1
0
Fork 0
firefox/ipc/glue/ForkServiceChild.h
Daniel Baumann 5e9a113729
Adding upstream version 140.0.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-25 09:37:52 +02:00

135 lines
4 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef __FORKSERVICE_CHILD_H_
#define __FORKSERVICE_CHILD_H_
#include "base/process_util.h"
#include "mozilla/GeckoArgs.h"
#include "nsIObserver.h"
#include "nsString.h"
#include "mozilla/ipc/MiniTransceiver.h"
#include "mozilla/ipc/LaunchError.h"
#include "mozilla/Mutex.h"
#include "mozilla/RefPtr.h"
#include "mozilla/Result.h"
#include "mozilla/StaticMutex.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/ThreadSafety.h"
#include <sys/types.h>
#include <poll.h>
namespace mozilla {
namespace ipc {
class GeckoChildProcessHost;
/**
* This is the interface to the fork server.
*
* When the chrome process calls |ForkServiceChild| to create a new
* process, this class send a message to the fork server through a
* pipe and get the PID of the new process from the reply.
*/
class ForkServiceChild final {
public:
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ForkServiceChild)
/**
* Ask the fork server to create a new process with given parameters.
*
* \param aArgs arguments with file attachments used in the content process.
* \param aOptions other options which will be used to create the process.
* Not all launch options are supported.
* \param aPid returns the PID of the content
* process created. \return true if success.
*/
Result<Ok, LaunchError> SendForkNewSubprocess(
geckoargs::ChildProcessArgs&& aArgs, base::LaunchOptions&& aOptions,
pid_t* aPid) MOZ_EXCLUDES(mMutex);
/**
* Contains a status value as from waitpid (for use with macros
* like WIFEXITED).
*/
struct ProcStatus {
int status;
};
/**
* Ask the fork server to call waitpid on a child process.
*
* \param aPid The process ID of the child process.
* \param aBlock Whether to block until the child process exits;
* use with caution.
*
* \return Ok(status) if the process exited; Err(0) if the process
* is still running; and Err(errno) if there was an error.
*/
Result<ProcStatus, int> SendWaitPid(pid_t aPid, bool aBlock);
/**
* Create a fork server process and the singleton of this class.
*
* This function uses |GeckoChildProcessHost| to launch the fork
* server, getting the fd of a pipe/socket to the fork server from
* it's |IPC::Channel|.
*/
static void StartForkServer();
static void StopForkServer();
/**
* Return the singleton. May return nullptr if the fork server is
* not running or in the process of being restarted.
*/
static RefPtr<ForkServiceChild> Get();
/**
* Returns whether the fork server was ever active. Thread-safe.
*/
static bool WasUsed() { return sForkServiceUsed; }
private:
ForkServiceChild(int aFd, GeckoChildProcessHost* aProcess);
~ForkServiceChild();
void OnError() MOZ_REQUIRES(mMutex);
static StaticMutex sMutex;
static StaticRefPtr<ForkServiceChild> sSingleton MOZ_GUARDED_BY(sMutex);
static Atomic<bool> sForkServiceUsed;
Mutex mMutex;
UniquePtr<MiniTransceiver> mTcver MOZ_GUARDED_BY(mMutex);
bool mFailed MOZ_GUARDED_BY(mMutex); // crashed or disconnected.
// mProcess is accessed only by the dtor so should be inherently
// thread-safe
GeckoChildProcessHost* mProcess;
};
/**
* Start a fork server at |xpcom-startup| from the chrome process.
*/
class ForkServerLauncher final : public nsIObserver {
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIOBSERVER
ForkServerLauncher();
static already_AddRefed<ForkServerLauncher> Create();
private:
friend class ForkServiceChild;
~ForkServerLauncher();
static void RestartForkServer();
static bool sHaveStartedClient;
static StaticRefPtr<ForkServerLauncher> sSingleton;
};
} // namespace ipc
} // namespace mozilla
#endif /* __FORKSERVICE_CHILD_H_ */