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Diffstat (limited to '')
-rw-r--r-- | dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/sysvshm_unix.go | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/sysvshm_unix.go b/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/sysvshm_unix.go new file mode 100644 index 0000000..5bb41d1 --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/sysvshm_unix.go @@ -0,0 +1,52 @@ +// Copyright 2021 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +//go:build (darwin && !ios) || linux +// +build darwin,!ios linux + +package unix + +import "unsafe" + +// SysvShmAttach attaches the Sysv shared memory segment associated with the +// shared memory identifier id. +func SysvShmAttach(id int, addr uintptr, flag int) ([]byte, error) { + addr, errno := shmat(id, addr, flag) + if errno != nil { + return nil, errno + } + + // Retrieve the size of the shared memory to enable slice creation + var info SysvShmDesc + + _, err := SysvShmCtl(id, IPC_STAT, &info) + if err != nil { + // release the shared memory if we can't find the size + + // ignoring error from shmdt as there's nothing sensible to return here + shmdt(addr) + return nil, err + } + + // Use unsafe to convert addr into a []byte. + b := unsafe.Slice((*byte)(unsafe.Pointer(addr)), int(info.Segsz)) + return b, nil +} + +// SysvShmDetach unmaps the shared memory slice returned from SysvShmAttach. +// +// It is not safe to use the slice after calling this function. +func SysvShmDetach(data []byte) error { + if len(data) == 0 { + return EINVAL + } + + return shmdt(uintptr(unsafe.Pointer(&data[0]))) +} + +// SysvShmGet returns the Sysv shared memory identifier associated with key. +// If the IPC_CREAT flag is specified a new segment is created. +func SysvShmGet(key, size, flag int) (id int, err error) { + return shmget(key, size, flag) +} |