1 files changed, 245 insertions, 0 deletions
diff --git a/src/runtime/testdata/testprogcgo/eintr.go b/src/runtime/testdata/testprogcgo/eintr.go
new file mode 100644
index 0000000..1722a75
--- /dev/null
+++ b/src/runtime/testdata/testprogcgo/eintr.go
@@ -0,0 +1,245 @@
+// 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.
+
+// +build !plan9,!windows
+
+package main
+
+/*
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+
+static int clearRestart(int sig) {
+	struct sigaction sa;
+
+	memset(&sa, 0, sizeof sa);
+	if (sigaction(sig, NULL, &sa) < 0) {
+		return errno;
+	}
+	sa.sa_flags &=~ SA_RESTART;
+	if (sigaction(sig, &sa, NULL) < 0) {
+		return errno;
+	}
+	return 0;
+}
+*/
+import "C"
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"os"
+	"os/exec"
+	"sync"
+	"syscall"
+	"time"
+)
+
+func init() {
+	register("EINTR", EINTR)
+	register("Block", Block)
+}
+
+// Test various operations when a signal handler is installed without
+// the SA_RESTART flag. This tests that the os and net APIs handle EINTR.
+func EINTR() {
+	if errno := C.clearRestart(C.int(syscall.SIGURG)); errno != 0 {
+		log.Fatal(syscall.Errno(errno))
+	}
+	if errno := C.clearRestart(C.int(syscall.SIGWINCH)); errno != 0 {
+		log.Fatal(syscall.Errno(errno))
+	}
+	if errno := C.clearRestart(C.int(syscall.SIGCHLD)); errno != 0 {
+		log.Fatal(syscall.Errno(errno))
+	}
+
+	var wg sync.WaitGroup
+	testPipe(&wg)
+	testNet(&wg)
+	testExec(&wg)
+	wg.Wait()
+	fmt.Println("OK")
+}
+
+// spin does CPU bound spinning and allocating for a millisecond,
+// to get a SIGURG.
+//go:noinline
+func spin() (float64, []byte) {
+	stop := time.Now().Add(time.Millisecond)
+	r1 := 0.0
+	r2 := make([]byte, 200)
+	for time.Now().Before(stop) {
+		for i := 1; i < 1e6; i++ {
+			r1 += r1 / float64(i)
+			r2 = append(r2, bytes.Repeat([]byte{byte(i)}, 100)...)
+			r2 = r2[100:]
+		}
+	}
+	return r1, r2
+}
+
+// winch sends a few SIGWINCH signals to the process.
+func winch() {
+	ticker := time.NewTicker(100 * time.Microsecond)
+	defer ticker.Stop()
+	pid := syscall.Getpid()
+	for n := 10; n > 0; n-- {
+		syscall.Kill(pid, syscall.SIGWINCH)
+		<-ticker.C
+	}
+}
+
+// sendSomeSignals triggers a few SIGURG and SIGWINCH signals.
+func sendSomeSignals() {
+	done := make(chan struct{})
+	go func() {
+		spin()
+		close(done)
+	}()
+	winch()
+	<-done
+}
+
+// testPipe tests pipe operations.
+func testPipe(wg *sync.WaitGroup) {
+	r, w, err := os.Pipe()
+	if err != nil {
+		log.Fatal(err)
+	}
+	if err := syscall.SetNonblock(int(r.Fd()), false); err != nil {
+		log.Fatal(err)
+	}
+	if err := syscall.SetNonblock(int(w.Fd()), false); err != nil {
+		log.Fatal(err)
+	}
+	wg.Add(2)
+	go func() {
+		defer wg.Done()
+		defer w.Close()
+		// Spin before calling Write so that the first ReadFull
+		// in the other goroutine will likely be interrupted
+		// by a signal.
+		sendSomeSignals()
+		// This Write will likely be interrupted by a signal
+		// as the other goroutine spins in the middle of reading.
+		// We write enough data that we should always fill the
+		// pipe buffer and need multiple write system calls.
+		if _, err := w.Write(bytes.Repeat([]byte{0}, 2<<20)); err != nil {
+			log.Fatal(err)
+		}
+	}()
+	go func() {
+		defer wg.Done()
+		defer r.Close()
+		b := make([]byte, 1<<20)
+		// This ReadFull will likely be interrupted by a signal,
+		// as the other goroutine spins before writing anything.
+		if _, err := io.ReadFull(r, b); err != nil {
+			log.Fatal(err)
+		}
+		// Spin after reading half the data so that the Write
+		// in the other goroutine will likely be interrupted
+		// before it completes.
+		sendSomeSignals()
+		if _, err := io.ReadFull(r, b); err != nil {
+			log.Fatal(err)
+		}
+	}()
+}
+
+// testNet tests network operations.
+func testNet(wg *sync.WaitGroup) {
+	ln, err := net.Listen("tcp4", "127.0.0.1:0")
+	if err != nil {
+		if errors.Is(err, syscall.EAFNOSUPPORT) || errors.Is(err, syscall.EPROTONOSUPPORT) {
+			return
+		}
+		log.Fatal(err)
+	}
+	wg.Add(2)
+	go func() {
+		defer wg.Done()
+		defer ln.Close()
+		c, err := ln.Accept()
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer c.Close()
+		cf, err := c.(*net.TCPConn).File()
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer cf.Close()
+		if err := syscall.SetNonblock(int(cf.Fd()), false); err != nil {
+			log.Fatal(err)
+		}
+		// See comments in testPipe.
+		sendSomeSignals()
+		if _, err := cf.Write(bytes.Repeat([]byte{0}, 2<<20)); err != nil {
+			log.Fatal(err)
+		}
+	}()
+	go func() {
+		defer wg.Done()
+		sendSomeSignals()
+		c, err := net.Dial("tcp", ln.Addr().String())
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer c.Close()
+		cf, err := c.(*net.TCPConn).File()
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer cf.Close()
+		if err := syscall.SetNonblock(int(cf.Fd()), false); err != nil {
+			log.Fatal(err)
+		}
+		// See comments in testPipe.
+		b := make([]byte, 1<<20)
+		if _, err := io.ReadFull(cf, b); err != nil {
+			log.Fatal(err)
+		}
+		sendSomeSignals()
+		if _, err := io.ReadFull(cf, b); err != nil {
+			log.Fatal(err)
+		}
+	}()
+}
+
+func testExec(wg *sync.WaitGroup) {
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		cmd := exec.Command(os.Args[0], "Block")
+		stdin, err := cmd.StdinPipe()
+		if err != nil {
+			log.Fatal(err)
+		}
+		cmd.Stderr = new(bytes.Buffer)
+		cmd.Stdout = cmd.Stderr
+		if err := cmd.Start(); err != nil {
+			log.Fatal(err)
+		}
+
+		go func() {
+			sendSomeSignals()
+			stdin.Close()
+		}()
+
+		if err := cmd.Wait(); err != nil {
+			log.Fatalf("%v:\n%s", err, cmd.Stdout)
+		}
+	}()
+}
+
+// Block blocks until stdin is closed.
+func Block() {
+	io.Copy(io.Discard, os.Stdin)
+}