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// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/memory/read_only_shared_memory_region.h"
#include <utility>
#include "build/build_config.h"
namespace base {
ReadOnlySharedMemoryRegion::CreateFunction*
ReadOnlySharedMemoryRegion::create_hook_ = nullptr;
// static
MappedReadOnlyRegion ReadOnlySharedMemoryRegion::Create(
size_t size,
SharedMemoryMapper* mapper) {
if (create_hook_) {
return create_hook_(size, mapper);
}
subtle::PlatformSharedMemoryRegion handle =
subtle::PlatformSharedMemoryRegion::CreateWritable(size);
if (!handle.IsValid()) {
return {};
}
auto result = handle.MapAt(0, handle.GetSize(), mapper);
if (!result.has_value()) {
return {};
}
WritableSharedMemoryMapping mapping(result.value(), size, handle.GetGUID(),
mapper);
#if BUILDFLAG(IS_MAC)
handle.ConvertToReadOnly(mapping.data());
#else
handle.ConvertToReadOnly();
#endif // BUILDFLAG(IS_MAC)
ReadOnlySharedMemoryRegion region(std::move(handle));
if (!region.IsValid() || !mapping.IsValid()) {
return {};
}
return {std::move(region), std::move(mapping)};
}
// static
ReadOnlySharedMemoryRegion ReadOnlySharedMemoryRegion::Deserialize(
subtle::PlatformSharedMemoryRegion handle) {
return ReadOnlySharedMemoryRegion(std::move(handle));
}
// static
subtle::PlatformSharedMemoryRegion
ReadOnlySharedMemoryRegion::TakeHandleForSerialization(
ReadOnlySharedMemoryRegion region) {
return std::move(region.handle_);
}
ReadOnlySharedMemoryRegion::ReadOnlySharedMemoryRegion() = default;
ReadOnlySharedMemoryRegion::ReadOnlySharedMemoryRegion(
ReadOnlySharedMemoryRegion&& region) = default;
ReadOnlySharedMemoryRegion& ReadOnlySharedMemoryRegion::operator=(
ReadOnlySharedMemoryRegion&& region) = default;
ReadOnlySharedMemoryRegion::~ReadOnlySharedMemoryRegion() = default;
ReadOnlySharedMemoryRegion ReadOnlySharedMemoryRegion::Duplicate() const {
return ReadOnlySharedMemoryRegion(handle_.Duplicate());
}
ReadOnlySharedMemoryMapping ReadOnlySharedMemoryRegion::Map(
SharedMemoryMapper* mapper) const {
return MapAt(0, handle_.GetSize(), mapper);
}
ReadOnlySharedMemoryMapping ReadOnlySharedMemoryRegion::MapAt(
uint64_t offset,
size_t size,
SharedMemoryMapper* mapper) const {
if (!IsValid()) {
return {};
}
auto result = handle_.MapAt(offset, size, mapper);
if (!result.has_value()) {
return {};
}
return ReadOnlySharedMemoryMapping(result.value(), size, handle_.GetGUID(),
mapper);
}
bool ReadOnlySharedMemoryRegion::IsValid() const {
return handle_.IsValid();
}
ReadOnlySharedMemoryRegion::ReadOnlySharedMemoryRegion(
subtle::PlatformSharedMemoryRegion handle)
: handle_(std::move(handle)) {
if (handle_.IsValid()) {
CHECK_EQ(handle_.GetMode(),
subtle::PlatformSharedMemoryRegion::Mode::kReadOnly);
}
}
} // namespace base
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