1// Copyright 2016 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// +build aix darwin dragonfly freebsd hurd linux netbsd openbsd solaris
6
7package runtime_test
8
9import (
10	"runtime"
11	"testing"
12	"unsafe"
13)
14
15// Test that the error value returned by mmap is positive, as that is
16// what the code in mem_bsd.go, mem_darwin.go, and mem_linux.go expects.
17// See the uses of ENOMEM in sysMap in those files.
18func TestMmapErrorSign(t *testing.T) {
19	p, err := runtime.Mmap(nil, ^uintptr(0)&^(runtime.GetPhysPageSize()-1), 0, runtime.MAP_ANON|runtime.MAP_PRIVATE, -1, 0)
20
21	if p != nil || err != runtime.ENOMEM {
22		t.Errorf("mmap = %v, %v, want nil, %v", p, err, runtime.ENOMEM)
23	}
24}
25
26func TestPhysPageSize(t *testing.T) {
27	// Mmap fails if the address is not page aligned, so we can
28	// use this to test if the page size is the true page size.
29	ps := runtime.GetPhysPageSize()
30
31	// Get a region of memory to play with. This should be page-aligned.
32	b, err := runtime.Mmap(nil, 2*ps, 0, runtime.MAP_ANON|runtime.MAP_PRIVATE, -1, 0)
33	if err != 0 {
34		t.Fatalf("Mmap: %v", err)
35	}
36
37	if runtime.GOOS == "aix" {
38		// AIX does not allow mapping a range that is already mapped.
39		runtime.Munmap(unsafe.Pointer(uintptr(b)), 2*ps)
40	}
41
42	// Mmap should fail at a half page into the buffer.
43	_, err = runtime.Mmap(unsafe.Pointer(uintptr(b)+ps/2), ps, 0, runtime.MAP_ANON|runtime.MAP_PRIVATE|runtime.MAP_FIXED, -1, 0)
44	if err == 0 {
45		t.Errorf("Mmap should have failed with half-page alignment %d, but succeeded: %v", ps/2, err)
46	}
47
48	// Mmap should succeed at a full page into the buffer.
49	_, err = runtime.Mmap(unsafe.Pointer(uintptr(b)+ps), ps, 0, runtime.MAP_ANON|runtime.MAP_PRIVATE|runtime.MAP_FIXED, -1, 0)
50	if err != 0 {
51		t.Errorf("Mmap at full-page alignment %d failed: %v", ps, err)
52	}
53}
54