TAO (The ACE ORB)

TAO (The ACE ORB)
Name	TAO (The ACE ORB)
Developer	DOCGroup
Released	1997
Latest release	1.8.5
Programming language	C++
Operating system	Cross-platform
License	BSD-like

TAO (The ACE ORB) TAO (The ACE ORB) is a real-time, CORBA-compliant open-source ORB implemented in C++ that emphasizes deterministic behavior for distributed, high-performance systems. It integrates with ACE and other middleware to provide low-latency, scalable interoperability suited to avionics, telecommunications, and embedded systems. TAO's design addresses real-time scheduling, quality of service, and fault tolerance through configurable policies and pluggable components.

Overview

TAO is built on a foundation combining ideas from Berkeley Software Distribution, Sun Microsystems, Object Management Group, Prentice Hall, Bjarne Stroustrup, Andrew S. Tanenbaum, Real-Time Specification for Java, POSIX, Intel Corporation, ARM Holdings, VxWorks, LynxOS, QNX Software Systems, Linux Foundation, Microsoft Corporation, Apple Inc., FreeBSD, NetBSD, OpenBSD, AdaCore, Wind River Systems, RTEMS Project, NASA, European Space Agency, Naval Research Laboratory, Defense Advanced Research Projects Agency, General Dynamics, Lockheed Martin, Northrop Grumman, Raytheon Technologies, Thales Group, Airbus, Boeing.

Architecture and Features

TAO's architecture draws on patterns and components influenced by Common Object Request Broker Architecture, CORBA, Distributed Computing Environment, OMG IDL, Portable Object Adapter, Interoperable Object Reference, Internet Engineering Task Force, Transmission Control Protocol, User Datagram Protocol, Real-time Transport Protocol, Extensible Markup Language, Simple Object Access Protocol, Representational State Transfer, Google, Facebook, Amazon (company), Netflix, Oracle Corporation, IBM, SAP SE, Siemens, Schneider Electric, General Electric, ABB Group, Siemens AG, Honeywell International, Emerson Electric.

Key features include pluggable protocols and threading models influenced by ACE (Adaptive Communication Environment), Reactor pattern, Proactor pattern, POSIX threads, Win32 API, Boost C++ Libraries, STLPort, C++ Standard Library. TAO supports real-time QoS policies, priority mapping, and ORB strategies inspired by Real-Time CORBA, RT-CORBA, OMG Real-time CORBA, Fault Tolerant CORBA, CORBA Component Model, Data Distribution Service, OMG DDS.

Implementation and Performance

Implementation details reflect optimizations and techniques from GCC, Clang (compiler), Microsoft Visual C++, Intel C++ Compiler, GNU Make, CMake, Autoconf, Automake, LLVM Project, Valgrind, gdb, perf (Linux tool), DTrace, SystemTap, OProfile, Intel VTune.

TAO achieves low latency and high throughput using strategies and algorithms related to Priority Inversion, Rate Monotonic Scheduling, Earliest Deadline First, Admission Control, Backpressure (computer networking), Zero-copy, Memory Pooling, Lock-Free Programming, Compare-and-Swap, Read-copy-update, Cache Coherence Protocol, NUMA (Non-Uniform Memory Access), Hyper-Threading, Simultaneous Multithreading, Symmetric Multiprocessing, ARM Cortex-A, Intel Xeon, IBM POWER.

Use Cases and Applications

TAO has been employed in domains and projects associated with Automatic Dependent Surveillance–Broadcast, Air Traffic Control, Integrated Modular Avionics, Joint Strike Fighter program, F-35 Lightning II, Aegis Combat System, Patriot (missile), Tactical Data Link, MIL-STD-1553, ARINC 653, European Passenger Name Record, Railway Signalling, Positive Train Control, Smart Grid, IEC 61850, SCADA, Distributed Simulation, High Frequency Trading, Financial Information eXchange, Bloomberg L.P., Thomson Reuters, Telecommunications, 3GPP, LTE (telecommunication), 5G NR, Cisco Systems, Juniper Networks, Ericsson, Nokia, Siemens Mobility.

Development History

TAO originated as part of academic and industrial collaborations influenced by efforts at University of California, Berkeley, Carnegie Mellon University, Washington University in St. Louis, Washington University School of Medicine, Iona Technologies, Princeton University, Massachusetts Institute of Technology, Stanford University, University of Illinois Urbana-Champaign, University of Cambridge, Imperial College London, ETH Zurich, École Polytechnique Fédérale de Lausanne, Tokyo Institute of Technology, Tsinghua University, KTH Royal Institute of Technology, Seoul National University, KAIST, Infosys, Tata Consultancy Services, IBM Research, Bell Labs, AT&T Laboratories Research, Hewlett-Packard Laboratories.

Major milestones were aligned with standards and events such as OMG Formal/Adopted Specifications, CORBA 2.0, CORBA 3.0, Real-Time CORBA 1.0, Embedded Systems Conference, Interop (conference), Embedded World, DEF CON, RSA Conference, IEEE Real-Time Systems Symposium, ACM SIGPLAN, ACM SIGCOMM, USENIX Annual Technical Conference.

Related Projects and Standards

Related middleware and standards include ACE (software) , CIAO (Component-Integrated ACE ORB), DAnCE (Deployment And Configuration Engine), OpenDDS, RTI Connext, PrismTech OpenSplice, ZeroC Ice, Apache Thrift, gRPC, Protocol Buffers, CORBA Components, OMG Services, ISO/IEC 9899, C++11, C++14, C++17, POSIX.1-2008, ARINC 653-1, DO-178C, DO-331, IEC 61508, ISO 26262, AUTOSAR, FACE (Future Airborne Capability Environment), OSEK/VDX.

Category:Middleware