Improved error catching and handling.

Author: AlchemicRaker

gradle.properties

@@ -3,7 +3,7 @@ minecraft_version = 1.12.2
 forge_version = 14.23.5.2847
 
 mod_name = OpenProlog
-mod_version=0.3.0
+mod_version=0.3.1
 opencomputers_version=1.7.5.192
 
 org.gradle.jvmargs = -Xmx2048m

src/main/java/com/syntheticentropy/ocpro/PrologArchitecture.java

@@ -29,6 +29,8 @@ public class PrologArchitecture implements Architecture {
     private FutureTask<Object> vmQueryResponseFutureTask;
     private int vmQuerySleepTicks;
 
+    private ExecutionResult forceExecutionResult;
+
     enum VMResponse {
         RunSynchronous,
         Wait,
@@ -65,6 +67,9 @@ public void runSynchronized() {
 
     @Override
     public ExecutionResult runThreaded(boolean isSynchronizedReturn) {
+        if (forceExecutionResult != null)
+            return forceExecutionResult;
+
         //Called for: synchronized return, init, or signal
         vmQueryResponse = VMResponse.None;
         vmQueryResponseFutureTask = new FutureTask<>(() -> "");
@@ -109,13 +114,19 @@ public ExecutionResult runThreaded(boolean isSynchronizedReturn) {
         }
         // (magical time where prolog engine resolves part of the query)
         try {
+            if (vm.exitException != null) {
+                return new ExecutionResult.Error(vm.exitException.getMessage());
+            }
+            if (vm.getState() == Thread.State.TERMINATED) {
+                return new ExecutionResult.Error("Terminated early");
+            }
             vmQueryResponseFutureTask.get(30, TimeUnit.SECONDS);
 //            vmQueryResponseFutureTask.get(3, TimeUnit.SECONDS);
         } catch (InterruptedException | ExecutionException | TimeoutException e) {
             if (vm.exitException != null) {
                 return new ExecutionResult.Error(vm.exitException.getMessage());
             }
-            return new ExecutionResult.Error("Some problem eh?");
+            return new ExecutionResult.Error("Some problem eh? (1)");
         }
 
         // a query has sent us something (or the thread exited)
@@ -137,7 +148,7 @@ public ExecutionResult runThreaded(boolean isSynchronizedReturn) {
         if (vm.exitException != null) {
             return new ExecutionResult.Error(vm.exitException.getMessage());
         }
-        return new ExecutionResult.Error("Some problem eh?");
+        return new ExecutionResult.Error("Some problem eh? (2)");
     }
 
     // a query calls this
@@ -179,6 +190,18 @@ public void waitingCall(int ticks) {
         }
     }
 
+    public void crash(String e) {
+        forceExecutionResult = new ExecutionResult.Error(e);
+
+        if (!vmQueryResponseFutureTask.isDone()) {
+            vmQueryResponseFutureTask.cancel(true);
+        }
+        if (!synchronizedFutureTask.isDone()) {
+            synchronizedFutureTask.cancel(true);
+        }
+//        machine.crash(e);
+    }
+
     @Override
     public boolean isInitialized() {
         return vm != null && vm.getState() != Thread.State.NEW;

src/main/java/com/syntheticentropy/ocpro/PrologVM.java

@@ -11,7 +11,7 @@ public class PrologVM extends Thread {
 
     JIPEngine jip;
     PrologArchitecture owner;
-    State state = State.Created;
+    public State state = State.Created;
     Exception exitException;
 
     @Override
@@ -27,12 +27,14 @@ public void run() {
                     queryTerm = jipQuery.nextSolution();
                 }
                 // TODO: in signal query mode, wait for and run signal queries until shutdown is requested
+                owner.crash("Query resolved early");
             } else {
                 // run main query
             }
         } catch (Exception e) {
+            state = State.Terminated;
             exitException = e;
-            owner.machine.crash(e.getMessage());
+            owner.crash(e.getMessage());
         }
     }