# HG changeset patch
# User Jaroslav Tulach <jaroslav.tulach@oracle.com>
# Date 1444119922 -7200
# Node ID 141fe31da7a2f415d83766a28803f8ad13f12965
# Parent  371045b1312d412bafa29882e6c3f7bfe6c0f8f1
Avoiding check for current stack depth on the initialization of debugger. Only when debugger is suspended the real check is needed.

diff -r 371045b1312d -r 141fe31da7a2 truffle/com.oracle.truffle.api.vm/src/com/oracle/truffle/api/vm/PolyglotEngine.java
--- a/truffle/com.oracle.truffle.api.vm/src/com/oracle/truffle/api/vm/PolyglotEngine.java	Thu Oct 01 20:32:49 2015 +0200
+++ b/truffle/com.oracle.truffle.api.vm/src/com/oracle/truffle/api/vm/PolyglotEngine.java	Tue Oct 06 10:25:22 2015 +0200
@@ -510,7 +510,7 @@
 
     @SuppressWarnings("try")
     private void evalImpl(TruffleLanguage<?>[] fillLang, Source s, Object[] result, Language l, CountDownLatch ready) {
-        try (Closeable d = SPI.executionStart(this, debugger, s)) {
+        try (Closeable d = SPI.executionStart(this, -1, debugger, s)) {
             TruffleLanguage<?> langImpl = l.getImpl(true);
             fillLang[0] = langImpl;
             result[0] = SPI.eval(langImpl, s);
@@ -527,7 +527,7 @@
         executor.execute(new Runnable() {
             @Override
             public void run() {
-                try (final Closeable c = SPI.executionStart(PolyglotEngine.this, debugger, null)) {
+                try (final Closeable c = SPI.executionStart(PolyglotEngine.this, -1, debugger, null)) {
                     res[0] = ForeignAccess.execute(foreignNode, frame, receiver, ForeignAccess.getArguments(frame).toArray());
                 } catch (IOException ex) {
                     res[1] = ex;
@@ -758,7 +758,7 @@
 
         @SuppressWarnings("try")
         private void invokeImpl(Object thiz, Object[] args, Object[] res, CountDownLatch done) {
-            try (final Closeable c = SPI.executionStart(PolyglotEngine.this, debugger, null)) {
+            try (final Closeable c = SPI.executionStart(PolyglotEngine.this, -1, debugger, null)) {
                 List<Object> arr = new ArrayList<>();
                 if (thiz == null) {
                     if (language != null) {
@@ -993,9 +993,9 @@
         }
 
         @Override
-        protected Closeable executionStart(Object obj, Debugger debugger, Source s) {
+        protected Closeable executionStart(Object obj, int currentDepth, Debugger debugger, Source s) {
             PolyglotEngine vm = (PolyglotEngine) obj;
-            return super.executionStart(vm, debugger, s);
+            return super.executionStart(vm, -1, debugger, s);
         }
 
         @Override
diff -r 371045b1312d -r 141fe31da7a2 truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/Debugger.java
--- a/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/Debugger.java	Thu Oct 01 20:32:49 2015 +0200
+++ b/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/Debugger.java	Tue Oct 06 10:25:22 2015 +0200
@@ -121,8 +121,8 @@
         Source.setFileCaching(true);
 
         // Initialize execution context stack
-        debugContext = new DebugExecutionContext(null, null);
-        prepareContinue();
+        debugContext = new DebugExecutionContext(null, null, 0);
+        debugContext.setStrategy(0, new Continue());
         debugContext.contextTrace("START EXEC DEFAULT");
 
         breakpointCallback = new BreakpointCallback() {
@@ -197,8 +197,8 @@
      * </ul>
      */
     @TruffleBoundary
-    void prepareContinue() {
-        debugContext.setStrategy(new Continue());
+    void prepareContinue(int depth) {
+        debugContext.setStrategy(depth, new Continue());
     }
 
     /**
@@ -702,12 +702,16 @@
         private MaterializedFrame haltedFrame;
 
         private DebugExecutionContext(Source executionSource, DebugExecutionContext previousContext) {
+            this(executionSource, previousContext, -1);
+        }
+
+        private DebugExecutionContext(Source executionSource, DebugExecutionContext previousContext, int depth) {
             this.source = executionSource;
             this.predecessor = previousContext;
             this.level = previousContext == null ? 0 : previousContext.level + 1;
 
             // "Base" is the number of stack frames for all nested (halted) executions.
-            this.contextStackBase = currentStackDepth();
+            this.contextStackBase = depth == -1 ? currentStackDepth() : depth;
             this.running = true;
             contextTrace("NEW CONTEXT");
         }
@@ -718,9 +722,13 @@
          * @param stepStrategy
          */
         void setStrategy(StepStrategy stepStrategy) {
+            setStrategy(currentStackDepth(), stepStrategy);
+        }
+
+        void setStrategy(int depth, StepStrategy stepStrategy) {
             if (this.strategy == null) {
                 this.strategy = stepStrategy;
-                this.strategy.enable(this, currentStackDepth());
+                this.strategy.enable(this, depth);
                 if (TRACE) {
                     contextTrace("SET MODE <none>-->" + stepStrategy.getName());
                 }
@@ -832,7 +840,7 @@
 
     }
 
-    void executionStarted(Source source) {
+    void executionStarted(int depth, Source source) {
         Source execSource = source;
         if (execSource == null) {
             execSource = lastSource;
@@ -840,8 +848,8 @@
             lastSource = execSource;
         }
         // Push a new execution context onto stack
-        debugContext = new DebugExecutionContext(execSource, debugContext);
-        prepareContinue();
+        debugContext = new DebugExecutionContext(execSource, debugContext, depth);
+        prepareContinue(depth);
         debugContext.contextTrace("START EXEC ");
         ACCESSOR.dispatchEvent(vm, new ExecutionEvent(this));
     }
@@ -863,8 +871,8 @@
     private static final class AccessorDebug extends Accessor {
 
         @Override
-        protected Closeable executionStart(Object vm, final Debugger debugger, Source s) {
-            debugger.executionStarted(s);
+        protected Closeable executionStart(Object vm, int currentDepth, final Debugger debugger, Source s) {
+            debugger.executionStarted(currentDepth, s);
             return new Closeable() {
                 @Override
                 public void close() throws IOException {
diff -r 371045b1312d -r 141fe31da7a2 truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/ExecutionEvent.java
--- a/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/ExecutionEvent.java	Thu Oct 01 20:32:49 2015 +0200
+++ b/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/ExecutionEvent.java	Tue Oct 06 10:25:22 2015 +0200
@@ -70,7 +70,7 @@
      * </ul>
      */
     public void prepareContinue() {
-        debugger.prepareContinue();
+        debugger.prepareContinue(-1);
     }
 
     /**
diff -r 371045b1312d -r 141fe31da7a2 truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/SuspendedEvent.java
--- a/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/SuspendedEvent.java	Thu Oct 01 20:32:49 2015 +0200
+++ b/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/SuspendedEvent.java	Tue Oct 06 10:25:22 2015 +0200
@@ -128,7 +128,7 @@
      * </ul>
      */
     public void prepareContinue() {
-        debugger.prepareContinue();
+        debugger.prepareContinue(-1);
     }
 
     /**
diff -r 371045b1312d -r 141fe31da7a2 truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/impl/Accessor.java
--- a/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/impl/Accessor.java	Thu Oct 01 20:32:49 2015 +0200
+++ b/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/impl/Accessor.java	Tue Oct 06 10:25:22 2015 +0200
@@ -281,10 +281,11 @@
     private static Reference<Object> previousVM = new WeakReference<>(null);
     private static Assumption oneVM = Truffle.getRuntime().createAssumption();
 
-    protected Closeable executionStart(Object vm, Debugger debugger, Source s) {
+    @SuppressWarnings("unused")
+    protected Closeable executionStart(Object vm, int currentDepth, Debugger debugger, Source s) {
         vm.getClass();
-        final Closeable debugClose = DEBUG.executionStart(vm, debugger, s);
         final Object prev = CURRENT_VM.get();
+        final Closeable debugClose = DEBUG.executionStart(vm, prev == null ? 0 : -1, debugger, s);
         if (!(vm == previousVM.get())) {
             previousVM = new WeakReference<>(vm);
             oneVM.invalidate();