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969570ce7c
Implements proposed API from https://golang.org/issue/46084. I chose
`SysvShmDesc` since it's a clearer name than `SysvShm`. Initially supports Darwin and Linux.
Solaris support has a blocker (https://golang.org/issue/46084#issuecomment-836980018)
For golang/go#46084
Change-Id: Ied0f768a74c448254adc3315348417825a7ec63e
GitHub-Last-Rev: befbd7af6b
GitHub-Pull-Request: golang/sys#110
Reviewed-on: https://go-review.googlesource.com/c/sys/+/327830
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
53 lines
1.4 KiB
Go
53 lines
1.4 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 && amd64) || (linux && !android)
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// +build darwin,amd64 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 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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