Merge pull request #2819 from N-Dekker/RegisterFactoryOnce

Modules/Core/Common/include/itkObjectFactoryBase.h

@@ -219,6 +219,25 @@ class ITKCommon_EXPORT ObjectFactoryBase : public Object
     CreateObjectFunctionBase::Pointer m_CreateObject;
   };
 
+  /** Registers the specified internal factory only once, even when `RegisterInternalFactoryOnce<TFactory>()` is called
+   * multiple times (possibly even by multiple threads) for the very same factory. */
+  template <typename TFactory>
+  static void
+  RegisterInternalFactoryOnce()
+  {
+    struct FactoryRegistration
+    {};
+
+    // Factory registration, made thread-safe by "magic statics" (as introduced with C++11).
+    static const FactoryRegistration staticFactoryRegistration = [] {
+      RegisterFactoryInternal(TFactory::New());
+      return FactoryRegistration{};
+    }();
+
+    (void)staticFactoryRegistration;
+  }
+
+
 protected:
   void
   PrintSelf(std::ostream & os, Indent indent) const override;

Modules/IO/BMP/src/itkBMPImageIOFactory.cxx

@@ -43,17 +43,10 @@ BMPImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool BMPImageIOFactoryHasBeenRegistered;
-
 void ITKIOBMP_EXPORT
      BMPImageIOFactoryRegister__Private()
 {
-  if (!BMPImageIOFactoryHasBeenRegistered)
-  {
-    BMPImageIOFactoryHasBeenRegistered = true;
-    BMPImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<BMPImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/BioRad/src/itkBioRadImageIOFactory.cxx

@@ -53,17 +53,10 @@ BioRadImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool BioRadImageIOFactoryHasBeenRegistered;
-
 void ITKIOBioRad_EXPORT
      BioRadImageIOFactoryRegister__Private()
 {
-  if (!BioRadImageIOFactoryHasBeenRegistered)
-  {
-    BioRadImageIOFactoryHasBeenRegistered = true;
-    BioRadImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<BioRadImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/Bruker/src/itkBruker2dseqImageIOFactory.cxx

@@ -56,16 +56,9 @@ Bruker2dseqImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool Bruker2dseqImageIOFactoryHasBeenRegistered;
-
 void ITKIOBruker_EXPORT
      Bruker2dseqImageIOFactoryRegister__Private()
 {
-  if (!Bruker2dseqImageIOFactoryHasBeenRegistered)
-  {
-    Bruker2dseqImageIOFactoryHasBeenRegistered = true;
-    Bruker2dseqImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<Bruker2dseqImageIOFactory>();
 }
 } // end namespace itk

Modules/IO/DCMTK/src/itkDCMTKImageIOFactory.cxx

@@ -43,17 +43,10 @@ DCMTKImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool DCMTKImageIOFactoryHasBeenRegistered;
-
 void ITKIODCMTK_EXPORT
      DCMTKImageIOFactoryRegister__Private()
 {
-  if (!DCMTKImageIOFactoryHasBeenRegistered)
-  {
-    DCMTKImageIOFactoryHasBeenRegistered = true;
-    DCMTKImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<DCMTKImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/GDCM/src/itkGDCMImageIOFactory.cxx

@@ -43,17 +43,10 @@ GDCMImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool GDCMImageIOFactoryHasBeenRegistered;
-
 void ITKIOGDCM_EXPORT
      GDCMImageIOFactoryRegister__Private()
 {
-  if (!GDCMImageIOFactoryHasBeenRegistered)
-  {
-    GDCMImageIOFactoryHasBeenRegistered = true;
-    GDCMImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<GDCMImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/GE/src/itkGE4ImageIOFactory.cxx

@@ -47,17 +47,10 @@ GE4ImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool GE4ImageIOFactoryHasBeenRegistered;
-
 void ITKIOGE_EXPORT
      GE4ImageIOFactoryRegister__Private()
 {
-  if (!GE4ImageIOFactoryHasBeenRegistered)
-  {
-    GE4ImageIOFactoryHasBeenRegistered = true;
-    GE4ImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<GE4ImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/GE/src/itkGE5ImageIOFactory.cxx

@@ -47,17 +47,10 @@ GE5ImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool GE5ImageIOFactoryHasBeenRegistered;
-
 void ITKIOGE_EXPORT
      GE5ImageIOFactoryRegister__Private()
 {
-  if (!GE5ImageIOFactoryHasBeenRegistered)
-  {
-    GE5ImageIOFactoryHasBeenRegistered = true;
-    GE5ImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<GE5ImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/GE/src/itkGEAdwImageIOFactory.cxx

@@ -47,17 +47,10 @@ GEAdwImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool GEAdwImageIOFactoryHasBeenRegistered;
-
 void ITKIOGE_EXPORT
      GEAdwImageIOFactoryRegister__Private()
 {
-  if (!GEAdwImageIOFactoryHasBeenRegistered)
-  {
-    GEAdwImageIOFactoryHasBeenRegistered = true;
-    GEAdwImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<GEAdwImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/GIPL/src/itkGiplImageIOFactory.cxx

@@ -43,17 +43,10 @@ GiplImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool GiplImageIOFactoryHasBeenRegistered;
-
 void ITKIOGIPL_EXPORT
      GiplImageIOFactoryRegister__Private()
 {
-  if (!GiplImageIOFactoryHasBeenRegistered)
-  {
-    GiplImageIOFactoryHasBeenRegistered = true;
-    GiplImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<GiplImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/HDF5/src/itkHDF5ImageIOFactory.cxx

@@ -47,17 +47,10 @@ HDF5ImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool HDF5ImageIOFactoryHasBeenRegistered;
-
 void ITKIOHDF5_EXPORT
      HDF5ImageIOFactoryRegister__Private()
 {
-  if (!HDF5ImageIOFactoryHasBeenRegistered)
-  {
-    HDF5ImageIOFactoryHasBeenRegistered = true;
-    HDF5ImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<HDF5ImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/JPEG/src/itkJPEGImageIOFactory.cxx

@@ -43,17 +43,10 @@ JPEGImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool JPEGImageIOFactoryHasBeenRegistered;
-
 void ITKIOJPEG_EXPORT
      JPEGImageIOFactoryRegister__Private()
 {
-  if (!JPEGImageIOFactoryHasBeenRegistered)
-  {
-    JPEGImageIOFactoryHasBeenRegistered = true;
-    JPEGImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<JPEGImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/JPEG2000/src/itkJPEG2000ImageIOFactory.cxx

@@ -44,17 +44,10 @@ JPEG2000ImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool JPEG2000ImageIOFactoryHasBeenRegistered;
-
 void ITKIOJPEG2000_EXPORT
      JPEG2000ImageIOFactoryRegister__Private()
 {
-  if (!JPEG2000ImageIOFactoryHasBeenRegistered)
-  {
-    JPEG2000ImageIOFactoryHasBeenRegistered = true;
-    JPEG2000ImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<JPEG2000ImageIOFactory>();
 }
 
 

Modules/IO/LSM/src/itkLSMImageIOFactory.cxx

@@ -53,17 +53,10 @@ LSMImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool LSMImageIOFactoryHasBeenRegistered;
-
 void ITKIOLSM_EXPORT
      LSMImageIOFactoryRegister__Private()
 {
-  if (!LSMImageIOFactoryHasBeenRegistered)
-  {
-    LSMImageIOFactoryHasBeenRegistered = true;
-    LSMImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<LSMImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/MINC/src/itkMINCImageIOFactory.cxx

@@ -43,17 +43,10 @@ MINCImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool MINCImageIOFactoryHasBeenRegistered;
-
 void ITKIOMINC_EXPORT
      MINCImageIOFactoryRegister__Private()
 {
-  if (!MINCImageIOFactoryHasBeenRegistered)
-  {
-    MINCImageIOFactoryHasBeenRegistered = true;
-    MINCImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<MINCImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/MRC/src/itkMRCImageIOFactory.cxx

@@ -53,17 +53,10 @@ MRCImageIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-
-static bool MRCImageIOFactoryHasBeenRegistered;
-
 void ITKIOMRC_EXPORT
      MRCImageIOFactoryRegister__Private()
 {
-  if (!MRCImageIOFactoryHasBeenRegistered)
-  {
-    MRCImageIOFactoryHasBeenRegistered = true;
-    MRCImageIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<MRCImageIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/MeshBYU/src/itkBYUMeshIOFactory.cxx

@@ -52,16 +52,10 @@ BYUMeshIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-static bool BYUMeshIOFactoryHasBeenRegistered;
-
 void ITKIOMeshBYU_EXPORT
      BYUMeshIOFactoryRegister__Private()
 {
-  if (!BYUMeshIOFactoryHasBeenRegistered)
-  {
-    BYUMeshIOFactoryHasBeenRegistered = true;
-    BYUMeshIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<BYUMeshIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/MeshFreeSurfer/src/itkFreeSurferAsciiMeshIOFactory.cxx

@@ -52,16 +52,10 @@ FreeSurferAsciiMeshIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-static bool FreeSurferAsciiMeshIOFactoryHasBeenRegistered;
-
 void ITKIOMeshFreeSurfer_EXPORT
      FreeSurferAsciiMeshIOFactoryRegister__Private()
 {
-  if (!FreeSurferAsciiMeshIOFactoryHasBeenRegistered)
-  {
-    FreeSurferAsciiMeshIOFactoryHasBeenRegistered = true;
-    FreeSurferAsciiMeshIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<FreeSurferAsciiMeshIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/MeshFreeSurfer/src/itkFreeSurferBinaryMeshIOFactory.cxx

@@ -52,16 +52,10 @@ FreeSurferBinaryMeshIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-static bool FreeSurferBinaryMeshIOFactoryHasBeenRegistered;
-
 void ITKIOMeshFreeSurfer_EXPORT
      FreeSurferBinaryMeshIOFactoryRegister__Private()
 {
-  if (!FreeSurferBinaryMeshIOFactoryHasBeenRegistered)
-  {
-    FreeSurferBinaryMeshIOFactoryHasBeenRegistered = true;
-    FreeSurferBinaryMeshIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<FreeSurferBinaryMeshIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/MeshGifti/src/itkGiftiMeshIOFactory.cxx

@@ -49,16 +49,10 @@ GiftiMeshIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-static bool GiftiMeshIOFactoryHasBeenRegistered;
-
 void ITKIOMeshGifti_EXPORT
      GiftiMeshIOFactoryRegister__Private()
 {
-  if (!GiftiMeshIOFactoryHasBeenRegistered)
-  {
-    GiftiMeshIOFactoryHasBeenRegistered = true;
-    GiftiMeshIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<GiftiMeshIOFactory>();
 }
 
 } // end namespace itk

Modules/IO/MeshOBJ/src/itkOBJMeshIOFactory.cxx

@@ -48,16 +48,10 @@ OBJMeshIOFactory::GetDescription() const
 
 // Undocumented API used to register during static initialization.
 // DO NOT CALL DIRECTLY.
-static bool OBJMeshIOFactoryHasBeenRegistered;
-
 void ITKIOMeshOBJ_EXPORT
      OBJMeshIOFactoryRegister__Private()
 {
-  if (!OBJMeshIOFactoryHasBeenRegistered)
-  {
-    OBJMeshIOFactoryHasBeenRegistered = true;
-    OBJMeshIOFactory::RegisterOneFactory();
-  }
+  ObjectFactoryBase::RegisterInternalFactoryOnce<OBJMeshIOFactory>();
 }
 
 } // end namespace itk