| // Copyright 2023 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. |
| |
| // Tests a goroutine sitting blocked in a syscall for |
| // an entire generation. This is a regression test for |
| // #65196. |
| |
| //go:build ignore |
| |
| package main |
| |
| import ( |
| "log" |
| "os" |
| "runtime/trace" |
| "syscall" |
| "time" |
| ) |
| |
| func main() { |
| // Create a pipe to block on. |
| var p [2]int |
| if err := syscall.Pipe(p[:]); err != nil { |
| log.Fatalf("failed to create pipe: %v", err) |
| } |
| rfd, wfd := p[0], p[1] |
| |
| // Create a goroutine that blocks on the pipe. |
| done := make(chan struct{}) |
| go func() { |
| var data [1]byte |
| _, err := syscall.Read(rfd, data[:]) |
| if err != nil { |
| log.Fatalf("failed to read from pipe: %v", err) |
| } |
| done <- struct{}{} |
| }() |
| |
| // Give the goroutine ample chance to block on the pipe. |
| time.Sleep(10 * time.Millisecond) |
| |
| // Start tracing. |
| if err := trace.Start(os.Stdout); err != nil { |
| log.Fatalf("failed to start tracing: %v", err) |
| } |
| |
| // This isn't enough to have a full generation pass by default, |
| // but it is generally enough in stress mode. |
| time.Sleep(100 * time.Millisecond) |
| |
| // Write to the pipe to unblock it. |
| if _, err := syscall.Write(wfd, []byte{10}); err != nil { |
| log.Fatalf("failed to write to pipe: %v", err) |
| } |
| |
| // Wait for the goroutine to unblock and start running. |
| // This is helpful to catch incorrect information written |
| // down for the syscall-blocked goroutine, since it'll start |
| // executing, and that execution information will be |
| // inconsistent. |
| <-done |
| |
| // Stop tracing. |
| trace.Stop() |
| } |