Fixed multiple issues causing dangling references to discarded queries

[simantics/platform.git] / bundles / org.simantics.db.impl / src / org / simantics / db / impl / BlockingAsyncProcedure.java

diff --git a/bundles/org.simantics.db.impl/src/org/simantics/db/impl/BlockingAsyncProcedure.java b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/BlockingAsyncProcedure.java
index c491fb377464e366f5b34e8e8eac2e0e205840c5..9f89a0d8fa2a4f2ede8474513ac9f8ae5ce33de1 100644 (file)
--- a/bundles/org.simantics.db.impl/src/org/simantics/db/impl/BlockingAsyncProcedure.java
+++ b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/BlockingAsyncProcedure.java
@@ -18,38 +18,37 @@ import org.simantics.db.impl.graph.ReadGraphImpl;
 import org.simantics.db.impl.query.AsyncReadEntry;
 import org.simantics.db.impl.query.PendingTaskSupport;
 import org.simantics.db.procedure.AsyncProcedure;
+import org.simantics.db.request.AsyncRead;
 
-public class BlockingAsyncProcedure<Result> implements AsyncProcedure<Result> {
+public class BlockingAsyncProcedure<Result> implements AsyncProcedure<Result>, Runnable {
 
     private static final Object NO_RESULT = new Object();
 
-    public final Object key;
-    public final ReadGraphImpl queryGraph;
-    public final ReadGraphImpl callerGraph;
-    public final AsyncProcedure<Result> procedure;
-    public PendingTaskSupport pendingTaskSupport;
-    public Object result = NO_RESULT;
-    public Throwable exception = null;
-
-    private ReadGraphImpl queryGraph() {
-        return queryGraph;
-    }
+    private final Object key;
+    private final ReadGraphImpl queryGraph;
+    private final ReadGraphImpl callerGraph;
+    private final AsyncReadEntry<Result> entry;
+    private final AsyncProcedure<Result> procedure;
+    private PendingTaskSupport pendingTaskSupport;
+    private final boolean needsToBlock;
+    private Object result = NO_RESULT;
+    private Throwable exception = null;
     
     public BlockingAsyncProcedure(ReadGraphImpl callerGraph, AsyncReadEntry<Result> entry, AsyncProcedure<Result> procedure, Object key, boolean needsToBlock) {
-
-        // A new graph for evaluating the query with correct parent and asyncBarrier
-        queryGraph = callerGraph.withParent(entry, () -> {
-
-            dispatchProcedure(queryGraph(), callerGraph, entry, procedure, needsToBlock);
-            
-        });
         
+        // A new graph for evaluating the query with correct parent and asyncBarrier
+        queryGraph = callerGraph.withParent(entry, this, needsToBlock);
         queryGraph.asyncBarrier.inc();
+        
+        // This makes sure that caller does not quit before dispatch
+        callerGraph.asyncBarrier.inc();
 
+        this.entry = entry;
         this.procedure = procedure;
         this.key = key;
         this.queryGraph.asyncBarrier.inc();
         this.callerGraph = callerGraph;
+        this.needsToBlock = needsToBlock;
         if (BarrierTracing.BOOKKEEPING) {
             BarrierTracing.registerBAP(this);
         }
@@ -84,7 +83,8 @@ public class BlockingAsyncProcedure<Result> implements AsyncProcedure<Result> {
     @SuppressWarnings("unchecked")
     public Result get() throws DatabaseException {
 
-        queryGraph.asyncBarrier.waitBarrier(key, queryGraph);
+        if(needsToBlock)
+            queryGraph.asyncBarrier.waitBarrier(key, queryGraph);
 
         if(exception != null) {
             if(exception instanceof DatabaseException) throw (DatabaseException)exception;
@@ -109,34 +109,39 @@ public class BlockingAsyncProcedure<Result> implements AsyncProcedure<Result> {
         return "." + procedure; 
     }
     
-    private void dispatchProcedure(ReadGraphImpl queryGraph, ReadGraphImpl parentGraph, AsyncReadEntry<Result> entry, AsyncProcedure<Result> procedure_, boolean needsToBlock) {
+    @Override
+    public void run() {
         
-        AsyncProcedure<Result> procedure = entry != null ? entry : procedure_;
+        AsyncProcedure<Result> procedure__ = entry != null ? entry : procedure;
 
-        ReadGraphImpl executeGraph = parentGraph.withParent(parentGraph.parent);
+        ReadGraphImpl executeGraph = callerGraph.withParent(callerGraph.parent, null, needsToBlock);
         executeGraph.asyncBarrier.inc();
+        
+        // This counters the inc in the constructor 
+        callerGraph.asyncBarrier.dec();
+        
         try {
-            if(procedure != null) {
-                procedure.execute(executeGraph, get());
+            if(procedure__ != null) {
+                procedure__.execute(executeGraph, get());
             }
         } catch (DatabaseException e) {
-            if(procedure != null) procedure.exception(executeGraph, e);
+            if(procedure__ != null) procedure__.exception(executeGraph, e);
             exception = e;
         } catch (Throwable t) {
             DatabaseException dbe = new DatabaseException(t);
-            if(procedure != null) procedure.exception(executeGraph, dbe);
+            if(procedure__ != null) procedure__.exception(executeGraph, dbe);
             exception = dbe;
         } finally {
 
             if (entry != null) {
                 assert(entry.isReady());
                 // This does not throw
-                entry.performFromCache(executeGraph, procedure_);
+                entry.performFromCache(executeGraph, procedure);
             }
 
             executeGraph.asyncBarrier.dec();
             if(needsToBlock)
-                executeGraph.asyncBarrier.waitBarrier(procedure, executeGraph);
+                executeGraph.asyncBarrier.waitBarrier(procedure__, executeGraph);
         }
 
         if (BarrierTracing.BOOKKEEPING) {
@@ -144,5 +149,33 @@ public class BlockingAsyncProcedure<Result> implements AsyncProcedure<Result> {
         }
 
     }
+    
+    public void print() {
+        System.err.println("BlockingAsyncProcedure");
+        System.err.println("-key: " + key);
+        System.err.println("-queryGraph: " + queryGraph);
+        System.err.println("-callerGraph: " + callerGraph);
+        System.err.println("-procedure: " + procedure);
+        System.err.println("-pendingTaskSupport: " + pendingTaskSupport);
+        System.err.println("-result: " + result);
+        System.err.println("-exception: " + exception);
+    }
+    
+    public Result performSync(AsyncRead<Result> request) throws DatabaseException {
+        try {
+            request.perform(queryGraph, this);
+        } finally {
+            dec();
+        }
+        return get();
+    }
+
+    public void performAsync(AsyncRead<Result> request) throws DatabaseException {
+        try {
+            request.perform(queryGraph, this);
+        } finally {
+            dec();
+        }
+    }
 
 }