CHANGELOG.md

Embedded Multicore Building Blocks (EMB²)
=========================================


Version 0.4.0
-------------

### Features:
  - Added C++ wrapper and tests for logging facilities

### Changes and improvements:
* Base:
  - Changed assertions on user input into checks with error code return
  - Improved checks and documentation in time, duration, and log
  - Added exceptions when errors occur that depend on user input
  - Added volatile keyword to member of internal atomic struct
  - Changed spin lock implementaion to yield every 1024 spins
* MTAPI:
  - Created defines for MTAPI version
  - Added missing fields in mtapi_info_t structure, in particular organization ID
  - Changed reporting of number of domains and nodes to "unlimited"
  - Changed group deleted and task state attributes to atomic
  - Enabled reuse of main thread, which is configurable via node attributes
  - Set result to MTAPI_NULL on error in mtapi_group_wait_any
  - Network plugin:
    - Disabled adress reuse for listening socket
	- Solved problem with port reuse on Linux
    - Set values to zero on failure for buffer pop operations
	- Improved protocol for better error handling
	- Changed signaling of task completion to atomic
	- Introduced tagging of operations
	- Improved task cancellation support
	- Changed sending of result messages to complete ones only
* Tasks:
  - Added function to query the maximum number of queues
  - Added function to query the task limit
  - Changed initalization in the implementaion of ExecutionPolicy
  - Made creation of groups and queues thread-safe as documented
* Dataflow:
  - Added connection chain test
  - Added connection checks in outputs
  - Added check for cycles in graph
  - Added default token count to network
  - Changed internal exceptions to assertions
  - Changed return type of operator >> to allow for connection chains
  - Changed semantics of source process (emit tokens only if function returns true)
  - Changed initalization so that the number of slices can now be set at runtime
  - Added automatic computation of maximum number of slices
  - Changed done sync to atomics
  - Removed Network::Make for simpler usage
  - Added Network:IsValid to check network for errors
* Containers:
  - Added missing PT_ASSERT calls in hazard pointer test
* All:
  - Resolved several Codesonar warnings

### Bug fixes:
* Base:
  - Fixed uninitialized variables in failure cases
  - Changed implementation of atomic store on Windows to ensure sequential consistency
  - Fixed memory leak in test for thread-specific storage
* MTAPI:
  - Fixed bug causing mtapi_task_wait to hang when a task was cancelled before it was running
  - Fixed potential null pointer dereferences
  - Fixed issue with AMD APP SDK in OpenCL plugin
  - Fixed race condition in OpenCL plugin
* Dataflow:
  - Fixed bug with global network instances in MTAPI scheduler
  - Fixed initalization of input
  - Fixed memory leaks
* Containers:
  - Fixed uninitialized variables in test

### Build system:
- Moved MTAPI plugins to folder mtapi_plugins_c
- Removed dependency on installed OpenCL SDK, adapted test to succeed when OpenCL is unavailable
- Resolved MSVC warnings and build problem

### Documentation:
- Changed documentation to reflect that atomics are initialized to zero by default
- Improved documentation for functions without error code return
- Updated year in license headers and tutorial
- Updated documentation of spinlock implementations
- Changed encoding of COPYING.md file to UTF-8
- Adapted tutorial and examples to reflect changes to dataflow_cpp
- Revised README.md to reflect new directory structure and removed UTF8 BOM


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
-------------

### Features:
- None

### Changes and improvements:
- Removed one function argument from algorithms::Invoke
- Added "explicit" specifier to base type constructor of Atomic<BaseType*>
- Added "const" qualifier to dereference operator and member access operator of AtomicPointer<>
- Changed AtomicBase<>::CompareAndSwap to atomically return expected value
- Replaced constant in dataflow_cpp_test_simple.cc with corresponding macro
- Added initialization of atomic variable in hazard_pointer_test.cc to avoid warning with GCC 5.1
- Changed initial value of allocated_object_from_different_thread
- Added tests for ID Pool and check for memory leaks
- Updated unit test for the UniqueLock::Swap

### Bug fixes:
- Fixed implementation of ID pool (provided fewer elements than specified by capacity)
- Fixed unsigned overflow bug in timed wait function of condition variables
- Fixed implementation of UniqueLock::Swap

### Build system:
- Improved CMake output for automatic initialization option
- Fixed cpplint and unsigned/signed warnings

### Documentation:
- Fixed documentation of UniqueLock class
- Updated README file


Version 0.3.0
-------------

### Features:
* MTAPI:
  - Implemented action plugin API
  - Implemented load balancing for distributed/heterogeneous systems
  - Implemented OpenCL action plugin
  - Implemented network action plugin
  - Added support for distributed/heterogeneous systems

### Changes and improvements:
* Base:
    - Moved tick types to internal namespace and added duration typedefs
* MTAPI:
  - Added multi-instance task support and test
  - Improved notification of worker threads
  - Moved interface for homogeneous systems to tasks_cpp
* Algorithms:
  - Restricted partitioners to random access iterators
  - Added unit tests for partitioners on large ranges
  - Refactored to use tasks_cpp
* Dataflow:
  - Removed spinlocks
  - Simplified registration of processes (only sources need to be added)
  - Increased number of task queues in unit test
  - Added assertion in unit test
  - Improved exception handling
  - Removed stray include
  - Refactored to use tasks_cpp

### Bug fixes:
- Fixed unit test for dataflow_cpp
- Fixed wait-free SPSC queue

### Build system:
- Fixed compilation for newer CMake Versions (>= 3.1)
- Changed task test to avoid Jenkins timeout
- Changed CMakeLists to avoid error if policy is unknown
- Added mtapi_network_c and mtapi_opencl_c to root CMakeLists
- Added tasks_cpp to test scripts / batch file
- Fixed cpplint warnings

### Documentation:
- Extended tutorial and examples regarding support for distributed/heterogeneous systems including plugins and new task interface
- Added Doxygen documentation for mtapi_opencl_c and mtapi_network_c
- Added Doxygen documentation to mtapi_ext.h
- Updated README and removed limitation to homogeneous systems
- Added missing concurrency tags in mtapi_cpp


Version 0.2.3
-------------

### Features:
- None

### Changes and improvements:
- Changed use of partitioners in ForEach, Reduce, Scan, Count, and MergeSort
- Added guard definition to QuickSort and MergeSort requiring random access iterators as inputs
- Unified behavior of algorithms on empty input
- Cleaned up MergeSort and Scan
- Extended computation of number of cores to take into account affinities
- Changed MTAPI_CHECK_STATUS in examples to use exit() instead of abort()
- Added overload for std::exception::what() in embb::base::Exception
- Added missing include in execution_policy.cc
- Added tests for Thread::ID (base_cpp), ExecutionPolicy (mtapi_cpp), and error cases in mtapi_c
- Added tests on empty and negative input ranges in algorithms

### Bug fixes:
- Fixed freeing of temporary buffer in MergeSortAllocate
- Fixed minor bugs in mtapi_c
- Fixed paths in Doxyfile.in template

### Build system:
- Added option to CMake to toggle automatic initialization of MTAPI C++ interface
- Changed run_tests_cygwin script to work with /bin/sh
- Modified create_tarball.sh script for completely automatic tarball creation
- Removed cppcheck warnings
- Removed cpplint warnings
- Updated partest

### Documentation:
- Added paragraphs in tutorial and README regarding performance impact of automatic initialization of MTAPI C++ interface
- Removed automatic collapsing of trees in Doxygen documentation due to incompatibility with latest versions of Doxygen
- Modified reference manual to consistently use function object concept
- Added description of default node attributes in mtapi_c and fixed typo in mtapi_cpp documentation
- Modified paragraph on documentation in README and fixed typo


Version 0.2.2
-------------

### Features:
- None

### Changes and improvements:
- Added checks for memory leaks in tests
- Added block size support in MergeSort
- Renamed all platform specific defines to EMBB_PLATFORM_*
- Changed all checks for platform specific defines to checks for EMBB_* defines
- Replaced C++11 initializer lists in examples with C++03 compliant statements
- Extended unit tests for MPMC queue with checks for relative order
- Added check for result of pthread_attr_destroy
- Added assert in embb_tss_get
- Moved ExecutionPolicy from algorithms to mtapi_cpp, removed Affinity

### Bug fixes:
- Fixed 64bit problem in atomics
- Fixed bug in dataflow_cpp causing network to hang
- Fixed bug in conversion of core_set
- Fixed fetch-and-add implementation to support armv7-a
- Fixed missing freeing of mutex attributes in case of error
- Fixed bug where closure was allocated with Allocation::New but deleted with operator delete
- Fixed inconsistent naming of unit test cases
- Fixed memory allocation in hazard pointer implementation by replacing calls to new and delete with EMB²-specific functions
- Fixed memory leak in tests for containers
- Fixed affinity implementation for FreeBSD

### Build system:
- Removed cppcheck warnings
- Removed cpplint warnings

### Documentation:
- Improved documentation of default values and priorities
- Revised template argument names in base_cpp and containers_cpp
- Moved ExecutionPolicy to CPP_MTAPI and Identity to CPP_ALGORITHMS Doxygen group
- Fixed description of token limit in tutorial
- Added Clang support to README
- Mentioned the ability to cross compile in README
- Added link to release files in README
- Minor corrections in README
- Updated copyright notice
- Changed year in tutorial.tex to 2015


Version 0.2.1
-------------

### Features:
- Added embb_core_count_available() implementation for FreeBSD.

### Changes and improvements:
- None

### Bug fixes:
- Fixed implementation of atomic operations on ARM.
- Fixed bug in HelpScan routine of hazard pointer implementation.
- Replaced inclusion of non-standard header malloc.h with stdlib.h.

### Build system:
- Added initial support for Clang.
- Added initial support for Travis.
- Fixed "Policy CMP0026 is not set" warning of CMake >= 3.0.2.
- Made build independent of build-dir / source-dir location.
- Fixed remaining GCC, Clang, MSVC, and cpplint warnings.
- Replaced /bin/bash with /usr/bin/env bash in scripts.
- Added executable flag to shell scripts.
- Omitted Doxygen "Makefiles" from tarball.
- Included patchlevel in name of installation directory on Linux.
- Added LaTeX .bbl and .blg files to ignore list.

### Documentation:
- Updated README file, created CHANGELOG file, and added markdown support.
- Corrected license in COPYING file (BSD 2-clause).
- Changed default Doxygen level for API to two.
- Added check for Doxyfile.in (if not present, do not add Doxygen target).
- Added PDF image of building blocks and updated tutorial.tex.
- Fixed typos and wording.


Version 0.2.0
-------------

- Initial version of open source release