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Diffstat (limited to 'vendor/golang.org/x/sys/unix/sysvshm_unix.go')
-rw-r--r--vendor/golang.org/x/sys/unix/sysvshm_unix.go52
1 files changed, 52 insertions, 0 deletions
diff --git a/vendor/golang.org/x/sys/unix/sysvshm_unix.go b/vendor/golang.org/x/sys/unix/sysvshm_unix.go
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index 0000000..5bb41d1
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+++ b/vendor/golang.org/x/sys/unix/sysvshm_unix.go
@@ -0,0 +1,52 @@
1// Copyright 2021 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 (darwin && !ios) || linux
6// +build darwin,!ios linux
7
8package unix
9
10import "unsafe"
11
12// SysvShmAttach attaches the Sysv shared memory segment associated with the
13// shared memory identifier id.
14func SysvShmAttach(id int, addr uintptr, flag int) ([]byte, error) {
15 addr, errno := shmat(id, addr, flag)
16 if errno != nil {
17 return nil, errno
18 }
19
20 // Retrieve the size of the shared memory to enable slice creation
21 var info SysvShmDesc
22
23 _, err := SysvShmCtl(id, IPC_STAT, &info)
24 if err != nil {
25 // release the shared memory if we can't find the size
26
27 // ignoring error from shmdt as there's nothing sensible to return here
28 shmdt(addr)
29 return nil, err
30 }
31
32 // Use unsafe to convert addr into a []byte.
33 b := unsafe.Slice((*byte)(unsafe.Pointer(addr)), int(info.Segsz))
34 return b, nil
35}
36
37// SysvShmDetach unmaps the shared memory slice returned from SysvShmAttach.
38//
39// It is not safe to use the slice after calling this function.
40func SysvShmDetach(data []byte) error {
41 if len(data) == 0 {
42 return EINVAL
43 }
44
45 return shmdt(uintptr(unsafe.Pointer(&data[0])))
46}
47
48// SysvShmGet returns the Sysv shared memory identifier associated with key.
49// If the IPC_CREAT flag is specified a new segment is created.
50func SysvShmGet(key, size, flag int) (id int, err error) {
51 return shmget(key, size, flag)
52}