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base / memory / shared_memory_switch.h [blame]
// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_MEMORY_SHARED_MEMORY_SWITCH_H_
#define BASE_MEMORY_SHARED_MEMORY_SWITCH_H_
#include <string_view>
#include "base/base_export.h"
#include "base/memory/read_only_shared_memory_region.h"
#include "base/memory/unsafe_shared_memory_region.h"
#include "base/types/expected.h"
#include "build/blink_buildflags.h"
#include "build/build_config.h"
#if !BUILDFLAG(USE_BLINK)
#error "This is only intended for platforms that use blink."
#endif
#if BUILDFLAG(IS_APPLE)
#include "base/apple/mach_port_rendezvous.h"
#endif
#if BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_APPLE)
#include "base/files/platform_file.h"
#include "base/posix/global_descriptors.h"
#endif
namespace base {
class CommandLine;
struct LaunchOptions;
namespace shared_memory {
// Indicates failure modes of deserializing a shared memory switch value.
enum class SharedMemoryError {
kNoError,
kUnexpectedTokensCount,
kParseInt0Failed,
kParseInt4Failed,
kUnexpectedHandleType,
kInvalidHandle,
kGetFDFailed,
kDeserializeGUIDFailed,
kDeserializeFailed,
kCreateTrialsFailed,
kUnexpectedSize,
};
// Updates `command_line` and `launch_options` to use `switch_name` to pass
// `read_only_memory_region` to child process that is about to be launched.
// This should be called in the parent process as a part of setting up the
// launch conditions of the child. This call will update the `command_line`
// and `launch_options`. On posix, where we prefer to use a zygote instead of
// using the launch_options to launch a new process, the platform
// `descriptor_to_share` is returned. The caller is expected to transmit the
// descriptor to the launch flow for the zygote.
BASE_EXPORT void AddToLaunchParameters(
std::string_view switch_name,
ReadOnlySharedMemoryRegion read_only_memory_region,
#if BUILDFLAG(IS_APPLE)
MachPortsForRendezvous::key_type rendezvous_key,
#elif BUILDFLAG(IS_POSIX)
GlobalDescriptors::Key descriptor_key,
ScopedFD& out_descriptor_to_share,
#endif
CommandLine* command_line,
LaunchOptions* launch_options);
// Updates `command_line` and `launch_options` to use `switch_name` to pass
// `unsafe_memory_region` to a child process that is about to be launched.
// This should be called in the parent process as a part of setting up the
// launch conditions of the child. This call will update the `command_line`
// and `launch_options`. On posix, where we prefer to use a zygote instead of
// using the launch_options to launch a new process, the platform
// `descriptor_to_share` is returned. The caller is expected to transmit the
// descriptor to the launch flow for the zygote.
BASE_EXPORT void AddToLaunchParameters(
std::string_view switch_name,
UnsafeSharedMemoryRegion unsafe_memory_region,
#if BUILDFLAG(IS_APPLE)
MachPortsForRendezvous::key_type rendezvous_key,
#elif BUILDFLAG(IS_POSIX)
GlobalDescriptors::Key descriptor_key,
ScopedFD& out_descriptor_to_share,
#endif
CommandLine* command_line,
LaunchOptions* launch_options);
// Returns an UnsafeSharedMemoryRegion deserialized from `switch_value`.
BASE_EXPORT expected<UnsafeSharedMemoryRegion, SharedMemoryError>
UnsafeSharedMemoryRegionFrom(std::string_view switch_value);
// Returns an ReadOnlySharedMemoryRegion deserialized from `switch_value`.
BASE_EXPORT expected<ReadOnlySharedMemoryRegion, SharedMemoryError>
ReadOnlySharedMemoryRegionFrom(std::string_view switch_value);
} // namespace shared_memory
} // namespace base
#endif // BASE_MEMORY_SHARED_MEMORY_SWITCH_H_