developed at the IBM Almaden Research Center, which uses atomic tran.sactions as a unified failure recovery mechanism for a client-server structured distributed system. Transactions allow failure atomicity for related activities at a single server or at a number of independent servers. Rather than bundling transaction management into a dedicated language or recoverable object manager, Quicksilver exposes the basic commit protocol and log recovery primi-tives, allowing clients and servers to tailor their recovery techniques to their specific needs. Servers can implement their own log recovery protocols rather than being required to use a system-defined protocol. These decisions allow servers to make their own choices to balance simplicity, efficiency, and recoverability. Categories and Subject Descriptors: D.4.3 [Operating Systems]: File System Management-distrib-uted file systems; file organization; maintenance; D.4.5 [Operating Systems]: Reliability-FauZt-tolerance; checkpoint/restart; H.2.4 [Database Management]: Systems--distributed systems; trun.s-action processing

This paper gives a survey of all common transparent distributed systems. We distinguish between Distributed File Systems (DFS) and Distributed Operating Systems (DOS). Our overview is focussed on systems providing at least access or location transparency. The paper is organized as follows: The introduction offers definitions of the features of each transparent distributed system as well as the services it is able to provide. We also propose a catalog of criteria that enables us to compare different systems independently of implementation done. The main entries we make are heterogeneity of the system's environment, communication strategy, as well as naming and security issues. Finally, we examine the reliability and availability of the separate systems and the way these issues are achieved. The following section consists of the survey. The description of each system is organized as follows: First, we introduce the main goal the system was developed for, the classification of th...

The C Threads package allows parallel programming in C under the MACH operating system. The package provides multiple threads of control for parallelism, shared variables, mutual exclusion for critical sections, and condition variables for synchronization of threads. This research was sponsored by the Defense Advanced Research Projects Agency (DoD), ARPA order 4864, monitored by the Space and Naval Warfare Systems Command under contract N00039-84-C-0467. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing official policies, either expressed or implied, of the Defense Advanced Research Projects Agency or of the U.S. Government. 1 1. Introduction MACH provides a set of low-level, language-independent primitives for manipulating threads of control [3]. The C Threads package is a run-time library that provides a C language interface to these facilities [1]. The constructs provided are similar to those found in Mesa ...

This report was prepared for the SEI Joint Program Office HQ ESC/AXS 5 Eglin Street Hanscom AFB, MA 01731-2116 The ideas and findings in this report should not be construed as an official DoD position. It is published in the interest of scientific and technical information exchange. FOR THE COMMANDER (signature on file) Thomas R. Miller, Lt Col, USAF, SEI Joint Program Office This work is sponsored by the U.S. Department of Defense. Copyright 1987 by Carnegie Mellon University. Permission to reproduce this document and to prepare derivative works from this document for internal use is granted, provided the copyright and \`No Warranty\' statements are included with all reproductions and derivative works. Requests for permission to reproduce this document or to prepare derivative works of this document for external and commercial use should be addressed to the SEI Licensing Agent. NO WARRANTY THIS CARNEGIE MELLON UNIVERSITY AND SOFTWARE ENGINEERING INSTITUTE MATERIAL IS FURNISHED ON AN \`AS-IS\' BASIS. CARNEGIE MELLON UNIVERSITY MAKES NO WARRANTIES OF ANY KIND, EITHER EXPRESSED OR IMPLIED, AS TO ANY MATTER INCLUDING, BUT NOT LIMITED TO, WARRANTY OF FITNESS FOR PURPOSE OR MERCHANTIBILITY, EXCLUSIVITY, OR RESULTS OBTAINED FROM USE OF THE MATERIAL. CARNEGIE MELLON UNIVERSITY DOES NOT MAKE ANY WARRANTY OF ANY KIND WITH RESPECT TO FREEDOM FROM PATENT, TRADEMARK, OR COPYRIGHT INFRINGEMENT. This work was created in the performance of Federal Government Contract Number F19628-95-C-0003 with Carnegie Mellon University for the operation of the Software Engineering Institute, a federally funded research and development center. The Government of the United States has a royalty-free government-purpose license to use, duplicate, or disclose the work, in whole or in part and in any mann...

The C Threads package allows parallel programming in C under the MACH operating system. The package provides multiple threads of control for parallelism, shared variables, mutual exclusion for critical sections, and condition variables for synchronization of threads. This research was sponsored by the Defense Advanced Research Projects Agency (DoD), ARPA order 4864, monitored by the Space and Naval Warfare Systems Command under contract N00039-84-C-0467. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing official policies, either expressed or implied, of the Defense Advanced Research Projects Agency or of the U.S. Government. 1 1. Introduction MACH provides a set of low-level, language-independent primitives for manipulating threads of control [3]. The C Threads package is a run-time library that provides a C language interface to these facilities [1]. The constructs provided are similar to those found in Mesa...