TEVD DOM changes committing to the physical disk

tsvm_core/src/net/torvald/tsvm/VM.kt

@@ -25,6 +25,7 @@ class VM(
     val worldInterface: WorldInterface,
     val roms: Array<VMProgramRom>, // first ROM must contain the BIOS
     _peripheralSlots: Int = 8,
+    val watchdogs: HashMap<String, VMWatchdog>
 ) {
 
     val peripheralSlots = _peripheralSlots.coerceIn(1,8)

tsvm_core/src/net/torvald/tsvm/VMWatchdog.kt

@@ -0,0 +1,56 @@
+package net.torvald.tsvm
+
+import com.badlogic.gdx.utils.Queue
+import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.VDUtil
+import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.VirtualDisk
+import java.io.File
+
+/**
+ * Created by minjaesong on 2022-12-18.
+ */
+abstract class VMWatchdog {
+
+    /** Seconds between sleep */
+    abstract val interval: Float
+    protected var akku = 0f
+
+    open fun update(delta: Float) {
+        akku += delta
+        while (akku > interval) {
+            consumeMessages()
+            println("[${this.javaClass.simpleName}] boop!")
+            akku -= interval
+        }
+    }
+
+    protected abstract fun consumeMessages()
+    abstract fun addMessage(message: Array<Any?>)
+
+}
+
+
+object TevdSyncWatchdog : VMWatchdog() {
+    override val interval = 5f
+
+    private val messageQueue = ArrayList<Pair<File, VirtualDisk>>()
+
+    override fun consumeMessages() {
+        synchronized(this) {
+            messageQueue.forEach { (outfile, dom) ->
+                VDUtil.dumpToRealMachine(dom, outfile)
+                println("[${this.javaClass.simpleName}] dump ${outfile.path}")
+            }
+            messageQueue.clear()
+        }
+    }
+
+    override fun addMessage(message: Array<Any?>) {
+        val file = message[0] as File
+        val dom = message[1] as VirtualDisk
+
+        val hasDup = messageQueue.fold(false) { acc, pair -> acc or (pair.first.path == file.path) }
+        if (!hasDup) {
+            messageQueue.add(file to dom)
+        }
+    }
+}

tsvm_core/src/net/torvald/tsvm/peripheral/TevdDiskDrive.kt

@@ -37,42 +37,18 @@ class TevdDiskDrive(private val vm: VM, private val driveNum: Int, private val t
     private val messageComposeBuffer = ByteArrayOutputStream(BLOCK_SIZE) // always use this and don't alter blockSendBuffer please
     private var blockSendBuffer = ByteArray(1)
     private var blockSendCount = 0
-
-    private val hasChanges = AtomicBoolean(false)
-
+    
     init {
         statusCode.set(TestDiskDrive.STATE_CODE_STANDBY)
 
         if (!tevdPath.exists()) {
             throw FileNotFoundException("Disk file '${theTevdPath}' not found")
         }
-
-        Thread {
-            while (vm.isRunning) {
-                println("TevdCommitWatchdog ping")
-                if (hasChanges.compareAndExchangeAcquire(true, false)) {
-                    printdbg("Disk has changes, committing... $theTevdPath")
-                    commit()
-                }
-                else {
-                    printdbg("Disk has no changes, skipping... $theTevdPath")
-                }
-                Thread.sleep(1000L * COMMIT_INTERVAL)
-            }
-        }.let {
-            it.start()
-            vm.contexts.add(it)
-        }
     }
 
 
-    companion object {
-        /** How often the changes in DOM (disk object model) should be saved to the physical drive when there are changes. Seconds. */
-        const val COMMIT_INTERVAL = 5
-    }
-
-    fun commit() {
-        VDUtil.dumpToRealMachine(DOM, tevdPath)
+    fun notifyDiskCommit() {
+        vm.watchdogs["TEVD_SYNC"]?.addMessage(arrayOf(tevdPath, DOM))
     }
 
 
@@ -140,8 +116,8 @@ class TevdDiskDrive(private val vm: VM, private val driveNum: Int, private val t
                 writeMode = false
                 appendMode = false
 
-                printdbg("Raising HasChanges flag (end of write)")
-                hasChanges.set(true)
+                printdbg("Notifying disk commit (end of write)")
+                notifyDiskCommit()
             }
         }
         else {
@@ -229,8 +205,8 @@ class TevdDiskDrive(private val vm: VM, private val driveNum: Int, private val t
                 }
                 try {
                     file.delete()
-                    printdbg("Raising HasChanges flag (file deleted)")
-                    hasChanges.set(true)
+                    printdbg("Notifying disk commit (file deleted)")
+                    notifyDiskCommit()
                 }
                 catch (e: SecurityException) {
                     statusCode.set(TestDiskDrive.STATE_CODE_SYSTEM_SECURITY_ERROR)
@@ -365,8 +341,8 @@ class TevdDiskDrive(private val vm: VM, private val driveNum: Int, private val t
                     val status = file.mkdir()
                     statusCode.set(if (status) 0 else 1)
                     if (status) {
-                        printdbg("Raising HasChanges flag (mkdir)")
-                        hasChanges.set(true)
+                        printdbg("Notifying disk commit (mkdir)")
+                        notifyDiskCommit()
                     }
                 }
                 catch (e: SecurityException) {
@@ -386,8 +362,8 @@ class TevdDiskDrive(private val vm: VM, private val driveNum: Int, private val t
                     val f1 = file.createNewFile()
                     statusCode.set(if (f1) TestDiskDrive.STATE_CODE_STANDBY else TestDiskDrive.STATE_CODE_OPERATION_FAILED)
                     if (f1) {
-                        printdbg("Raising HasChanges flag (mkfile)")
-                        hasChanges.set(true)
+                        printdbg("Notifying disk commit (mkfile)")
+                        notifyDiskCommit()
                     }
                     return
                 }
@@ -411,8 +387,8 @@ class TevdDiskDrive(private val vm: VM, private val driveNum: Int, private val t
                     val f1 = file.setLastModified(vm.worldInterface.currentTimeInMills())
                     statusCode.set(if (f1) TestDiskDrive.STATE_CODE_STANDBY else TestDiskDrive.STATE_CODE_OPERATION_FAILED)
                     if (f1) {
-                        printdbg("Raising HasChanges flag (touch)")
-                        hasChanges.set(true)
+                        printdbg("Notifying disk commit (touch)")
+                        notifyDiskCommit()
                     }
                     return
                 }

tsvm_core/src/net/torvald/tsvm/vdc/V2kRunTest.kt

@@ -15,7 +15,7 @@ import net.torvald.tsvm.peripheral.GraphicsAdapter
 
 class V2kRunTest : ApplicationAdapter() {
 
-    val vm = VM("./assets", 64.kB(), TheRealWorld(), arrayOf())
+    val vm = VM("./assets", 64.kB(), TheRealWorld(), arrayOf(), watchdogs = hashMapOf())
     lateinit var gpu: GraphicsAdapter
 
     lateinit var batch: SpriteBatch