process.h

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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2019, Google Inc.
 *
 * Process object
 */

#pragma once

#include <signal.h>
#include <string>
#include <vector>

#include <libcamera/base/class.h>
#include <libcamera/base/signal.h>
#include <libcamera/base/unique_fd.h>

namespace libcamera {

class EventNotifier;

class Process final
{
public:
    enum ExitStatus {
        NotExited,
        NormalExit,
        SignalExit,
    };

    Process();
    ~Process();

    int start(const std::string &path,
          const std::vector<std::string> &args = std::vector<std::string>(),
          const std::vector<int> &fds = std::vector<int>());

    ExitStatus exitStatus() const { return exitStatus_; }
    int exitCode() const { return exitCode_; }

    void kill();

    Signal<enum ExitStatus, int> finished;

private:
    LIBCAMERA_DISABLE_COPY_AND_MOVE(Process)

    void closeAllFdsExcept(const std::vector<int> &fds);
    int isolate();
    void died(int wstatus);

    pid_t pid_;
    bool running_;
    enum ExitStatus exitStatus_;
    int exitCode_;

    friend class ProcessManager;
};

class ProcessManager
{
public:
    ProcessManager();
    ~ProcessManager();

    void registerProcess(Process *proc);

    static ProcessManager *instance();

    int writePipe() const;

    const struct sigaction &oldsa() const;

private:
    static ProcessManager *self_;

    void sighandler();

    std::list<Process *> processes_;

    struct sigaction oldsa_;

    EventNotifier *sigEvent_;
    UniqueFD pipe_[2];
};

} /* namespace libcamera */