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7d69d983c4
This change syncs the IBM internal version of sys/unix with the public repository. There are a variety of new syscalls and const definitions that have been accumulated over the past few years to support developers using Go on the platform. Old simulations of calls like 'epoll' and 'fstatfs' have been replaced with their real counterparts. The zos/s390x syscalls also have extensive trampolining to handle zos systems that might not have support for some of these new system calls. Closes golang/go#67071 Change-Id: I973d9e0abca2b05365308cf2b890438e50ae5957 Reviewed-on: https://go-review.googlesource.com/c/sys/+/582035 Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Bill O'Farrell <billotosyr@gmail.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
52 lines
1.4 KiB
Go
52 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 && !ios) || linux || zos
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package unix
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import "unsafe"
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// SysvShmAttach attaches the Sysv shared memory segment associated with the
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// shared memory identifier id.
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func SysvShmAttach(id int, addr uintptr, flag int) ([]byte, error) {
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addr, errno := shmat(id, addr, flag)
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if errno != nil {
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return nil, errno
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}
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// Retrieve the size of the shared memory to enable slice creation
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var info SysvShmDesc
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_, err := SysvShmCtl(id, IPC_STAT, &info)
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if err != nil {
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// release the shared memory if we can't find the size
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// ignoring error from shmdt as there's nothing sensible to return here
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shmdt(addr)
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return nil, err
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}
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// Use unsafe to convert addr into a []byte.
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b := unsafe.Slice((*byte)(unsafe.Pointer(addr)), int(info.Segsz))
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return b, nil
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}
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// SysvShmDetach unmaps the shared memory slice returned from SysvShmAttach.
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//
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// It is not safe to use the slice after calling this function.
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func SysvShmDetach(data []byte) error {
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if len(data) == 0 {
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return EINVAL
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}
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return shmdt(uintptr(unsafe.Pointer(&data[0])))
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}
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// SysvShmGet returns the Sysv shared memory identifier associated with key.
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// If the IPC_CREAT flag is specified a new segment is created.
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func SysvShmGet(key, size, flag int) (id int, err error) {
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return shmget(key, size, flag)
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}
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