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Diffstat (limited to 'vendor/golang.org/x/sys/unix/sysvshm_unix.go')
-rw-r--r--vendor/golang.org/x/sys/unix/sysvshm_unix.go61
1 files changed, 61 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..0bb4c8d
--- /dev/null
+++ b/vendor/golang.org/x/sys/unix/sysvshm_unix.go
@@ -0,0 +1,61 @@
+// 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"
+
+ "golang.org/x/sys/internal/unsafeheader"
+)
+
+// 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.
+ // TODO: convert to unsafe.Slice once we can assume Go 1.17
+ var b []byte
+ hdr := (*unsafeheader.Slice)(unsafe.Pointer(&b))
+ hdr.Data = unsafe.Pointer(addr)
+ hdr.Cap = int(info.Segsz)
+ hdr.Len = 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)
+}