b37e69d434
The `ProcessManager` is a singleton class to handle `SIGCHLD` signals and report the exit status to the particular `Process` instance. However, having a singleton in a library is not favourable and it is even less favourable if it installs a signal handler. Using pidfd it is possible to avoid the need for the signal handler; and the `Process` objects can watch their pidfd themselves, eliminating the need for the `ProcessManager` class altogether. `P_PIDFD` for `waitid()` was introduced in Linux 5.4, so this change raises the minimum supported kernel version. `clone3()`, `CLONE_PIDFD`, `pidfd_send_signal()` were all introduced earlier. Furthermore, the call to the `unshare()` system call can be removed as those options can be passed to `clone3()` directly. Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
58 lines
948 B
C++
58 lines
948 B
C++
/* SPDX-License-Identifier: LGPL-2.1-or-later */
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/*
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* Copyright (C) 2019, Google Inc.
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*
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* Process object
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*/
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#pragma once
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#include <string>
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#include <libcamera/base/class.h>
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#include <libcamera/base/signal.h>
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#include <libcamera/base/span.h>
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#include <libcamera/base/unique_fd.h>
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namespace libcamera {
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class EventNotifier;
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class Process final
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{
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public:
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enum ExitStatus {
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NotExited,
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NormalExit,
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SignalExit,
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};
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Process();
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~Process();
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int start(const std::string &path,
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Span<const std::string> args = {},
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Span<const int> fds = {});
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ExitStatus exitStatus() const { return exitStatus_; }
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int exitCode() const { return exitCode_; }
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void kill();
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Signal<enum ExitStatus, int> finished;
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private:
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LIBCAMERA_DISABLE_COPY_AND_MOVE(Process)
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void onPidfdNotify();
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pid_t pid_;
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enum ExitStatus exitStatus_;
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int exitCode_;
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UniqueFD pidfd_;
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std::unique_ptr<EventNotifier> pidfdNotify_;
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};
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} /* namespace libcamera */
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