106 lines
3.1 KiB
Go
106 lines
3.1 KiB
Go
// Copyright 2018 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.
|
|
|
|
//go:build !plan9 && !windows && !js
|
|
|
|
package runtime_test
|
|
|
|
import (
|
|
"io"
|
|
"os/exec"
|
|
"syscall"
|
|
"testing"
|
|
"time"
|
|
)
|
|
|
|
// Issue #27250. Spurious wakeups to pthread_cond_timedwait_relative_np
|
|
// shouldn't cause semasleep to retry with the same timeout which would
|
|
// cause indefinite spinning.
|
|
func TestSpuriousWakeupsNeverHangSemasleep(t *testing.T) {
|
|
if *flagQuick {
|
|
t.Skip("-quick")
|
|
}
|
|
t.Parallel() // Waits for a program to sleep for 1s.
|
|
|
|
exe, err := buildTestProg(t, "testprog")
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
|
|
cmd := exec.Command(exe, "After1")
|
|
stdout, err := cmd.StdoutPipe()
|
|
if err != nil {
|
|
t.Fatalf("StdoutPipe: %v", err)
|
|
}
|
|
beforeStart := time.Now()
|
|
if err := cmd.Start(); err != nil {
|
|
t.Fatalf("Failed to start command: %v", err)
|
|
}
|
|
doneCh := make(chan error, 1)
|
|
go func() {
|
|
doneCh <- cmd.Wait()
|
|
close(doneCh)
|
|
}()
|
|
t.Cleanup(func() {
|
|
cmd.Process.Kill()
|
|
<-doneCh
|
|
})
|
|
|
|
// Wait for After1 to close its stdout so that we know the runtime's SIGIO
|
|
// handler is registered.
|
|
b, err := io.ReadAll(stdout)
|
|
if len(b) > 0 {
|
|
t.Logf("read from testprog stdout: %s", b)
|
|
}
|
|
if err != nil {
|
|
t.Fatalf("error reading from testprog: %v", err)
|
|
}
|
|
|
|
// Wait for an arbitrary timeout longer than one second. The subprocess itself
|
|
// attempts to sleep for one second, but if the machine running the test is
|
|
// heavily loaded that subprocess may not schedule very quickly even if the
|
|
// bug remains fixed. (This is fine, because if the bug really is unfixed we
|
|
// can keep the process hung indefinitely, as long as we signal it often
|
|
// enough.)
|
|
timeout := 10 * time.Second
|
|
|
|
// The subprocess begins sleeping for 1s after it writes to stdout, so measure
|
|
// the timeout from here (not from when we started creating the process).
|
|
// That should reduce noise from process startup overhead.
|
|
ready := time.Now()
|
|
|
|
// With the repro running, we can continuously send to it
|
|
// a signal that the runtime considers non-terminal,
|
|
// such as SIGIO, to spuriously wake up
|
|
// pthread_cond_timedwait_relative_np.
|
|
ticker := time.NewTicker(200 * time.Millisecond)
|
|
defer ticker.Stop()
|
|
for {
|
|
select {
|
|
case now := <-ticker.C:
|
|
if now.Sub(ready) > timeout {
|
|
t.Error("Program failed to return on time and has to be killed, issue #27520 still exists")
|
|
// Send SIGQUIT to get a goroutine dump.
|
|
// Stop sending SIGIO so that the program can clean up and actually terminate.
|
|
cmd.Process.Signal(syscall.SIGQUIT)
|
|
return
|
|
}
|
|
|
|
// Send the pesky signal that toggles spinning
|
|
// indefinitely if #27520 is not fixed.
|
|
cmd.Process.Signal(syscall.SIGIO)
|
|
|
|
case err := <-doneCh:
|
|
if err != nil {
|
|
t.Fatalf("The program returned but unfortunately with an error: %v", err)
|
|
}
|
|
if time.Since(beforeStart) < 1*time.Second {
|
|
// The program was supposed to sleep for a full (monotonic) second;
|
|
// it should not return before that has elapsed.
|
|
t.Fatalf("The program stopped too quickly.")
|
|
}
|
|
return
|
|
}
|
|
}
|
|
}
|