File: buffer.cc

package info (click to toggle)
chromium 139.0.7258.127-1
  • links: PTS, VCS
  • area: main
  • in suites:
  • size: 6,122,068 kB
  • sloc: cpp: 35,100,771; ansic: 7,163,530; javascript: 4,103,002; python: 1,436,920; asm: 946,517; xml: 746,709; pascal: 187,653; perl: 88,691; sh: 88,436; objc: 79,953; sql: 51,488; cs: 44,583; fortran: 24,137; makefile: 22,147; tcl: 15,277; php: 13,980; yacc: 8,984; ruby: 7,485; awk: 3,720; lisp: 3,096; lex: 1,327; ada: 727; jsp: 228; sed: 36
file content (128 lines) | stat: -rw-r--r-- 3,954 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "gpu/command_buffer/common/buffer.h"

#include <stddef.h>
#include <stdint.h>
#include <ostream>

#include "base/atomic_sequence_num.h"
#include "base/bits.h"
#include "base/check_op.h"
#include "base/format_macros.h"
#include "base/no_destructor.h"
#include "base/numerics/safe_math.h"
#include "base/strings/stringprintf.h"

namespace gpu {
namespace {

// Global atomic to generate unique buffer IDs.
base::AtomicSequenceNumber g_next_buffer_id;

}  // namespace

const base::UnsafeSharedMemoryRegion& BufferBacking::shared_memory_region()
    const {
  static const base::NoDestructor<base::UnsafeSharedMemoryRegion>
      kInvalidRegion;
  return *kInvalidRegion;
}

base::UnguessableToken BufferBacking::GetGUID() const {
  return base::UnguessableToken();
}

MemoryBufferBacking::MemoryBufferBacking(uint32_t size, uint32_t alignment)
    : memory_(new char[size + alignment]), size_(size), alignment_(alignment) {}

MemoryBufferBacking::~MemoryBufferBacking() = default;

const void* MemoryBufferBacking::GetMemory() const {
  return alignment_ > 0 ? base::bits::AlignUp(memory_.get(), alignment_)
                        : memory_.get();
}

uint32_t MemoryBufferBacking::GetSize() const {
  return size_;
}

SharedMemoryBufferBacking::SharedMemoryBufferBacking(
    base::UnsafeSharedMemoryRegion shared_memory_region,
    base::WritableSharedMemoryMapping shared_memory_mapping)
    : shared_memory_region_(std::move(shared_memory_region)),
      shared_memory_mapping_(std::move(shared_memory_mapping)) {
  DCHECK_EQ(shared_memory_region_.GetGUID(), shared_memory_mapping_.guid());
  DCHECK_LE(shared_memory_mapping_.size(), static_cast<size_t>(UINT32_MAX));
}

SharedMemoryBufferBacking::~SharedMemoryBufferBacking() = default;

const base::UnsafeSharedMemoryRegion&
SharedMemoryBufferBacking::shared_memory_region() const {
  return shared_memory_region_;
}

base::UnguessableToken SharedMemoryBufferBacking::GetGUID() const {
  return shared_memory_region_.GetGUID();
}

const void* SharedMemoryBufferBacking::GetMemory() const {
  return shared_memory_mapping_.memory();
}

uint32_t SharedMemoryBufferBacking::GetSize() const {
  return static_cast<uint32_t>(shared_memory_mapping_.size());
}

Buffer::Buffer(std::unique_ptr<BufferBacking> backing)
    : backing_(std::move(backing)),
      memory_(backing_->GetMemory()),
      size_(backing_->GetSize()) {
  DCHECK(memory_) << "The memory must be mapped to create a Buffer";
}

Buffer::~Buffer() = default;

void* Buffer::GetDataAddress(uint32_t data_offset, uint32_t data_size) const {
  base::CheckedNumeric<uint32_t> end = data_offset;
  end += data_size;
  if (!end.IsValid() || end.ValueOrDie() > static_cast<uint32_t>(size_))
    return nullptr;
  return static_cast<uint8_t*>(memory_) + data_offset;
}

void* Buffer::GetDataAddressAndSize(uint32_t data_offset,
                                    uint32_t* data_size) const {
  if (data_offset > static_cast<uint32_t>(size_))
    return nullptr;
  *data_size = GetRemainingSize(data_offset);
  return static_cast<uint8_t*>(memory_) + data_offset;
}

uint32_t Buffer::GetRemainingSize(uint32_t data_offset) const {
  if (data_offset > static_cast<uint32_t>(size_))
    return 0;
  return static_cast<uint32_t>(size_) - data_offset;
}

int32_t GetNextBufferId() {
  // 0 is a reserved value.
  return g_next_buffer_id.GetNext() + 1;
}

base::trace_event::MemoryAllocatorDumpGuid GetBufferGUIDForTracing(
    uint64_t tracing_process_id,
    int32_t buffer_id) {
  return base::trace_event::MemoryAllocatorDumpGuid(base::StringPrintf(
      "gpu-buffer-x-process/%" PRIx64 "/%d", tracing_process_id, buffer_id));
}

} // namespace gpu