From c85c74a0c59fa0ea27552a79681d1a87d9ede418 Mon Sep 17 00:00:00 2001
From: san <san@opencascade.com>
Date: Wed, 3 Dec 2008 12:56:23 +0000
Subject: [PATCH] Debug from PARAVIS team: - Initialize Python + threads in
 main() in light SALOME - Make Python console work in light SALOME

---
 src/PyInterp/PyInterp_Interp.cxx | 27 ++++++++++++++-----------
 src/SUITApp/SUITApp.cxx          | 34 ++++++++++++++++++++++----------
 2 files changed, 40 insertions(+), 21 deletions(-)

diff --git a/src/PyInterp/PyInterp_Interp.cxx b/src/PyInterp/PyInterp_Interp.cxx
index 891d02908..98a6bfd3c 100644
--- a/src/PyInterp/PyInterp_Interp.cxx
+++ b/src/PyInterp/PyInterp_Interp.cxx
@@ -249,24 +249,29 @@ void PyInterp_Interp::initialize()
 /*!
   \brief Initialize Python interpreter.
 
-  Set program name, initialize interpreter, set program arguments,
-  initiaize threads.
+  In case if Python is not initialized, it sets program name, initializes the interpreter, sets program arguments,
+  initializes threads. 
+  Otherwise, it just obtains the global interpreter and thread states. This is important for light SALOME configuration, 
+  as in full SALOME this is done at SalomeApp level.
+  \sa SalomeApp_PyInterp class
  */
 void PyInterp_Interp::initPython()
 {
-  if (Py_IsInitialized())
-    return;
+  if (!Py_IsInitialized()){
+    // Python is not initialized
+    Py_SetProgramName(_argv[0]);
+    Py_Initialize(); // Initialize the interpreter
+    PySys_SetArgv(_argc, _argv);
+    PyEval_InitThreads(); // Create (and acquire) the interpreter lock
+  }
 
-  // Python is not initialized
-  Py_SetProgramName(_argv[0]);
-  Py_Initialize(); // Initialize the interpreter
-  PySys_SetArgv(_argc, _argv);
-  PyEval_InitThreads(); // Create (and acquire) the interpreter lock
-  _interp = PyThreadState_Get()->interp;
+  if ( _interp == NULL )
+    _interp = PyThreadState_Get()->interp;
   if (PyType_Ready(&PyStdOut_Type) < 0) {
     PyErr_Print();
   }
-  _gtstate = PyEval_SaveThread(); // Release global thread state
+  if ( _gtstate == NULL )
+    _gtstate = PyEval_SaveThread(); // Release global thread state
 }
 
 /*!
diff --git a/src/SUITApp/SUITApp.cxx b/src/SUITApp/SUITApp.cxx
index c3caeef5b..1d7e3660b 100644
--- a/src/SUITApp/SUITApp.cxx
+++ b/src/SUITApp/SUITApp.cxx
@@ -18,11 +18,23 @@
 //
 #if defined WIN32
 
+#ifdef SUIT_ENABLE_PYTHON
 #undef SUIT_ENABLE_PYTHON
-//#else
-//#include "SUITconfig.h"
 #endif
 
+#else //#if defined WIN32
+
+#ifndef SUIT_ENABLE_PYTHON
+// NOTE: DO NOT DELETE THIS DEFINITION ON LINUX
+// or make sure Python is initialized in main() in any case
+// Otherwise, application based on light SALOME and using Python 
+// are unlikely to work properly.
+#define SUIT_ENABLE_PYTHON
+#include <Python.h>
+#endif
+
+#endif //#if defined WIN32
+
 #include "SUITApp_Application.h"
 
 #include <SUIT_Session.h>
@@ -32,9 +44,6 @@
 #include <QtxSplash.h>
 
 #include <SUIT_LicenseDlg.h>
-#ifdef SUIT_ENABLE_PYTHON
-#include <Python.h>
-#endif
 
 #include <QDir>
 #include <QFile>
@@ -158,11 +167,16 @@ private:
   bool  myIniFormat;
 };
 
-int main( int args, char* argv[] )
+int main( int argc, char* argv[] )
 {
 #ifdef SUIT_ENABLE_PYTHON
-  Py_Initialize();
-  PySys_SetArgv( args, argv );
+  // First of all initialize Python, as in complex multi-component applications
+  // someone else might initialize it some way unsuitable for light SALOME!
+  Py_SetProgramName( argv[0] );
+  Py_Initialize(); // Initialize the interpreter
+  PySys_SetArgv( argc,  argv );
+  PyEval_InitThreads(); // Create (and acquire) the interpreter lock
+  PyEval_ReleaseLock(); // Let the others use Python API until we need it again
 #endif
 
   //qInstallMsgHandler( MessageOutput );
@@ -172,7 +186,7 @@ int main( int args, char* argv[] )
   bool iniFormat        = false;
   bool noSplash         = false;
   bool useLicense       = false;
-  for ( int i = 1; i < args /*&& !noExceptHandling*/; i++ )
+  for ( int i = 1; i < argc /*&& !noExceptHandling*/; i++ )
   {
     if ( !strcmp( argv[i], "--noexcepthandling" ) )
       noExceptHandling = true;
@@ -186,7 +200,7 @@ int main( int args, char* argv[] )
       argList.append( QString( argv[i] ) );
   }
 
-  SUITApp_Application app( args, argv );
+  SUITApp_Application app( argc, argv );
 
   int result = -1;
 
-- 
2.39.2