Interrupts WIP #230

src/main/java/net/simon987/mar/server/assembly/CPU.java

@@ -45,6 +45,11 @@ public class CPU implements MongoSerializable {
      */
     private int codeSectionOffset;
 
+    private int interruptVectorTableOffset;
+    private final int graceInstructionCount;
+    private int graceInstructionLeft;
+    private boolean isGracePeriod;
+
     /**
      * Instruction pointer, always points to the next instruction
      */
@@ -57,14 +62,10 @@ public class CPU implements MongoSerializable {
 
     private int registerSetSize;
 
-    private static final char EXECUTION_COST_ADDR = 0x0050;
+    private static final char EXECUTION_COST_ADDR = 0x0150;
-    private static final char EXECUTED_INS_ADDR = 0x0051;
+    private static final char EXECUTED_INS_ADDR = 0x0151;
-
-    public CPU() {
-        instructionSet = new DefaultInstructionSet();
-        registerSet = new DefaultRegisterSet();
-        codeSectionOffset = GameServer.INSTANCE.getConfig().getInt("org_offset");
 
+    private void addInstructions() {
         instructionSet.add(new JmpInstruction(this));
         instructionSet.add(new JnzInstruction(this));
         instructionSet.add(new JzInstruction(this));
@@ -91,7 +92,20 @@ public class CPU implements MongoSerializable {
         instructionSet.add(new PopfInstruction(this));
         instructionSet.add(new JnaInstruction(this));
         instructionSet.add(new JaInstruction(this));
+        instructionSet.add(new IntInstruction(this));
+        instructionSet.add(new IretInstruction(this));
+    }
 
+    public CPU() {
+        instructionSet = new DefaultInstructionSet();
+        registerSet = new DefaultRegisterSet();
+        IServerConfiguration config = GameServer.INSTANCE.getConfig();
+        codeSectionOffset = config.getInt("org_offset");
+        graceInstructionCount = config.getInt("grace_instruction_count");
+
+        interruptVectorTableOffset = config.getInt("ivt_offset");
+
+        addInstructions();
         status = new Status();
     }
 
@@ -102,41 +116,32 @@ public class CPU implements MongoSerializable {
         instructionSet = new DefaultInstructionSet();
         registerSet = new DefaultRegisterSet();
         codeSectionOffset = config.getInt("org_offset");
+        graceInstructionCount = config.getInt("grace_instruction_count");
 
-        instructionSet.add(new JmpInstruction(this));
+        interruptVectorTableOffset = config.getInt("ivt_offset");
-        instructionSet.add(new JnzInstruction(this));
+
-        instructionSet.add(new JzInstruction(this));
+        addInstructions();
-        instructionSet.add(new JgInstruction(this));
-        instructionSet.add(new JgeInstruction(this));
-        instructionSet.add(new JleInstruction(this));
-        instructionSet.add(new JlInstruction(this));
-        instructionSet.add(new PushInstruction(this));
-        instructionSet.add(new PopInstruction(this));
-        instructionSet.add(new CallInstruction(this));
-        instructionSet.add(new RetInstruction(this));
-        instructionSet.add(new MulInstruction(this));
-        instructionSet.add(new DivInstruction(this));
-        instructionSet.add(new JnsInstruction(this));
-        instructionSet.add(new JsInstruction(this));
-        instructionSet.add(new HwiInstruction(this));
-        instructionSet.add(new HwqInstruction(this));
-        instructionSet.add(new XchgInstruction(this));
-        instructionSet.add(new JcInstruction(this));
-        instructionSet.add(new JncInstruction(this));
-        instructionSet.add(new JnoInstruction(this));
-        instructionSet.add(new JoInstruction(this));
-        instructionSet.add(new PushfInstruction(this));
-        instructionSet.add(new PopfInstruction(this));
-        instructionSet.add(new JnaInstruction(this));
-        instructionSet.add(new JaInstruction(this));
 
         status = new Status();
         memory = new Memory(config.getInt("memory_size"));
     }
 
+    /**
+     * Sets the IP to IVT + number and pushes flags then the old IP
+     */
+    public void interrupt(int number) {
+        Instruction push = instructionSet.get(PushInstruction.OPCODE);
+        push.execute(status.toWord(), status);
+        push.execute(ip, status);
+
+        this.setIp((char) memory.get(interruptVectorTableOffset + number));
+    }
+
     public void reset() {
         status.clear();
         ip = codeSectionOffset;
+        graceInstructionLeft = graceInstructionCount;
+        isGracePeriod = false;
     }
 
     public int execute(int timeout) {
@@ -151,17 +156,16 @@ public class CPU implements MongoSerializable {
         while (!status.isBreakFlag()) {
             counter++;
 
-            if (counter % 10000 == 0) {
+            if (isGracePeriod) {
-                if (System.currentTimeMillis() > (startTime + timeout)) {
+                if (graceInstructionLeft-- == 0) {
-                    LogManager.LOGGER.fine("CPU Timeout " + this + " after " + counter + "instructions (" + timeout + "ms): " + (double) counter / ((double) timeout / 1000) / 1000000 + "MHz");
+                    writeExecutionStats(timeout, counter);
-
-                    //Write execution cost and instruction count to memory
-                    memory.set(EXECUTION_COST_ADDR, timeout);
-                    memory.set(EXECUTED_INS_ADDR, Util.getHigherWord(counter));
-                    memory.set(EXECUTED_INS_ADDR + 1, Util.getLowerWord(counter));
-
                     return timeout;
                 }
+            } else if (counter % 10000 == 0) {
+                if (System.currentTimeMillis() > (startTime + timeout)) {
+                    interrupt(32);
+                    isGracePeriod = true;
+                }
             }
 
             //fetch instruction
@@ -184,15 +188,17 @@ public class CPU implements MongoSerializable {
 
 //        LogManager.LOGGER.fine(counter + " instruction in " + elapsed + "ms : " + (double) counter / (elapsed / 1000) / 1000000 + "MHz");
 
-
+        writeExecutionStats(elapsed, counter);
-        //Write execution cost and instruction count to memory
-        memory.set(EXECUTION_COST_ADDR, elapsed);
-        memory.set(EXECUTED_INS_ADDR, Util.getHigherWord(counter));
-        memory.set(EXECUTED_INS_ADDR + 1, Util.getLowerWord(counter));
 
         return elapsed;
     }
 
+    private void writeExecutionStats(int timeout, int counter) {
+        memory.set(EXECUTION_COST_ADDR, timeout);
+        memory.set(EXECUTED_INS_ADDR, Util.getHigherWord(counter));
+        memory.set(EXECUTED_INS_ADDR + 1, Util.getLowerWord(counter));
+    }
+
     public void executeInstruction(Instruction instruction, int source, int destination) {
 
         //Execute the instruction

src/main/java/net/simon987/mar/server/assembly/Instruction.java

@@ -59,7 +59,6 @@ public abstract class Instruction {
      */
     public Status execute(Target dst, int dstIndex, int src, Status status) {
 
-
         return status;
     }
 

src/main/java/net/simon987/mar/server/assembly/Status.java

@@ -133,7 +133,7 @@ public class Status implements Cloneable {
         this.errorFlag = errorFlag;
     }
 
-    public char toByte() {
+    public char toWord() {
         char stat = 0;
         stat = (char) (stat | ((signFlag ? 1 : 0) << 3));
         stat = (char) (stat | ((zeroFlag ? 1 : 0) << 2));
@@ -142,7 +142,7 @@ public class Status implements Cloneable {
         return stat;
     }
 
-    public void fromByte(char stat) {
+    public void fromWord(char stat) {
         setSignFlag((stat & (1 << 3)) != 0);
         setZeroFlag((stat & (1 << 2)) != 0);
         setCarryFlag((stat & (1 << 1)) != 0);

src/main/java/net/simon987/mar/server/assembly/instruction/IntInstruction.java

@@ -0,0 +1,35 @@
+package net.simon987.mar.server.assembly.instruction;
+
+import net.simon987.mar.server.assembly.*;
+
+/**
+ *  Software Interrupt
+ *  Pushes the flags register and the IP to the stack then
+ *  Sets the IP to the CPU [ivt_offset + src].
+ */
+public class IntInstruction extends Instruction {
+
+    public static final int OPCODE = 48;
+    private final CPU cpu;
+
+    public IntInstruction(CPU cpu) {
+        super("int", OPCODE);
+        this.cpu = cpu;
+    }
+
+    @Override
+    public Status execute(int src, Status status) {
+        cpu.interrupt(src);
+        return status;
+    }
+
+    @Override
+    public boolean operandsValid(Operand o1, Operand o2) {
+        return false;
+    }
+
+    @Override
+    public boolean operandValid(Operand o1) {
+        return o1.getType() == OperandType.IMMEDIATE16 && o1.getData() < 256;
+    }
+}

src/main/java/net/simon987/mar/server/assembly/instruction/IretInstruction.java

@@ -0,0 +1,43 @@
+package net.simon987.mar.server.assembly.instruction;
+
+import net.simon987.mar.server.assembly.*;
+
+/**
+ * Interrupt Return
+ *
+ * Pops the IP and status flag from the stack.
+ */
+public class IretInstruction extends Instruction {
+
+    public static final int OPCODE = 49;
+    private final CPU cpu;
+
+    public IretInstruction(CPU cpu) {
+        super("iret", OPCODE);
+        this.cpu = cpu;
+    }
+
+    public Status execute(Status status) {
+        RegisterSet reg = cpu.getRegisterSet();
+
+        cpu.setIp((char) cpu.getMemory().get(reg.get(7))); //IP = (SP + 0)
+        status.fromWord((char) cpu.getMemory().get(reg.get(7) + 1)); //Status = (SP + 1)
+        reg.set(7, reg.get(7) + 2); //Increment SP (stack grows towards smaller)
+        return status;
+    }
+
+    @Override
+    public boolean noOperandsValid() {
+        return true;
+    }
+
+    @Override
+    public boolean operandsValid(Operand o1, Operand o2) {
+        return false;
+    }
+
+    @Override
+    public boolean operandValid(Operand o1) {
+        return false;
+    }
+}

src/main/java/net/simon987/mar/server/assembly/instruction/PopfInstruction.java

@@ -29,7 +29,7 @@ public class PopfInstruction extends Instruction {
         char flags = (char) cpu.getMemory().get(sp.getValue());
 
         // Overwrite the CPU flags
-        status.fromByte(flags);
+        status.fromWord(flags);
 
         // Increment SP
         sp.setValue(sp.getValue() + 1);

src/main/java/net/simon987/mar/server/assembly/instruction/PushfInstruction.java

@@ -28,7 +28,7 @@ public class PushfInstruction extends Instruction {
         sp.setValue(sp.getValue() - 1);
 
         // Push the current flags
-        cpu.getMemory().set(sp.getValue(), status.toByte());
+        cpu.getMemory().set(sp.getValue(), status.toWord());
 
         return status;
     }

src/main/resources/config.properties

@@ -44,7 +44,9 @@ wg_createNewOnRequest=0
 
 #CPU
 tick_length=1000
-org_offset=512
+org_offset=4096
+ivt_offset=0
+grace_instruction_count=10000
 stack_bottom=65536
 memory_size=65536
 user_timeout=100

src/test/java/net/simon987/mar/server/assembly/TestHelper.java

@@ -8,8 +8,6 @@ import net.simon987.mar.server.assembly.exception.CancelledException;
 
 public class TestHelper {
 
-    private static final int TIMEOUT = 100;
-
     public static Assembler getTestAsm() {
         IServerConfiguration config = getTestConfig();
         CPU cpu = getTestCpu();
@@ -20,7 +18,9 @@ public class TestHelper {
         IServerConfiguration configuration = new FakeConfiguration();
 
         configuration.setInt("memory_size", 65536);
-        configuration.setInt("org_offset", 400);
+        configuration.setInt("org_offset", 4096);
+        configuration.setInt("ivt_offset", 0);
+        configuration.setInt("grace_instruction_count", 10000);
         return configuration;
     }
 
@@ -36,6 +36,10 @@ public class TestHelper {
     }
 
     public static TestExecutionResult executeCode(String code) {
+        return executeCode(code, 100);
+    }
+
+    public static TestExecutionResult executeCode(String code, int timeout) {
         AssemblyResult ar = getTestAsm().parse(code);
         CPU cpu = TestHelper.getTestCpu();
 
@@ -50,7 +54,7 @@ public class TestHelper {
         cpu.setCodeSectionOffset(ar.getCodeSectionOffset());
 
         cpu.reset();
-        cpu.execute(TIMEOUT);
+        cpu.execute(timeout);
 
         return new TestExecutionResult(cpu.getState(), host.callHistory, ar);
     }

src/test/java/net/simon987/mar/server/assembly/instruction/IntInstructionTest.java

@@ -0,0 +1,48 @@
+package net.simon987.mar.server.assembly.instruction;
+
+import net.simon987.mar.server.TestExecutionResult;
+import net.simon987.mar.server.assembly.TestHelper;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class IntInstructionTest {
+
+    @Test
+    public void intSimple1() {
+        String code = "" +
+                "isr:                   \n" +
+                "   MOV X, 0x1234       \n" +
+                "   IRET                \n" +
+                ".text                  \n" +
+                "MOV [32], isr          \n" +
+                "INT 32                 \n" +
+                "MOV Y, 0x4567          \n" +
+                "brk                    \n";
+
+        TestExecutionResult res = TestHelper.executeCode(code);
+
+        assertEquals(0x1234, res.regValue("X"));
+        assertEquals(0x4567, res.regValue("Y"));
+    }
+
+    @Test
+    public void intExecutionLimit() {
+        String code = "" +
+                "isr:                   \n" +
+                "   MOV X, 0x1234       \n" +
+                "   BRK                 \n" +
+                ".text                  \n" +
+                "MOV [32], isr          \n" +
+                "loop:                  \n" +
+                "ADD A, 1               \n" +
+                "JMP loop               \n" +
+                "MOV Y, 0x4567          \n" +
+                "brk                    \n";
+
+        TestExecutionResult res = TestHelper.executeCode(code, 10);
+
+        assertEquals(0x1234, res.regValue("X"));
+        assertEquals(0, res.regValue("Y"));
+    }
+}