libgo: update to Go 1.15.3 release
Change-Id: Id414d567a1a57ca9529eb83c64fbfc4f16afafd1
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/265717
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
diff --git a/libgo/MERGE b/libgo/MERGE
index cfbf488..4b158c0 100644
--- a/libgo/MERGE
+++ b/libgo/MERGE
@@ -1,4 +1,4 @@
-9706f510a5e2754595d716bd64be8375997311fb
+1984ee00048b63eacd2155cd6d74a2d13e998272
The first line of this file holds the git revision number of the
last merge done from the master library sources.
diff --git a/libgo/VERSION b/libgo/VERSION
index c19def3..93c7b2d 100644
--- a/libgo/VERSION
+++ b/libgo/VERSION
@@ -1 +1 @@
-go1.15.2
+go1.15.3
diff --git a/libgo/go/bytes/bytes.go b/libgo/go/bytes/bytes.go
index aa07b9f..ce52649 100644
--- a/libgo/go/bytes/bytes.go
+++ b/libgo/go/bytes/bytes.go
@@ -227,19 +227,26 @@
continue
}
r, width = utf8.DecodeRune(s[i:])
- if r == utf8.RuneError {
- for _, r = range chars {
- if r == utf8.RuneError {
+ if r != utf8.RuneError {
+ // r is 2 to 4 bytes
+ if len(chars) == width {
+ if chars == string(r) {
return i
}
+ continue
}
- continue
+ // Use bytealg.IndexString for performance if available.
+ if bytealg.MaxLen >= width {
+ if bytealg.IndexString(chars, string(r)) >= 0 {
+ return i
+ }
+ continue
+ }
}
- // r is 2 to 4 bytes. Using strings.Index is more reasonable, but as the bytes
- // package should not import the strings package, use bytealg.IndexString
- // instead. And this does not seem to lose much performance.
- if chars == string(r) || bytealg.IndexString(chars, string(r)) >= 0 {
- return i
+ for _, ch := range chars {
+ if r == ch {
+ return i
+ }
}
}
return -1
@@ -304,19 +311,26 @@
}
r, size := utf8.DecodeLastRune(s[:i])
i -= size
- if r == utf8.RuneError {
- for _, r = range chars {
- if r == utf8.RuneError {
+ if r != utf8.RuneError {
+ // r is 2 to 4 bytes
+ if len(chars) == size {
+ if chars == string(r) {
return i
}
+ continue
}
- continue
+ // Use bytealg.IndexString for performance if available.
+ if bytealg.MaxLen >= size {
+ if bytealg.IndexString(chars, string(r)) >= 0 {
+ return i
+ }
+ continue
+ }
}
- // r is 2 to 4 bytes. Using strings.Index is more reasonable, but as the bytes
- // package should not import the strings package, use bytealg.IndexString
- // instead. And this does not seem to lose much performance.
- if chars == string(r) || bytealg.IndexString(chars, string(r)) >= 0 {
- return i
+ for _, ch := range chars {
+ if r == ch {
+ return i
+ }
}
}
return -1
diff --git a/libgo/go/cmd/cgo/gcc.go b/libgo/go/cmd/cgo/gcc.go
index f774cbb..37bafcf 100644
--- a/libgo/go/cmd/cgo/gcc.go
+++ b/libgo/go/cmd/cgo/gcc.go
@@ -2459,6 +2459,18 @@
tt := *t
tt.C = &TypeRepr{"%s %s", []interface{}{dt.Kind, tag}}
tt.Go = c.Ident("struct{}")
+ if dt.Kind == "struct" {
+ // We don't know what the representation of this struct is, so don't let
+ // anyone allocate one on the Go side. As a side effect of this annotation,
+ // pointers to this type will not be considered pointers in Go. They won't
+ // get writebarrier-ed or adjusted during a stack copy. This should handle
+ // all the cases badPointerTypedef used to handle, but hopefully will
+ // continue to work going forward without any more need for cgo changes.
+ tt.NotInHeap = true
+ // TODO: we should probably do the same for unions. Unions can't live
+ // on the Go heap, right? It currently doesn't work for unions because
+ // they are defined as a type alias for struct{}, not a defined type.
+ }
typedef[name.Name] = &tt
break
}
@@ -2529,6 +2541,7 @@
}
t.Go = name
t.BadPointer = sub.BadPointer
+ t.NotInHeap = sub.NotInHeap
if unionWithPointer[sub.Go] {
unionWithPointer[t.Go] = true
}
@@ -2539,6 +2552,7 @@
tt := *t
tt.Go = sub.Go
tt.BadPointer = sub.BadPointer
+ tt.NotInHeap = sub.NotInHeap
typedef[name.Name] = &tt
}
@@ -3047,6 +3061,7 @@
// non-pointers in this type.
// TODO: Currently our best solution is to find these manually and list them as
// they come up. A better solution is desired.
+// Note: DEPRECATED. There is now a better solution. Search for NotInHeap in this file.
func (c *typeConv) badPointerTypedef(dt *dwarf.TypedefType) bool {
if c.badCFType(dt) {
return true
diff --git a/libgo/go/cmd/cgo/main.go b/libgo/go/cmd/cgo/main.go
index 6de6d69..7fc2508 100644
--- a/libgo/go/cmd/cgo/main.go
+++ b/libgo/go/cmd/cgo/main.go
@@ -151,7 +151,8 @@
Go ast.Expr
EnumValues map[string]int64
Typedef string
- BadPointer bool
+ BadPointer bool // this pointer type should be represented as a uintptr (deprecated)
+ NotInHeap bool // this type should have a go:notinheap annotation
}
// A FuncType collects information about a function type in both the C and Go worlds.
diff --git a/libgo/go/cmd/cgo/out.go b/libgo/go/cmd/cgo/out.go
index 1d23fc1..dd03f7d 100644
--- a/libgo/go/cmd/cgo/out.go
+++ b/libgo/go/cmd/cgo/out.go
@@ -113,6 +113,9 @@
sort.Strings(typedefNames)
for _, name := range typedefNames {
def := typedef[name]
+ if def.NotInHeap {
+ fmt.Fprintf(fgo2, "//go:notinheap\n")
+ }
fmt.Fprintf(fgo2, "type %s ", name)
// We don't have source info for these types, so write them out without source info.
// Otherwise types would look like:
diff --git a/libgo/go/cmd/go/internal/base/goflags.go b/libgo/go/cmd/go/internal/base/goflags.go
index 3476613..f29cc3c 100644
--- a/libgo/go/cmd/go/internal/base/goflags.go
+++ b/libgo/go/cmd/go/internal/base/goflags.go
@@ -153,3 +153,20 @@
}
}
}
+
+// InGOFLAGS returns whether GOFLAGS contains the given flag, such as "-mod".
+func InGOFLAGS(flag string) bool {
+ for _, goflag := range GOFLAGS() {
+ name := goflag
+ if strings.HasPrefix(name, "--") {
+ name = name[1:]
+ }
+ if i := strings.Index(name, "="); i >= 0 {
+ name = name[:i]
+ }
+ if name == flag {
+ return true
+ }
+ }
+ return false
+}
diff --git a/libgo/go/cmd/go/internal/version/version.go b/libgo/go/cmd/go/internal/version/version.go
index ac2ae50..a5b1365 100644
--- a/libgo/go/cmd/go/internal/version/version.go
+++ b/libgo/go/cmd/go/internal/version/version.go
@@ -53,7 +53,14 @@
func runVersion(cmd *base.Command, args []string) {
if len(args) == 0 {
- if *versionM || *versionV {
+ // If any of this command's flags were passed explicitly, error
+ // out, because they only make sense with arguments.
+ //
+ // Don't error if the flags came from GOFLAGS, since that can be
+ // a reasonable use case. For example, imagine GOFLAGS=-v to
+ // turn "verbose mode" on for all Go commands, which should not
+ // break "go version".
+ if (!base.InGOFLAGS("-m") && *versionM) || (!base.InGOFLAGS("-v") && *versionV) {
fmt.Fprintf(os.Stderr, "go version: flags can only be used with arguments\n")
base.SetExitStatus(2)
return
diff --git a/libgo/go/cmd/go/internal/work/init.go b/libgo/go/cmd/go/internal/work/init.go
index dad3b10..c168364 100644
--- a/libgo/go/cmd/go/internal/work/init.go
+++ b/libgo/go/cmd/go/internal/work/init.go
@@ -254,34 +254,18 @@
case "":
// ok
case "readonly", "vendor", "mod":
- if !cfg.ModulesEnabled && !inGOFLAGS("-mod") {
+ if !cfg.ModulesEnabled && !base.InGOFLAGS("-mod") {
base.Fatalf("build flag -mod=%s only valid when using modules", cfg.BuildMod)
}
default:
base.Fatalf("-mod=%s not supported (can be '', 'mod', 'readonly', or 'vendor')", cfg.BuildMod)
}
if !cfg.ModulesEnabled {
- if cfg.ModCacheRW && !inGOFLAGS("-modcacherw") {
+ if cfg.ModCacheRW && !base.InGOFLAGS("-modcacherw") {
base.Fatalf("build flag -modcacherw only valid when using modules")
}
- if cfg.ModFile != "" && !inGOFLAGS("-mod") {
+ if cfg.ModFile != "" && !base.InGOFLAGS("-mod") {
base.Fatalf("build flag -modfile only valid when using modules")
}
}
}
-
-func inGOFLAGS(flag string) bool {
- for _, goflag := range base.GOFLAGS() {
- name := goflag
- if strings.HasPrefix(name, "--") {
- name = name[1:]
- }
- if i := strings.Index(name, "="); i >= 0 {
- name = name[:i]
- }
- if name == flag {
- return true
- }
- }
- return false
-}
diff --git a/libgo/go/cmd/go/testdata/script/version.txt b/libgo/go/cmd/go/testdata/script/version.txt
index 0123ac6..87cb6be 100644
--- a/libgo/go/cmd/go/testdata/script/version.txt
+++ b/libgo/go/cmd/go/testdata/script/version.txt
@@ -9,6 +9,12 @@
! go version -v
stderr 'with arguments'
+# Neither of the two flags above should be an issue via GOFLAGS.
+env GOFLAGS='-m -v'
+go version
+stdout '^go version'
+env GOFLAGS=
+
env GO111MODULE=on
# Skip the builds below if we are running in short mode.
[short] skip
diff --git a/libgo/go/internal/bytealg/index_generic.go b/libgo/go/internal/bytealg/index_generic.go
index 3dc1c6b..c595c23 100644
--- a/libgo/go/internal/bytealg/index_generic.go
+++ b/libgo/go/internal/bytealg/index_generic.go
@@ -17,42 +17,8 @@
// IndexString returns the index of the first instance of b in a, or -1 if b is not present in a.
// Requires 2 <= len(b) <= MaxLen.
-func IndexString(s, substr string) int {
- // This is a partial copy of strings.Index, here because bytes.IndexAny and bytes.LastIndexAny
- // call bytealg.IndexString. Some platforms have an optimized assembly version of this function.
- // This implementation is used for those that do not. Although the pure Go implementation here
- // works for the case of len(b) > MaxLen, we do not require that its assembly implementation also
- // supports the case of len(b) > MaxLen. And we do not guarantee that this function supports the
- // case of len(b) > MaxLen.
- n := len(substr)
- c0 := substr[0]
- c1 := substr[1]
- i := 0
- t := len(s) - n + 1
- fails := 0
- for i < t {
- if s[i] != c0 {
- o := IndexByteString(s[i:t], c0)
- if o < 0 {
- return -1
- }
- i += o
- }
- if s[i+1] == c1 && s[i:i+n] == substr {
- return i
- }
- i++
- fails++
- if fails >= 4+i>>4 && i < t {
- // See comment in src/bytes/bytes.go.
- j := IndexRabinKarp(s[i:], substr)
- if j < 0 {
- return -1
- }
- return i + j
- }
- }
- return -1
+func IndexString(a, b string) int {
+ panic("unimplemented")
}
// Cutover reports the number of failures of IndexByte we should tolerate
diff --git a/libgo/go/internal/poll/fd_unix.go b/libgo/go/internal/poll/fd_unix.go
index f177ccf..10cf173 100644
--- a/libgo/go/internal/poll/fd_unix.go
+++ b/libgo/go/internal/poll/fd_unix.go
@@ -152,7 +152,7 @@
p = p[:maxRW]
}
for {
- n, err := ignoringEINTR(syscall.Read, fd.Sysfd, p)
+ n, err := ignoringEINTR(func() (int, error) { return syscall.Read(fd.Sysfd, p) })
if err != nil {
n = 0
if err == syscall.EAGAIN && fd.pd.pollable() {
@@ -264,7 +264,7 @@
if fd.IsStream && max-nn > maxRW {
max = nn + maxRW
}
- n, err := ignoringEINTR(syscall.Write, fd.Sysfd, p[nn:max])
+ n, err := ignoringEINTR(func() (int, error) { return syscall.Write(fd.Sysfd, p[nn:max]) })
if n > 0 {
nn += n
}
@@ -423,7 +423,7 @@
}
defer fd.decref()
for {
- n, err := ignoringEINTR(syscall.ReadDirent, fd.Sysfd, buf)
+ n, err := ignoringEINTR(func() (int, error) { return syscall.ReadDirent(fd.Sysfd, buf) })
if err != nil {
n = 0
if err == syscall.EAGAIN && fd.pd.pollable() {
@@ -514,7 +514,7 @@
return 0, err
}
defer fd.writeUnlock()
- return ignoringEINTR(syscall.Write, fd.Sysfd, p)
+ return ignoringEINTR(func() (int, error) { return syscall.Write(fd.Sysfd, p) })
}
// RawRead invokes the user-defined function f for a read operation.
@@ -562,9 +562,9 @@
// installed without setting SA_RESTART. None of these are the common case,
// but there are enough of them that it seems that we can't avoid
// an EINTR loop.
-func ignoringEINTR(fn func(fd int, p []byte) (int, error), fd int, p []byte) (int, error) {
+func ignoringEINTR(fn func() (int, error)) (int, error) {
for {
- n, err := fn(fd, p)
+ n, err := fn()
if err != syscall.EINTR {
return n, err
}
diff --git a/libgo/go/runtime/chan.go b/libgo/go/runtime/chan.go
index de1d80a..b909d47 100644
--- a/libgo/go/runtime/chan.go
+++ b/libgo/go/runtime/chan.go
@@ -267,6 +267,11 @@
gp.waiting = mysg
gp.param = nil
c.sendq.enqueue(mysg)
+ // Signal to anyone trying to shrink our stack that we're about
+ // to park on a channel. The window between when this G's status
+ // changes and when we set gp.activeStackChans is not safe for
+ // stack shrinking.
+ atomic.Store8(&gp.parkingOnChan, 1)
gopark(chanparkcommit, unsafe.Pointer(&c.lock), waitReasonChanSend, traceEvGoBlockSend, 2)
// Ensure the value being sent is kept alive until the
// receiver copies it out. The sudog has a pointer to the
@@ -586,6 +591,11 @@
mysg.c = c
gp.param = nil
c.recvq.enqueue(mysg)
+ // Signal to anyone trying to shrink our stack that we're about
+ // to park on a channel. The window between when this G's status
+ // changes and when we set gp.activeStackChans is not safe for
+ // stack shrinking.
+ atomic.Store8(&gp.parkingOnChan, 1)
gopark(chanparkcommit, unsafe.Pointer(&c.lock), waitReasonChanReceive, traceEvGoBlockRecv, 2)
// someone woke us up
@@ -663,7 +673,19 @@
func chanparkcommit(gp *g, chanLock unsafe.Pointer) bool {
// There are unlocked sudogs that point into gp's stack. Stack
// copying must lock the channels of those sudogs.
+ // Set activeStackChans here instead of before we try parking
+ // because we could self-deadlock in stack growth on the
+ // channel lock.
gp.activeStackChans = true
+ // Mark that it's safe for stack shrinking to occur now,
+ // because any thread acquiring this G's stack for shrinking
+ // is guaranteed to observe activeStackChans after this store.
+ atomic.Store8(&gp.parkingOnChan, 0)
+ // Make sure we unlock after setting activeStackChans and
+ // unsetting parkingOnChan. The moment we unlock chanLock
+ // we risk gp getting readied by a channel operation and
+ // so gp could continue running before everything before
+ // the unlock is visible (even to gp itself).
unlock((*mutex)(chanLock))
return true
}
diff --git a/libgo/go/runtime/chan_test.go b/libgo/go/runtime/chan_test.go
index ac81d40..85d3e04 100644
--- a/libgo/go/runtime/chan_test.go
+++ b/libgo/go/runtime/chan_test.go
@@ -628,6 +628,62 @@
<-done
}
+func TestNoShrinkStackWhileParking(t *testing.T) {
+ // The goal of this test is to trigger a "racy sudog adjustment"
+ // throw. Basically, there's a window between when a goroutine
+ // becomes available for preemption for stack scanning (and thus,
+ // stack shrinking) but before the goroutine has fully parked on a
+ // channel. See issue 40641 for more details on the problem.
+ //
+ // The way we try to induce this failure is to set up two
+ // goroutines: a sender and a reciever that communicate across
+ // a channel. We try to set up a situation where the sender
+ // grows its stack temporarily then *fully* blocks on a channel
+ // often. Meanwhile a GC is triggered so that we try to get a
+ // mark worker to shrink the sender's stack and race with the
+ // sender parking.
+ //
+ // Unfortunately the race window here is so small that we
+ // either need a ridiculous number of iterations, or we add
+ // "usleep(1000)" to park_m, just before the unlockf call.
+ const n = 10
+ send := func(c chan<- int, done chan struct{}) {
+ for i := 0; i < n; i++ {
+ c <- i
+ // Use lots of stack briefly so that
+ // the GC is going to want to shrink us
+ // when it scans us. Make sure not to
+ // do any function calls otherwise
+ // in order to avoid us shrinking ourselves
+ // when we're preempted.
+ stackGrowthRecursive(20)
+ }
+ done <- struct{}{}
+ }
+ recv := func(c <-chan int, done chan struct{}) {
+ for i := 0; i < n; i++ {
+ // Sleep here so that the sender always
+ // fully blocks.
+ time.Sleep(10 * time.Microsecond)
+ <-c
+ }
+ done <- struct{}{}
+ }
+ for i := 0; i < n*20; i++ {
+ c := make(chan int)
+ done := make(chan struct{})
+ go recv(c, done)
+ go send(c, done)
+ // Wait a little bit before triggering
+ // the GC to make sure the sender and
+ // reciever have gotten into their groove.
+ time.Sleep(50 * time.Microsecond)
+ runtime.GC()
+ <-done
+ <-done
+ }
+}
+
func TestSelectDuplicateChannel(t *testing.T) {
// This test makes sure we can queue a G on
// the same channel multiple times.
diff --git a/libgo/go/runtime/export_test.go b/libgo/go/runtime/export_test.go
index 482d014..369230a 100644
--- a/libgo/go/runtime/export_test.go
+++ b/libgo/go/runtime/export_test.go
@@ -355,7 +355,11 @@
}
for i := mheap_.pages.start; i < mheap_.pages.end; i++ {
- pg := mheap_.pages.chunkOf(i).scavenged.popcntRange(0, pallocChunkPages)
+ chunk := mheap_.pages.tryChunkOf(i)
+ if chunk == nil {
+ continue
+ }
+ pg := chunk.scavenged.popcntRange(0, pallocChunkPages)
slow.HeapReleased += uint64(pg) * pageSize
}
for _, p := range allp {
@@ -752,11 +756,7 @@
// Returns nil if the PallocData's L2 is missing.
func (p *PageAlloc) PallocData(i ChunkIdx) *PallocData {
ci := chunkIdx(i)
- l2 := (*pageAlloc)(p).chunks[ci.l1()]
- if l2 == nil {
- return nil
- }
- return (*PallocData)(&l2[ci.l2()])
+ return (*PallocData)((*pageAlloc)(p).tryChunkOf(ci))
}
// AddrRange represents a range over addresses.
@@ -896,7 +896,10 @@
lock(&mheap_.lock)
chunkLoop:
for i := mheap_.pages.start; i < mheap_.pages.end; i++ {
- chunk := mheap_.pages.chunkOf(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.
@@ -977,10 +980,9 @@
}
func MSpanCountAlloc(bits []byte) int {
- s := mspan{
- nelems: uintptr(len(bits) * 8),
- gcmarkBits: (*gcBits)(unsafe.Pointer(&bits[0])),
- }
+ s := (*mspan)(mheap_.spanalloc.alloc())
+ s.nelems = uintptr(len(bits) * 8)
+ s.gcmarkBits = (*gcBits)(unsafe.Pointer(&bits[0]))
return s.countAlloc()
}
diff --git a/libgo/go/runtime/internal/atomic/atomic_test.go b/libgo/go/runtime/internal/atomic/atomic_test.go
index 0c1125c..b0a8fa0 100644
--- a/libgo/go/runtime/internal/atomic/atomic_test.go
+++ b/libgo/go/runtime/internal/atomic/atomic_test.go
@@ -220,3 +220,13 @@
}
}
}
+
+func TestStorepNoWB(t *testing.T) {
+ var p [2]*int
+ for i := range p {
+ atomic.StorepNoWB(unsafe.Pointer(&p[i]), unsafe.Pointer(new(int)))
+ }
+ if p[0] == p[1] {
+ t.Error("Bad escape analysis of StorepNoWB")
+ }
+}
diff --git a/libgo/go/runtime/mpagealloc.go b/libgo/go/runtime/mpagealloc.go
index 8b3c62c..c90a637 100644
--- a/libgo/go/runtime/mpagealloc.go
+++ b/libgo/go/runtime/mpagealloc.go
@@ -326,7 +326,20 @@
s.scav.scavLWM = maxSearchAddr
}
+// tryChunkOf returns the bitmap data for the given chunk.
+//
+// Returns nil if the chunk data has not been mapped.
+func (s *pageAlloc) tryChunkOf(ci chunkIdx) *pallocData {
+ l2 := s.chunks[ci.l1()]
+ if l2 == nil {
+ return nil
+ }
+ return &l2[ci.l2()]
+}
+
// chunkOf returns the chunk at the given chunk index.
+//
+// The chunk index must be valid or this method may throw.
func (s *pageAlloc) chunkOf(ci chunkIdx) *pallocData {
return &s.chunks[ci.l1()][ci.l2()]
}
diff --git a/libgo/go/runtime/proc_test.go b/libgo/go/runtime/proc_test.go
index b9828d9..a8f0dc3 100644
--- a/libgo/go/runtime/proc_test.go
+++ b/libgo/go/runtime/proc_test.go
@@ -529,9 +529,17 @@
<-done
}
+var padData [128]uint64
+
func stackGrowthRecursive(i int) {
var pad [128]uint64
- if i != 0 && pad[0] == 0 {
+ pad = padData
+ for j := range pad {
+ if pad[j] != 0 {
+ return
+ }
+ }
+ if i != 0 {
stackGrowthRecursive(i - 1)
}
}
diff --git a/libgo/go/runtime/runtime2.go b/libgo/go/runtime/runtime2.go
index 5029dba..bf3fbac 100644
--- a/libgo/go/runtime/runtime2.go
+++ b/libgo/go/runtime/runtime2.go
@@ -450,6 +450,10 @@
// copying needs to acquire channel locks to protect these
// areas of the stack.
activeStackChans bool
+ // parkingOnChan indicates that the goroutine is about to
+ // park on a chansend or chanrecv. Used to signal an unsafe point
+ // for stack shrinking. It's a boolean value, but is updated atomically.
+ parkingOnChan uint8
raceignore int8 // ignore race detection events
sysblocktraced bool // StartTrace has emitted EvGoInSyscall about this goroutine
@@ -940,11 +944,6 @@
// panics
// This is the gccgo version.
-//
-// This is marked go:notinheap because _panic values must only ever
-// live on the stack.
-//
-//go:notinheap
type _panic struct {
// The next entry in the stack.
link *_panic
diff --git a/libgo/go/runtime/select.go b/libgo/go/runtime/select.go
index cf5d0c7..c8910b8 100644
--- a/libgo/go/runtime/select.go
+++ b/libgo/go/runtime/select.go
@@ -7,6 +7,7 @@
// This file contains the implementation of Go select statements.
import (
+ "runtime/internal/atomic"
"unsafe"
)
@@ -72,7 +73,20 @@
func selparkcommit(gp *g, _ unsafe.Pointer) bool {
// There are unlocked sudogs that point into gp's stack. Stack
// copying must lock the channels of those sudogs.
+ // Set activeStackChans here instead of before we try parking
+ // because we could self-deadlock in stack growth on a
+ // channel lock.
gp.activeStackChans = true
+ // Mark that it's safe for stack shrinking to occur now,
+ // because any thread acquiring this G's stack for shrinking
+ // is guaranteed to observe activeStackChans after this store.
+ atomic.Store8(&gp.parkingOnChan, 0)
+ // Make sure we unlock after setting activeStackChans and
+ // unsetting parkingOnChan. The moment we unlock any of the
+ // channel locks we risk gp getting readied by a channel operation
+ // and so gp could continue running before everything before the
+ // unlock is visible (even to gp itself).
+
// This must not access gp's stack (see gopark). In
// particular, it must not access the *hselect. That's okay,
// because by the time this is called, gp.waiting has all
@@ -313,6 +327,11 @@
// wait for someone to wake us up
gp.param = nil
+ // Signal to anyone trying to shrink our stack that we're about
+ // to park on a channel. The window between when this G's status
+ // changes and when we set gp.activeStackChans is not safe for
+ // stack shrinking.
+ atomic.Store8(&gp.parkingOnChan, 1)
gopark(selparkcommit, nil, waitReasonSelect, traceEvGoBlockSelect, 1)
gp.activeStackChans = false
diff --git a/libgo/go/runtime/trace/trace_stack_test.go b/libgo/go/runtime/trace/trace_stack_test.go
index cfc0419..f856fdc 100644
--- a/libgo/go/runtime/trace/trace_stack_test.go
+++ b/libgo/go/runtime/trace/trace_stack_test.go
@@ -252,6 +252,7 @@
{trace.EvGoSysCall, []frame{
{"syscall.read", 0},
{"syscall.Read", 0},
+ {"internal/poll.(*FD).Read.func1", 0},
{"internal/poll.ignoringEINTR", 0},
{"internal/poll.(*FD).Read", 0},
{"os.(*File).read", 0},
diff --git a/libgo/go/testing/benchmark.go b/libgo/go/testing/benchmark.go
index 5276600..e9687bf 100644
--- a/libgo/go/testing/benchmark.go
+++ b/libgo/go/testing/benchmark.go
@@ -242,7 +242,7 @@
if b.skipped {
tag = "SKIP"
}
- if b.chatty && (len(b.output) > 0 || b.finished) {
+ if b.chatty != nil && (len(b.output) > 0 || b.finished) {
b.trimOutput()
fmt.Fprintf(b.w, "--- %s: %s\n%s", tag, b.name, b.output)
}
@@ -523,10 +523,9 @@
}
main := &B{
common: common{
- name: "Main",
- w: os.Stdout,
- chatty: *chatty,
- bench: true,
+ name: "Main",
+ w: os.Stdout,
+ bench: true,
},
importPath: importPath,
benchFunc: func(b *B) {
@@ -537,6 +536,9 @@
benchTime: benchTime,
context: ctx,
}
+ if Verbose() {
+ main.chatty = newChattyPrinter(main.w)
+ }
main.runN(1)
return !main.failed
}
@@ -549,7 +551,7 @@
benchName := benchmarkName(b.name, procs)
// If it's chatty, we've already printed this information.
- if !b.chatty {
+ if b.chatty == nil {
fmt.Fprintf(b.w, "%-*s\t", ctx.maxLen, benchName)
}
// Recompute the running time for all but the first iteration.
@@ -576,7 +578,7 @@
continue
}
results := r.String()
- if b.chatty {
+ if b.chatty != nil {
fmt.Fprintf(b.w, "%-*s\t", ctx.maxLen, benchName)
}
if *benchmarkMemory || b.showAllocResult {
@@ -639,7 +641,7 @@
atomic.StoreInt32(&sub.hasSub, 1)
}
- if b.chatty {
+ if b.chatty != nil {
labelsOnce.Do(func() {
fmt.Printf("goos: %s\n", runtime.GOOS)
fmt.Printf("goarch: %s\n", runtime.GOARCH)
diff --git a/libgo/go/testing/sub_test.go b/libgo/go/testing/sub_test.go
index 8eb0084..5ed3fc4 100644
--- a/libgo/go/testing/sub_test.go
+++ b/libgo/go/testing/sub_test.go
@@ -483,10 +483,12 @@
signal: make(chan bool),
name: "Test",
w: buf,
- chatty: tc.chatty,
},
context: ctx,
}
+ if tc.chatty {
+ root.chatty = newChattyPrinter(root.w)
+ }
ok := root.Run(tc.desc, tc.f)
ctx.release()
@@ -665,11 +667,13 @@
signal: make(chan bool),
name: "root",
w: buf,
- chatty: tc.chatty,
},
benchFunc: func(b *B) { ok = b.Run("test", tc.f) }, // Use Run to catch failure.
benchTime: benchTimeFlag{d: 1 * time.Microsecond},
}
+ if tc.chatty {
+ root.chatty = newChattyPrinter(root.w)
+ }
root.runN(1)
if ok != !tc.failed {
t.Errorf("%s:ok: got %v; want %v", tc.desc, ok, !tc.failed)
@@ -741,9 +745,13 @@
}
}
-type funcWriter func([]byte) (int, error)
+type funcWriter struct {
+ write func([]byte) (int, error)
+}
-func (fw funcWriter) Write(b []byte) (int, error) { return fw(b) }
+func (fw *funcWriter) Write(b []byte) (int, error) {
+ return fw.write(b)
+}
func TestRacyOutput(t *T) {
var runs int32 // The number of running Writes
@@ -761,9 +769,10 @@
var wg sync.WaitGroup
root := &T{
- common: common{w: funcWriter(raceDetector), chatty: true},
+ common: common{w: &funcWriter{raceDetector}},
context: newTestContext(1, newMatcher(regexp.MatchString, "", "")),
}
+ root.chatty = newChattyPrinter(root.w)
root.Run("", func(t *T) {
for i := 0; i < 100; i++ {
wg.Add(1)
diff --git a/libgo/go/testing/testing.go b/libgo/go/testing/testing.go
index fe6929d..80282fc 100644
--- a/libgo/go/testing/testing.go
+++ b/libgo/go/testing/testing.go
@@ -325,7 +325,6 @@
cpuListStr *string
parallel *int
testlog *string
- printer *testPrinter
haveExamples bool // are there examples?
@@ -335,55 +334,45 @@
numFailed uint32 // number of test failures
)
-type testPrinter struct {
- chatty bool
-
+type chattyPrinter struct {
+ w io.Writer
lastNameMu sync.Mutex // guards lastName
lastName string // last printed test name in chatty mode
}
-func newTestPrinter(chatty bool) *testPrinter {
- return &testPrinter{
- chatty: chatty,
- }
+func newChattyPrinter(w io.Writer) *chattyPrinter {
+ return &chattyPrinter{w: w}
}
-func (p *testPrinter) Print(testName, out string) {
- p.Fprint(os.Stdout, testName, out)
-}
-
-func (p *testPrinter) Fprint(w io.Writer, testName, out string) {
+// Updatef prints a message about the status of the named test to w.
+//
+// The formatted message must include the test name itself.
+func (p *chattyPrinter) Updatef(testName, format string, args ...interface{}) {
p.lastNameMu.Lock()
defer p.lastNameMu.Unlock()
- if !p.chatty ||
- strings.HasPrefix(out, "--- PASS: ") ||
- strings.HasPrefix(out, "--- FAIL: ") ||
- strings.HasPrefix(out, "--- SKIP: ") ||
- strings.HasPrefix(out, "=== RUN ") ||
- strings.HasPrefix(out, "=== CONT ") ||
- strings.HasPrefix(out, "=== PAUSE ") {
- // If we're buffering test output (!p.chatty), we don't really care which
- // test is emitting which line so long as they are serialized.
- //
- // If the message already implies an association with a specific new test,
- // we don't need to check what the old test name was or log an extra CONT
- // line for it. (We're updating it anyway, and the current message already
- // includes the test name.)
- p.lastName = testName
- fmt.Fprint(w, out)
- return
- }
+ // Since the message already implies an association with a specific new test,
+ // we don't need to check what the old test name was or log an extra CONT line
+ // for it. (We're updating it anyway, and the current message already includes
+ // the test name.)
+ p.lastName = testName
+ fmt.Fprintf(p.w, format, args...)
+}
+
+// Printf prints a message, generated by the named test, that does not
+// necessarily mention that tests's name itself.
+func (p *chattyPrinter) Printf(testName, format string, args ...interface{}) {
+ p.lastNameMu.Lock()
+ defer p.lastNameMu.Unlock()
if p.lastName == "" {
p.lastName = testName
} else if p.lastName != testName {
- // Always printed as-is, with 0 decoration or indentation. So, we skip
- // printing to w.
- fmt.Printf("=== CONT %s\n", testName)
+ fmt.Fprintf(p.w, "=== CONT %s\n", testName)
p.lastName = testName
}
- fmt.Fprint(w, out)
+
+ fmt.Fprintf(p.w, format, args...)
}
// The maximum number of stack frames to go through when skipping helper functions for
@@ -405,12 +394,12 @@
cleanupName string // Name of the cleanup function.
cleanupPc []uintptr // The stack trace at the point where Cleanup was called.
- chatty bool // A copy of the chatty flag.
- bench bool // Whether the current test is a benchmark.
- finished bool // Test function has completed.
- hasSub int32 // Written atomically.
- raceErrors int // Number of races detected during test.
- runner string // Function name of tRunner running the test.
+ chatty *chattyPrinter // A copy of chattyPrinter, if the chatty flag is set.
+ bench bool // Whether the current test is a benchmark.
+ finished bool // Test function has completed.
+ hasSub int32 // Written atomically.
+ raceErrors int // Number of races detected during test.
+ runner string // Function name of tRunner running the test.
parent *common
level int // Nesting depth of test or benchmark.
@@ -572,12 +561,31 @@
p.mu.Lock()
defer p.mu.Unlock()
- printer.Fprint(p.w, testName, fmt.Sprintf(format, args...))
-
c.mu.Lock()
defer c.mu.Unlock()
- io.Copy(p.w, bytes.NewReader(c.output))
- c.output = c.output[:0]
+
+ if len(c.output) > 0 {
+ format += "%s"
+ args = append(args[:len(args):len(args)], c.output)
+ c.output = c.output[:0] // but why?
+ }
+
+ if c.chatty != nil && p.w == c.chatty.w {
+ // We're flushing to the actual output, so track that this output is
+ // associated with a specific test (and, specifically, that the next output
+ // is *not* associated with that test).
+ //
+ // Moreover, if c.output is non-empty it is important that this write be
+ // atomic with respect to the output of other tests, so that we don't end up
+ // with confusing '=== CONT' lines in the middle of our '--- PASS' block.
+ // Neither humans nor cmd/test2json can parse those easily.
+ // (See https://golang.org/issue/40771.)
+ c.chatty.Updatef(testName, format, args...)
+ } else {
+ // We're flushing to the output buffer of the parent test, which will
+ // itself follow a test-name header when it is finally flushed to stdout.
+ fmt.Fprintf(p.w, format, args...)
+ }
}
type indenter struct {
@@ -746,13 +754,13 @@
}
panic("Log in goroutine after " + c.name + " has completed")
} else {
- if c.chatty {
+ if c.chatty != nil {
if c.bench {
// Benchmarks don't print === CONT, so we should skip the test
// printer and just print straight to stdout.
fmt.Print(c.decorate(s, depth+1))
} else {
- printer.Print(c.name, c.decorate(s, depth+1))
+ c.chatty.Printf(c.name, "%s", c.decorate(s, depth+1))
}
return
@@ -1019,34 +1027,22 @@
t.parent.sub = append(t.parent.sub, t)
t.raceErrors += race.Errors()
- if t.chatty {
- // Print directly to root's io.Writer so there is no delay.
- root := t.parent
- for ; root.parent != nil; root = root.parent {
- }
- root.mu.Lock()
+ if t.chatty != nil {
// Unfortunately, even though PAUSE indicates that the named test is *no
// longer* running, cmd/test2json interprets it as changing the active test
// for the purpose of log parsing. We could fix cmd/test2json, but that
// won't fix existing deployments of third-party tools that already shell
// out to older builds of cmd/test2json — so merely fixing cmd/test2json
// isn't enough for now.
- printer.Fprint(root.w, t.name, fmt.Sprintf("=== PAUSE %s\n", t.name))
- root.mu.Unlock()
+ t.chatty.Updatef(t.name, "=== PAUSE %s\n", t.name)
}
t.signal <- true // Release calling test.
<-t.parent.barrier // Wait for the parent test to complete.
t.context.waitParallel()
- if t.chatty {
- // Print directly to root's io.Writer so there is no delay.
- root := t.parent
- for ; root.parent != nil; root = root.parent {
- }
- root.mu.Lock()
- printer.Fprint(root.w, t.name, fmt.Sprintf("=== CONT %s\n", t.name))
- root.mu.Unlock()
+ if t.chatty != nil {
+ t.chatty.Updatef(t.name, "=== CONT %s\n", t.name)
}
t.start = time.Now()
@@ -1197,14 +1193,8 @@
}
t.w = indenter{&t.common}
- if t.chatty {
- // Print directly to root's io.Writer so there is no delay.
- root := t.parent
- for ; root.parent != nil; root = root.parent {
- }
- root.mu.Lock()
- printer.Fprint(root.w, t.name, fmt.Sprintf("=== RUN %s\n", t.name))
- root.mu.Unlock()
+ if t.chatty != nil {
+ t.chatty.Updatef(t.name, "=== RUN %s\n", t.name)
}
// Instead of reducing the running count of this test before calling the
// tRunner and increasing it afterwards, we rely on tRunner keeping the
@@ -1369,8 +1359,6 @@
flag.Parse()
}
- printer = newTestPrinter(Verbose())
-
if *parallel < 1 {
fmt.Fprintln(os.Stderr, "testing: -parallel can only be given a positive integer")
flag.Usage()
@@ -1415,7 +1403,7 @@
format := "--- %s: %s (%s)\n"
if t.Failed() {
t.flushToParent(t.name, format, "FAIL", t.name, dstr)
- } else if t.chatty {
+ } else if t.chatty != nil {
if t.Skipped() {
t.flushToParent(t.name, format, "SKIP", t.name, dstr)
} else {
@@ -1476,10 +1464,12 @@
signal: make(chan bool),
barrier: make(chan bool),
w: os.Stdout,
- chatty: *chatty,
},
context: ctx,
}
+ if Verbose() {
+ t.chatty = newChattyPrinter(t.w)
+ }
tRunner(t, func(t *T) {
for _, test := range tests {
t.Run(test.Name, test.F)
diff --git a/libgo/misc/cgo/test/testdata/issue41761.go b/libgo/misc/cgo/test/testdata/issue41761.go
new file mode 100644
index 0000000..919c749
--- /dev/null
+++ b/libgo/misc/cgo/test/testdata/issue41761.go
@@ -0,0 +1,20 @@
+// Copyright 2020 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.
+
+package cgotest
+
+/*
+ typedef struct S S;
+*/
+import "C"
+
+import (
+ "cgotest/issue41761a"
+ "testing"
+)
+
+func test41761(t *testing.T) {
+ var x issue41761a.T
+ _ = (*C.struct_S)(x.X)
+}
diff --git a/libgo/misc/cgo/test/testdata/issue41761a/a.go b/libgo/misc/cgo/test/testdata/issue41761a/a.go
new file mode 100644
index 0000000..ca5c181
--- /dev/null
+++ b/libgo/misc/cgo/test/testdata/issue41761a/a.go
@@ -0,0 +1,14 @@
+// Copyright 2020 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.
+
+package issue41761a
+
+/*
+ typedef struct S S;
+*/
+import "C"
+
+type T struct {
+ X *C.S
+}
