  func (t *SemTable) Enqueue(addr *uint32) {
  1295  	s := acquireSudog()
  1296  	s.releasetime = 0
  1297  	s.acquiretime = 0
  1298  	s.ticket = 0
  1299  	t.semTable.rootFor(addr).queue(addr, s, false)
  1300  }
  1301  
  1302  // Dequeue simulates dequeuing a waiter for a semaphore (or lock) at addr.
  1303  //
  1304  // Returns true if there actually was a waiter to be dequeued.
  1305  func (t *SemTable) Dequeue(addr *uint32) bool {
  1306  	s, _, _ := t.semTable.rootFor(addr).dequeue(addr)
  1307  	if s != nil {
  1308  		releaseSudog(s)
  1309  		return true
  1310  	}
  1311  	return false
  1312  }
  1313  
  1314  // mspan wrapper for testing.
  1315  type MSpan mspan
  1316  
  1317  // Allocate an mspan for testing.
  1318  func AllocMSpan() *MSpan {
  1319  	var s *mspan
  1320  	systemstack(func() {
  1321  		lock(&mheap_.lock)
  1322  		s = (*mspan)(mheap_.spanalloc.alloc())
  1323  		s.init(0, 0)
  1324  		unlock(&mheap_.lock)
  1325  	})
  1326  	return (*MSpan)(s)
  1327  }
  1328  
  1329  // Free an allocated mspan.
  1330  func FreeMSpan(s *MSpan) {
  1331  	systemstack(func() {
  1332  		lock(&mheap_.lock)
  1333  		mheap_.spanalloc.free(unsafe.Pointer(s))
  1334  		unlock(&mheap_.lock)
  1335  	})
  1336  }
  1337  
  1338  func MSpanCountAlloc(ms *MSpan, bits []byte) int {
  1339  	s := (*mspan)(ms)
  1340  	s.nelems = uint16(len(bits) * 8)
  1341  	s.gcmarkBits = (*gcBits)(unsafe.Pointer(&bits[0]))
  1342  	result := s.countAlloc()
  1343  	s.gcmarkBits = nil
  1344  	return result
  1345  }
  1346  
  1347  const (
  1348  	TimeHistSubBucketBits = timeHistSubBucketBits
  1349  	TimeHistNumSubBuckets = timeHistNumSubBuckets
  1350  	TimeHistNumBuckets    = timeHistNumBuckets
  1351  	TimeHistMinBucketBits = timeHistMinBucketBits
  1352  	TimeHistMaxBucketBits = timeHistMaxBucketBits
  1353  )
  1354  
  1355  type TimeHistogram timeHistogram
  1356  
  1357  // Count returns the counts for the given bucket, subBucket indices.
  1358  // Returns true if the bucket was valid, otherwise returns the counts
  1359  // for the overflow bucket if bucket > 0 or the underflow bucket if
  1360  // bucket < 0, and false.
  1361  func (th *TimeHistogram) Count(bucket, subBucket int) (uint64, bool) {
  1362  	t := (*timeHistogram)(th)
  1363  	if bucket < 0 {
  1364  		return t.underflow.Load(), false
  1365  	}
  1366  	i := bucket*TimeHistNumSubBuckets + subBucket
  1367  	if i >= len(t.counts) {
  1368  		return t.overflow.Load(), false
  1369  	}
  1370  	return t.counts[i].Load(), true
  1371  }
  1372  
  1373  func (th *TimeHistogram) Record(duration int64) {
  1374  	(*timeHistogram)(th).record(duration)
  1375  }
  1376  
  1377  var TimeHistogramMetricsBuckets = timeHistogramMetricsBuckets
  1378  
  1379  func SetIntArgRegs(a int) int {
  1380  	lock(&finlock)
  1381  	old := intArgRegs
  1382  	if a >= 0 {
  1383  		intArgRegs = a
  1384  	}
  1385  	unlock(&finlock)
  1386  	return old
  1387  }
  1388  
  1389  func FinalizerGAsleep() bool {
  1390  	return fingStatus.Load()&fingWait != 0
  1391  }
  1392  
  1393  // For GCTestMoveStackOnNextCall, it's important not to introduce an
  1394  // extra layer of call, since then there's a return before the "real"
  1395  // next call.
  1396  var GCTestMoveStackOnNextCall = gcTestMoveStackOnNextCall
  1397  
  1398  // For GCTestIsReachable, it's important that we do this as a call so
  1399  // escape analysis can see through it.
  1400  func GCTestIsReachable(ptrs ...unsafe.Pointer) (mask uint64) {
  1401  	return gcTestIsReachable(ptrs...)
  1402  }
  1403  
  1404  // For GCTestPointerClass, it's important that we do this as a call so
  1405  // escape analysis can see through it.
  1406  //
  1407  // This is nosplit because gcTestPointerClass is.
  1408  //
  1409  //go:nosplit
  1410  func GCTestPointerClass(p unsafe.Pointer) string {
  1411  	return gcTestPointerClass(p)
  1412  }
  1413  
  1414  const Raceenabled = raceenabled
  1415  
  1416  const (
  1417  	GCBackgroundUtilization            = gcBackgroundUtilization
  1418  	GCGoalUtilization                  = gcGoalUtilization
  1419  	DefaultHeapMinimum                 = defaultHeapMinimum
  1420  	MemoryLimitHeapGoalHeadroomPercent = memoryLimitHeapGoalHeadroomPercent
  1421  	MemoryLimitMinHeapGoalHeadroom     = memoryLimitMinHeapGoalHeadroom
  1422  )
  1423  
  1424  type GCController struct {
  1425  	gcControllerState
  1426  }
  1427  
  1428  func NewGCController(gcPercent int, memoryLimit int64) *GCController {
  1429  	// Force the controller to escape. We're going to
  1430  	// do 64-bit atomics on it, and if it gets stack-allocated
  1431  	// on a 32-bit architecture, it may get allocated unaligned
  1432  	// space.
  1433  	g := Escape(new(GCController))
  1434  	g.gcControllerState.test = true // Mark it as a test copy.
  1435  	g.init(int32(gcPercent), memoryLimit)
  1436  	return g
  1437  }
  1438  
  1439  func (c *GCController) StartCycle(stackSize, globalsSize uint64, scannableFrac float64, gomaxprocs int) {
  1440  	trigger, _ := c.trigger()
  1441  	if c.heapMarked > trigger {
  1442  		trigger = c.heapMarked
  1443  	}
  1444  	c.maxStackScan.Store(stackSize)
  1445  	c.globalsScan.Store(globalsSize)
  1446  	c.heapLive.Store(trigger)
  1447  	c.heapScan.Add(int64(float64(trigger-c.heapMarked) * scannableFrac))
  1448  	c.startCycle(0, gomaxprocs, gcTrigger{kind: gcTriggerHeap})
  1449  }
  1450  
  1451  func (c *GCController) AssistWorkPerByte() float64 {
  1452  	return c.assistWorkPerByte.Load()
  1453  }
  1454  
  1455  func (c *GCController) HeapGoal() uint64 {
  1456  	return c.heapGoal()
  1457  }
  1458  
  1459  func (c *GCController) HeapLive() uint64 {
  1460  	return c.heapLive.Load()
  1461  }
  1462  
  1463  func (c *GCController) HeapMarked() uint64 {
  1464  	return c.heapMarked
  1465  }
  1466  
  1467  func (c *GCController) Triggered() uint64 {
  1468  	return c.triggered
  1469  }
  1470  
  1471  type GCControllerReviseDelta struct {
  1472  	HeapLive        int64
  1473  	HeapScan        int64
  1474  	HeapScanWork    int64
  1475  	StackScanWork   int64
  1476  	GlobalsScanWork int64
  1477  }
  1478  
  1479  func (c *GCController) Revise(d GCControllerReviseDelta) {
  1480  	c.heapLive.Add(d.HeapLive)
  1481  	c.heapScan.Add(d.HeapScan)
  1482  	c.heapScanWork.Add(d.HeapScanWork)
  1483  	c.stackScanWork.Add(d.StackScanWork)
  1484  	c.globalsScanWork.Add(d.GlobalsScanWork)
  1485  	c.revise()
  1486  }
  1487  
  1488  func (c *GCController) EndCycle(bytesMarked uint64, assistTime, elapsed int64, gomaxprocs int) {
  1489  	c.assistTime.Store(assistTime)
  1490  	c.endCycle(elapsed, gomaxprocs, false)
  1491  	c.resetLive(bytesMarked)
  1492  	c.commit(false)
  1493  }
  1494  
  1495  func (c *GCController) AddIdleMarkWorker() bool {
  1496  	return c.addIdleMarkWorker()
  1497  }
  1498  
  1499  func (c *GCController) NeedIdleMarkWorker() bool {
  1500  	return c.needIdleMarkWorker()
  1501  }
  1502  
  1503  func (c *GCController) RemoveIdleMarkWorker() {
  1504  	c.removeIdleMarkWorker()
  1505  }
  1506  
  1507  func (c *GCController) SetMaxIdleMarkWorkers(max int32) {
  1508  	c.setMaxIdleMarkWorkers(max)
  1509  }
  1510  
  1511  var alwaysFalse bool
  1512  var escapeSink any
  1513  
  1514  func Escape[T any](x T) T {
  1515  	if alwaysFalse {
  1516  		escapeSink = x
  1517  	}
  1518  	return x
  1519  }
  1520  
  1521  // Acquirem blocks preemption.
  1522  func Acquirem() {
  1523  	acquirem()
  1524  }
  1525  
  1526  func Releasem() {
  1527  	releasem(getg().m)
  1528  }
  1529  
  1530  // GoschedIfBusy is an explicit preemption check to call back
  1531  // into the scheduler. This is useful for tests that run code
  1532  // which spend most of their time as non-preemptible, as it
  1533  // can be placed right after becoming preemptible again to ensure
  1534  // that the scheduler gets a chance to preempt the goroutine.
  1535  func GoschedIfBusy() {
  1536  	goschedIfBusy()
  1537  }
  1538  
  1539  type PIController struct {
  1540  	piController
  1541  }
  1542  
  1543  func NewPIController(kp, ti, tt, min, max float64) *PIController {
  1544  	return &PIController{piController{
  1545  		kp:  kp,
  1546  		ti:  ti,
  1547  		tt:  tt,
  1548  		min: min,
  1549  		max: max,
  1550  	}}
  1551  }
  1552  
  1553  func (c *PIController) Next(input, setpoint, period float64) (float64, bool) {
  1554  	return c.piController.next(input, setpoint, period)
  1555  }
  1556  
  1557  const (
  1558  	CapacityPerProc          = capacityPerProc
  1559  	GCCPULimiterUpdatePeriod = gcCPULimiterUpdatePeriod
  1560  )
  1561  
  1562  type GCCPULimiter struct {
  1563  	limiter gcCPULimiterState
  1564  }
  1565  
  1566  func NewGCCPULimiter(now int64, gomaxprocs int32) *GCCPULimiter {
  1567  	// Force the controller to escape. We're going to
  1568  	// do 64-bit atomics on it, and if it gets stack-allocated
  1569  	// on a 32-bit architecture, it may get allocated unaligned
  1570  	// space.
  1571  	l := Escape(new(GCCPULimiter))
  1572  	l.limiter.test = true
  1573  	l.limiter.resetCapacity(now, gomaxprocs)
  1574  	return l
  1575  }
  1576  
  1577  func (l *GCCPULimiter) Fill() uint64 {
  1578  	return l.limiter.bucket.fill
  1579  }
  1580  
  1581  func (l *GCCPULimiter) Capacity() uint64 {
  1582  	return l.limiter.bucket.capacity
  1583  }
  1584  
  1585  func (l *GCCPULimiter) Overflow() uint64 {
  1586  	return l.limiter.overflow
  1587  }
  1588  
  1589  func (l *GCCPULimiter) Limiting() bool {
  1590  	return l.limiter.limiting()
  1591  }
  1592  
  1593  func (l *GCCPULimiter) NeedUpdate(now int64) bool {
  1594  	return l.limiter.needUpdate(now)
  1595  }
  1596  
  1597  func (l *GCCPULimiter) StartGCTransition(enableGC bool, now int64) {
  1598  	l.limiter.startGCTransition(enableGC, now)
  1599  }
  1600  
  1601  func (l *GCCPULimiter) FinishGCTransition(now int64) {
  1602  	l.limiter.finishGCTransition(now)
  1603  }
  1604  
  1605  func (l *GCCPULimiter) Update(now int64) {
  1606  	l.limiter.update(now)
  1607  }
  1608  
  1609  func (l *GCCPULimiter) AddAssistTime(t int64) {
  1610  	l.limiter.addAssistTime(t)
  1611  }
  1612  
  1613  func (l *GCCPULimiter) ResetCapacity(now int64, nprocs int32) {
  1614  	l.limiter.resetCapacity(now, nprocs)
  1615  }
  1616  
  1617  const ScavengePercent = scavengePercent
  1618  
  1619  type Scavenger struct {
  1620  	Sleep      func(int64) int64
  1621  	Scavenge   func(uintptr) (uintptr, int64)
  1622  	ShouldStop func() bool
  1623  	GoMaxProcs func() int32
  1624  
  1625  	released  atomic.Uintptr
  1626  	scavenger scavengerState
  1627  	stop      chan<- struct{}
  1628  	done      <-chan struct{}
  1629  }
  1630  
  1631  func (s *Scavenger) Start() {
  1632  	if s.Sleep == nil || s.Scavenge == nil || s.ShouldStop == nil || s.GoMaxProcs == nil {
  1633  		panic("must populate all stubs")
  1634  	}
  1635  
  1636  	// Install hooks.
  1637  	s.scavenger.sleepStub = s.Sleep
  1638  	s.scavenger.scavenge = s.Scavenge
  1639  	s.scavenger.shouldStop = s.ShouldStop
  1640  	s.scavenger.gomaxprocs = s.GoMaxProcs
  1641  
  1642  	// Start up scavenger goroutine, and wait for it to be ready.
  1643  	stop := make(chan struct{})
  1644  	s.stop = stop
  1645  	done := make(chan struct{})
  1646  	s.done = done
  1647  	go func() {
  1648  		// This should match bgscavenge, loosely.
  1649  		s.scavenger.init()
  1650  		s.scavenger.park()
  1651  		for {
  1652  			select {
  1653  			case <-stop:
  1654  				close(done)
  1655  				return
  1656  			default:
  1657  			}
  1658  			released, workTime := s.scavenger.run()
  1659  			if released == 0 {
  1660  				s.scavenger.park()
  1661  				continue
  1662  			}
  1663  			s.released.Add(released)
  1664  			s.scavenger.sleep(workTime)
  1665  		}
  1666  	}()
  1667  	if !s.BlockUntilParked(1e9 /* 1 second */) {
  1668  		panic("timed out waiting for scavenger to get ready")
  1669  	}
  1670  }
  1671  
  1672  // BlockUntilParked blocks until the scavenger parks, or until
  1673  // timeout is exceeded. Returns true if the scavenger parked.
  1674  //
  1675  // Note that in testing, parked means something slightly different.
  1676  // In anger, the scavenger parks to sleep, too, but in testing,
  1677  // it only parks when it actually has no work to do.
  1678  func (s *Scavenger) BlockUntilParked(timeout int64) bool {
  1679  	// Just spin, waiting for it to park.
  1680  	//
  1681  	// The actual parking process is racy with respect to
  1682  	// wakeups, which is fine, but for testing we need something
  1683  	// a bit more robust.
  1684  	start := nanotime()
  1685  	for nanotime()-start < timeout {
  1686  		lock(&s.scavenger.lock)
  1687  		parked := s.scavenger.parked
  1688  		unlock(&s.scavenger.lock)
  1689  		if parked {
  1690  			return true
  1691  		}
  1692  		Gosched()
  1693  	}
  1694  	return false
  1695  }
  1696  
  1697  // Released returns how many bytes the scavenger released.
  1698  func (s *Scavenger) Released() uintptr {
  1699  	return s.released.Load()
  1700  }
  1701  
  1702  // Wake wakes up a parked scavenger to keep running.
  1703  func (s *Scavenger) Wake() {
  1704  	s.scavenger.wake()
  1705  }
  1706  
  1707  // Stop cleans up the scavenger's resources. The scavenger
  1708  // must be parked for this to work.
  1709  func (s *Scavenger) Stop() {
  1710  	lock(&s.scavenger.lock)
  1711  	parked := s.scavenger.parked
  1712  	unlock(&s.scavenger.lock)
  1713  	if !parked {
  1714  		panic("tried to clean up scavenger that is not parked")
  1715  	}
  1716  	close(s.stop)
  1717  	s.Wake()
  1718  	<-s.done
  1719  }
  1720  
  1721  type ScavengeIndex struct {
  1722  	i scavengeIndex
  1723  }
  1724  
  1725  func NewScavengeIndex(min, max ChunkIdx) *ScavengeIndex {
  1726  	s := new(ScavengeIndex)
  1727  	// This is a bit lazy but we easily guarantee we'll be able
  1728  	// to reference all the relevant chunks. The worst-case
  1729  	// memory usage here is 512 MiB, but tests generally use
  1730  	// small offsets from BaseChunkIdx, which results in ~100s
  1731  	// of KiB in memory use.
  1732  	//
  1733  	// This may still be worth making better, at least by sharing
  1734  	// this fairly large array across calls with a sync.Pool or
  1735  	// something. Currently, when the tests are run serially,
  1736  	// it takes around 0.5s. Not all that much, but if we have
  1737  	// a lot of tests like this it could add up.
  1738  	s.i.chunks = make([]atomicScavChunkData, max)
  1739  	s.i.min.Store(uintptr(min))
  1740  	s.i.max.Store(uintptr(max))
  1741  	s.i.minHeapIdx.Store(uintptr(min))
  1742  	s.i.test = true
  1743  	return s
  1744  }
  1745  
  1746  func (s *ScavengeIndex) Find(force bool) (ChunkIdx, uint) {
  1747  	ci, off := s.i.find(force)
  1748  	return ChunkIdx(ci), off
  1749  }
  1750  
  1751  func (s *ScavengeIndex) AllocRange(base, limit uintptr) {
  1752  	sc, ec := chunkIndex(base), chunkIndex(limit-1)
  1753  	si, ei := chunkPageIndex(base), chunkPageIndex(limit-1)
  1754  
  1755  	if sc == ec {
  1756  		// The range doesn't cross any chunk boundaries.
  1757  		s.i.alloc(sc, ei+1-si)
  1758  	} else {
  1759  		// The range crosses at least one chunk boundary.
  1760  		s.i.alloc(sc, pallocChunkPages-si)
  1761  		for c := sc + 1; c < ec; c++ {
  1762  			s.i.alloc(c, pallocChunkPages)
  1763  		}
  1764  		s.i.alloc(ec, ei+1)
  1765  	}
  1766  }
  1767  
  1768  func (s *ScavengeIndex) FreeRange(base, limit uintptr) {
  1769  	sc, ec := chunkIndex(base), chunkIndex(limit-1)
  1770  	si, ei := chunkPageIndex(base), chunkPageIndex(limit-1)
  1771  
  1772  	if sc == ec {
  1773  		// The range doesn't cross any chunk boundaries.
  1774  		s.i.free(sc, si, ei+1-si)
  1775  	} else {
  1776  		// The range crosses at least one chunk boundary.
  1777  		s.i.free(sc, si, pallocChunkPages-si)
  1778  		for c := sc + 1; c < ec; c++ {
  1779  			s.i.free(c, 0, pallocChunkPages)
  1780  		}
  1781  		s.i.free(ec, 0, ei+1)
  1782  	}
  1783  }
  1784  
  1785  func (s *ScavengeIndex) ResetSearchAddrs() {
  1786  	for _, a := range []*atomicOffAddr{&s.i.searchAddrBg, &s.i.searchAddrForce} {
  1787  		addr, marked := a.Load()
  1788  		if marked {
  1789  			a.StoreUnmark(addr, addr)
  1790  		}
  1791  		a.Clear()
  1792  	}
  1793  	s.i.freeHWM = minOffAddr
  1794  }
  1795  
  1796  func (s *ScavengeIndex) NextGen() {
  1797  	s.i.nextGen()
  1798  }
  1799  
  1800  func (s *ScavengeIndex) SetEmpty(ci ChunkIdx) {
  1801  	s.i.setEmpty(chunkIdx(ci))
  1802  }
  1803  
  1804  func CheckPackScavChunkData(gen uint32, inUse, lastInUse uint16, flags uint8) bool {
  1805  	sc0 := scavChunkData{
  1806  		gen:            gen,
  1807  		inUse:          inUse,
  1808  		lastInUse:      lastInUse,
  1809  		scavChunkFlags: scavChunkFlags(flags),
  1810  	}
  1811  	scp := sc0.pack()
  1812  	sc1 := unpackScavChunkData(scp)
  1813  	return sc0 == sc1
  1814  }
  1815  
  1816  const GTrackingPeriod = gTrackingPeriod
  1817  
  1818  var ZeroBase = unsafe.Pointer(&zerobase)
  1819  
  1820  const UserArenaChunkBytes = userArenaChunkBytes
  1821  
  1822  type UserArena struct {
  1823  	arena *userArena
  1824  }
  1825  
  1826  func NewUserArena() *UserArena {
  1827  	return &UserArena{newUserArena()}
  1828  }
  1829  
  1830  func (a *UserArena) New(out *any) {
  1831  	i := efaceOf(out)
  1832  	typ := i._type
  1833  	if typ.Kind() != abi.Pointer {
  1834  		panic("new result of non-ptr type")
  1835  	}
  1836  	typ = (*ptrtype)(unsafe.Pointer(typ)).Elem
  1837  	i.data = a.arena.new(typ)
  1838  }
  1839  
  1840  func (a *UserArena) Slice(sl any, cap int) {
  1841  	a.arena.slice(sl, cap)
  1842  }
  1843  
  1844  func (a *UserArena) Free() {
  1845  	a.arena.free()
  1846  }
  1847  
  1848  func GlobalWaitingArenaChunks() int {
  1849  	n := 0
  1850  	systemstack(func() {
  1851  		lock(&mheap_.lock)
  1852  		for s := mheap_.userArena.quarantineList.first; s != nil; s = s.next {
  1853  			n++
  1854  		}
  1855  		unlock(&mheap_.lock)
  1856  	})
  1857  	return n
  1858  }
  1859  
  1860  func UserArenaClone[T any](s T) T {
  1861  	return arena_heapify(s).(T)
  1862  }
  1863  
  1864  var AlignUp = alignUp
  1865  
  1866  func BlockUntilEmptyFinalizerQueue(timeout int64) bool {
  1867  	return blockUntilEmptyFinalizerQueue(timeout)
  1868  }
  1869  
  1870  func BlockUntilEmptyCleanupQueue(timeout int64) bool {
  1871  	return gcCleanups.blockUntilEmpty(timeout)
  1872  }
  1873  
  1874  func FrameStartLine(f *Frame) int {
  1875  	return f.startLine
  1876  }
  1877  
  1878  // PersistentAlloc allocates some memory that lives outside the Go heap.
  1879  // This memory will never be freed; use sparingly.
  1880  func PersistentAlloc(n, align uintptr) unsafe.Pointer {
  1881  	return persistentalloc(n, align, &memstats.other_sys)
  1882  }
  1883  
  1884  const TagAlign = tagAlign
  1885  
  1886  // FPCallers works like Callers and uses frame pointer unwinding to populate
  1887  // pcBuf with the return addresses of the physical frames on the stack.
  1888  func FPCallers(pcBuf []uintptr) int {
  1889  	return fpTracebackPCs(unsafe.Pointer(getfp()), pcBuf)
  1890  }
  1891  
  1892  const FramePointerEnabled = framepointer_enabled
  1893  
  1894  var (
  1895  	IsPinned      = isPinned
  1896  	GetPinCounter = pinnerGetPinCounter
  1897  )
  1898  
  1899  func SetPinnerLeakPanic(f func()) {
  1900  	pinnerLeakPanic = f
  1901  }
  1902  func GetPinnerLeakPanic() func() {
  1903  	return pinnerLeakPanic
  1904  }
  1905  
  1906  var testUintptr uintptr
  1907  
  1908  func MyGenericFunc[T any]() {
  1909  	systemstack(func() {
  1910  		testUintptr = 4
  1911  	})
  1912  }
  1913  
  1914  func UnsafePoint(pc uintptr) bool {
  1915  	fi := findfunc(pc)
  1916  	v := pcdatavalue(fi, abi.PCDATA_UnsafePoint, pc)
  1917  	switch v {
  1918  	case abi.UnsafePointUnsafe:
  1919  		return true
  1920  	case abi.UnsafePointSafe:
  1921  		return false
  1922  	case abi.UnsafePointRestart1, abi.UnsafePointRestart2, abi.UnsafePointRestartAtEntry:
  1923  		// These are all interruptible, they just encode a nonstandard
  1924  		// way of recovering when interrupted.
  1925  		return false
  1926  	default:
  1927  		var buf [20]byte
  1928  		panic("invalid unsafe point code " + string(itoa(buf[:], uint64(v))))
  1929  	}
  1930  }
  1931  
  1932  type TraceMap struct {
  1933  	traceMap
  1934  }
  1935  
  1936  func (m *TraceMap) PutString(s string) (uint64, bool) {
  1937  	return m.traceMap.put(unsafe.Pointer(unsafe.StringData(s)), uintptr(len(s)))
  1938  }
  1939  
  1940  func (m *TraceMap) Reset() {
  1941  	m.traceMap.reset()
  1942  }
  1943  
  1944  func SetSpinInGCMarkDone(spin bool) {
  1945  	gcDebugMarkDone.spinAfterRaggedBarrier.Store(spin)
  1946  }
  1947  
  1948  func GCMarkDoneRestarted() bool {
  1949  	// Only read this outside of the GC. If we're running during a GC, just report false.
  1950  	mp := acquirem()
  1951  	if gcphase != _GCoff {
  1952  		releasem(mp)
  1953  		return false
  1954  	}
  1955  	restarted := gcDebugMarkDone.restartedDueTo27993
  1956  	releasem(mp)
  1957  	return restarted
  1958  }
  1959  
  1960  func GCMarkDoneResetRestartFlag() {
  1961  	mp := acquirem()
  1962  	for gcphase != _GCoff {
  1963  		releasem(mp)
  1964  		Gosched()
  1965  		mp = acquirem()
  1966  	}
  1967  	gcDebugMarkDone.restartedDueTo27993 = false
  1968  	releasem(mp)
  1969  }
  1970  
  1971  type BitCursor struct {
  1972  	b bitCursor
  1973  }
  1974  
  1975  func NewBitCursor(buf *byte) BitCursor {
  1976  	return BitCursor{b: bitCursor{ptr: buf, n: 0}}
  1977  }
  1978  
  1979  func (b BitCursor) Write(data *byte, cnt uintptr) {
  1980  	b.b.write(data, cnt)
  1981  }
  1982  func (b BitCursor) Offset(cnt uintptr) BitCursor {
  1983  	return BitCursor{b: b.b.offset(cnt)}
  1984  }
  1985  
  1986  const (
  1987  	BubbleAssocUnbubbled     = bubbleAssocUnbubbled
  1988  	BubbleAssocCurrentBubble = bubbleAssocCurrentBubble
  1989  	BubbleAssocOtherBubble   = bubbleAssocOtherBubble
  1990  )
  1991  
  1992  type TraceStackTable traceStackTable
  1993  
  1994  func (t *TraceStackTable) Reset() {
  1995  	t.tab.reset()
  1996  }
  1997  
  1998  func TraceStack(gp *G, tab *TraceStackTable) {
  1999  	traceStack(0, gp, (*traceStackTable)(tab))
  2000  }
  2001  
  2002  var X86HasAVX = &x86HasAVX
  2003  
  2004  var DebugDecorateMappings = &debug.decoratemappings
  2005  
  2006  func SetVMANameSupported() bool { return setVMANameSupported() }
  2007  
  2008  type ListHead struct {
  2009  	l listHead
  2010  }
  2011  
  2012  func (head *ListHead) Init(off uintptr) {
  2013  	head.l.init(off)
  2014  }
  2015  
  2016  type ListNode struct {
  2017  	l listNode
  2018  }
  2019  
  2020  func (head *ListHead) Push(p unsafe.Pointer) {
  2021  	head.l.push(p)
  2022  }
  2023  
  2024  func (head *ListHead) Pop() unsafe.Pointer {
  2025  	return head.l.pop()
  2026  }
  2027  
  2028  func (head *ListHead) Remove(p unsafe.Pointer) {
  2029  	head.l.remove(p)
  2030  }
  2031  
  2032  type ListHeadManual struct {
  2033  	l listHeadManual
  2034  }
  2035  
  2036  func (head *ListHeadManual) Init(off uintptr) {
  2037  	head.l.init(off)
  2038  }
  2039  
  2040  type ListNodeManual struct {
  2041  	l listNodeManual
  2042  }
  2043  
  2044  func (head *ListHeadManual) Push(p unsafe.Pointer) {
  2045  	head.l.push(p)
  2046  }
  2047  
  2048  func (head *ListHeadManual) Pop() unsafe.Pointer {
  2049  	return head.l.pop()
  2050  }
  2051  
  2052  func (head *ListHeadManual) Remove(p unsafe.Pointer) {
  2053  	head.l.remove(p)
  2054  }
  2055  
  2056  func Hexdumper(base uintptr, wordBytes int, mark func(addr uintptr, start func()), data ...[]byte) string {
  2057  	buf := make([]byte, 0, 2048)
  2058  	getg().writebuf = buf
  2059  	h := hexdumper{addr: base, addrBytes: 4, wordBytes: uint8(wordBytes)}
  2060  	if mark != nil {
  2061  		h.mark = func(addr uintptr, m hexdumpMarker) {
  2062  			mark(addr, m.start)
  2063  		}
  2064  	}
  2065  	for _, d := range data {
  2066  		h.write(d)
  2067  	}
  2068  	h.close()
  2069  	n := len(getg().writebuf)
  2070  	getg().writebuf = nil
  2071  	if n == cap(buf) {
  2072  		panic("Hexdumper buf too small")
  2073  	}
  2074  	return string(buf[:n])
  2075  }
  2076  
  2077  func HexdumpWords(p, bytes uintptr) string {
  2078  	buf := make([]byte, 0, 2048)
  2079  	getg().writebuf = buf
  2080  	hexdumpWords(p, bytes, nil)
  2081  	n := len(getg().writebuf)
  2082  	getg().writebuf = nil
  2083  	if n == cap(buf) {
  2084  		panic("HexdumpWords buf too small")
  2085  	}
  2086  	return string(buf[:n])
  2087  }
  2088  
  2089  // DumpPrintQuoted provides access to print(quoted()) for the tests in
  2090  // runtime/print_quoted_test.go, allowing us to test that implementation.
  2091  func DumpPrintQuoted(s string) string {
  2092  	gp := getg()
  2093  	gp.writebuf = make([]byte, 0, 1<<20)
  2094  	print(quoted(s))
  2095  	buf := gp.writebuf
  2096  	gp.writebuf = nil
  2097  
  2098  	return string(buf)
  2099  }
  2100  
  2101  // DumpPrint returns the output of print(v).
  2102  func DumpPrint[T any](v T) string {
  2103  	gp := getg()
  2104  	gp.writebuf = make([]byte, 0, 2048)
  2105  	print(v)
  2106  	buf := gp.writebuf
  2107  	gp.writebuf = nil
  2108  
  2109  	return string(buf)
  2110  }
  2111  
  2112  var (
  2113  	Float64Bytes    = float64Bytes
  2114  	Float32Bytes    = float32Bytes
  2115  	Complex128Bytes = complex128Bytes
  2116  	Complex64Bytes  = complex64Bytes
  2117  )
  2118
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