From: tkorvola <Timo.Korvola@vtt.fi>
Date: Wed, 1 Feb 2017 17:48:01 +0000 (+0200)
Subject: Mind the threads in writeSCL.
X-Git-Tag: v1.31.0~4
X-Git-Url: https://gerrit.simantics.org/r/gitweb?p=simantics%2Fpython.git;a=commitdiff_plain;h=1a64cbed776f5011b685b7d32bc4c217f1ae4264

Mind the threads in writeSCL.

Both JNIEnv and PyThreadState are per thread.  So check that we are
in the main thread before messing with JNIEnv.  Writes from other
threads (possibly created in Python) are just dropped; those seem
difficult to do right.

Also unlock GIL while calling the Java method.

Change-Id: I49a447e22ba4411800445f7149f5bc257a082e4f
---

diff --git a/org.simantics.pythonlink.win32.x86_64/jnipython.dll b/org.simantics.pythonlink.win32.x86_64/jnipython.dll
index e533946..ab792ab 100644
Binary files a/org.simantics.pythonlink.win32.x86_64/jnipython.dll and b/org.simantics.pythonlink.win32.x86_64/jnipython.dll differ
diff --git a/org.simantics.pythonlink.win32.x86_64/src/sclpy.c b/org.simantics.pythonlink.win32.x86_64/src/sclpy.c
index 686221e..428a45a 100644
--- a/org.simantics.pythonlink.win32.x86_64/src/sclpy.c
+++ b/org.simantics.pythonlink.win32.x86_64/src/sclpy.c
@@ -53,19 +53,26 @@ writeToSCL(PyObject *self, PyObject *args)
 		Py_UNICODE *what;
 		Py_ssize_t length;
 		if (!PyArg_ParseTuple(args, "u#", &what, &length))
-			return Py_BuildValue("");
+			Py_RETURN_NONE;
 
 		{
-    		jclass writerClass = (*env)->FindClass(env, WRITER_CLASS);
-    		jmethodID writeMethod = (*env)->GetMethodID(env, writerClass, "write", "([CII)V");
-    		jcharArray chars = (*env)->NewCharArray(env, (jsize)length);
-
-    		(*env)->SetCharArrayRegion(env, chars, 0, length, what);
-    		(*env)->CallVoidMethod(env, sclWriter, writeMethod, chars, 0, length);
+			PyThreadState *my_ts = PyThreadState_Get();
+			if (my_ts == main_ts) {
+				jclass writerClass = (*env)->FindClass(env, WRITER_CLASS);
+				jmethodID writeMethod = (*env)->GetMethodID(env, writerClass, "write", "([CII)V");
+				jcharArray chars = (*env)->NewCharArray(env, (jsize)length);
+
+				(*env)->SetCharArrayRegion(env, chars, 0, length, what);
+				Py_BEGIN_ALLOW_THREADS
+				(*env)->CallVoidMethod(env, sclWriter, writeMethod, chars, 0, length);
+				Py_END_ALLOW_THREADS
+			} else {
+				//TODO
+			}
 		}
     }
 
-    return Py_BuildValue("");
+	Py_RETURN_NONE;
 }
 
 static PyMethodDef sclWriterMethods[] = {