nbpipe_test.go

Documentation: runtime

     1  // Copyright 2019 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build unix
     6  
     7  package runtime_test
     8  
     9  import (
    10  	"runtime"
    11  	"syscall"
    12  	"testing"
    13  	"unsafe"
    14  )
    15  
    16  func TestNonblockingPipe(t *testing.T) {
    17  	// NonblockingPipe is the test name for nonblockingPipe.
    18  	r, w, errno := runtime.NonblockingPipe()
    19  	if errno != 0 {
    20  		t.Fatal(syscall.Errno(errno))
    21  	}
    22  	defer runtime.Close(w)
    23  
    24  	checkIsPipe(t, r, w)
    25  	checkNonblocking(t, r, "reader")
    26  	checkCloseonexec(t, r, "reader")
    27  	checkNonblocking(t, w, "writer")
    28  	checkCloseonexec(t, w, "writer")
    29  
    30  	// Test that fcntl returns an error as expected.
    31  	if runtime.Close(r) != 0 {
    32  		t.Fatalf("Close(%d) failed", r)
    33  	}
    34  	val, errno := runtime.Fcntl(r, syscall.F_GETFD, 0)
    35  	if val != -1 {
    36  		t.Errorf("Fcntl succeeded unexpectedly")
    37  	} else if syscall.Errno(errno) != syscall.EBADF {
    38  		t.Errorf("Fcntl failed with error %v, expected %v", syscall.Errno(errno), syscall.EBADF)
    39  	}
    40  }
    41  
    42  func checkIsPipe(t *testing.T, r, w int32) {
    43  	bw := byte(42)
    44  	if n := runtime.Write(uintptr(w), unsafe.Pointer(&bw), 1); n != 1 {
    45  		t.Fatalf("Write(w, &b, 1) == %d, expected 1", n)
    46  	}
    47  	var br byte
    48  	if n := runtime.Read(r, unsafe.Pointer(&br), 1); n != 1 {
    49  		t.Fatalf("Read(r, &b, 1) == %d, expected 1", n)
    50  	}
    51  	if br != bw {
    52  		t.Errorf("pipe read %d, expected %d", br, bw)
    53  	}
    54  }
    55  
    56  func checkNonblocking(t *testing.T, fd int32, name string) {
    57  	t.Helper()
    58  	flags, errno := runtime.Fcntl(fd, syscall.F_GETFL, 0)
    59  	if flags == -1 {
    60  		t.Errorf("fcntl(%s, F_GETFL) failed: %v", name, syscall.Errno(errno))
    61  	} else if flags&syscall.O_NONBLOCK == 0 {
    62  		t.Errorf("O_NONBLOCK not set in %s flags %#x", name, flags)
    63  	}
    64  }
    65  
    66  func checkCloseonexec(t *testing.T, fd int32, name string) {
    67  	t.Helper()
    68  	flags, errno := runtime.Fcntl(fd, syscall.F_GETFD, 0)
    69  	if flags == -1 {
    70  		t.Errorf("fcntl(%s, F_GETFD) failed: %v", name, syscall.Errno(errno))
    71  	} else if flags&syscall.FD_CLOEXEC == 0 {
    72  		t.Errorf("FD_CLOEXEC not set in %s flags %#x", name, flags)
    73  	}
    74  }
    75
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