1 // Copyright 2016 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef MOJO_PUBLIC_CPP_SYSTEM_MESSAGE_H_
6 #define MOJO_PUBLIC_CPP_SYSTEM_MESSAGE_H_
7
8 #include <limits>
9
10 #include "base/macros.h"
11 #include "base/strings/string_piece.h"
12 #include "mojo/public/c/system/message_pipe.h"
13 #include "mojo/public/cpp/system/handle.h"
14
15 namespace mojo {
16
17 const MojoMessageHandle kInvalidMessageHandleValue =
18 MOJO_MESSAGE_HANDLE_INVALID;
19
20 // Handle wrapper base class for a |MojoMessageHandle|.
21 class MessageHandle {
22 public:
MessageHandle()23 MessageHandle() : value_(kInvalidMessageHandleValue) {}
MessageHandle(MojoMessageHandle value)24 explicit MessageHandle(MojoMessageHandle value) : value_(value) {}
~MessageHandle()25 ~MessageHandle() {}
26
swap(MessageHandle & other)27 void swap(MessageHandle& other) {
28 MojoMessageHandle temp = value_;
29 value_ = other.value_;
30 other.value_ = temp;
31 }
32
is_valid()33 bool is_valid() const { return value_ != kInvalidMessageHandleValue; }
34
value()35 const MojoMessageHandle& value() const { return value_; }
mutable_value()36 MojoMessageHandle* mutable_value() { return &value_; }
set_value(MojoMessageHandle value)37 void set_value(MojoMessageHandle value) { value_ = value; }
38
Close()39 void Close() {
40 DCHECK(is_valid());
41 MojoResult result = MojoFreeMessage(value_);
42 ALLOW_UNUSED_LOCAL(result);
43 DCHECK_EQ(MOJO_RESULT_OK, result);
44 }
45
46 private:
47 MojoMessageHandle value_;
48 };
49
50 using ScopedMessageHandle = ScopedHandleBase<MessageHandle>;
51
AllocMessage(size_t num_bytes,const MojoHandle * handles,size_t num_handles,MojoAllocMessageFlags flags,ScopedMessageHandle * handle)52 inline MojoResult AllocMessage(size_t num_bytes,
53 const MojoHandle* handles,
54 size_t num_handles,
55 MojoAllocMessageFlags flags,
56 ScopedMessageHandle* handle) {
57 DCHECK_LE(num_bytes, std::numeric_limits<uint32_t>::max());
58 DCHECK_LE(num_handles, std::numeric_limits<uint32_t>::max());
59 MojoMessageHandle raw_handle;
60 MojoResult rv = MojoAllocMessage(static_cast<uint32_t>(num_bytes), handles,
61 static_cast<uint32_t>(num_handles), flags,
62 &raw_handle);
63 if (rv != MOJO_RESULT_OK)
64 return rv;
65
66 handle->reset(MessageHandle(raw_handle));
67 return MOJO_RESULT_OK;
68 }
69
GetMessageBuffer(MessageHandle message,void ** buffer)70 inline MojoResult GetMessageBuffer(MessageHandle message, void** buffer) {
71 DCHECK(message.is_valid());
72 return MojoGetMessageBuffer(message.value(), buffer);
73 }
74
NotifyBadMessage(MessageHandle message,const base::StringPiece & error)75 inline MojoResult NotifyBadMessage(MessageHandle message,
76 const base::StringPiece& error) {
77 DCHECK(message.is_valid());
78 return MojoNotifyBadMessage(message.value(), error.data(), error.size());
79 }
80
81 } // namespace mojo
82
83 #endif // MOJO_PUBLIC_CPP_SYSTEM_MESSAGE_H_
84