99 lines
3.5 KiB
C++
99 lines
3.5 KiB
C++
// 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/shared_memory_mapping.h"
|
|
|
|
#include <cstdint>
|
|
#include <utility>
|
|
|
|
#include "base/bits.h"
|
|
#include "base/logging.h"
|
|
#include "base/memory/shared_memory_security_policy.h"
|
|
#include "base/memory/shared_memory_tracker.h"
|
|
#include "base/system/sys_info.h"
|
|
#include "base/unguessable_token.h"
|
|
#include "build/build_config.h"
|
|
|
|
namespace base {
|
|
|
|
SharedMemoryMapping::SharedMemoryMapping() = default;
|
|
|
|
SharedMemoryMapping::SharedMemoryMapping(SharedMemoryMapping&& mapping) noexcept
|
|
: mapped_span_(std::exchange(mapping.mapped_span_, span<uint8_t>())),
|
|
size_(mapping.size_),
|
|
guid_(mapping.guid_),
|
|
mapper_(mapping.mapper_) {}
|
|
|
|
SharedMemoryMapping& SharedMemoryMapping::operator=(
|
|
SharedMemoryMapping&& mapping) noexcept {
|
|
Unmap();
|
|
mapped_span_ = std::exchange(mapping.mapped_span_, span<uint8_t>());
|
|
size_ = mapping.size_;
|
|
guid_ = mapping.guid_;
|
|
mapper_ = mapping.mapper_;
|
|
return *this;
|
|
}
|
|
|
|
SharedMemoryMapping::~SharedMemoryMapping() {
|
|
Unmap();
|
|
}
|
|
|
|
SharedMemoryMapping::SharedMemoryMapping(span<uint8_t> mapped_span,
|
|
size_t size,
|
|
const UnguessableToken& guid,
|
|
SharedMemoryMapper* mapper)
|
|
: mapped_span_(mapped_span), size_(size), guid_(guid), mapper_(mapper) {
|
|
// Note: except on Windows, `mapped_span_.size() == size_`.
|
|
SharedMemoryTracker::GetInstance()->IncrementMemoryUsage(*this);
|
|
}
|
|
|
|
void SharedMemoryMapping::Unmap() {
|
|
if (!IsValid())
|
|
return;
|
|
|
|
SharedMemorySecurityPolicy::ReleaseReservationForMapping(size_);
|
|
SharedMemoryTracker::GetInstance()->DecrementMemoryUsage(*this);
|
|
|
|
SharedMemoryMapper* mapper = mapper_;
|
|
if (!mapper)
|
|
mapper = SharedMemoryMapper::GetDefaultInstance();
|
|
|
|
// The backing mapper expects offset to be aligned to
|
|
// `SysInfo::VMAllocationGranularity()`, so replicate the alignment that was
|
|
// done when originally mapping in the region.
|
|
uint8_t* aligned_data =
|
|
bits::AlignDown(mapped_span_.data(), SysInfo::VMAllocationGranularity());
|
|
size_t adjusted_size =
|
|
mapped_span_.size() +
|
|
static_cast<size_t>(mapped_span_.data() - aligned_data);
|
|
span<uint8_t> span_to_unmap = make_span(aligned_data, adjusted_size);
|
|
mapper->Unmap(span_to_unmap);
|
|
}
|
|
|
|
ReadOnlySharedMemoryMapping::ReadOnlySharedMemoryMapping() = default;
|
|
ReadOnlySharedMemoryMapping::ReadOnlySharedMemoryMapping(
|
|
ReadOnlySharedMemoryMapping&&) noexcept = default;
|
|
ReadOnlySharedMemoryMapping& ReadOnlySharedMemoryMapping::operator=(
|
|
ReadOnlySharedMemoryMapping&&) noexcept = default;
|
|
ReadOnlySharedMemoryMapping::ReadOnlySharedMemoryMapping(
|
|
span<uint8_t> mapped_span,
|
|
size_t size,
|
|
const UnguessableToken& guid,
|
|
SharedMemoryMapper* mapper)
|
|
: SharedMemoryMapping(mapped_span, size, guid, mapper) {}
|
|
|
|
WritableSharedMemoryMapping::WritableSharedMemoryMapping() = default;
|
|
WritableSharedMemoryMapping::WritableSharedMemoryMapping(
|
|
WritableSharedMemoryMapping&&) noexcept = default;
|
|
WritableSharedMemoryMapping& WritableSharedMemoryMapping::operator=(
|
|
WritableSharedMemoryMapping&&) noexcept = default;
|
|
WritableSharedMemoryMapping::WritableSharedMemoryMapping(
|
|
span<uint8_t> mapped_span,
|
|
size_t size,
|
|
const UnguessableToken& guid,
|
|
SharedMemoryMapper* mapper)
|
|
: SharedMemoryMapping(mapped_span, size, guid, mapper) {}
|
|
|
|
} // namespace base
|