rss-tools: vendor/golang.org/x/sys/unix/mremap.go (58cc1bd492af31e6c9acf65e690474c8c1edf164)

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// Copyright 2023 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 linux || netbsd

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package unix

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import "unsafe"

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type mremapMmapper struct {

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	mmapper

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	mremap func(oldaddr uintptr, oldlength uintptr, newlength uintptr, flags int, newaddr uintptr) (xaddr uintptr, err error)

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var mapper = &mremapMmapper{

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	mmapper: mmapper{

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		active: make(map[*byte][]byte),

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		mmap:   mmap,

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		munmap: munmap,

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},

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	mremap: mremap,

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func (m *mremapMmapper) Mremap(oldData []byte, newLength int, flags int) (data []byte, err error) {

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	if newLength <= 0 || len(oldData) == 0 || len(oldData) != cap(oldData) || flags&mremapFixed != 0 {

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		return nil, EINVAL

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	pOld := &oldData[cap(oldData)-1]

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	m.Lock()

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	defer m.Unlock()

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	bOld := m.active[pOld]

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	if bOld == nil || &bOld[0] != &oldData[0] {

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		return nil, EINVAL

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	newAddr, errno := m.mremap(uintptr(unsafe.Pointer(&bOld[0])), uintptr(len(bOld)), uintptr(newLength), flags, 0)

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	if errno != nil {

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		return nil, errno

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	bNew := unsafe.Slice((*byte)(unsafe.Pointer(newAddr)), newLength)

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	pNew := &bNew[cap(bNew)-1]

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	if flags&mremapDontunmap == 0 {

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		delete(m.active, pOld)

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	m.active[pNew] = bNew

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	return bNew, nil

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func Mremap(oldData []byte, newLength int, flags int) (data []byte, err error) {

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	return mapper.Mremap(oldData, newLength, flags)

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func MremapPtr(oldAddr unsafe.Pointer, oldSize uintptr, newAddr unsafe.Pointer, newSize uintptr, flags int) (ret unsafe.Pointer, err error) {

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	xaddr, err := mapper.mremap(uintptr(oldAddr), oldSize, newSize, flags, uintptr(newAddr))

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	return unsafe.Pointer(xaddr), err

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1	// Copyright 2023 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.
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5	//go:build linux \|\| netbsd
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7	package unix
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9	import "unsafe"
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11	type mremapMmapper struct {
12	mmapper
13	mremap func(oldaddr uintptr, oldlength uintptr, newlength uintptr, flags int, newaddr uintptr) (xaddr uintptr, err error)
14	}
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16	var mapper = &mremapMmapper{
17	mmapper: mmapper{
18	active: make(map[*byte][]byte),
19	mmap: mmap,
20	munmap: munmap,
21	},
22	mremap: mremap,
23	}
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25	func (m *mremapMmapper) Mremap(oldData []byte, newLength int, flags int) (data []byte, err error) {
26	if newLength <= 0 \|\| len(oldData) == 0 \|\| len(oldData) != cap(oldData) \|\| flags&mremapFixed != 0 {
27	return nil, EINVAL
28	}
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30	pOld := &oldData[cap(oldData)-1]
31	m.Lock()
32	defer m.Unlock()
33	bOld := m.active[pOld]
34	if bOld == nil \|\| &bOld[0] != &oldData[0] {
35	return nil, EINVAL
36	}
37	newAddr, errno := m.mremap(uintptr(unsafe.Pointer(&bOld[0])), uintptr(len(bOld)), uintptr(newLength), flags, 0)
38	if errno != nil {
39	return nil, errno
40	}
41	bNew := unsafe.Slice((*byte)(unsafe.Pointer(newAddr)), newLength)
42	pNew := &bNew[cap(bNew)-1]
43	if flags&mremapDontunmap == 0 {
44	delete(m.active, pOld)
45	}
46	m.active[pNew] = bNew
47	return bNew, nil
48	}
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50	func Mremap(oldData []byte, newLength int, flags int) (data []byte, err error) {
51	return mapper.Mremap(oldData, newLength, flags)
52	}
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54	func MremapPtr(oldAddr unsafe.Pointer, oldSize uintptr, newAddr unsafe.Pointer, newSize uintptr, flags int) (ret unsafe.Pointer, err error) {
55	xaddr, err := mapper.mremap(uintptr(oldAddr), oldSize, newSize, flags, uintptr(newAddr))
56	return unsafe.Pointer(xaddr), err
57	}