1 // Copyright 2014 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 #include "mojo/system/raw_shared_buffer.h"
6
7 #include "base/logging.h"
8 #include "mojo/embedder/platform_handle_utils.h"
9
10 namespace mojo {
11 namespace system {
12
13 // static
Create(size_t num_bytes)14 RawSharedBuffer* RawSharedBuffer::Create(size_t num_bytes) {
15 DCHECK_GT(num_bytes, 0u);
16
17 RawSharedBuffer* rv = new RawSharedBuffer(num_bytes);
18 if (!rv->Init()) {
19 // We can't just delete it directly, due to the "in destructor" (debug)
20 // check.
21 scoped_refptr<RawSharedBuffer> deleter(rv);
22 return NULL;
23 }
24
25 return rv;
26 }
27
CreateFromPlatformHandle(size_t num_bytes,embedder::ScopedPlatformHandle platform_handle)28 RawSharedBuffer* RawSharedBuffer::CreateFromPlatformHandle(
29 size_t num_bytes,
30 embedder::ScopedPlatformHandle platform_handle) {
31 DCHECK_GT(num_bytes, 0u);
32
33 RawSharedBuffer* rv = new RawSharedBuffer(num_bytes);
34 if (!rv->InitFromPlatformHandle(platform_handle.Pass())) {
35 // We can't just delete it directly, due to the "in destructor" (debug)
36 // check.
37 scoped_refptr<RawSharedBuffer> deleter(rv);
38 return NULL;
39 }
40
41 return rv;
42 }
43
Map(size_t offset,size_t length)44 scoped_ptr<RawSharedBufferMapping> RawSharedBuffer::Map(size_t offset,
45 size_t length) {
46 if (!IsValidMap(offset, length))
47 return scoped_ptr<RawSharedBufferMapping>();
48
49 return MapNoCheck(offset, length);
50 }
51
IsValidMap(size_t offset,size_t length)52 bool RawSharedBuffer::IsValidMap(size_t offset, size_t length) {
53 if (offset > num_bytes_ || length == 0)
54 return false;
55
56 // Note: This is an overflow-safe check of |offset + length > num_bytes_|
57 // (that |num_bytes >= offset| is verified above).
58 if (length > num_bytes_ - offset)
59 return false;
60
61 return true;
62 }
63
MapNoCheck(size_t offset,size_t length)64 scoped_ptr<RawSharedBufferMapping> RawSharedBuffer::MapNoCheck(size_t offset,
65 size_t length) {
66 DCHECK(IsValidMap(offset, length));
67 return MapImpl(offset, length);
68 }
69
DuplicatePlatformHandle()70 embedder::ScopedPlatformHandle RawSharedBuffer::DuplicatePlatformHandle() {
71 return embedder::DuplicatePlatformHandle(handle_.get());
72 }
73
PassPlatformHandle()74 embedder::ScopedPlatformHandle RawSharedBuffer::PassPlatformHandle() {
75 DCHECK(HasOneRef());
76 return handle_.Pass();
77 }
78
RawSharedBuffer(size_t num_bytes)79 RawSharedBuffer::RawSharedBuffer(size_t num_bytes) : num_bytes_(num_bytes) {
80 }
81
~RawSharedBuffer()82 RawSharedBuffer::~RawSharedBuffer() {
83 }
84
85 } // namespace system
86 } // namespace mojo
87