зеркало из https://github.com/golang/sys.git
88 строки
2.1 KiB
Go
88 строки
2.1 KiB
Go
// Copyright 2020 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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//go:build zos && s390x
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// +build zos,s390x
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// This test is based on mmap_unix_test, but tweaked for z/OS, which does not support memadvise
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// or anonymous mmapping.
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package unix_test
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import (
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"fmt"
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"io/ioutil"
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"os"
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"path/filepath"
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"testing"
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"golang.org/x/sys/unix"
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)
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func TestMmap(t *testing.T) {
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tmpdir := mktmpdir(t)
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filename := filepath.Join(filepath.Join(tmpdir, "testdata"), "memmapped_file")
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destination, err := os.Create(filename)
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if err != nil {
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t.Fatal("os.Create:", err)
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return
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}
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defer os.RemoveAll(tmpdir)
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fmt.Fprintf(destination, "%s\n", "0 <- Flipped between 0 and 1 when test runs successfully")
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fmt.Fprintf(destination, "%s\n", "//Do not change contents - mmap test relies on this")
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destination.Close()
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fd, err := unix.Open(filename, unix.O_RDWR, 0777)
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if err != nil {
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t.Fatalf("Open: %v", err)
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}
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b, err := unix.Mmap(fd, 0, 8, unix.PROT_READ, unix.MAP_SHARED)
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if err != nil {
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t.Fatalf("Mmap: %v", err)
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}
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if err := unix.Mprotect(b, unix.PROT_READ|unix.PROT_WRITE); err != nil {
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t.Fatalf("Mprotect: %v", err)
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}
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// Flip flag in test file via mapped memory
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flagWasZero := true
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if b[0] == '0' {
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b[0] = '1'
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} else if b[0] == '1' {
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b[0] = '0'
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flagWasZero = false
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}
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if err := unix.Msync(b, unix.MS_SYNC); err != nil {
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t.Fatalf("Msync: %v", err)
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}
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// Read file from FS to ensure flag flipped after msync
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buf, err := ioutil.ReadFile(filename)
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if err != nil {
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t.Fatalf("Could not read mmapped file from disc for test: %v", err)
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}
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if flagWasZero && buf[0] != '1' || !flagWasZero && buf[0] != '0' {
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t.Error("Flag flip in MAP_SHARED mmapped file not visible")
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}
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if err := unix.Munmap(b); err != nil {
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t.Fatalf("Munmap: %v", err)
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}
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}
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func mktmpdir(t *testing.T) string {
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tmpdir, err := ioutil.TempDir("", "memmapped_file")
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if err != nil {
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t.Fatal("mktmpdir:", err)
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}
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if err := os.Mkdir(filepath.Join(tmpdir, "testdata"), 0700); err != nil {
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os.RemoveAll(tmpdir)
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t.Fatal("mktmpdir:", err)
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}
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return tmpdir
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}
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