Make the fuchsia mojo/public repo the source of truth.

mojo/public/go/system/shared_buffer.go

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package system
-
-// SharedBufferHandle is a handle for a buffer that can be shared between
-// applications.
-type SharedBufferHandle interface {
-        Handle
-
-        // DuplicateBufferHandle duplicates the handle to a buffer.
-        DuplicateBufferHandle(opts *DuplicateBufferHandleOptions) (MojoResult, SharedBufferHandle)
-
-        // MapBuffer maps the requested part of the shared buffer given by handle
-        // into memory with specified flags. On success, it returns slice that
-        // points to the requested shared buffer.
-        MapBuffer(offset uint64, numBytes int, flags MojoMapBufferFlags) (MojoResult, []byte)
-
-        // UnmapBuffer unmaps a buffer that was returned by MapBuffer.
-        UnmapBuffer(buffer []byte) MojoResult
-
-        // Gets the shared buffer information (buffer size, and the specified flags).
-        GetBufferInformation() (MojoResult, MojoBufferInformation)
-}
-
-type sharedBuffer struct {
-        // baseHandle should always be the first component of this struct,
-        // see |finalizeHandle()| for more details.
-        baseHandle
-}
-
-func (h *sharedBuffer) DuplicateBufferHandle(opts *DuplicateBufferHandleOptions) (MojoResult, SharedBufferHandle) {
-        var flags uint32
-        if opts != nil {
-                flags = uint32(opts.Flags)
-        }
-        h.core.mu.Lock()
-        r, dup := sysImpl.DuplicateBufferHandle(uint32(h.mojoHandle), flags)
-        h.core.mu.Unlock()
-        return MojoResult(r), core.AcquireNativeHandle(MojoHandle(dup)).ToSharedBufferHandle()
-}
-
-func (h *sharedBuffer) MapBuffer(offset uint64, numBytes int, flags MojoMapBufferFlags) (MojoResult, []byte) {
-        h.core.mu.Lock()
-        r, buf := sysImpl.MapBuffer(uint32(h.mojoHandle), offset, uint64(numBytes), uint32(flags))
-        h.core.mu.Unlock()
-        if r != 0 {
-                return MojoResult(r), nil
-        }
-
-        return MojoResult(r), buf
-}
-
-func (h *sharedBuffer) UnmapBuffer(buffer []byte) MojoResult {
-        h.core.mu.Lock()
-        r := sysImpl.UnmapBuffer(buffer)
-        h.core.mu.Unlock()
-        return MojoResult(r)
-}
-
-func (h *sharedBuffer) GetBufferInformation() (MojoResult, MojoBufferInformation) {
-        h.core.mu.Lock()
-        r, flags, numBytes := sysImpl.GetBufferInformation(uint32(h.mojoHandle))
-        h.core.mu.Unlock()
-
-        if r != 0 {
-                return MojoResult(r), MojoBufferInformation{}
-        }
-
-        return MojoResult(r), MojoBufferInformation{
-                Flags:    MojoBufferInformationFlags(flags),
-                NumBytes: numBytes}
-}