From e8b2c836e8f67902c21806879758ae1d8b54d887 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20N=C3=BCcke?= <florian@nuecke.de>
Date: Sat, 8 Jan 2022 07:46:08 +0100
Subject: [PATCH] Clean up worker thread join logic a bit and fire resuming
 event immediately to avoid performance issues/race conditions for some
 devices (e.g. network cards).

---
 .../HardDriveVMDeviceWithInitialData.java     |  4 +--
 .../oc2/common/vm/AbstractVirtualMachine.java |  2 --
 .../java/li/cil/oc2/common/vm/VMRunner.java   | 36 +++++++++----------
 3 files changed, 19 insertions(+), 23 deletions(-)

diff --git a/src/main/java/li/cil/oc2/common/bus/device/item/HardDriveVMDeviceWithInitialData.java b/src/main/java/li/cil/oc2/common/bus/device/item/HardDriveVMDeviceWithInitialData.java
index 77dc6014..829acc83 100644
--- a/src/main/java/li/cil/oc2/common/bus/device/item/HardDriveVMDeviceWithInitialData.java
+++ b/src/main/java/li/cil/oc2/common/bus/device/item/HardDriveVMDeviceWithInitialData.java
@@ -2,7 +2,7 @@ package li.cil.oc2.common.bus.device.item;
 
 import com.google.common.eventbus.Subscribe;
 import com.google.common.io.ByteStreams;
-import li.cil.oc2.api.bus.device.vm.event.VMResumingRunningEvent;
+import li.cil.oc2.api.bus.device.vm.event.VMResumedRunningEvent;
 import li.cil.oc2.common.util.Location;
 import li.cil.sedna.api.device.BlockDevice;
 import li.cil.sedna.device.block.ByteBufferBlockDevice;
@@ -39,7 +39,7 @@ public final class HardDriveVMDeviceWithInitialData extends HardDriveVMDevice {
     }
 
     @Subscribe
-    public void handleResumingRunningEvent(final VMResumingRunningEvent event) {
+    public void handleResumedRunningEvent(final VMResumedRunningEvent event) {
         if (copyJob != null) {
             try {
                 copyJob.get();
diff --git a/src/main/java/li/cil/oc2/common/vm/AbstractVirtualMachine.java b/src/main/java/li/cil/oc2/common/vm/AbstractVirtualMachine.java
index 481c325d..ce4710cb 100644
--- a/src/main/java/li/cil/oc2/common/vm/AbstractVirtualMachine.java
+++ b/src/main/java/li/cil/oc2/common/vm/AbstractVirtualMachine.java
@@ -167,9 +167,7 @@ public abstract class AbstractVirtualMachine implements VirtualMachine {
     private void joinWorkerThread() {
         if (runner != null) {
             try {
-                state.context.postEvent(new VMPausingEvent());
                 runner.join();
-                runner.scheduleResumeEvent();
             } catch (final Throwable e) {
                 LOGGER.error(e);
                 runner = null;
diff --git a/src/main/java/li/cil/oc2/common/vm/VMRunner.java b/src/main/java/li/cil/oc2/common/vm/VMRunner.java
index 1f5b3285..fe2dbce7 100644
--- a/src/main/java/li/cil/oc2/common/vm/VMRunner.java
+++ b/src/main/java/li/cil/oc2/common/vm/VMRunner.java
@@ -1,10 +1,7 @@
 package li.cil.oc2.common.vm;
 
 import li.cil.ceres.api.Serialized;
-import li.cil.oc2.api.bus.device.vm.event.VMInitializationException;
-import li.cil.oc2.api.bus.device.vm.event.VMInitializingEvent;
-import li.cil.oc2.api.bus.device.vm.event.VMResumedRunningEvent;
-import li.cil.oc2.api.bus.device.vm.event.VMResumingRunningEvent;
+import li.cil.oc2.api.bus.device.vm.event.*;
 import li.cil.oc2.common.Constants;
 import li.cil.oc2.common.bus.RPCDeviceBusAdapter;
 import li.cil.oc2.common.vm.context.global.GlobalVMContext;
@@ -40,7 +37,7 @@ public class VMRunner implements Runnable {
 
     ///////////////////////////////////////////////////////////////////
 
-    private boolean firedResumeEvent;
+    private boolean firedResumedRunningEvent;
     @Serialized private boolean firedInitializationEvent;
     @Serialized private Component runtimeError;
 
@@ -57,10 +54,6 @@ public class VMRunner implements Runnable {
 
     ///////////////////////////////////////////////////////////////////
 
-    public void scheduleResumeEvent() {
-        firedResumeEvent = false;
-    }
-
     @Nullable
     public Component getRuntimeError() {
         return runtimeError;
@@ -79,14 +72,20 @@ public class VMRunner implements Runnable {
     }
 
     public void join() throws Throwable {
-        if (lastSchedule != null) {
-            try {
-                lastSchedule.get();
-            } catch (final InterruptedException e) {
-                // We do not mind this.
-            } catch (final ExecutionException e) {
-                throw e.getCause();
+        context.postEvent(new VMPausingEvent());
+        try {
+            if (lastSchedule != null) {
+                try {
+                    lastSchedule.get();
+                } catch (final InterruptedException e) {
+                    // We do not mind this.
+                } catch (final ExecutionException e) {
+                    throw e.getCause();
+                }
             }
+        } finally {
+            context.postEvent(new VMResumingRunningEvent());
+            firedResumedRunningEvent = false;
         }
     }
 
@@ -136,9 +135,8 @@ public class VMRunner implements Runnable {
             }
         }
 
-        if (!firedResumeEvent) {
-            firedResumeEvent = true;
-            context.postEvent(new VMResumingRunningEvent());
+        if (!firedResumedRunningEvent) {
+            firedResumedRunningEvent = true;
             context.postEvent(new VMResumedRunningEvent());
         }
     }