core/command: improve dead instance selection

Prints dead instances if they exist, as well as allowing dead instance
selection for a substring if no live instances exist.

src/core/instanceinfo.cpp

@@ -3,12 +3,12 @@
 #include <qdatastream.h>
 
 QDataStream& operator<<(QDataStream& stream, const InstanceInfo& info) {
-	stream << info.instanceId << info.configPath << info.shellId << info.launchTime;
+	stream << info.instanceId << info.configPath << info.shellId << info.launchTime << info.pid;
 	return stream;
 }
 
 QDataStream& operator>>(QDataStream& stream, InstanceInfo& info) {
-	stream >> info.instanceId >> info.configPath >> info.shellId >> info.launchTime;
+	stream >> info.instanceId >> info.configPath >> info.shellId >> info.launchTime >> info.pid;
 	return stream;
 }
 

src/core/instanceinfo.hpp

@@ -3,12 +3,14 @@
 #include <qdatetime.h>
 #include <qlogging.h>
 #include <qstring.h>
+#include <sys/types.h>
 
 struct InstanceInfo {
 	QString instanceId;
 	QString configPath;
 	QString shellId;
 	QDateTime launchTime;
+	pid_t pid = -1;
 
 	static InstanceInfo CURRENT; // NOLINT
 };

src/core/paths.cpp

@@ -9,6 +9,7 @@
 #include <qdir.h>
 #include <qlogging.h>
 #include <qloggingcategory.h>
+#include <qpair.h>
 #include <qstandardpaths.h>
 #include <qtenvironmentvariables.h>
 #include <qtversionchecks.h>
@@ -367,29 +368,30 @@ bool QsPaths::checkLock(const QString& path, InstanceLockInfo* info, bool allowD
 	return true;
 }
 
-QVector<InstanceLockInfo> QsPaths::collectInstances(const QString& path, bool fallbackDead) {
+QPair<QVector<InstanceLockInfo>, QVector<InstanceLockInfo>>
+QsPaths::collectInstances(const QString& path) {
 	qCDebug(logPaths) << "Collecting instances from" << path;
-	auto instances = QVector<InstanceLockInfo>();
+	auto liveInstances = QVector<InstanceLockInfo>();
+	auto deadInstances = QVector<InstanceLockInfo>();
 	auto dir = QDir(path);
 
 	InstanceLockInfo info;
 	for (auto& entry: dir.entryList(QDir::Dirs | QDir::NoDotAndDotDot)) {
 		auto path = dir.filePath(entry);
 
-		if (QsPaths::checkLock(path, &info, fallbackDead)) {
-			if (fallbackDead && info.pid != -1) {
-				fallbackDead = false;
-				instances.clear();
-			}
-
+		if (QsPaths::checkLock(path, &info, true)) {
 			qCDebug(logPaths).nospace() << "Found instance " << info.instance.instanceId << " (pid "
 			                            << info.pid << ") at " << path;
 
-			instances.push_back(info);
+			if (info.pid == -1) {
+				deadInstances.push_back(info);
+			} else {
+				liveInstances.push_back(info);
+			}
 		} else {
 			qCDebug(logPaths) << "Skipped potential instance at" << path;
 		}
 	}
 
-	return instances;
+	return qMakePair(liveInstances, deadInstances);
 }

src/core/paths.hpp

@@ -1,6 +1,7 @@
 #pragma once
 #include <qdatetime.h>
 #include <qdir.h>
+#include <qpair.h>
 #include <qtypes.h>
 
 #include "instanceinfo.hpp"
@@ -22,7 +23,8 @@ public:
 	static QString ipcPath(const QString& id);
 	static bool
 	checkLock(const QString& path, InstanceLockInfo* info = nullptr, bool allowDead = false);
-	static QVector<InstanceLockInfo> collectInstances(const QString& path, bool fallbackDead = false);
+	static QPair<QVector<InstanceLockInfo>, QVector<InstanceLockInfo>>
+	collectInstances(const QString& path);
 
 	QDir* baseRunDir();
 	QDir* shellRunDir();

src/launch/command.cpp

@@ -3,6 +3,7 @@
 #include <cerrno>
 #include <cstdio>
 #include <cstring>
+#include <utility>
 
 #include <qconfig.h>
 #include <qcontainerfwd.h>
@@ -177,14 +178,33 @@ int selectInstance(CommandState& cmd, InstanceLockInfo* instance, bool deadFallb
 		}
 	} else if (!cmd.instance.id->isEmpty()) {
 		path = basePath->filePath("by-pid");
-		auto instances = QsPaths::collectInstances(path, deadFallback);
+		auto [liveInstances, deadInstances] = QsPaths::collectInstances(path);
 
-		instances.removeIf([&](const InstanceLockInfo& info) {
+		liveInstances.removeIf([&](const InstanceLockInfo& info) {
 			return !info.instance.instanceId.startsWith(*cmd.instance.id);
 		});
 
+		deadInstances.removeIf([&](const InstanceLockInfo& info) {
+			return !info.instance.instanceId.startsWith(*cmd.instance.id);
+		});
+
+		auto instances = liveInstances.isEmpty() && deadFallback ? deadInstances : liveInstances;
+
 		if (instances.isEmpty()) {
-			qCInfo(logBare) << "No running instances start with" << *cmd.instance.id;
+			if (deadFallback) {
+				qCInfo(logBare) << "No instances start with" << *cmd.instance.id;
+			} else {
+				qCInfo(logBare) << "No running instances start with" << *cmd.instance.id;
+
+				if (!deadInstances.isEmpty()) {
+					qCInfo(logBare) << "Some dead instances match:";
+
+					for (auto& instance: deadInstances) {
+						qCInfo(logBare).noquote() << " -" << instance.instance.instanceId;
+					}
+				}
+			}
+
 			return -1;
 		} else if (instances.length() != 1) {
 			qCInfo(logBare) << "More than one instance starts with" << *cmd.instance.id;
@@ -208,14 +228,29 @@ int selectInstance(CommandState& cmd, InstanceLockInfo* instance, bool deadFallb
 
 		path = QDir(basePath->filePath("by-path")).filePath(pathId);
 
-		auto instances = QsPaths::collectInstances(path, deadFallback);
+		auto [liveInstances, deadInstances] = QsPaths::collectInstances(path);
+
+		auto instances = liveInstances;
+		if (instances.isEmpty() && deadFallback) {
+			instances = deadInstances;
+		}
+
 		sortInstances(
 		    instances,
 		    cmd.config.newest || (!instances.empty() && instances.first().pid == -1)
 		);
 
 		if (instances.isEmpty()) {
-			qCInfo(logBare) << "No running instances for" << configFilePath;
+			if (liveInstances.isEmpty() && deadInstances.length() > 1) {
+				qCInfo(logBare) << "No running instances for" << configFilePath;
+				qCInfo(logBare) << "Dead instances:";
+				sortInstances(deadInstances, cmd.config.newest);
+				for (auto& instance: deadInstances) {
+					qCInfo(logBare).noquote() << " -" << instance.instance.instanceId;
+				}
+			} else {
+				qCInfo(logBare) << "No running instances for" << configFilePath;
+			}
 			return -1;
 		}
 
@@ -276,7 +311,18 @@ int listInstances(CommandState& cmd) {
 		path = QDir(basePath->filePath("by-path")).filePath(pathId);
 	}
 
-	auto instances = QsPaths::collectInstances(path);
+	auto [liveInstances, deadInstances] = QsPaths::collectInstances(path);
+
+	sortInstances(liveInstances, cmd.config.newest);
+
+	QList<InstanceLockInfo> instances;
+	if (cmd.instance.includeDead) {
+		sortInstances(deadInstances, cmd.config.newest);
+		instances = std::move(deadInstances);
+		instances.append(liveInstances);
+	} else {
+		instances = std::move(liveInstances);
+	}
 
 	if (instances.isEmpty()) {
 		if (cmd.instance.all) {
@@ -286,7 +332,6 @@ int listInstances(CommandState& cmd) {
 			qCInfo(logBare) << "Use --all to list all instances.";
 		}
 	} else {
-		sortInstances(instances, cmd.config.newest);
 
 		if (cmd.output.json) {
 			auto array = QJsonArray();
@@ -295,7 +340,7 @@ int listInstances(CommandState& cmd) {
 				auto json = QJsonObject();
 
 				json["id"] = instance.instance.instanceId;
-				json["pid"] = instance.pid;
+				json["pid"] = instance.instance.pid;
 				json["shell_id"] = instance.instance.shellId;
 				json["config_path"] = instance.instance.configPath;
 				json["launch_time"] = instance.instance.launchTime.toString(Qt::ISODate);
@@ -319,12 +364,18 @@ int listInstances(CommandState& cmd) {
 				                      .arg(remMinutes)
 				                      .arg(remSeconds);
 
+				auto isDead = instance.pid == -1;
+				auto gray = !cmd.log.noColor && isDead;
+
 				qCInfo(logBare).noquote().nospace()
-				    << "Instance " << instance.instance.instanceId << ":\n"
-				    << "  Process ID: " << instance.pid << '\n'
+				    << (gray ? "\033[90m" : "") << "Instance " << instance.instance.instanceId
+				    << (isDead ? " (dead)" : "") << ":\n"
+				    << "  Process ID: " << instance.instance.pid << '\n'
 				    << "  Shell ID: " << instance.instance.shellId << '\n'
 				    << "  Config path: " << instance.instance.configPath << '\n'
-				    << "  Launch time: " << launchTimeStr << " (running for " << runtimeStr << ")\n";
+				    << "  Launch time: " << launchTimeStr
+				    << (isDead ? "" : " (running for " + runtimeStr + ")") << '\n'
+				    << (gray ? "\033[0m" : "");
 			}
 		}
 	}

src/launch/launch.cpp

@@ -128,6 +128,7 @@ int launch(const LaunchArgs& args, char** argv, QCoreApplication* coreApplicatio
 	    .configPath = args.configPath,
 	    .shellId = shellId,
 	    .launchTime = qs::Common::LAUNCH_TIME,
+	    .pid = getpid(),
 	};
 
 #if CRASH_REPORTER

src/launch/launch_p.hpp

@@ -61,6 +61,7 @@ struct CommandState {
 		QStringOption id;
 		pid_t pid = -1; // NOLINT (include)
 		bool all = false;
+		bool includeDead = false;
 	} instance;
 
 	struct {

src/launch/parsecommand.cpp

@@ -163,6 +163,9 @@ int parseCommand(int argc, char** argv, CommandState& state) {
 
 		sub->add_flag("-j,--json", state.output.json, "Output the list as a json.");
 
+		sub->add_flag("--show-dead", state.instance.includeDead)
+		    ->description("Include dead instances in the list.");
+
 		addConfigSelection(sub, true)->excludes(all);
 		addLoggingOptions(sub, false, true);