From 541043d2b49cad04b250ca168831b1078c6fc2f7 Mon Sep 17 00:00:00 2001
From: Ivailo Monev <xakepa10@gmail.com>
Date: Mon, 16 May 2022 12:15:48 +0300
Subject: [PATCH] plasma: optimize kill runner

attempting to cleanup every 50ms or create KSysGuard::Processes pointer
and suspend matching before the term length is checked is sub-optimal

Signed-off-by: Ivailo Monev <xakepa10@gmail.com>
---
 plasma/runners/kill/killrunner.cpp | 51 ++++----------------------------------
 plasma/runners/kill/killrunner.h   | 26 +++----------------
 2 files changed, 8 insertions(+), 69 deletions(-)

diff --git a/plasma/runners/kill/killrunner.cpp b/plasma/runners/kill/killrunner.cpp
index 07a2fa55..5c61a893 100644
--- a/plasma/runners/kill/killrunner.cpp
+++ b/plasma/runners/kill/killrunner.cpp
@@ -26,26 +26,16 @@
 #include <KUser>
 #include <kauthaction.h>
 
-#include "ksysguard/processcore/processes.h"
-#include "ksysguard/processcore/process.h"
 #include "killrunner_config.h"
 
 #include <signal.h>
 
 KillRunner::KillRunner(QObject *parent, const QVariantList& args)
-        : Plasma::AbstractRunner(parent, args),
-          m_processes(0)
+        : Plasma::AbstractRunner(parent, args)
 {
     Q_UNUSED(args);
     setObjectName(QLatin1String("Kill Runner"));
     reloadConfiguration();
-
-    connect(this, SIGNAL(prepare()), this, SLOT(prep()));
-    connect(this, SIGNAL(teardown()), this, SLOT(cleanup()));
-
-    m_delayedCleanupTimer.setInterval(50);
-    m_delayedCleanupTimer.setSingleShot(true);
-    connect(&m_delayedCleanupTimer, SIGNAL(timeout()), this, SLOT(cleanup()));
 }
 
 KillRunner::~KillRunner()
@@ -68,27 +58,6 @@ void KillRunner::reloadConfiguration()
     setSyntaxes(syntaxes);
 }
 
-void KillRunner::prep()
-{
-    m_delayedCleanupTimer.stop();
-}
-
-void KillRunner::cleanup()
-{
-    if (!m_processes) {
-        return;
-    }
-
-    if (m_prepLock.tryLockForWrite()) {
-        delete m_processes;
-        m_processes = 0;
-
-        m_prepLock.unlock();
-    } else {
-        m_delayedCleanupTimer.stop();
-    }
-}
-
 void KillRunner::match(Plasma::RunnerContext &context)
 {
     QString term = context.query();
@@ -97,19 +66,6 @@ void KillRunner::match(Plasma::RunnerContext &context)
         return;
     }
 
-    m_prepLock.lockForRead();
-    if (!m_processes) {
-        m_prepLock.unlock();
-        m_prepLock.lockForWrite();
-        if (!m_processes) {
-            suspendMatching(true);
-            m_processes = new KSysGuard::Processes();
-            m_processes->updateAllProcesses();
-            suspendMatching(false);
-        }
-    }
-    m_prepLock.unlock();
-
     term = term.right(term.length() - m_triggerWord.length());
 
     if (term.length() < 2)  {
@@ -117,7 +73,10 @@ void KillRunner::match(Plasma::RunnerContext &context)
     }
 
     QList<Plasma::QueryMatch> matches;
-    const QList<KSysGuard::Process *> processlist = m_processes->getAllProcesses();
+    KSysGuard::Processes *processes = new KSysGuard::Processes();
+    processes->updateAllProcesses();
+    const QList<KSysGuard::Process *> processlist = processes->getAllProcesses();
+    processes->deleteLater();
     foreach (const KSysGuard::Process *process, processlist) {
         if (!context.isValid()) {
             return;
diff --git a/plasma/runners/kill/killrunner.h b/plasma/runners/kill/killrunner.h
index 76bd0068..92e5dd37 100644
--- a/plasma/runners/kill/killrunner.h
+++ b/plasma/runners/kill/killrunner.h
@@ -20,19 +20,12 @@
 #ifndef KILLRUNNER_H
 #define KILLRUNNER_H
 
-#include <QReadWriteLock>
-#include <QTimer>
-
+#include <QAction>
 #include <Plasma/AbstractRunner>
 
+#include "ksysguard/processcore/processes.h"
+#include "ksysguard/processcore/process.h"
 #include "killrunner_config.h"
-#include <QAction>
-
-namespace KSysGuard
-{
-    class Processes;
-    class Process;
-}
 
 class KillRunner : public Plasma::AbstractRunner
 {
@@ -47,10 +40,6 @@ public:
     QList<QAction*> actionsForMatch(const Plasma::QueryMatch &match);
     void reloadConfiguration();
 
-private Q_SLOTS:
-    void prep();
-    void cleanup();
-
 private:
     /** @param uid the uid of the user
       * @return the username of the user with the UID uid
@@ -62,15 +51,6 @@ private:
 
     /** How to sort */
     KillRunnerConfig::Sort m_sorting;
-
-    /** process lister */
-    KSysGuard::Processes *m_processes;
-
-    /** lock for initializing m_processes */
-    QReadWriteLock m_prepLock;
-
-    /** timer for retrying the cleanup due to lock contention */
-    QTimer m_delayedCleanupTimer;
 };
 K_EXPORT_PLASMA_RUNNER(kill, KillRunner)
 
-- 
2.11.0