mirror of
https://github.com/golang/go
synced 2024-11-08 12:36:13 -07:00
4c943abb95
Fixes for #49680, #49695, #45867, and #49370 all assumed that SetGCPercent(-1) doesn't block until the GC's mark phase is done, but it actually does. The cause of 3 of those 4 failures comes from the fact that at the beginning of the sweep phase, the GC does try to preempt every P once, and this may run concurrently with test code. In the fourth case, the issue was likely that only *one* of the debug_test.go tests was missing a call to SetGCPercent(-1). Just to be safe, leave a TODO there for now to remove the extraneous runtime.GC calls, but leave the calls in. Updates #49680, #49695, #45867, and #49370. Change-Id: Ibf4e64addfba18312526968bcf40f1f5d54eb3f1 Reviewed-on: https://go-review.googlesource.com/c/go/+/369815 Reviewed-by: Austin Clements <austin@google.com> Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
68 lines
1.7 KiB
Go
68 lines
1.7 KiB
Go
// Copyright 2014 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// Test that SIGSETXID runs on signal stack, since it's likely to
|
|
// overflow if it runs on the Go stack.
|
|
|
|
package cgotest
|
|
|
|
/*
|
|
#include <sys/types.h>
|
|
#include <unistd.h>
|
|
*/
|
|
import "C"
|
|
|
|
import (
|
|
"runtime"
|
|
"runtime/debug"
|
|
"sync/atomic"
|
|
"testing"
|
|
|
|
"cgotest/issue9400"
|
|
)
|
|
|
|
func test9400(t *testing.T) {
|
|
// We synchronize through a shared variable, so we need two procs
|
|
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(2))
|
|
|
|
// Start signaller
|
|
atomic.StoreInt32(&issue9400.Baton, 0)
|
|
go func() {
|
|
// Wait for RewindAndSetgid
|
|
for atomic.LoadInt32(&issue9400.Baton) == 0 {
|
|
runtime.Gosched()
|
|
}
|
|
// Broadcast SIGSETXID
|
|
runtime.LockOSThread()
|
|
C.setgid(0)
|
|
// Indicate that signalling is done
|
|
atomic.StoreInt32(&issue9400.Baton, 0)
|
|
}()
|
|
|
|
// Grow the stack and put down a test pattern
|
|
const pattern = 0x123456789abcdef
|
|
var big [1024]uint64 // len must match assembly
|
|
for i := range big {
|
|
big[i] = pattern
|
|
}
|
|
|
|
// Disable GC for the duration of the test.
|
|
// This avoids a potential GC deadlock when spinning in uninterruptable ASM below #49695.
|
|
defer debug.SetGCPercent(debug.SetGCPercent(-1))
|
|
// SetGCPercent waits until the mark phase is over, but the runtime
|
|
// also preempts at the start of the sweep phase, so make sure that's
|
|
// done too. See #49695.
|
|
runtime.GC()
|
|
|
|
// Temporarily rewind the stack and trigger SIGSETXID
|
|
issue9400.RewindAndSetgid()
|
|
|
|
// Check test pattern
|
|
for i := range big {
|
|
if big[i] != pattern {
|
|
t.Fatalf("entry %d of test pattern is wrong; %#x != %#x", i, big[i], uint64(pattern))
|
|
}
|
|
}
|
|
}
|