keyboard input to use properly open/closed input stream

src/net/torvald/tsvm/VM.kt

@@ -9,6 +9,7 @@ import net.torvald.tsvm.peripheral.PeriBase
 import org.luaj.vm2.LuaValue
 import java.io.InputStream
 import java.io.OutputStream
+import java.io.PrintStream
 import java.util.*
 import kotlin.math.ceil
 import kotlin.random.Random
@@ -68,9 +69,14 @@ class VM(
 
     internal fun getIO(): IOSpace = peripheralTable[0].peripheral as IOSpace
 
-    lateinit var printStream: OutputStream
-    lateinit var errorStream: OutputStream
-    lateinit var inputStream: InputStream
+    //lateinit var printStream: OutputStream
+    //lateinit var errorStream: OutputStream
+    //lateinit var inputStream: InputStream // InputStream should not be a singleton, as it HAS TO open and close the stream.
+    // Printstreams don't need that so they're singleton.
+
+    var getPrintStream: () -> OutputStream = { TODO() }
+    var getErrorStream: () -> OutputStream = { TODO() }
+    var getInputStream: () -> InputStream = { TODO() }
 
     init {
         peripheralTable[0] = PeripheralEntry(

src/net/torvald/tsvm/VMGUI.kt

@@ -44,9 +44,9 @@ class VMGUI(val appConfig: LwjglApplicationConfiguration) : ApplicationAdapter()
         batch.projectionMatrix = camera.combined
         Gdx.gl20.glViewport(0, 0, appConfig.width, appConfig.height)
 
-        vm.printStream = gpu.getPrintStream()
-        vm.errorStream = gpu.getErrorStream()
-        vm.inputStream = gpu.getInputStream()
+        vm.getPrintStream = { gpu.getPrintStream() }
+        vm.getErrorStream = { gpu.getErrorStream() }
+        vm.getInputStream = { gpu.getInputStream() }
 
         // TEST PRG
         vmRunner = VMRunnerFactory(vm, "js")

src/net/torvald/tsvm/VMJSR223Delegate.kt

@@ -15,24 +15,25 @@ class VMJSR223Delegate(val vm: VM) {
 
     fun print(s: String) {
         //print("[Nashorn] $s")
-        vm.printStream.write(s.toByteArray())
+        vm.getPrintStream().write(s.toByteArray())
     }
     fun println(s: String) {
         //println("[Nashorn] $s")
-        vm.printStream.write((s + '\n').toByteArray())
+        vm.getPrintStream().write((s + '\n').toByteArray())
     }
     fun println() = print('\n')
 
-    fun readKey() = vm.inputStream.read()
+    //fun readKey() = vm.inputStream.read()
 
     /**
      * Read series of key inputs until Enter/Return key is pressed
      */
     fun read(): String {
+        val inputStream = vm.getInputStream()
         val sb = StringBuilder()
         var key: Int
         do {
-            key = readKey()
+            key = inputStream.read()
 
             if ((key == 8 && sb.isNotEmpty()) || key in 0x20..0x7E) {
                 this.print("${key.toChar()}")
@@ -45,6 +46,7 @@ class VMJSR223Delegate(val vm: VM) {
         } while (key != 13 && key != 10)
         this.println()
 
+        inputStream.close()
         return sb.toString()
     }
 }

src/net/torvald/tsvm/peripheral/GraphicsAdapter.kt

@@ -368,7 +368,7 @@ class GraphicsAdapter(val vm: VM, val lcdMode: Boolean = false) : GlassTty(Compa
 
     private lateinit var PRINTSTREAM_INSTANCE: OutputStream
     private lateinit var ERRORSTREAM_INSTANCE: OutputStream
-    private lateinit var INPUTSTREAM_INSTANCE: InputStream
+    //private lateinit var INPUTSTREAM_INSTANCE: InputStream
 
     override fun getPrintStream(): OutputStream {
         try {
@@ -412,27 +412,32 @@ class GraphicsAdapter(val vm: VM, val lcdMode: Boolean = false) : GlassTty(Compa
         }
     }
 
+    /**
+     * As getting the keyboard input now requires proper open and closing, the inputstream cannot be a singleton, unlike
+     * the printstream.
+     */
     override fun getInputStream(): InputStream {
-        try {
-            return INPUTSTREAM_INSTANCE
-        }
-        catch (e: UninitializedPropertyAccessException) {
-            INPUTSTREAM_INSTANCE = object : InputStream() {
+        return object : InputStream() {
 
-                override fun read(): Int {
-                    var key: Byte
-                    do {
-                        Thread.sleep(4L) // if spinning rate is too fast, this function fail.
-                        // Possible cause: Input event handling of GDX is done on separate thread
-                        key = vm.getIO().mmio_read(37L)!!
-                    } while (key == (-1).toByte())
-
-                    //println("[stdin] key = $key")
-                    return key.toInt().and(255)
-                }
+            init {
+                vm.getIO().mmio_write(38L, 1)
             }
 
-            return INPUTSTREAM_INSTANCE
+            override fun read(): Int {
+                var key: Byte
+                do {
+                    Thread.sleep(4L) // if spinning rate is too fast, this function fail.
+                    // Possible cause: Input event handling of GDX is done on separate thread
+                    key = vm.getIO().mmio_read(37L)!!
+                } while (key == (-1).toByte())
+
+                //println("[stdin] key = $key")
+                return key.toInt().and(255)
+            }
+
+            override fun close() {
+                vm.getIO().mmio_write(38L, 0)
+            }
         }
     }
 

src/net/torvald/tsvm/peripheral/IOSpace.kt

@@ -22,6 +22,8 @@ class IOSpace(val vm: VM) : PeriBase, InputProcessor {
     private var mouseY: Short = 0
     private var mouseDown = false
 
+    private var keyboardInputRequested = false
+
     override fun peek(addr: Long): Byte? {
         return mmio_read(addr)
     }
@@ -37,7 +39,8 @@ class IOSpace(val vm: VM) : PeriBase, InputProcessor {
             in 32..33 -> (mouseX.toInt() shr (adi - 32).times(8)).toByte()
             in 34..35 -> (mouseY.toInt() shr (adi - 34).times(8)).toByte()
             36L -> if (mouseDown) 1 else 0
-            37L -> keyboardBuffer.removeHead() ?: -1
+            37L -> keyboardBuffer.removeTail() ?: -1
+            38L -> if (keyboardInputRequested) 1 else 0
             else -> -1
         }
     }
@@ -46,6 +49,11 @@ class IOSpace(val vm: VM) : PeriBase, InputProcessor {
         val adi = addr.toInt()
         val bi = byte.toInt().and(255)
         when (addr) {
+            37L -> keyboardBuffer.appendHead(byte)
+            38L -> {
+                keyboardInputRequested = (byte != 0.toByte())
+                if (keyboardInputRequested) keyboardBuffer.clear()
+            }
         }
     }
 
@@ -67,11 +75,13 @@ class IOSpace(val vm: VM) : PeriBase, InputProcessor {
     }
 
     override fun keyTyped(p0: Char): Boolean {
-        try {
-            keyboardBuffer.appendTail(p0.toByte())
+        if (keyboardInputRequested) {
+            keyboardBuffer.appendHead(p0.toByte())
+            return true
+        }
+        else {
+            return false
         }
-        catch (e: StackOverflowError) { /* if stack overflow, simply stop reading more keys */ }
-        return true
     }
 
     override fun scrolled(p0: Int): Boolean {

src/net/torvald/util/CircularArray.kt

@@ -84,6 +84,7 @@ class CircularArray<T>(val size: Int, val overwriteOnOverflow: Boolean): Iterabl
         // even if overflowing is enabled, appending at tail causes head element to be altered, therefore such action
         // must be blocked by throwing overflow error
 
+        // if you think this behaviour is wrong, you're confusing appendHead() with appendTail(). Use appendHead() and removeTail()
         if (overflow) {
             throw StackOverflowError()
         }