X-Git-Url: https://gerrit.simantics.org/r/gitweb?a=blobdiff_plain;f=org.simantics.pythonlink%2Fsrc%2Forg%2Fsimantics%2Fpythonlink%2FPythonContext.java;fp=org.simantics.pythonlink%2Fsrc%2Forg%2Fsimantics%2Fpythonlink%2FPythonContext.java;h=62703f0795f0d80c6b915cf5c4022d7cfa3c71cd;hb=8885425046e0f89893c0e1ee0fe5c27948dcd2be;hp=16b02348196b4326f70f4475173a94677928c433;hpb=1ea9a623d145875880b543e8eea62e801561fba9;p=simantics%2Fpython.git

diff --git a/org.simantics.pythonlink/src/org/simantics/pythonlink/PythonContext.java b/org.simantics.pythonlink/src/org/simantics/pythonlink/PythonContext.java
index 16b0234..62703f0 100644
--- a/org.simantics.pythonlink/src/org/simantics/pythonlink/PythonContext.java
+++ b/org.simantics.pythonlink/src/org/simantics/pythonlink/PythonContext.java
@@ -1,6 +1,9 @@
 package org.simantics.pythonlink;
 
 import java.io.Closeable;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.concurrent.Callable;
@@ -14,18 +17,57 @@ import org.simantics.databoard.binding.Binding;
 import org.simantics.databoard.binding.error.BindingException;
 import org.simantics.databoard.binding.mutable.Variant;
 import org.simantics.scl.runtime.SCLContext;
-import org.simantics.scl.runtime.reporting.SCLReportingHandler;
 
 public class PythonContext implements Closeable {
-    private long contextID;
+    protected static final String PYTHON_SCL_WRITER = "python.scl.writer";
+	//TODO Replace with a count of open contexts and call Py_Finalize when the last one closes.
+	private static Boolean isPyInitialized = false;
+	
+	// A writer that is called by the sys.stdout and sys.stderr streams in Python
+    private static final Writer pythonWriter = new Writer() {
+    	Writer defaultWriter = new OutputStreamWriter(System.out);
+    	
+		@Override
+		public void close() throws IOException {
+			throw new IllegalStateException("This writer should never be closed!");
+		}
+
+		@Override
+		public void flush() throws IOException {
+	    	Writer writer = getPythonWriter();
+	    	synchronized (writer) {
+	    		writer.flush();
+	    	}
+		}
+
+		@Override
+		public void write(char[] cbuf, int off, int len) throws IOException {
+	    	Writer writer = getPythonWriter();
+	    	synchronized (writer) {
+	    		writer.write(cbuf, off, len);
+	    	}
+		}
+		
+		// Get a thread-specific Writer instance
+		private Writer getPythonWriter() {
+			SCLContext sclContext = SCLContext.getCurrent();
+			Writer writer = (Writer) sclContext.get(PYTHON_SCL_WRITER);
+			return writer != null ? writer : defaultWriter;
+		}
+    };
     
-    public interface Listener {
+    private static synchronized void ensurePythonInit() {
+		if (!isPyInitialized) {
+			execute(() -> initializePython(pythonWriter));
+			isPyInitialized = true;
+		}
+	}
+
+	public interface Listener {
     	void updated(String variableName);
     	void closed();
     }
     
-    static ExecutorService pythonExecutor = Executors.newSingleThreadExecutor();
-    
     Set<Listener> listeners = new HashSet<>();
     
     public enum VariableType {
@@ -43,8 +85,15 @@ public class PythonContext implements Closeable {
     
     static Pattern namePattern = Pattern.compile("([a-zA-Z_][a-zA-Z_0-9]*)");
     
-    PythonContext() {
+    // Really a C pointer.
+    private long contextID;
+
+	PythonContext() {
+		ensurePythonInit();
         contextID = execute(() -> createContextImpl());
+        if (contextID == 0) {
+        	throw new PythonException("Python initialization has failed");
+        }
     }
     
     public void addListener(Listener listener) {
@@ -56,7 +105,7 @@ public class PythonContext implements Closeable {
     }
     
     @Override
-    public void close() {
+    public synchronized void close() {
         long id = contextID;
         contextID = 0;
         if (id != 0) execute(() -> deleteContextImpl(id));
@@ -76,18 +125,35 @@ public class PythonContext implements Closeable {
         close();
     }
     
-    public void executePythonStatement(String statement) {
+    public void executePythonStatement(String statement, Writer writer) {
     	SCLContext sclContext = SCLContext.getCurrent();
     	
         execute(() -> {
         	SCLContext.push(sclContext);
-        	executePythonStatementImpl( contextID, statement );
+        	Writer oldWriter = (Writer) sclContext.put(PYTHON_SCL_WRITER, writer);
+        	try {
+	    		executePythonStatementImpl( contextID, statement );
+	    		pythonWriter.flush();
+			} catch (IOException e) {
+				e.printStackTrace();
+			} finally {
+				if (oldWriter != null) {
+					sclContext.put(PYTHON_SCL_WRITER, oldWriter);
+				}
+				else {
+					sclContext.remove(PYTHON_SCL_WRITER);
+				}
+        	}
         	SCLContext.pop();
         });
         
     	for (Listener l : listeners) { l.updated(null); }
     }
 
+    public void executePythonStatement(String statement) {
+    	executePythonStatement(statement, new SCLReportingWriter());
+    }
+
     // Setters
     
     public void setPythonBooleanVariable(String variableName, boolean value) {
@@ -247,7 +313,9 @@ public class PythonContext implements Closeable {
             throw new IllegalArgumentException("Invalid Python variable name " + variableName);
     }
     
-    static void execute(Runnable job) {
+    static final ExecutorService pythonExecutor = Executors.newSingleThreadExecutor();
+
+	static void execute(Runnable job) {
         try {
             pythonExecutor.submit(job).get();
         } catch (InterruptedException | ExecutionException e) {
@@ -264,6 +332,8 @@ public class PythonContext implements Closeable {
     }
     
     // Native function declarations
+    private static native void initializePython(Writer writer);
+    
     private static native long createContextImpl();
     private static native void deleteContextImpl(long contextID);