diff options
Diffstat (limited to 'vendor/golang.org/x/sys/unix/sysvshm_unix.go')
| -rw-r--r-- | vendor/golang.org/x/sys/unix/sysvshm_unix.go | 52 |
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 new file mode 100644 index 0000000..5bb41d1 --- /dev/null +++ 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 | |||
| 8 | package unix | ||
| 9 | |||
| 10 | import "unsafe" | ||
| 11 | |||
| 12 | // SysvShmAttach attaches the Sysv shared memory segment associated with the | ||
| 13 | // shared memory identifier id. | ||
| 14 | func 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. | ||
| 40 | func 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. | ||
| 50 | func SysvShmGet(key, size, flag int) (id int, err error) { | ||
| 51 | return shmget(key, size, flag) | ||
| 52 | } | ||
