| 
 PACE OverviewPACE is an OS abstraction layer designed for lightweight
            and/or verified systems. It offers these benefits: 
            
              A strict POSIX.1-like, low-level interface. Its
                interface is "POSIX compatible"; by that we mean as
                close to POSIX.1 as it can be, given that PACE is not
                an operating system. And, to avoid name conflicts with
                OS APIs, all low-level PACE function names have
                the pace_ prefix.
              
              The low-level interface is a C file, so that it can be
                used in both C and C++ programs.
              
              The low-level interface is partitioned into multiple
                files, one per POSIX.1 section.
               
 ACE uses PACEThe ADAPTIVE Communication Environment
            (ACE)
            is a freely available, open-source, object-oriented
            (OO)
            framework that implements many core design patterns for
            concurrent communication software.
           ACE is currently built on an
            
              OS Adaptation Layer that abstracts away specific
            computer architecture / platform dependencies therfore
            allowing ACE to be portable across any platform that the
            adaptation layer supports.
           ACE also forms the foundation upon which
            TAO
            is built. The combination of implementing TAO (adding
            specific functionality to ACE) and the ever shifting sands
            of vendor-specific operating systems has grown the ACE
            adapatation layer from a small core of critial functions to
            over 30,000 lines of interdependent code. The development of
            TAO tied in with requests from our sponsors as well as
            suggestions from the development community at large
            contributed to our decision to re-engineer ACE' adaptation
            layer. PACE is one part of this effort.
           
 PACE ObjectivesSome objectives of this phase of ACE' development (PACE)
            include:
           
            
              ACE Developers: Make the low level abstraction
                layer code more maintainable.(reduce file size and file interdependence - improve 
                  code modularity)
              ACE Users: Reduce ACE' footprint.(this is not a one-step task by any stretch of the
                  imagination, but we will begin breaking out the code
                  into separate files - allowing developers the
                  opportunity option to compile and link specific
                  object files to their executables instead of the
                  entire ACE adaptation layer library)
              ACE Users: Update the adaptation layer to be
                POSIX compliant.(see next)
              ACE Users: Split the adaptation layer to support
                both a C API (PACE) as well as a set of
                C++ wrapper classes (ACE_OS) allowing
                both C & C++ developers to call
                directly into the low level API.(encapslate POSIX and system calls in C
                  wrappers and re-write the (ACE_OS) adaptation layer to
                  transparently call into the POSIX emulation API
                  (PACE))
              ACE Users: ACE will not change its public
                interface, it will only add low level C
                operations to its repertoire. As is obvious, software
                built on this adaptation layer is portable across the
                various platforms that ACE supports. This provides
                backward compatilibity for people already using the
                current C++ (ACE_OS) adaptation layer of 
                ACE. This is an open-source project maintained by: 
           | 
      
        | 
 Additional information regarding
            ACE
            and
            PACE
            and
            TAO
            is available as well as a
            
              full source distribution of TAO + ACE + PACE.
           If you have any questions, suggestions or contributions
            regarding PACE, please
            write
            to us or subscribe to the pace-users mailing list
            (send email to
            
              majordomo@cs.wustl.edu
            with "subscribe pace-users" in the body,
            not the subject line ;-)
           
 
              Doc Group 
            
            
Last modified: Sun May 13 14:45:55 CDT 2001
           |