Change the default of allow-thread to false

This process introduced many unnecessary calls to
the Py_BEGIN/END_ALLOW_THREAD macro to PySide,
which had a negative impact on the overall behavior
when studying the responsiveness of UIs with threads.

Some tests were adapted to include the new allow-thread
behavior.

[ChangeLog][shiboken] The default of the "allow-thread" attribute
has been changed to false as it was observed to cause performance
issues when using threads.

Task-number: PYSIDE-803
Change-Id: I2cd67c86340f7bf7a2c5694869d17fe2027a0abb
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Christian Tismer <tismer@stackless.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

3 files changed, 10 insertions, 7 deletions

diff --git a/sources/shiboken2/ApiExtractor/abstractmetalang.cpp b/sources/shiboken2/ApiExtractor/abstractmetalang.cpp
index 5ae671d87..0ce7df00a 100644
--- a/sources/shiboken2/ApiExtractor/abstractmetalang.cpp
+++ b/sources/shiboken2/ApiExtractor/abstractmetalang.cpp
@@ -819,9 +819,11 @@ bool AbstractMetaFunction::allowThread() const
     case TypeSystem::AllowThread::Allow:
         break;
     case TypeSystem::AllowThread::Auto:
-    case TypeSystem::AllowThread::Unspecified:
         result = autoDetectAllowThread();
         break;
+    case TypeSystem::AllowThread::Unspecified:
+        result = false;
+        break;
     }
     if (!result)
         qCDebug(lcShiboken).noquote() << msgDisallowThread(this);
diff --git a/sources/shiboken2/ApiExtractor/tests/testmodifyfunction.cpp b/sources/shiboken2/ApiExtractor/tests/testmodifyfunction.cpp
index 922f1c23f..4fd4269f6 100644
--- a/sources/shiboken2/ApiExtractor/tests/testmodifyfunction.cpp
+++ b/sources/shiboken2/ApiExtractor/tests/testmodifyfunction.cpp
@@ -256,9 +256,9 @@ struct A {
     // Nothing specified, true
     const AbstractMetaFunction *f1 = classA->findFunction(QLatin1String("f1"));
     QVERIFY(f1);
-    QVERIFY(f1->allowThread());
+    QVERIFY(!f1->allowThread());
 
-    // 'auto' specified, should be true for nontrivial function
+    // 'auto' specified, should be false for nontrivial function
     const AbstractMetaFunction *f2 = classA->findFunction(QLatin1String("f2"));
     QVERIFY(f2);
     QVERIFY(f2->allowThread());
@@ -349,7 +349,7 @@ struct A : public Base {
     <object-type name='A'/>
 </typesystem>)XML")
          << false << false << false // exception
-         << true; // allowthread
+         << false; // allowthread
 
     // Modify one function
     QTest::newRow("modify-function1")
@@ -363,7 +363,7 @@ struct A : public Base {
     </object-type>
 </typesystem>)XML")
          << false << false << true // exception
-         << true; // allowthread
+         << false; // allowthread
 
     // Flip defaults by modifying functions
     QTest::newRow("modify-function2")
@@ -378,7 +378,7 @@ struct A : public Base {
     </object-type>
 </typesystem>)XML")
          << true << false << false // exception
-         << true; // allowthread
+         << false; // allowthread
 
     // Activate on type system level
     QTest::newRow("typesystem-on")
@@ -428,7 +428,7 @@ struct A : public Base {
     </object-type>
 </typesystem>)XML")
          << true << false << false // exception
-         << true; // allowthread
+         << false; // allowthread
 }
 
 void TestModifyFunction::testScopedModifications()
diff --git a/sources/shiboken2/doc/typesystem_manipulating_objects.rst b/sources/shiboken2/doc/typesystem_manipulating_objects.rst
index c04a4fa27..f76289bc4 100644
--- a/sources/shiboken2/doc/typesystem_manipulating_objects.rst
+++ b/sources/shiboken2/doc/typesystem_manipulating_objects.rst
@@ -119,6 +119,7 @@ modify-function
     lengthy I/O operations or similar. It has performance costs, though.
     The value ``auto`` means that it will be turned off for functions for which
     it is deemed to be safe, for example, simple getters.
+    The attribute defaults to ``false``.
 
     The ``exception-handling`` attribute specifies whether to generate exception
     handling code (nest the function call into try / catch statements). It accepts