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Change-Id: I8b05b5cea86d41423dac9fd96a5000a6daa1e8c3 Reviewed-on: https://go-review.googlesource.com/c/sys/+/690816 Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com> Reviewed-by: Mark Freeman <mark@golang.org> Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
51 lines
1.3 KiB
Go
51 lines
1.3 KiB
Go
// Copyright 2021 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 (darwin && !ios) || (linux && !android)
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package unix_test
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import (
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"log"
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"golang.org/x/sys/unix"
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)
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func ExampleSysvShmGet() {
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// create shared memory region of 1024 bytes
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id, err := unix.SysvShmGet(unix.IPC_PRIVATE, 1024, unix.IPC_CREAT|unix.IPC_EXCL|0o600)
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if err != nil {
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log.Fatal("sysv shm create failed:", err)
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}
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// warning: sysv shared memory segments persist even after a process
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// is destroyed, so it's very important to explicitly delete it when you
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// don't need it anymore.
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defer func() {
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_, err := unix.SysvShmCtl(id, unix.IPC_RMID, nil)
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if err != nil {
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log.Fatal(err)
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}
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}()
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// to use a shared memory region you must attach to it
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b, err := unix.SysvShmAttach(id, 0, 0)
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if err != nil {
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log.Fatal("sysv attach failed:", err)
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}
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// you should detach from the segment when finished with it. The byte
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// slice is no longer valid after detaching
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defer func() {
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if err = unix.SysvShmDetach(b); err != nil {
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log.Fatal("sysv detach failed:", err)
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}
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}()
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// Changes to the contents of the byte slice are reflected in other
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// mappings of the shared memory identifer in this and other processes
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b[42] = 'h'
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b[43] = 'i'
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}
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