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// Copyright 2018 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.
#include "base/memory/platform_shared_memory_region.h"
#include "base/memory/shared_memory_mapping.h"
#include "base/numerics/checked_math.h"
namespace base {
namespace subtle {
// static
PlatformSharedMemoryRegion PlatformSharedMemoryRegion::CreateWritable(
size_t size) {
return Create(Mode::kWritable, size);
}
// static
PlatformSharedMemoryRegion PlatformSharedMemoryRegion::CreateUnsafe(
size_t size) {
return Create(Mode::kUnsafe, size);
}
PlatformSharedMemoryRegion::PlatformSharedMemoryRegion() = default;
PlatformSharedMemoryRegion::PlatformSharedMemoryRegion(
PlatformSharedMemoryRegion&& other) = default;
PlatformSharedMemoryRegion& PlatformSharedMemoryRegion::operator=(
PlatformSharedMemoryRegion&& other) = default;
PlatformSharedMemoryRegion::~PlatformSharedMemoryRegion() = default;
PlatformSharedMemoryRegion::ScopedPlatformHandle
PlatformSharedMemoryRegion::PassPlatformHandle() {
return std::move(handle_);
}
bool PlatformSharedMemoryRegion::MapAt(off_t offset,
size_t size,
void** memory,
size_t* mapped_size) const {
if (!IsValid())
return false;
if (size == 0)
return false;
size_t end_byte;
if (!CheckAdd(offset, size).AssignIfValid(&end_byte) || end_byte > size_) {
return false;
}
bool success = MapAtInternal(offset, size, memory, mapped_size);
if (success) {
DCHECK_EQ(
0U, reinterpret_cast<uintptr_t>(*memory) & (kMapMinimumAlignment - 1));
}
return success;
}
} // namespace subtle
} // namespace base