Merge branch 'development' into embb517_mutex_based_atomics

.travis.yml

-# Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+# Copyright (c) 2014-2016, Siemens AG. All rights reserved.
 # SPDX-License-Identifier: BSD-2-Clause
 
 language: cpp

CHANGELOG.md

-Embedded Multicore Building Blocks (EMB²)
+Embedded Multicore Building Blocks (EMB²)
 =========================================
 
+Version 0.3.2
+-------------
+
+### Features:
+- Added central spinlock implementation for C/C++ and removed existing (decentral) ones
+
+### Changes and improvements:
+- Reworked and optimized hazard pointer implementation
+- Adjusted interfaces of value pool and object pool
+- Replaced C style casts
+
+### Bug fixes:
+- Fixed ordering of destruction and deallocation in value pool
+- Fixed potential use of uninitialized memory in WaitFreeArrayValuePool and LockFreeTreeValuePool
+
+### Build system:
+- Given user the ability to append compiler flags
+- Let Cmake return an error on Doxygen warnings when WARNINGS_ARE_ERRORS is enabled
+- Fixed cpplint warnings
+
+### Documentation:
+- Added mutex concept
+- Corrected library ordering/names in README (section "Using the Library")
+- Improved exception messages
+- Fixed typos in condition_var_test.cc
+
+
 Version 0.3.1
 -------------
 

CMakeCommon/CheckEnableTests.cmake

-# Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+# Copyright (c) 2014-2016, Siemens AG. All rights reserved.
 # 
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:

CMakeCommon/CopyInstallFiles.cmake

-# Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+# Copyright (c) 2014-2016, Siemens AG. All rights reserved.
 # 
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:

CMakeCommon/CreateDoxygenDocumentationTarget.cmake

-# Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+# Copyright (c) 2014-2016, Siemens AG. All rights reserved.
 # 
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -40,13 +40,30 @@ function (CreateDoxygenDocumentationTarget)
     if (TARGET doxygen)
       # Do nothing, since the repeated adding causes an error
     else()
-      add_custom_target (
-        doxygen 
-        #ALL
-        COMMAND ${DOXYGEN_EXECUTABLE} ${PROJECT_BINARY_DIR}/Doxyfile
-        SOURCES ${PROJECT_BINARY_DIR}/Doxyfile)
-        # IF you do NOT want the documentation to be generated EVERY time you build the project
-        # then leave out the 'ALL' keyword from the above command.
+
+    FILE(WRITE ${CMAKE_BINARY_DIR}/doxygen_makefile.cmake "
+MESSAGE(STATUS \"Running Doxygen\")
+EXECUTE_PROCESS(
+COMMAND \${EXE} \${IN}
+ERROR_VARIABLE  DOXYGEN_OUT_ERR
+RESULT_VARIABLE DOXYGEN_OUT_RESULT)
+STRING(LENGTH \"\${DOXYGEN_OUT_ERR}\" LENGTH_ERR)
+IF ( NOT \${LENGTH_ERR} STREQUAL \"0\" )
+  MESSAGE (WARNING \"Doxygen produced following warnings and or/errors: \${DOXYGEN_OUT_ERR}\")
+  IF ( \${WARNINGS_ARE_ERRORS} STREQUAL ON OR NOT \${DOXYGEN_OUT_RESULT} STREQUAL \"0\" )
+    MESSAGE (FATAL_ERROR \"Exiting doxygen generation due to errors (or warnings, if WARNINGS_ARE_ERRORS is enabled)\")
+  ENDIF ()
+ENDIF ()
+")
+
+      add_custom_target(doxygen)
+      add_custom_command(
+        TARGET doxygen
+        COMMAND ${CMAKE_COMMAND}
+          -DEXE=${DOXYGEN_EXECUTABLE}
+          -DIN=${PROJECT_BINARY_DIR}/Doxyfile
+          -DWARNINGS_ARE_ERRORS=${WARNINGS_ARE_ERRORS}
+          -P ${CMAKE_BINARY_DIR}/doxygen_makefile.cmake)
     endif()
   endif()
 endfunction()

CMakeCommon/GroupSourcesMSVC.cmake

-# Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+# Copyright (c) 2014-2016, Siemens AG. All rights reserved.
 # 
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:

CMakeCommon/SetCompilerFlags.cmake

-# Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+# Copyright (c) 2014-2016, Siemens AG. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -90,10 +90,19 @@ function(SetVisualStudioCompilerFlags)
     # Locally suppressed warnings (should not be globally suppressed):
     # 4640 -> Information that local static variable initialization is not
     #         thread-safe.
+    #
+    # VS 2015 specific warnings:
+    # 5026 -> Move constructor was implicitly defined as deleted
+    # 5027 -> Move assignment operator was implicitly defined as deleted
+    #
     set(warning_flags "/Wall /wd4820 /wd4514 /wd4668 /wd4710 /wd4350 /wd4571 /wd4625 /wd4626 /wd4711 /wd4255")
     if (WARNINGS_ARE_ERRORS STREQUAL ON)
       set(warning_flags "${warning_flags} /WX")
     endif()
+    string(FIND "${CMAKE_GENERATOR}" "Visual Studio 14 2015" vs2015_state)
+    if (vs2015_state EQUAL 0)
+      set(warning_flags "${warning_flags} /wd5026 /wd5027")
+    endif()
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${warning_flags}" PARENT_SCOPE)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${warning_flags}" PARENT_SCOPE)
   endif()

CMakeCommon/SetInstallPaths.cmake

-# Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+# Copyright (c) 2014-2016, Siemens AG. All rights reserved.
 # 
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:

CMakeLists.txt

-# Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+# Copyright (c) 2014-2016, Siemens AG. All rights reserved.
 # 
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -28,7 +28,7 @@ cmake_minimum_required (VERSION 2.8.9)
 # Version number
 set (EMBB_BASE_VERSION_MAJOR 0)
 set (EMBB_BASE_VERSION_MINOR 3)
-set (EMBB_BASE_VERSION_PATCH 1)
+set (EMBB_BASE_VERSION_PATCH 2)
 
 # Fix compilation for CMake versions >= 3.1
 #
@@ -53,13 +53,9 @@ if(POLICY CMP0053)
   cmake_policy(SET CMP0053 OLD)
 endif(POLICY CMP0053)
 
-
-include(CMakeCommon/FindOpenCL.cmake)
-IF(NOT OpenCL_FOUND)
-  MESSAGE( STATUS "OpenCL is not there, will build without MTAPI OpenCL Plugin." )
-ENDIF()
-
-
+# give the user the possibility, to append compiler flags
+set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${EXTRA_CMAKE_CXX_FLAGS}")
+set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${EXTRA_CMAKE_C_FLAGS}")
 
 if(NOT CMAKE_BUILD_TYPE)
 set(CMAKE_BUILD_TYPE "Release" CACHE STRING
@@ -86,6 +82,7 @@ option(USE_EXCEPTIONS "Specify whether exceptions should be activated in C++" ON
 option(INSTALL_DOCS "Specify whether Doxygen docs should be installed" ON)
 option(WARNINGS_ARE_ERRORS "Specify whether warnings should be treated as errors" OFF)
 option(USE_AUTOMATIC_INITIALIZATION "Specify whether the MTAPI C++ interface, algorithms and dataflow should automatically intialize the MTAPI node if no explicit initialization is present" ON)
+option(BUILD_OPENCL_PLUGIN "Specify whether the MTAPI OpenCL plugin should be built" OFF)
 
 ## LOCAL INSTALLATION OF SUBPROJECT BINARIES
 #
@@ -144,7 +141,7 @@ set(EXPECTED_EMBB_TEST_EXECUTABLES "embb_algorithms_cpp_test"
                 )
 
 # if opencl is there, we also expect the mtapi opencl test to be generated
-if(OpenCL_FOUND)
+if(BUILD_OPENCL_PLUGIN STREQUAL ON)
   list(APPEND EXPECTED_EMBB_TEST_EXECUTABLES "embb_mtapi_opencl_c_test")
 endif()
 
@@ -179,9 +176,9 @@ CheckPartestInstall(${BUILD_TESTS} partest_includepath partest_libpath)
 add_subdirectory(base_c)
 add_subdirectory(base_cpp)
 add_subdirectory(mtapi_c)
-add_subdirectory(mtapi_network_c)
-if(OpenCL_FOUND)
-  add_subdirectory(mtapi_opencl_c)
+add_subdirectory(mtapi_plugins_c/mtapi_network_c)
+if(BUILD_OPENCL_PLUGIN STREQUAL ON)
+  add_subdirectory(mtapi_plugins_c/mtapi_opencl_c)
 endif()
 add_subdirectory(tasks_cpp)
 add_subdirectory(mtapi_cpp)

COPYING.md

-Embedded Multicore Building Blocks (EMB²)
+Embedded Multicore Building Blocks (EMB²)
 =========================================
 
 Overview
@@ -13,7 +13,7 @@ license (see file include\embb\mtapi\c\mtapi.h).
 License
 -------
 
-Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+Copyright (c) 2014-2016, Siemens AG. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:

README.md

@@ -98,7 +98,8 @@ postfixed with either "_cpp" or "_c" for the C++ and C versions, respectively.
 Currently, EMB² contains the following components:
 
   - base: base_c, base_cpp
-  - mtapi: mtapi_c, mtapi_network_c, mtapi_opencl_c, mtapi_cpp
+  - mtapi: mtapi_c, mtapi_cpp and
+    mtapi_plugins_c (mtapi_network_c and mtapi_opencl_c)
   - tasks: tasks_cpp
   - algorithms: algorithms_cpp
   - dataflow: dataflow_cpp
@@ -270,8 +271,8 @@ If you want to use the C++ functionalities of EMB², you have to link the
 following libraries (names will be different on Windows and on Linux) in the
 given order:
 
-    embb_base, embb_base_cpp, embb_mtapi_c, embb_mtapi_cpp, embb_containers_cpp,
-    embb_algorithms_cpp, embb_dataflow_cpp
+    embb_dataflow_cpp, embb_algorithms_cpp, embb_containers_cpp,
+    embb_mtapi_cpp, embb_mtapi_c, embb_base_cpp, embb_base_c
 
 The C++ header files can be included as follows:
 
@@ -284,7 +285,7 @@ The C++ header files can be included as follows:
 
 The following libraries have to be linked in the given order:
 
-    embb_base_c, mtapi_c
+    embb_mtapi_c, embb_base_c
 
 The C header files can be included as follows:
 

algorithms_cpp/include/embb/algorithms/algorithms.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/count.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/for_each.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/identity.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/internal/count-inl.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/internal/for_each-inl.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/internal/merge_sort-inl.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/internal/partition-inl.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/internal/partition.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/internal/quick_sort-inl.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/internal/reduce-inl.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/internal/scan-inl.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/invoke.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/merge_sort.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/quick_sort.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/reduce.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/scan.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/include/embb/algorithms/zip_iterator.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/src/dummy.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/count_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/count_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/for_each_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/for_each_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/invoke_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/invoke_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/main.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/merge_sort_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/merge_sort_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/partitioner_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/partitioner_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/quick_sort_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/quick_sort_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/reduce_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/reduce_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/scan_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/scan_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/zip_iterator_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

algorithms_cpp/test/zip_iterator_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/atomic.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/base.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/condition_variable.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/core_set.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/counter.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/duration.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/errors.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/atomic/and_assign.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/atomic/atomic_sizes.h.in

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/atomic/atomic_variables.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -39,7 +39,7 @@
   EMBB_ATOMIC_PARAMETER_ATOMIC_TYPE_SUFFIX) \
   typedef struct \
 { \
-  EMBB_ATOMIC_PARAMETER_TYPE_NATIVE internal_variable; \
+  volatile EMBB_ATOMIC_PARAMETER_TYPE_NATIVE internal_variable; \
 } EMBB_CAT2(embb_atomic_, EMBB_ATOMIC_PARAMETER_ATOMIC_TYPE_SUFFIX);
 
 EMBB_ATOMIC_INTERNAL_DEFINE_VARIABLE(char, char)

base_c/include/embb/base/c/internal/atomic/compare_and_swap.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/atomic/fetch_and_add.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/atomic/generate_atomic_implementation_template.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/atomic/load.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/atomic/memory_barrier.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/atomic/or_assign.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/atomic/store.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/atomic/swap.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/atomic/xor_assign.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/bitset.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/cmake_config.h.in

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/config.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/macro_helper.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/platform.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/thread_index.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/internal/unused.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/log.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -28,6 +28,7 @@
 #define EMBB_BASE_C_LOG_H_
 
 #include <embb/base/c/internal/config.h>
+#include <stdarg.h>
 
 /**
  * \defgroup C_LOG Logging
@@ -197,6 +198,13 @@ void embb_log_error(
                                             \c message */
   );
 
+/* function for internal use only */
+void embb_log_write_internal(
+  char const * channel,
+  embb_log_level_t log_level,
+  char const * message,
+  va_list argp);
+
 #ifdef __cplusplus
 }
 #endif

base_c/include/embb/base/c/memory_allocation.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/mutex.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -46,12 +46,25 @@ extern "C" {
 
 #include <embb/base/c/internal/platform.h>
 #include <embb/base/c/errors.h>
+#include <embb/base/c/atomic.h>
 
 #ifdef DOXYGEN
 /**
  * Opaque type representing a mutex.
  */
 typedef opaque_type embb_mutex_t;
+
+/**
+ * Opaque type representing a spinlock.
+ */
+typedef opaque_type embb_spinlock_t;
+#else
+/**
+ * Spinlock type, treat as opaque.
+ */
+typedef struct {
+  embb_atomic_int atomic_spin_variable_;
+} embb_spinlock_t;
 #endif /* DOXYGEN */
 
 /**
@@ -147,6 +160,89 @@ void embb_mutex_destroy(
   /**< [IN/OUT] Pointer to mutex */
   );
 
+/**
+ * Initializes a spinlock
+ *
+ * \pre \c spinlock is uninitialized
+ * \post \c spinlock is initialized
+ * \return EMBB_SUCCESS if spinlock could be initialized \n
+ *         EMBB_ERROR otherwise
+ * \memory (Potentially) allocates dynamic memory
+ * \notthreadsafe
+ * \see embb_spinlock_destroy()
+ */
+int embb_spin_init(
+  embb_spinlock_t* spinlock
+  /**< [OUT] Pointer to spinlock */
+  );
+
+/**
+ * Spins until the spinlock can be locked and locks it.
+ *
+ * \note This method yields the current thread in regular,
+ *       implementation-defined intervals.
+ *
+ * \pre \c spinlock is initialized \n
+ * \post If successful, \c spinlock is locked.
+ * \return EMBB_SUCCESS if spinlock could be locked. \n
+ *         EMBB_ERROR if an error occurred.
+ * \threadsafe
+ * \see embb_spinlock_try_lock(), embb_mutex_unlock()
+ */
+int embb_spin_lock(
+  embb_spinlock_t* spinlock
+  /**< [IN/OUT] Pointer to spinlock */
+  );
+
+/**
+ * Tries to lock the spinlock and returns if not successful.
+ *
+ * \pre \c spinlock is initialized
+ * \post If successful, \c spinlock is locked
+ *
+ * \return EMBB_SUCCESS if spinlock could be locked \n
+ *         EMBB_BUSY if spinlock could not be locked \n
+ *         EMBB_ERROR if an error occurred
+ * \threadsafe
+ * \see embb_spin_lock(), embb_spin_unlock()
+ */
+int embb_spin_try_lock(
+  embb_spinlock_t* spinlock,
+  /**< [IN/OUT] Pointer to spinlock */
+  unsigned int max_number_spins
+  /**< [IN] Maximal count of spins to perform, trying to acquire lock. Note that
+   * passing 0 here results in not trying to obtain the lock at all.
+   */
+  );
+
+/**
+ * Unlocks a locked spinlock.
+ *
+ * \pre \c spinlock has been locked by the current thread.
+ * \post If successful, \c spinlock is unlocked.
+ * \return EMBB_SUCCESS if the operation was successful \n
+ *         EMBB_ERROR otherwise
+ * \threadsafe
+ * \see embb_spin_lock(), embb_spin_try_lock()
+ */
+int embb_spin_unlock(
+  embb_spinlock_t* spinlock
+  /**< [IN/OUT] Pointer to spinlock */
+  );
+
+/**
+ * Destroys a spinlock and frees its resources.
+ *
+ * \pre \c spinlock has been initialized
+ * \post \c spinlock is uninitialized
+ * \notthreadsafe
+ * \see embb_spin_init()
+ */
+void embb_spin_destroy(
+  embb_spinlock_t* spinlock
+  /**< [IN/OUT] Pointer to spinlock */
+  );
+
 #ifdef __cplusplus
 } /* Close extern "C" { */
 #endif

base_c/include/embb/base/c/thread.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/thread_specific_storage.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/include/embb/base/c/time.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/src/atomic.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/src/condition_variable.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/src/core_set.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/src/counter.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/src/duration.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/src/internal/thread_index.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -128,6 +128,20 @@ void embb_internal_thread_index_set_max(unsigned int max) {
   *embb_max_number_thread_indices() = max;
 }
 
+/**
+ * \pre the calling thread is the only active thread
+ *
+ * \post the thread indices count and calling thread index is reset
+ */
 void embb_internal_thread_index_reset() {
+  /** This function is only called in tests, usually when all other threads
+   * except the main thread have terminated. However, the main thread still has
+   * potentially stored its old index value in its thread local storage,
+   * which might be assigned additionally to another thread (as the counter is
+   * reset), which may lead to hard to detect bugs. Therefore, reset the thread
+   * local thread id here.
+   */
+  embb_internal_thread_index_var = UINT_MAX;
+
   embb_counter_init(embb_thread_index_counter());
 }

base_c/src/log.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -59,7 +59,7 @@ void embb_log_set_log_function(
   embb_log_global_log_function = func;
 }
 
-static void embb_log_write_internal(
+void embb_log_write_internal(
   char const * channel,
   embb_log_level_t log_level,
   char const * message,
@@ -75,18 +75,20 @@ static void embb_log_write_internal(
       log_context = (void*)stdout;
     }
     switch (log_level) {
-    case EMBB_LOG_LEVEL_INFO:
-      log_level_str = "INFO ";
-      break;
     case EMBB_LOG_LEVEL_ERROR:
       log_level_str = "ERROR";
       break;
+    case EMBB_LOG_LEVEL_WARNING:
+      log_level_str = "WARN ";
+      break;
+    case EMBB_LOG_LEVEL_INFO:
+      log_level_str = "INFO ";
+      break;
     case EMBB_LOG_LEVEL_TRACE:
       log_level_str = "TRACE";
       break;
 
     case EMBB_LOG_LEVEL_NONE:
-    case EMBB_LOG_LEVEL_WARNING:
     default:
       log_level_str = "     ";
       break;

base_c/src/memory_allocation.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/src/mutex.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -25,6 +25,7 @@
  */
 
 #include <embb/base/c/mutex.h>
+#include <embb/base/c/thread.h>
 #include <assert.h>
 
 #include <embb/base/c/internal/unused.h>
@@ -115,3 +116,59 @@ void embb_mutex_destroy(embb_mutex_t* mutex) {
 }
 
 #endif /* EMBB_PLATFORM_THREADING_POSIXTHREADS */
+
+int embb_spin_init(embb_spinlock_t* spinlock) {
+  // For now, store the initial value. In the future will use atomic init
+  // function (as soon as available).
+  embb_atomic_store_int(&spinlock->atomic_spin_variable_, 0);
+  return EMBB_SUCCESS;
+}
+
+int embb_spin_lock(embb_spinlock_t* spinlock) {
+  int expected = 0;
+  int spins = 1;
+
+  // try to swap the
+  while (0 == embb_atomic_compare_and_swap_int(
+    &spinlock->atomic_spin_variable_, &expected, 1)) {
+    if (0 == (spins & 1023)) {
+      embb_thread_yield();
+    }
+    spins++;
+    // reset expected, as CAS might change it...
+    expected = 0;
+  }
+  return EMBB_SUCCESS;
+}
+
+int embb_spin_try_lock(embb_spinlock_t* spinlock,
+  unsigned int max_number_spins) {
+  if (max_number_spins == 0)
+    return EMBB_BUSY;
+
+  int expected = 0;
+  while (0 == embb_atomic_compare_and_swap_int(
+    &spinlock->atomic_spin_variable_,
+    &expected, 1)) {
+    max_number_spins--;
+    if (0 == max_number_spins) {
+      return EMBB_BUSY;
+    }
+    expected = 0;
+  }
+
+  return EMBB_SUCCESS;
+}
+
+int embb_spin_unlock(embb_spinlock_t* spinlock) {
+  int expected = 1;
+  return embb_atomic_compare_and_swap_int(&spinlock->atomic_spin_variable_,
+    &expected, 0) ?
+  EMBB_SUCCESS : EMBB_ERROR;
+}
+
+void embb_spin_destroy(embb_spinlock_t* spinlock) {
+  // for now, doing nothing here... in future, will call the respective
+  // destroy function for atomics...
+  EMBB_UNUSED(spinlock);
+}

base_c/src/thread.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/src/thread_specific_storage.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/src/time.c

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/test/alloc_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/test/alloc_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/test/condition_var_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/test/condition_var_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/test/core_set_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/test/core_set_test.h

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:

base_c/test/counter_test.cc

 /*
- * Copyright (c) 2014-2015, Siemens AG. All rights reserved.
+ * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met: