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content / browser / utility_process_host.h [blame]
// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_UTILITY_PROCESS_HOST_H_
#define CONTENT_BROWSER_UTILITY_PROCESS_HOST_H_
#include <memory>
#include <optional>
#include <string>
#include <vector>
#include "base/environment.h"
#include "base/memory/weak_ptr.h"
#include "base/process/launch.h"
#include "build/build_config.h"
#include "build/chromecast_buildflags.h"
#include "content/browser/child_process_launcher.h"
#include "content/common/child_process.mojom.h"
#include "content/common/content_export.h"
#include "content/public/browser/browser_child_process_host_delegate.h"
#include "content/public/common/zygote/zygote_buildflags.h"
#include "mojo/public/cpp/bindings/generic_pending_receiver.h"
#include "mojo/public/cpp/bindings/pending_receiver.h"
#include "sandbox/policy/mojom/sandbox.mojom.h"
#include "third_party/abseil-cpp/absl/types/variant.h"
#if BUILDFLAG(USE_ZYGOTE)
#include "content/public/common/zygote/zygote_handle.h"
#endif // BUILDFLAG(USE_ZYGOTE)
namespace base {
class Thread;
} // namespace base
#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_WIN) || BUILDFLAG(IS_CHROMEOS_ASH) || \
BUILDFLAG(IS_MAC)
namespace viz {
class GpuClient;
} // namespace viz
#endif
namespace content {
class BrowserChildProcessHostImpl;
class InProcessChildThreadParams;
struct ChildProcessData;
typedef base::Thread* (*UtilityMainThreadFactoryFunction)(
const InProcessChildThreadParams&);
// This class acts as the browser-side host to a utility child process. A
// utility process is a short-lived process that is created to run a specific
// task. This class lives solely on the IO thread.
// If you need a single method call in the process, use StartFooBar(p).
// If you need multiple batches of work to be done in the process, use
// StartBatchMode(), then multiple calls to StartFooBar(p), then finish with
// EndBatchMode().
// If you need to bind Mojo interfaces, use Start() to start the child
// process and then call BindInterface().
//
// Note: If your class keeps a ptr to an object of this type, grab a weak ptr to
// avoid a use after free since this object is deleted synchronously but the
// client notification is asynchronous. See http://crbug.com/108871.
class CONTENT_EXPORT UtilityProcessHost
: public BrowserChildProcessHostDelegate {
public:
static void RegisterUtilityMainThreadFactory(
UtilityMainThreadFactoryFunction create);
// Interface which may be passed to a UtilityProcessHost on construction. All
// methods are called from the IO thread.
class Client {
public:
virtual ~Client() {}
virtual void OnProcessLaunched(const base::Process& process) {}
virtual void OnProcessTerminatedNormally() {}
virtual void OnProcessCrashed() {}
};
// This class is self-owned. It must be instantiated using new, and shouldn't
// be deleted manually.
// TODO(crbug.com/40254698): Make it clearer the caller of the
// constructor do not own memory. A static method to create them + private
// constructor could be better.
UtilityProcessHost();
explicit UtilityProcessHost(std::unique_ptr<Client> client);
UtilityProcessHost(const UtilityProcessHost&) = delete;
UtilityProcessHost& operator=(const UtilityProcessHost&) = delete;
~UtilityProcessHost() override;
base::WeakPtr<UtilityProcessHost> AsWeakPtr();
// Makes the process run with a specific sandbox type, or unsandboxed if
// Sandbox::kNoSandbox is specified.
void SetSandboxType(sandbox::mojom::Sandbox sandbox_type);
// Returns information about the utility child process.
const ChildProcessData& GetData();
#if BUILDFLAG(IS_POSIX)
void SetEnv(const base::EnvironmentMap& env);
#endif
// Starts the utility process.
bool Start();
// Sets the name of the process to appear in the task manager.
void SetName(const std::u16string& name);
// Sets the name used for metrics reporting. This should not be a localized
// name. This is recorded to metrics, so update UtilityProcessNameHash enum in
// enums.xml if new values are passed here.
void SetMetricsName(const std::string& metrics_name);
void set_child_flags(int flags) { child_flags_ = flags; }
// Provides extra switches to append to the process's command line.
void SetExtraCommandLineSwitches(std::vector<std::string> switches);
// Allows the child process to bind viz.mojom.Gpu.
void SetAllowGpuClient();
#if BUILDFLAG(IS_WIN)
// Specifies libraries to preload before the sandbox is locked down. Paths
// should be absolute.
void SetPreloadLibraries(const std::vector<base::FilePath>& preloads);
#endif // BUILDFLAG(IS_WIN)
#if BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_MAC)
// Adds to ChildProcessLauncherFileData::files_to_preload, which maps |key| ->
// |file| in the new process's base::FileDescriptorStore.
void AddFileToPreload(std::string key,
absl::variant<base::FilePath, base::ScopedFD> file);
#endif
#if BUILDFLAG(USE_ZYGOTE)
void SetZygoteForTesting(ZygoteCommunication* handle);
#endif // BUILDFLAG(USE_ZYGOTE)
// Returns a control interface for the running child process.
mojom::ChildProcess* GetChildProcess();
private:
// Starts the child process if needed, returns true on success.
bool StartProcess();
// BrowserChildProcessHostDelegate:
void OnProcessLaunched() override;
void OnProcessLaunchFailed(int error_code) override;
void OnProcessCrashed(int exit_code) override;
std::optional<std::string> GetServiceName() override;
void BindHostReceiver(mojo::GenericPendingReceiver receiver) override;
// Launch the child process with switches that will setup this sandbox type.
sandbox::mojom::Sandbox sandbox_type_;
// ChildProcessHost flags to use when starting the child process.
int child_flags_;
// Map of environment variables to values.
base::EnvironmentMap env_;
// True if StartProcess() has been called.
bool started_;
// The process name used to identify the process in task manager.
std::u16string name_;
// The non-localized name used for metrics reporting.
std::string metrics_name_;
// Child process host implementation.
std::unique_ptr<BrowserChildProcessHostImpl> process_;
// Used in single-process mode instead of |process_|.
std::unique_ptr<base::Thread> in_process_thread_;
// Extra command line switches to append.
std::vector<std::string> extra_switches_;
#if BUILDFLAG(IS_WIN)
// Libraries to load before sandbox lockdown. Only used on Windows.
std::vector<base::FilePath> preload_libraries_;
#endif // BUILDFLAG(IS_WIN)
// Extra files and file descriptors to preload in the new process.
std::unique_ptr<ChildProcessLauncherFileData> file_data_;
#if BUILDFLAG(USE_ZYGOTE)
std::optional<raw_ptr<ZygoteCommunication>> zygote_for_testing_;
#endif // BUILDFLAG(USE_ZYGOTE)
// Indicates whether the process has been successfully launched yet, or if
// launch failed.
enum class LaunchState {
kLaunchInProgress,
kLaunchComplete,
kLaunchFailed,
};
LaunchState launch_state_ = LaunchState::kLaunchInProgress;
#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_WIN) || BUILDFLAG(IS_CHROMEOS_ASH) || \
BUILDFLAG(IS_MAC)
bool allowed_gpu_;
std::unique_ptr<viz::GpuClient, base::OnTaskRunnerDeleter> gpu_client_;
#endif
std::unique_ptr<Client> client_;
// Used to vend weak pointers, and should always be declared last.
base::WeakPtrFactory<UtilityProcessHost> weak_ptr_factory_{this};
};
} // namespace content
#endif // CONTENT_BROWSER_UTILITY_PROCESS_HOST_H_