[processing] Default to allowing background execution of algorithms

Since the underlying issues with the Python bindings are now fixed, in most cases we can safely default to allowing an algorithm to run in a background thread!! So now we make this the default, and require individual algorithms which are NOT thread safe to declare this. This includes algorithms which directly manipulate the current project or layers (such as setting layer styles), alter the selections in layers, or which rely on 3rd party libraries (for now, SAGA and GRASS algorithms are marked as not thread safe... TODO - someone more familiar with these libraries can investigate and remove the flag if appropriate). Also models are marked as non-thread safe. TODO: only flag an individual model as thread-unsafe if any of its child algorithms report this flag.
qgis · Jan 29, 2018 · a05d941 · a05d941
1 parent 070e137
commit a05d941
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Showing 117 changed files with 89 additions and 288 deletions.
diff --git a/python/core/processing/models/qgsprocessingmodelalgorithm.sip.in b/python/core/processing/models/qgsprocessingmodelalgorithm.sip.in
@@ -47,6 +47,8 @@ Constructor for QgsProcessingModelAlgorithm.
 
     virtual QString helpUrl() const;
 
+    virtual Flags flags() const;
+
 
     virtual bool canExecute( QString *errorMessage /Out/ = 0 ) const;
 

diff --git a/python/core/processing/qgsprocessingalgorithm.sip.in b/python/core/processing/qgsprocessingalgorithm.sip.in
@@ -44,7 +44,7 @@ Abstract base class for processing algorithms.
       FlagSupportsBatch,
       FlagCanCancel,
       FlagRequiresMatchingCrs,
-      FlagCanRunInBackground,
+      FlagNoThreading,
       FlagDeprecated,
     };
     typedef QFlags<QgsProcessingAlgorithm::Flag> Flags;

diff --git a/python/plugins/processing/algs/grass7/Grass7Algorithm.py b/python/plugins/processing/algs/grass7/Grass7Algorithm.py
@@ -151,6 +151,10 @@ def icon(self):
     def svgIconPath(self):
         return QgsApplication.iconPath("providerGrass.svg")
 
+    def flags(self):
+        # TODO - maybe it's safe to background thread this?
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def tr(self, string, context=''):
         if context == '':
             context = self.__class__.__name__

diff --git a/python/plugins/processing/algs/qgis/CreateAttributeIndex.py b/python/plugins/processing/algs/qgis/CreateAttributeIndex.py
@@ -27,6 +27,7 @@
 
 from qgis.core import (QgsVectorDataProvider,
                        QgsFields,
+                       QgsProcessingAlgorithm,
                        QgsProcessingParameterVectorLayer,
                        QgsProcessingParameterField,
                        QgsProcessingOutputVectorLayer)
@@ -56,6 +57,9 @@ def initAlgorithm(self, config=None):
                                                       self.tr('Attribute to index'), None, self.INPUT))
         self.addOutput(QgsProcessingOutputVectorLayer(self.OUTPUT, self.tr('Indexed layer')))
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def name(self):
         return 'createattributeindex'
 

diff --git a/python/plugins/processing/algs/qgis/DefineProjection.py b/python/plugins/processing/algs/qgis/DefineProjection.py
@@ -29,6 +29,7 @@
 import re
 
 from qgis.core import (QgsProcessing,
+                       QgsProcessingAlgorithm,
                        QgsProcessingParameterVectorLayer,
                        QgsProcessingParameterCrs,
                        QgsProcessingOutputVectorLayer)
@@ -65,6 +66,9 @@ def name(self):
     def displayName(self):
         return self.tr('Define current projection')
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def processAlgorithm(self, parameters, context, feedback):
         layer = self.parameterAsVectorLayer(parameters, self.INPUT, context)
         crs = self.parameterAsCrs(parameters, self.CRS, context)

diff --git a/python/plugins/processing/algs/qgis/EliminateSelection.py b/python/plugins/processing/algs/qgis/EliminateSelection.py
@@ -33,6 +33,7 @@
                        QgsFeature,
                        QgsFeatureSink,
                        QgsGeometry,
+                       QgsProcessingAlgorithm,
                        QgsProcessingException,
                        QgsProcessingUtils,
                        QgsProcessingParameterVectorLayer,
@@ -67,6 +68,9 @@ def groupId(self):
     def __init__(self):
         super().__init__()
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def initAlgorithm(self, config=None):
         self.modes = [self.tr('Largest Area'),
                       self.tr('Smallest Area'),

diff --git a/python/plugins/processing/algs/qgis/ExecuteSQL.py b/python/plugins/processing/algs/qgis/ExecuteSQL.py
@@ -28,6 +28,7 @@
 from qgis.core import (QgsVirtualLayerDefinition,
                        QgsVectorLayer,
                        QgsWkbTypes,
+                       QgsProcessingAlgorithm,
                        QgsProcessingParameterMultipleLayers,
                        QgsProcessingParameterString,
                        QgsProcessingParameterEnum,
@@ -62,6 +63,9 @@ def groupId(self):
     def __init__(self):
         super().__init__()
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def initAlgorithm(self, config=None):
         self.addParameter(QgsProcessingParameterMultipleLayers(name=self.INPUT_DATASOURCES,
                                                                description=self.tr('Additional input datasources (called input1, .., inputN in the query)'),

diff --git a/python/plugins/processing/algs/qgis/ImportIntoSpatialite.py b/python/plugins/processing/algs/qgis/ImportIntoSpatialite.py
@@ -27,6 +27,7 @@
 
 from qgis.core import (QgsDataSourceUri,
                        QgsFeatureSink,
+                       QgsProcessingAlgorithm,
                        QgsVectorLayerExporter,
                        QgsProcessingException,
                        QgsProcessingParameterFeatureSource,
@@ -76,6 +77,9 @@ def initAlgorithm(self, config=None):
         self.addParameter(QgsProcessingParameterBoolean(self.DROP_STRING_LENGTH, self.tr('Drop length constraints on character fields'), False))
         self.addParameter(QgsProcessingParameterBoolean(self.FORCE_SINGLEPART, self.tr('Create single-part geometries instead of multi-part'), False))
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def name(self):
         return 'importintospatialite'
 

diff --git a/python/plugins/processing/algs/qgis/RandomSelection.py b/python/plugins/processing/algs/qgis/RandomSelection.py
@@ -32,6 +32,7 @@
 from qgis.core import (QgsFeatureSink,
                        QgsProcessingException,
                        QgsProcessingUtils,
+                       QgsProcessingAlgorithm,
                        QgsProcessingParameterVectorLayer,
                        QgsProcessingParameterEnum,
                        QgsProcessingParameterNumber,
@@ -59,6 +60,9 @@ def group(self):
     def groupId(self):
         return 'vectorselection'
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def __init__(self):
         super().__init__()
 

diff --git a/python/plugins/processing/algs/qgis/RandomSelectionWithinSubsets.py b/python/plugins/processing/algs/qgis/RandomSelectionWithinSubsets.py
@@ -33,6 +33,7 @@
 from qgis.core import (QgsFeatureRequest,
                        QgsProcessingException,
                        QgsProcessingUtils,
+                       QgsProcessingAlgorithm,
                        QgsProcessingParameterVectorLayer,
                        QgsProcessingParameterEnum,
                        QgsProcessingParameterField,
@@ -65,6 +66,9 @@ def groupId(self):
     def __init__(self):
         super().__init__()
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def initAlgorithm(self, config=None):
         self.methods = [self.tr('Number of selected features'),
                         self.tr('Percentage of selected features')]

diff --git a/python/plugins/processing/algs/qgis/SelectByAttribute.py b/python/plugins/processing/algs/qgis/SelectByAttribute.py
@@ -28,6 +28,7 @@
 from qgis.PyQt.QtCore import QVariant
 from qgis.core import (QgsExpression,
                        QgsProcessingException,
+                       QgsProcessingAlgorithm,
                        QgsProcessingParameterVectorLayer,
                        QgsProcessingParameterField,
                        QgsProcessingParameterEnum,
@@ -71,6 +72,9 @@ def groupId(self):
     def __init__(self):
         super().__init__()
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def initAlgorithm(self, config=None):
         self.i18n_operators = ['=',
                                '!=',

diff --git a/python/plugins/processing/algs/qgis/SelectByExpression.py b/python/plugins/processing/algs/qgis/SelectByExpression.py
@@ -26,6 +26,7 @@
 
 from qgis.core import (QgsExpression,
                        QgsVectorLayer,
+                       QgsProcessingAlgorithm,
                        QgsProcessingException,
                        QgsProcessingParameterVectorLayer,
                        QgsProcessingParameterExpression,
@@ -50,6 +51,9 @@ def groupId(self):
     def __init__(self):
         super().__init__()
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def initAlgorithm(self, config=None):
         self.methods = [self.tr('creating new selection'),
                         self.tr('adding to current selection'),

diff --git a/python/plugins/processing/algs/qgis/SetRasterStyle.py b/python/plugins/processing/algs/qgis/SetRasterStyle.py
@@ -29,7 +29,8 @@
 
 from qgis.PyQt.QtXml import QDomDocument
 
-from qgis.core import (QgsProcessingParameterRasterLayer,
+from qgis.core import (QgsProcessingAlgorithm,
+                       QgsProcessingParameterRasterLayer,
                        QgsProcessingParameterFile,
                        QgsProcessingOutputRasterLayer)
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
@@ -50,6 +51,9 @@ def groupId(self):
     def __init__(self):
         super().__init__()
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def initAlgorithm(self, config=None):
         self.addParameter(QgsProcessingParameterRasterLayer(self.INPUT,
                                                             self.tr('Raster layer')))

diff --git a/python/plugins/processing/algs/qgis/SetVectorStyle.py b/python/plugins/processing/algs/qgis/SetVectorStyle.py
@@ -25,7 +25,8 @@
 
 __revision__ = '$Format:%H$'
 
-from qgis.core import (QgsProcessingParameterFile,
+from qgis.core import (QgsProcessingAlgorithm,
+                       QgsProcessingParameterFile,
                        QgsProcessingParameterVectorLayer,
                        QgsProcessingOutputVectorLayer)
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
@@ -46,6 +47,9 @@ def groupId(self):
     def __init__(self):
         super().__init__()
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def initAlgorithm(self, config=None):
         self.addParameter(QgsProcessingParameterVectorLayer(self.INPUT,
                                                             self.tr('Vector layer')))

diff --git a/python/plugins/processing/algs/qgis/SpatialIndex.py b/python/plugins/processing/algs/qgis/SpatialIndex.py
@@ -28,6 +28,7 @@
 import os
 
 from qgis.core import (QgsVectorDataProvider,
+                       QgsProcessingAlgorithm,
                        QgsProcessingParameterVectorLayer,
                        QgsProcessingOutputVectorLayer,
                        QgsProcessing)
@@ -57,6 +58,9 @@ def initAlgorithm(self, config=None):
                                                             [QgsProcessing.TypeVectorPolygon, QgsProcessing.TypeVectorPoint, QgsProcessing.TypeVectorLine]))
         self.addOutput(QgsProcessingOutputVectorLayer(self.OUTPUT, self.tr('Indexed layer')))
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def name(self):
         return 'createspatialindex'
 

diff --git a/python/plugins/processing/algs/qgis/SpatialiteExecuteSQL.py b/python/plugins/processing/algs/qgis/SpatialiteExecuteSQL.py
@@ -26,6 +26,7 @@
 __revision__ = '$Format:%H$'
 
 from qgis.core import (QgsDataSourceUri,
+                       QgsProcessingAlgorithm,
                        QgsProcessingException,
                        QgsProcessingParameterVectorLayer,
                        QgsProcessingParameterString)
@@ -58,6 +59,9 @@ def name(self):
     def displayName(self):
         return self.tr('SpatiaLite execute SQL')
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def processAlgorithm(self, parameters, context, feedback):
         database = self.parameterAsVectorLayer(parameters, self.DATABASE, context)
         databaseuri = database.dataProvider().dataSourceUri()

diff --git a/python/plugins/processing/algs/qgis/TruncateTable.py b/python/plugins/processing/algs/qgis/TruncateTable.py
@@ -25,7 +25,8 @@
 
 __revision__ = '$Format:%H$'
 
-from qgis.core import (QgsProcessingParameterVectorLayer,
+from qgis.core import (QgsProcessingAlgorithm,
+                       QgsProcessingParameterVectorLayer,
                        QgsProcessingOutputVectorLayer,
                        QgsProcessingException)
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
@@ -53,6 +54,9 @@ def initAlgorithm(self, config=None):
                                                             self.tr('Input Layer')))
         self.addOutput(QgsProcessingOutputVectorLayer(self.OUTPUT, self.tr('Truncated layer')))
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def name(self):
         return 'truncatetable'
 

diff --git a/python/plugins/processing/algs/saga/SagaAlgorithm.py b/python/plugins/processing/algs/saga/SagaAlgorithm.py
@@ -33,6 +33,7 @@
                        QgsProcessingException,
                        QgsMessageLog,
                        QgsProcessing,
+                       QgsProcessingAlgorithm,
                        QgsProcessingParameterRasterLayer,
                        QgsProcessingParameterFeatureSource,
                        QgsProcessingParameterBoolean,
@@ -99,6 +100,10 @@ def groupId(self):
     def shortHelpString(self):
         return shortHelp.get(self.id(), None)
 
+    def flags(self):
+        # TODO - maybe it's safe to background thread this?
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def defineCharacteristicsFromFile(self):
         with open(self.description_file) as lines:
             line = lines.readline().strip('\n').strip()

diff --git a/python/plugins/processing/gui/AlgorithmDialog.py b/python/plugins/processing/gui/AlgorithmDialog.py
@@ -251,7 +251,7 @@ def on_complete(ok, results):
 
                     self.finish(ok, results, context, feedback)
 
-                if self.algorithm().flags() & QgsProcessingAlgorithm.FlagCanRunInBackground:
+                if not (self.algorithm().flags() & QgsProcessingAlgorithm.FlagNoThreading):
                     # Make sure the Log tab is visible before executing the algorithm
                     self.showLog()
 

diff --git a/src/3d/processing/qgsalgorithmtessellate.cpp b/src/3d/processing/qgsalgorithmtessellate.cpp
@@ -31,11 +31,6 @@ QString QgsTessellateAlgorithm::displayName() const
   return QObject::tr( "Tessellate" );
 }
 
-QgsProcessingAlgorithm::Flags QgsTessellateAlgorithm::flags() const
-{
-  return QgsProcessingFeatureBasedAlgorithm::flags() | QgsProcessingAlgorithm::FlagCanRunInBackground;
-}
-
 QStringList QgsTessellateAlgorithm::tags() const
 {
   return QObject::tr( "3d,triangle" ).split( ',' );

diff --git a/src/3d/processing/qgsalgorithmtessellate.h b/src/3d/processing/qgsalgorithmtessellate.h
@@ -36,7 +36,6 @@ class QgsTessellateAlgorithm : public QgsProcessingFeatureBasedAlgorithm
     QgsTessellateAlgorithm() = default;
     QString name() const override;
     QString displayName() const override;
-    Flags flags() const override;
     QStringList tags() const override;
     QString group() const override;
     QString shortHelpString() const override;

diff --git a/src/analysis/processing/qgsalgorithmaddincrementalfield.cpp b/src/analysis/processing/qgsalgorithmaddincrementalfield.cpp
@@ -19,11 +19,6 @@
 
 ///@cond PRIVATE
 
-QgsProcessingAlgorithm::Flags QgsAddIncrementalFieldAlgorithm::flags() const
-{
-  return QgsProcessingFeatureBasedAlgorithm::flags() | QgsProcessingAlgorithm::FlagCanRunInBackground;
-}
-
 QString QgsAddIncrementalFieldAlgorithm::name() const
 {
   return QStringLiteral( "addautoincrementalfield" );

diff --git a/src/analysis/processing/qgsalgorithmaddincrementalfield.h b/src/analysis/processing/qgsalgorithmaddincrementalfield.h
@@ -34,7 +34,6 @@ class QgsAddIncrementalFieldAlgorithm : public QgsProcessingFeatureBasedAlgorith
   public:
 
     QgsAddIncrementalFieldAlgorithm() = default;
-    Flags flags() const override;
     QString name() const override;
     QString displayName() const override;
     QStringList tags() const override;

diff --git a/src/analysis/processing/qgsalgorithmassignprojection.cpp b/src/analysis/processing/qgsalgorithmassignprojection.cpp
@@ -19,11 +19,6 @@
 
 ///@cond PRIVATE
 
-QgsProcessingAlgorithm::Flags QgsAssignProjectionAlgorithm::flags() const
-{
-  return QgsProcessingFeatureBasedAlgorithm::flags() | QgsProcessingAlgorithm::FlagCanRunInBackground;
-}
-
 QString QgsAssignProjectionAlgorithm::name() const
 {
   return QStringLiteral( "assignprojection" );

diff --git a/src/analysis/processing/qgsalgorithmassignprojection.h b/src/analysis/processing/qgsalgorithmassignprojection.h
@@ -34,7 +34,6 @@ class QgsAssignProjectionAlgorithm : public QgsProcessingFeatureBasedAlgorithm
   public:
 
     QgsAssignProjectionAlgorithm() = default;
-    Flags flags() const override;
     QString name() const override;
     QString displayName() const override;
     QStringList tags() const override;

diff --git a/src/analysis/processing/qgsalgorithmboundary.cpp b/src/analysis/processing/qgsalgorithmboundary.cpp
@@ -19,11 +19,6 @@
 
 ///@cond PRIVATE
 
-QgsProcessingAlgorithm::Flags QgsBoundaryAlgorithm::flags() const
-{
-  return QgsProcessingFeatureBasedAlgorithm::flags() | QgsProcessingAlgorithm::FlagCanRunInBackground;
-}
-
 QString QgsBoundaryAlgorithm::name() const
 {
   return QStringLiteral( "boundary" );

diff --git a/src/analysis/processing/qgsalgorithmboundary.h b/src/analysis/processing/qgsalgorithmboundary.h
@@ -34,7 +34,6 @@ class QgsBoundaryAlgorithm : public QgsProcessingFeatureBasedAlgorithm
   public:
 
     QgsBoundaryAlgorithm() = default;
-    Flags flags() const override;
     QString name() const override;
     QString displayName() const override;
     QStringList tags() const override;