io/process!: replace manageLifetime with startDetached

In most cases this is what was desired for usages of
manageLifetime. Starting the process in a detached state also makes
sure the process hierarchy will not result in the child being killed when
Quickshell is killed.

Author: outfoxxed

src/io/CMakeLists.txt

@@ -7,8 +7,6 @@ qt_add_library(quickshell-io STATIC
 	ipchandler.cpp
 )
 
-add_library(quickshell-io-init OBJECT init.cpp)
-
 if (SOCKETS)
 	target_sources(quickshell-io PRIVATE socket.cpp)
 endif()
@@ -24,9 +22,7 @@ qt_add_qml_module(quickshell-io
 install_qml_module(quickshell-io)
 
 target_link_libraries(quickshell-io PRIVATE Qt::Quick)
-target_link_libraries(quickshell-io-init PRIVATE Qt::Qml)
-
-target_link_libraries(quickshell PRIVATE quickshell-ioplugin quickshell-io-init)
+target_link_libraries(quickshell PRIVATE quickshell-ioplugin)
 
 qs_module_pch(quickshell-io)
 

src/io/init.cpp

@@ -8,6 +8,7 @@
 #include <qmap.h>
 #include <qobject.h>
 #include <qprocess.h>
+#include <qqmlinfo.h>
 #include <qtmetamacros.h>
 #include <qtypes.h>
 #include <qvariant.h>
@@ -16,10 +17,6 @@
 #include "../core/qmlglobal.hpp"
 #include "datastream.hpp"
 
-// When the process ends this have no parent and is just leaked,
-// meaning the destructor never runs and they are never killed.
-static DisownedProcessContext* disownedCtx; // NOLINT
-
 Process::Process(QObject* parent): QObject(parent) {
 	QObject::connect(
 	    QuickshellSettings::instance(),
@@ -29,13 +26,6 @@ Process::Process(QObject* parent): QObject(parent) {
 	);
 }
 
-Process::~Process() {
-	if (!this->mLifetimeManaged && this->process != nullptr) {
-		if (disownedCtx == nullptr) disownedCtx = new DisownedProcessContext(); // NOLINT
-		disownedCtx->reparent(this->process);
-	}
-}
-
 bool Process::isRunning() const { return this->process != nullptr; }
 
 void Process::setRunning(bool running) {
@@ -183,14 +173,6 @@ void Process::setStdinEnabled(bool enabled) {
 	emit this->stdinEnabledChanged();
 }
 
-bool Process::isLifetimeManaged() const { return this->mLifetimeManaged; }
-
-void Process::setLifetimeManaged(bool managed) {
-	if (managed == this->mLifetimeManaged) return;
-	this->mLifetimeManaged = managed;
-	emit this->lifetimeManagedChanged();
-}
-
 void Process::startProcessIfReady() {
 	if (this->process != nullptr || !this->targetRunning || this->mCommand.isEmpty()) return;
 	this->targetRunning = false;
@@ -215,8 +197,30 @@ void Process::startProcessIfReady() {
 	if (this->mStderrParser == nullptr) this->process->closeReadChannel(QProcess::StandardError);
 	if (!this->mStdinEnabled) this->process->closeWriteChannel();
 
+	this->setupEnvironment(this->process);
+	this->process->start(cmd, args);
+}
+
+void Process::startDetached() {
+	if (this->mCommand.isEmpty()) {
+		qmlWarning(this) << "Cannot start process as command is empty.";
+		return;
+	}
+
+	auto& cmd = this->mCommand.first();
+	auto args = this->mCommand.sliced(1);
+
+	QProcess process;
+
+	this->setupEnvironment(&process);
+	process.setProgram(cmd);
+	process.setArguments(args);
+	process.startDetached();
+}
+
+void Process::setupEnvironment(QProcess* process) {
 	if (!this->mWorkingDirectory.isEmpty()) {
-		this->process->setWorkingDirectory(this->mWorkingDirectory);
+		process->setWorkingDirectory(this->mWorkingDirectory);
 	}
 
 	if (!this->mEnvironment.isEmpty() || this->mClearEnvironment) {
@@ -237,10 +241,8 @@ void Process::startProcessIfReady() {
 			}
 		}
 
-		this->process->setProcessEnvironment(env);
+		process->setProcessEnvironment(env);
 	}
-
-	this->process->start(cmd, args);
 }
 
 void Process::onStarted() {
@@ -291,13 +293,3 @@ void Process::write(const QString& data) {
 	if (this->process == nullptr) return;
 	this->process->write(data.toUtf8());
 }
-
-void DisownedProcessContext::reparent(QProcess* process) {
-	process->setParent(this);
-	QObject::connect(process, &QProcess::finished, this, [process]() { process->deleteLater(); });
-}
-
-void DisownedProcessContext::destroyInstance() {
-	delete disownedCtx;
-	disownedCtx = nullptr;
-}

src/io/process.cpp

@@ -46,6 +46,9 @@ class Process: public QObject {
 	///   onRunningChanged: if (!running) running = true
 	/// }
 	/// ```
+	///
+	/// > [!NOTE] See @@startDetached() to prevent the process from being killed by Quickshell
+	/// > if Quickshell is killed or the configuration is reloaded.
 	Q_PROPERTY(bool running READ isRunning WRITE setRunning NOTIFY runningChanged);
 	/// The process ID of the running process or `null` if @@running is false.
 	Q_PROPERTY(QVariant processId READ processId NOTIFY processIdChanged);
@@ -125,20 +128,11 @@ class Process: public QObject {
 	/// If stdin is enabled. Defaults to false. If this property is false the process's stdin channel
 	/// will be closed and @@write() will do nothing, even if set back to true.
 	Q_PROPERTY(bool stdinEnabled READ stdinEnabled WRITE setStdinEnabled NOTIFY stdinEnabledChanged);
-	/// If the process should be killed when the Process object is destroyed or quickshell exits.
-	/// Defaults to true.
-	///
-	/// This property may be changed while the process is running and will affect it.
-	///
-	/// > [!WARNING] If set to false the process will still be killed if the quickshell config reloads.
-	/// > It will not be killed if quickshell exits normally or crashes.
-	Q_PROPERTY(bool manageLifetime READ isLifetimeManaged WRITE setLifetimeManaged NOTIFY lifetimeManagedChanged);
 	// clang-format on
 	QML_ELEMENT;
 
 public:
 	explicit Process(QObject* parent = nullptr);
-	~Process() override;
 	Q_DISABLE_COPY_MOVE(Process);
 
 	/// Sends a signal to the process if @@running is true, otherwise does nothing.
@@ -147,6 +141,12 @@ class Process: public QObject {
 	/// Writes to the process's stdin. Does nothing if @@running is false.
 	Q_INVOKABLE void write(const QString& data);
 
+	/// Launches an instance of the process detached from quickshell.
+	///
+	/// The subprocess will not be tracked, @@running will be false,
+	/// and the subprocess will not be killed by Quickshell.
+	Q_INVOKABLE void startDetached();
+
 	[[nodiscard]] bool isRunning() const;
 	void setRunning(bool running);
 
@@ -173,9 +173,6 @@ class Process: public QObject {
 	[[nodiscard]] bool stdinEnabled() const;
 	void setStdinEnabled(bool enabled);
 
-	[[nodiscard]] bool isLifetimeManaged() const;
-	void setLifetimeManaged(bool managed);
-
 signals:
 	void started();
 	void exited(qint32 exitCode, QProcess::ExitStatus exitStatus);
@@ -189,7 +186,6 @@ class Process: public QObject {
 	void stdoutParserChanged();
 	void stderrParserChanged();
 	void stdinEnabledChanged();
-	void lifetimeManagedChanged();
 
 private slots:
 	void onStarted();
@@ -203,6 +199,7 @@ private slots:
 
 private:
 	void startProcessIfReady();
+	void setupEnvironment(QProcess* process);
 
 	QProcess* process = nullptr;
 	QList<QString> mCommand;
@@ -216,15 +213,4 @@ private slots:
 	bool targetRunning = false;
 	bool mStdinEnabled = false;
 	bool mClearEnvironment = false;
-	bool mLifetimeManaged = true;
-};
-
-class DisownedProcessContext: public QObject {
-	Q_OBJECT;
-
-	void reparent(QProcess* process);
-	friend class Process;
-
-public:
-	static void destroyInstance();
 };