summaryrefslogtreecommitdiffstats
path: root/src/runtime/stack_test.go
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--src/runtime/stack_test.go939
1 files changed, 939 insertions, 0 deletions
diff --git a/src/runtime/stack_test.go b/src/runtime/stack_test.go
new file mode 100644
index 0000000..dfb29a9
--- /dev/null
+++ b/src/runtime/stack_test.go
@@ -0,0 +1,939 @@
+// Copyright 2012 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 runtime_test
+
+import (
+ "bytes"
+ "fmt"
+ "reflect"
+ "regexp"
+ . "runtime"
+ "strings"
+ "sync"
+ "sync/atomic"
+ "testing"
+ "time"
+ _ "unsafe" // for go:linkname
+)
+
+// TestStackMem measures per-thread stack segment cache behavior.
+// The test consumed up to 500MB in the past.
+func TestStackMem(t *testing.T) {
+ const (
+ BatchSize = 32
+ BatchCount = 256
+ ArraySize = 1024
+ RecursionDepth = 128
+ )
+ if testing.Short() {
+ return
+ }
+ defer GOMAXPROCS(GOMAXPROCS(BatchSize))
+ s0 := new(MemStats)
+ ReadMemStats(s0)
+ for b := 0; b < BatchCount; b++ {
+ c := make(chan bool, BatchSize)
+ for i := 0; i < BatchSize; i++ {
+ go func() {
+ var f func(k int, a [ArraySize]byte)
+ f = func(k int, a [ArraySize]byte) {
+ if k == 0 {
+ time.Sleep(time.Millisecond)
+ return
+ }
+ f(k-1, a)
+ }
+ f(RecursionDepth, [ArraySize]byte{})
+ c <- true
+ }()
+ }
+ for i := 0; i < BatchSize; i++ {
+ <-c
+ }
+
+ // The goroutines have signaled via c that they are ready to exit.
+ // Give them a chance to exit by sleeping. If we don't wait, we
+ // might not reuse them on the next batch.
+ time.Sleep(10 * time.Millisecond)
+ }
+ s1 := new(MemStats)
+ ReadMemStats(s1)
+ consumed := int64(s1.StackSys - s0.StackSys)
+ t.Logf("Consumed %vMB for stack mem", consumed>>20)
+ estimate := int64(8 * BatchSize * ArraySize * RecursionDepth) // 8 is to reduce flakiness.
+ if consumed > estimate {
+ t.Fatalf("Stack mem: want %v, got %v", estimate, consumed)
+ }
+ // Due to broken stack memory accounting (https://golang.org/issue/7468),
+ // StackInuse can decrease during function execution, so we cast the values to int64.
+ inuse := int64(s1.StackInuse) - int64(s0.StackInuse)
+ t.Logf("Inuse %vMB for stack mem", inuse>>20)
+ if inuse > 4<<20 {
+ t.Fatalf("Stack inuse: want %v, got %v", 4<<20, inuse)
+ }
+}
+
+// Test stack growing in different contexts.
+func TestStackGrowth(t *testing.T) {
+ if *flagQuick {
+ t.Skip("-quick")
+ }
+
+ t.Parallel()
+
+ var wg sync.WaitGroup
+
+ // in a normal goroutine
+ var growDuration time.Duration // For debugging failures
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ start := time.Now()
+ growStack(nil)
+ growDuration = time.Since(start)
+ }()
+ wg.Wait()
+ t.Log("first growStack took", growDuration)
+
+ // in locked goroutine
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ LockOSThread()
+ growStack(nil)
+ UnlockOSThread()
+ }()
+ wg.Wait()
+
+ // in finalizer
+ var finalizerStart time.Time
+ var started, progress uint32
+ wg.Add(1)
+ s := new(string) // Must be of a type that avoids the tiny allocator, or else the finalizer might not run.
+ SetFinalizer(s, func(ss *string) {
+ defer wg.Done()
+ finalizerStart = time.Now()
+ atomic.StoreUint32(&started, 1)
+ growStack(&progress)
+ })
+ setFinalizerTime := time.Now()
+ s = nil
+
+ if d, ok := t.Deadline(); ok {
+ // Pad the timeout by an arbitrary 5% to give the AfterFunc time to run.
+ timeout := time.Until(d) * 19 / 20
+ timer := time.AfterFunc(timeout, func() {
+ // Panic — instead of calling t.Error and returning from the test — so
+ // that we get a useful goroutine dump if the test times out, especially
+ // if GOTRACEBACK=system or GOTRACEBACK=crash is set.
+ if atomic.LoadUint32(&started) == 0 {
+ panic("finalizer did not start")
+ } else {
+ panic(fmt.Sprintf("finalizer started %s ago (%s after registration) and ran %d iterations, but did not return", time.Since(finalizerStart), finalizerStart.Sub(setFinalizerTime), atomic.LoadUint32(&progress)))
+ }
+ })
+ defer timer.Stop()
+ }
+
+ GC()
+ wg.Wait()
+ t.Logf("finalizer started after %s and ran %d iterations in %v", finalizerStart.Sub(setFinalizerTime), atomic.LoadUint32(&progress), time.Since(finalizerStart))
+}
+
+// ... and in init
+//func init() {
+// growStack()
+//}
+
+func growStack(progress *uint32) {
+ n := 1 << 10
+ if testing.Short() {
+ n = 1 << 8
+ }
+ for i := 0; i < n; i++ {
+ x := 0
+ growStackIter(&x, i)
+ if x != i+1 {
+ panic("stack is corrupted")
+ }
+ if progress != nil {
+ atomic.StoreUint32(progress, uint32(i))
+ }
+ }
+ GC()
+}
+
+// This function is not an anonymous func, so that the compiler can do escape
+// analysis and place x on stack (and subsequently stack growth update the pointer).
+func growStackIter(p *int, n int) {
+ if n == 0 {
+ *p = n + 1
+ GC()
+ return
+ }
+ *p = n + 1
+ x := 0
+ growStackIter(&x, n-1)
+ if x != n {
+ panic("stack is corrupted")
+ }
+}
+
+func TestStackGrowthCallback(t *testing.T) {
+ t.Parallel()
+ var wg sync.WaitGroup
+
+ // test stack growth at chan op
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ c := make(chan int, 1)
+ growStackWithCallback(func() {
+ c <- 1
+ <-c
+ })
+ }()
+
+ // test stack growth at map op
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ m := make(map[int]int)
+ growStackWithCallback(func() {
+ _, _ = m[1]
+ m[1] = 1
+ })
+ }()
+
+ // test stack growth at goroutine creation
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ growStackWithCallback(func() {
+ done := make(chan bool)
+ go func() {
+ done <- true
+ }()
+ <-done
+ })
+ }()
+ wg.Wait()
+}
+
+func growStackWithCallback(cb func()) {
+ var f func(n int)
+ f = func(n int) {
+ if n == 0 {
+ cb()
+ return
+ }
+ f(n - 1)
+ }
+ for i := 0; i < 1<<10; i++ {
+ f(i)
+ }
+}
+
+// TestDeferPtrs tests the adjustment of Defer's argument pointers (p aka &y)
+// during a stack copy.
+func set(p *int, x int) {
+ *p = x
+}
+func TestDeferPtrs(t *testing.T) {
+ var y int
+
+ defer func() {
+ if y != 42 {
+ t.Errorf("defer's stack references were not adjusted appropriately")
+ }
+ }()
+ defer set(&y, 42)
+ growStack(nil)
+}
+
+type bigBuf [4 * 1024]byte
+
+// TestDeferPtrsGoexit is like TestDeferPtrs but exercises the possibility that the
+// stack grows as part of starting the deferred function. It calls Goexit at various
+// stack depths, forcing the deferred function (with >4kB of args) to be run at
+// the bottom of the stack. The goal is to find a stack depth less than 4kB from
+// the end of the stack. Each trial runs in a different goroutine so that an earlier
+// stack growth does not invalidate a later attempt.
+func TestDeferPtrsGoexit(t *testing.T) {
+ for i := 0; i < 100; i++ {
+ c := make(chan int, 1)
+ go testDeferPtrsGoexit(c, i)
+ if n := <-c; n != 42 {
+ t.Fatalf("defer's stack references were not adjusted appropriately (i=%d n=%d)", i, n)
+ }
+ }
+}
+
+func testDeferPtrsGoexit(c chan int, i int) {
+ var y int
+ defer func() {
+ c <- y
+ }()
+ defer setBig(&y, 42, bigBuf{})
+ useStackAndCall(i, Goexit)
+}
+
+func setBig(p *int, x int, b bigBuf) {
+ *p = x
+}
+
+// TestDeferPtrsPanic is like TestDeferPtrsGoexit, but it's using panic instead
+// of Goexit to run the Defers. Those two are different execution paths
+// in the runtime.
+func TestDeferPtrsPanic(t *testing.T) {
+ for i := 0; i < 100; i++ {
+ c := make(chan int, 1)
+ go testDeferPtrsGoexit(c, i)
+ if n := <-c; n != 42 {
+ t.Fatalf("defer's stack references were not adjusted appropriately (i=%d n=%d)", i, n)
+ }
+ }
+}
+
+func testDeferPtrsPanic(c chan int, i int) {
+ var y int
+ defer func() {
+ if recover() == nil {
+ c <- -1
+ return
+ }
+ c <- y
+ }()
+ defer setBig(&y, 42, bigBuf{})
+ useStackAndCall(i, func() { panic(1) })
+}
+
+//go:noinline
+func testDeferLeafSigpanic1() {
+ // Cause a sigpanic to be injected in this frame.
+ //
+ // This function has to be declared before
+ // TestDeferLeafSigpanic so the runtime will crash if we think
+ // this function's continuation PC is in
+ // TestDeferLeafSigpanic.
+ *(*int)(nil) = 0
+}
+
+// TestDeferLeafSigpanic tests defer matching around leaf functions
+// that sigpanic. This is tricky because on LR machines the outer
+// function and the inner function have the same SP, but it's critical
+// that we match up the defer correctly to get the right liveness map.
+// See issue #25499.
+func TestDeferLeafSigpanic(t *testing.T) {
+ // Push a defer that will walk the stack.
+ defer func() {
+ if err := recover(); err == nil {
+ t.Fatal("expected panic from nil pointer")
+ }
+ GC()
+ }()
+ // Call a leaf function. We must set up the exact call stack:
+ //
+ // defering function -> leaf function -> sigpanic
+ //
+ // On LR machines, the leaf function will have the same SP as
+ // the SP pushed for the defer frame.
+ testDeferLeafSigpanic1()
+}
+
+// TestPanicUseStack checks that a chain of Panic structs on the stack are
+// updated correctly if the stack grows during the deferred execution that
+// happens as a result of the panic.
+func TestPanicUseStack(t *testing.T) {
+ pc := make([]uintptr, 10000)
+ defer func() {
+ recover()
+ Callers(0, pc) // force stack walk
+ useStackAndCall(100, func() {
+ defer func() {
+ recover()
+ Callers(0, pc) // force stack walk
+ useStackAndCall(200, func() {
+ defer func() {
+ recover()
+ Callers(0, pc) // force stack walk
+ }()
+ panic(3)
+ })
+ }()
+ panic(2)
+ })
+ }()
+ panic(1)
+}
+
+func TestPanicFar(t *testing.T) {
+ var xtree *xtreeNode
+ pc := make([]uintptr, 10000)
+ defer func() {
+ // At this point we created a large stack and unwound
+ // it via recovery. Force a stack walk, which will
+ // check the stack's consistency.
+ Callers(0, pc)
+ }()
+ defer func() {
+ recover()
+ }()
+ useStackAndCall(100, func() {
+ // Kick off the GC and make it do something nontrivial.
+ // (This used to force stack barriers to stick around.)
+ xtree = makeTree(18)
+ // Give the GC time to start scanning stacks.
+ time.Sleep(time.Millisecond)
+ panic(1)
+ })
+ _ = xtree
+}
+
+type xtreeNode struct {
+ l, r *xtreeNode
+}
+
+func makeTree(d int) *xtreeNode {
+ if d == 0 {
+ return new(xtreeNode)
+ }
+ return &xtreeNode{makeTree(d - 1), makeTree(d - 1)}
+}
+
+// use about n KB of stack and call f
+func useStackAndCall(n int, f func()) {
+ if n == 0 {
+ f()
+ return
+ }
+ var b [1024]byte // makes frame about 1KB
+ useStackAndCall(n-1+int(b[99]), f)
+}
+
+func useStack(n int) {
+ useStackAndCall(n, func() {})
+}
+
+func growing(c chan int, done chan struct{}) {
+ for n := range c {
+ useStack(n)
+ done <- struct{}{}
+ }
+ done <- struct{}{}
+}
+
+func TestStackCache(t *testing.T) {
+ // Allocate a bunch of goroutines and grow their stacks.
+ // Repeat a few times to test the stack cache.
+ const (
+ R = 4
+ G = 200
+ S = 5
+ )
+ for i := 0; i < R; i++ {
+ var reqchans [G]chan int
+ done := make(chan struct{})
+ for j := 0; j < G; j++ {
+ reqchans[j] = make(chan int)
+ go growing(reqchans[j], done)
+ }
+ for s := 0; s < S; s++ {
+ for j := 0; j < G; j++ {
+ reqchans[j] <- 1 << uint(s)
+ }
+ for j := 0; j < G; j++ {
+ <-done
+ }
+ }
+ for j := 0; j < G; j++ {
+ close(reqchans[j])
+ }
+ for j := 0; j < G; j++ {
+ <-done
+ }
+ }
+}
+
+func TestStackOutput(t *testing.T) {
+ b := make([]byte, 1024)
+ stk := string(b[:Stack(b, false)])
+ if !strings.HasPrefix(stk, "goroutine ") {
+ t.Errorf("Stack (len %d):\n%s", len(stk), stk)
+ t.Errorf("Stack output should begin with \"goroutine \"")
+ }
+}
+
+func TestStackAllOutput(t *testing.T) {
+ b := make([]byte, 1024)
+ stk := string(b[:Stack(b, true)])
+ if !strings.HasPrefix(stk, "goroutine ") {
+ t.Errorf("Stack (len %d):\n%s", len(stk), stk)
+ t.Errorf("Stack output should begin with \"goroutine \"")
+ }
+}
+
+func TestStackPanic(t *testing.T) {
+ // Test that stack copying copies panics correctly. This is difficult
+ // to test because it is very unlikely that the stack will be copied
+ // in the middle of gopanic. But it can happen.
+ // To make this test effective, edit panic.go:gopanic and uncomment
+ // the GC() call just before freedefer(d).
+ defer func() {
+ if x := recover(); x == nil {
+ t.Errorf("recover failed")
+ }
+ }()
+ useStack(32)
+ panic("test panic")
+}
+
+func BenchmarkStackCopyPtr(b *testing.B) {
+ c := make(chan bool)
+ for i := 0; i < b.N; i++ {
+ go func() {
+ i := 1000000
+ countp(&i)
+ c <- true
+ }()
+ <-c
+ }
+}
+
+func countp(n *int) {
+ if *n == 0 {
+ return
+ }
+ *n--
+ countp(n)
+}
+
+func BenchmarkStackCopy(b *testing.B) {
+ c := make(chan bool)
+ for i := 0; i < b.N; i++ {
+ go func() {
+ count(1000000)
+ c <- true
+ }()
+ <-c
+ }
+}
+
+func count(n int) int {
+ if n == 0 {
+ return 0
+ }
+ return 1 + count(n-1)
+}
+
+func BenchmarkStackCopyNoCache(b *testing.B) {
+ c := make(chan bool)
+ for i := 0; i < b.N; i++ {
+ go func() {
+ count1(1000000)
+ c <- true
+ }()
+ <-c
+ }
+}
+
+func count1(n int) int {
+ if n <= 0 {
+ return 0
+ }
+ return 1 + count2(n-1)
+}
+
+func count2(n int) int { return 1 + count3(n-1) }
+func count3(n int) int { return 1 + count4(n-1) }
+func count4(n int) int { return 1 + count5(n-1) }
+func count5(n int) int { return 1 + count6(n-1) }
+func count6(n int) int { return 1 + count7(n-1) }
+func count7(n int) int { return 1 + count8(n-1) }
+func count8(n int) int { return 1 + count9(n-1) }
+func count9(n int) int { return 1 + count10(n-1) }
+func count10(n int) int { return 1 + count11(n-1) }
+func count11(n int) int { return 1 + count12(n-1) }
+func count12(n int) int { return 1 + count13(n-1) }
+func count13(n int) int { return 1 + count14(n-1) }
+func count14(n int) int { return 1 + count15(n-1) }
+func count15(n int) int { return 1 + count16(n-1) }
+func count16(n int) int { return 1 + count17(n-1) }
+func count17(n int) int { return 1 + count18(n-1) }
+func count18(n int) int { return 1 + count19(n-1) }
+func count19(n int) int { return 1 + count20(n-1) }
+func count20(n int) int { return 1 + count21(n-1) }
+func count21(n int) int { return 1 + count22(n-1) }
+func count22(n int) int { return 1 + count23(n-1) }
+func count23(n int) int { return 1 + count1(n-1) }
+
+type stkobjT struct {
+ p *stkobjT
+ x int64
+ y [20]int // consume some stack
+}
+
+// Sum creates a linked list of stkobjTs.
+func Sum(n int64, p *stkobjT) {
+ if n == 0 {
+ return
+ }
+ s := stkobjT{p: p, x: n}
+ Sum(n-1, &s)
+ p.x += s.x
+}
+
+func BenchmarkStackCopyWithStkobj(b *testing.B) {
+ c := make(chan bool)
+ for i := 0; i < b.N; i++ {
+ go func() {
+ var s stkobjT
+ Sum(100000, &s)
+ c <- true
+ }()
+ <-c
+ }
+}
+
+func BenchmarkIssue18138(b *testing.B) {
+ // Channel with N "can run a goroutine" tokens
+ const N = 10
+ c := make(chan []byte, N)
+ for i := 0; i < N; i++ {
+ c <- make([]byte, 1)
+ }
+
+ for i := 0; i < b.N; i++ {
+ <-c // get token
+ go func() {
+ useStackPtrs(1000, false) // uses ~1MB max
+ m := make([]byte, 8192) // make GC trigger occasionally
+ c <- m // return token
+ }()
+ }
+}
+
+func useStackPtrs(n int, b bool) {
+ if b {
+ // This code contributes to the stack frame size, and hence to the
+ // stack copying cost. But since b is always false, it costs no
+ // execution time (not even the zeroing of a).
+ var a [128]*int // 1KB of pointers
+ a[n] = &n
+ n = *a[0]
+ }
+ if n == 0 {
+ return
+ }
+ useStackPtrs(n-1, b)
+}
+
+type structWithMethod struct{}
+
+func (s structWithMethod) caller() string {
+ _, file, line, ok := Caller(1)
+ if !ok {
+ panic("Caller failed")
+ }
+ return fmt.Sprintf("%s:%d", file, line)
+}
+
+func (s structWithMethod) callers() []uintptr {
+ pc := make([]uintptr, 16)
+ return pc[:Callers(0, pc)]
+}
+
+func (s structWithMethod) stack() string {
+ buf := make([]byte, 4<<10)
+ return string(buf[:Stack(buf, false)])
+}
+
+func (s structWithMethod) nop() {}
+
+func TestStackWrapperCaller(t *testing.T) {
+ var d structWithMethod
+ // Force the compiler to construct a wrapper method.
+ wrapper := (*structWithMethod).caller
+ // Check that the wrapper doesn't affect the stack trace.
+ if dc, ic := d.caller(), wrapper(&d); dc != ic {
+ t.Fatalf("direct caller %q != indirect caller %q", dc, ic)
+ }
+}
+
+func TestStackWrapperCallers(t *testing.T) {
+ var d structWithMethod
+ wrapper := (*structWithMethod).callers
+ // Check that <autogenerated> doesn't appear in the stack trace.
+ pcs := wrapper(&d)
+ frames := CallersFrames(pcs)
+ for {
+ fr, more := frames.Next()
+ if fr.File == "<autogenerated>" {
+ t.Fatalf("<autogenerated> appears in stack trace: %+v", fr)
+ }
+ if !more {
+ break
+ }
+ }
+}
+
+func TestStackWrapperStack(t *testing.T) {
+ var d structWithMethod
+ wrapper := (*structWithMethod).stack
+ // Check that <autogenerated> doesn't appear in the stack trace.
+ stk := wrapper(&d)
+ if strings.Contains(stk, "<autogenerated>") {
+ t.Fatalf("<autogenerated> appears in stack trace:\n%s", stk)
+ }
+}
+
+type I interface {
+ M()
+}
+
+func TestStackWrapperStackPanic(t *testing.T) {
+ t.Run("sigpanic", func(t *testing.T) {
+ // nil calls to interface methods cause a sigpanic.
+ testStackWrapperPanic(t, func() { I.M(nil) }, "runtime_test.I.M")
+ })
+ t.Run("panicwrap", func(t *testing.T) {
+ // Nil calls to value method wrappers call panicwrap.
+ wrapper := (*structWithMethod).nop
+ testStackWrapperPanic(t, func() { wrapper(nil) }, "runtime_test.(*structWithMethod).nop")
+ })
+}
+
+func testStackWrapperPanic(t *testing.T, cb func(), expect string) {
+ // Test that the stack trace from a panicking wrapper includes
+ // the wrapper, even though elide these when they don't panic.
+ t.Run("CallersFrames", func(t *testing.T) {
+ defer func() {
+ err := recover()
+ if err == nil {
+ t.Fatalf("expected panic")
+ }
+ pcs := make([]uintptr, 10)
+ n := Callers(0, pcs)
+ frames := CallersFrames(pcs[:n])
+ for {
+ frame, more := frames.Next()
+ t.Log(frame.Function)
+ if frame.Function == expect {
+ return
+ }
+ if !more {
+ break
+ }
+ }
+ t.Fatalf("panicking wrapper %s missing from stack trace", expect)
+ }()
+ cb()
+ })
+ t.Run("Stack", func(t *testing.T) {
+ defer func() {
+ err := recover()
+ if err == nil {
+ t.Fatalf("expected panic")
+ }
+ buf := make([]byte, 4<<10)
+ stk := string(buf[:Stack(buf, false)])
+ if !strings.Contains(stk, "\n"+expect) {
+ t.Fatalf("panicking wrapper %s missing from stack trace:\n%s", expect, stk)
+ }
+ }()
+ cb()
+ })
+}
+
+func TestCallersFromWrapper(t *testing.T) {
+ // Test that invoking CallersFrames on a stack where the first
+ // PC is an autogenerated wrapper keeps the wrapper in the
+ // trace. Normally we elide these, assuming that the wrapper
+ // calls the thing you actually wanted to see, but in this
+ // case we need to keep it.
+ pc := reflect.ValueOf(I.M).Pointer()
+ frames := CallersFrames([]uintptr{pc})
+ frame, more := frames.Next()
+ if frame.Function != "runtime_test.I.M" {
+ t.Fatalf("want function %s, got %s", "runtime_test.I.M", frame.Function)
+ }
+ if more {
+ t.Fatalf("want 1 frame, got > 1")
+ }
+}
+
+func TestTracebackSystemstack(t *testing.T) {
+ if GOARCH == "ppc64" || GOARCH == "ppc64le" {
+ t.Skip("systemstack tail call not implemented on ppc64x")
+ }
+
+ // Test that profiles correctly jump over systemstack,
+ // including nested systemstack calls.
+ pcs := make([]uintptr, 20)
+ pcs = pcs[:TracebackSystemstack(pcs, 5)]
+ // Check that runtime.TracebackSystemstack appears five times
+ // and that we see TestTracebackSystemstack.
+ countIn, countOut := 0, 0
+ frames := CallersFrames(pcs)
+ var tb bytes.Buffer
+ for {
+ frame, more := frames.Next()
+ fmt.Fprintf(&tb, "\n%s+0x%x %s:%d", frame.Function, frame.PC-frame.Entry, frame.File, frame.Line)
+ switch frame.Function {
+ case "runtime.TracebackSystemstack":
+ countIn++
+ case "runtime_test.TestTracebackSystemstack":
+ countOut++
+ }
+ if !more {
+ break
+ }
+ }
+ if countIn != 5 || countOut != 1 {
+ t.Fatalf("expected 5 calls to TracebackSystemstack and 1 call to TestTracebackSystemstack, got:%s", tb.String())
+ }
+}
+
+func TestTracebackAncestors(t *testing.T) {
+ goroutineRegex := regexp.MustCompile(`goroutine [0-9]+ \[`)
+ for _, tracebackDepth := range []int{0, 1, 5, 50} {
+ output := runTestProg(t, "testprog", "TracebackAncestors", fmt.Sprintf("GODEBUG=tracebackancestors=%d", tracebackDepth))
+
+ numGoroutines := 3
+ numFrames := 2
+ ancestorsExpected := numGoroutines
+ if numGoroutines > tracebackDepth {
+ ancestorsExpected = tracebackDepth
+ }
+
+ matches := goroutineRegex.FindAllStringSubmatch(output, -1)
+ if len(matches) != 2 {
+ t.Fatalf("want 2 goroutines, got:\n%s", output)
+ }
+
+ // Check functions in the traceback.
+ fns := []string{"main.recurseThenCallGo", "main.main", "main.printStack", "main.TracebackAncestors"}
+ for _, fn := range fns {
+ if !strings.Contains(output, "\n"+fn+"(") {
+ t.Fatalf("expected %q function in traceback:\n%s", fn, output)
+ }
+ }
+
+ if want, count := "originating from goroutine", ancestorsExpected; strings.Count(output, want) != count {
+ t.Errorf("output does not contain %d instances of %q:\n%s", count, want, output)
+ }
+
+ if want, count := "main.recurseThenCallGo(...)", ancestorsExpected*(numFrames+1); strings.Count(output, want) != count {
+ t.Errorf("output does not contain %d instances of %q:\n%s", count, want, output)
+ }
+
+ if want, count := "main.recurseThenCallGo(0x", 1; strings.Count(output, want) != count {
+ t.Errorf("output does not contain %d instances of %q:\n%s", count, want, output)
+ }
+ }
+}
+
+// Test that defer closure is correctly scanned when the stack is scanned.
+func TestDeferLiveness(t *testing.T) {
+ output := runTestProg(t, "testprog", "DeferLiveness", "GODEBUG=clobberfree=1")
+ if output != "" {
+ t.Errorf("output:\n%s\n\nwant no output", output)
+ }
+}
+
+func TestDeferHeapAndStack(t *testing.T) {
+ P := 4 // processors
+ N := 10000 //iterations
+ D := 200 // stack depth
+
+ if testing.Short() {
+ P /= 2
+ N /= 10
+ D /= 10
+ }
+ c := make(chan bool)
+ for p := 0; p < P; p++ {
+ go func() {
+ for i := 0; i < N; i++ {
+ if deferHeapAndStack(D) != 2*D {
+ panic("bad result")
+ }
+ }
+ c <- true
+ }()
+ }
+ for p := 0; p < P; p++ {
+ <-c
+ }
+}
+
+// deferHeapAndStack(n) computes 2*n
+func deferHeapAndStack(n int) (r int) {
+ if n == 0 {
+ return 0
+ }
+ if n%2 == 0 {
+ // heap-allocated defers
+ for i := 0; i < 2; i++ {
+ defer func() {
+ r++
+ }()
+ }
+ } else {
+ // stack-allocated defers
+ defer func() {
+ r++
+ }()
+ defer func() {
+ r++
+ }()
+ }
+ r = deferHeapAndStack(n - 1)
+ escapeMe(new([1024]byte)) // force some GCs
+ return
+}
+
+// Pass a value to escapeMe to force it to escape.
+var escapeMe = func(x any) {}
+
+// Test that when F -> G is inlined and F is excluded from stack
+// traces, G still appears.
+func TestTracebackInlineExcluded(t *testing.T) {
+ defer func() {
+ recover()
+ buf := make([]byte, 4<<10)
+ stk := string(buf[:Stack(buf, false)])
+
+ t.Log(stk)
+
+ if not := "tracebackExcluded"; strings.Contains(stk, not) {
+ t.Errorf("found but did not expect %q", not)
+ }
+ if want := "tracebackNotExcluded"; !strings.Contains(stk, want) {
+ t.Errorf("expected %q in stack", want)
+ }
+ }()
+ tracebackExcluded()
+}
+
+// tracebackExcluded should be excluded from tracebacks. There are
+// various ways this could come up. Linking it to a "runtime." name is
+// rather synthetic, but it's easy and reliable. See issue #42754 for
+// one way this happened in real code.
+//
+//go:linkname tracebackExcluded runtime.tracebackExcluded
+//go:noinline
+func tracebackExcluded() {
+ // Call an inlined function that should not itself be excluded
+ // from tracebacks.
+ tracebackNotExcluded()
+}
+
+// tracebackNotExcluded should be inlined into tracebackExcluded, but
+// should not itself be excluded from the traceback.
+func tracebackNotExcluded() {
+ var x *int
+ *x = 0
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-19 13:30:45 +0000