Sun Microsystems, IBM. JavaOS for Business, Reference Manual, Version 2.1, Oct. 1998  Home/Search   Document Not in Database   Summary   Related Articles   Check

....mechanisms. Java popularized a protection mechanism that is based on a combination of type safe intermediate code and load time program verification. Several other research groups have been building Javabased operating systems: Sun s JavaOS [14] which was later replaced by JavaOS for Business [18], JN [16] JKernel [11] KaffeOS [2] and Joust [9] But they are either limited by a monolithic structure or are built upon a full featured OS and JVM. Furthermore, no performance figures for OS related functionality are published. KaffeOS and JKernel are two projects that try to overcome the ....

Sun Microsystems, IBM. JavaOS for Business, Reference Manual, Version 2.1, Oct. 1998

....EWSD, Ericsson AXE, Nortel Cellular and other digital switching systems. Each agent interacts with its respective manager in order to deliver events to the SIS database and receive commands from SisTerm. Agents and managers use extensively RPC. In addition, the EWSD agent uses SunLink X. 25 [18, 19, 20] to implement the low level communication with the switching system. SunLink X.25 provides a socket based API that allows developers to interact with X.25 devices. Monitor is the software that implements the supervision of proprietary equipments of TELEMIG s plant. It communicates with a bus of ....

Sun Microsystems, USA.SunLink X.25: Reference Manual, 1995.

....that each row selected from employees table should be joined with rows from departments table that have the same department values. The P.Y entry shows that the corresponding manager value is to be printed. Finally, in one approach to graphical interfaces (similar to the one used in SunSimplify [87]) the user first selects the database tables to be used in the query (employee table and manager table in our example) Each selected table appears on the screen as a frame consisting of attribute slots. The user can then fill in attribute slots by typing on the keyboard, he she can join ....

Sun Microsystems Inc. SunSimplify 2.0 Reference Manual, 1989.

....file system calls, passing them out to the servers. This module is built on the Stackable Layers framework, which is described below. Finally, an object oriented programming interface is provided using the ILU system. 3.1 VFS and Stackable Layers Our implementation platform is SunOS 4.1. 1 [Sun90], which is a variant of UNIX [RT74] As with most modern versions of UNIX, SunOS uses the Virtual File System (VFS) Kle86] The key concept of VFS is the vnode (virtual node) The vnode is an attempt to provide an abstract data type for the basic kernel representation of a file. Each vnode has a ....

....Extensible Operating Systems A number of approaches to extensibility have been tried. As described previously, early attempts to add extensibility interfaces to the operating system included streams [Rit84] and dynamically loaded device drivers. The later is included in systems such as SunOS 4. x [Sun90] and Chorus [Arm91] Both streams and loadable drivers originally arose from the need to deal with hardware heterogeneity. These two examples are illustrative of somewhat different approaches to extension. Streams are an attempt to modularize and restructure serial I O. Similar initiatives were ....

Sun Microsystems, Inc. SunOS 4.1.1 Reference Manual, March 1990.

....operation does not require an expensive kernel call. Furthermore, lightweight threads enable an application program to use a thread management system, most appropriate to the problem domain. Mach Cthreads [60, 173, 212] the University of Washington threads [165, 9] SunOS LWP and threads [113, 127, 189], are a few popular lightweight thread implementations. A lightweight thread generally executes in the context of a middleweight or a heavyweight thread. Specifically, the threads library schedules lightweight threads on top of middleweight or heavyweight threads, which in turn are scheduled by ....

Sun Microsystem Inc. Sun OS 4.0 Reference Manual, November 1987. Section 3L.

....personnel are responsible for those machines. Now that we have reached a fairly stable 44 Lisa IV Fall 90 Manheimer, Warsaw, Clark, and Rowe The Depot . framework we intend to branch out a bit. # We need to investigate newly available technologies, e.g. translucent file systems[4], and evaluate how we can use them to improve on the simplicity and transparency of the system. Acknowledgments Disclaimer This work was jointly funded by the NIST Automated Manufacturing Research Facility (AMRF, project 734 3385) and Scientific and Technical Research Services (STRS, project ....

Sun Microsystems Incorporated, "TFS", SunOS 4.1 Reference Manual, Vol 2, p. 1494.

....dictated by this abstract arrangement. Thus it provides both the public interface to the application and the internal interface between its components. 6 arch. is a holdover from early depot days; plat. or platform. probably would have been more appropriate. 7 SunOS exportfs (8) man page[1]. 40 Lisa IV Fall 90 Manheimer, Warsaw, Clark, and Rowe The Depot . arch src include lisp . depot (i.e. depot anApp src ) anApp bin lib . Figure 2 Abstract Client View of anApp The Origin Client Mapping The mapping between the origin view and the client view is the crux ....

....and they can be divided between combinations of fileservers. By establishing alternative copies of entire origin hierarchies we provide the basis for both staged release of software upgrades 10 Loopback mounts must be last in etc fstab; see the warnings section of the SunOS 4 mount(8) man page[1]. 42 Lisa IV Fall 90 Manheimer, Warsaw, Clark, and Rowe The Depot . and fallback redundancy to increase reliability by reducing critical points of failure. Multiple .primary Origins Provide Redundancy By creating multiple .primary origin hierarchies for crucial applications we are able ....

Sun Microsystems Incorporated, SunOS 4.1 Reference Manual.

....previous example with X as the intrudercontrolled system and observe the actions performed by the intruder. 1. X sends a number of probe packets to B and A, trying to determine whether there exists any kind of trust relationship among hosts A and B. Commands such as showmount, rpcinfo, and finger [18] were utilized for this purpose. 2. X sends a number of TCP SYN packets, i.e. packets containing the SYN flag set with some arbitrary initial sequence numbers to host A. However, the source IP address of these packets have been forged, so that they appear to be coming from some host which does ....

....responds by sending a SYN ACK packet, and performs a state transition to the SYN RCVD state. ffl Kongur does not send any other packet to Ararat. Ararat remains in the SYN RCVD state until the connection establishment timer expires. The sequence of packets, as observed by the output of tcpdump [18] is as follows. 23:26:51.475103 Kongur.32781 Ararat.ftp: S 4188491776:4188491776(0) win 8760 mss 1460 (DF) 23:26:51.477716 Ararat.ftp Kongur2.32781: S 1382592000:1382592000(0) ack 4188491777 win 4096 mss 1460 We observe that port 32781 of Kongur sends a SYN packet to the ftp port of ....

SUN MICROSYSTEMS INC., SunOS 5.4 Reference Manual, Mountain View, CA, 1994.

....be available where the problems are on Unix workstations. To allow such tools to be constructed, a kernel must contain some facility that gives user level programs access to raw, unprocessed network traffic. 7] Most of today s workstation operating systems contain such a facility, e.g. NIT[10] in 3 This is a preprint of a paper to be presented at the 1993 Winter USENIX conference, January 25 29, 1993, San Diego, CA. y This work was supported by the Director, Office of Energy Research, Scientific Computing Staff, of the U.S. Department of Energy under Contract No. ....

....be filtered in place (e.g. where the network interface DMA engine put it) rather than copied to some other kernel buffer before filtering. Thus, if the packet is not accepted, only those bytes that were needed by the filtering process are referenced by the host. In contrast, SunOS sSTREAMS NIT [10] copies the packets before filtering and as a result suffers a performance degradation. The STREAMS packet filter module (nit pf(4M) sits on top of the packet capture module (nit if(4M) Each packet received is copied to an mbuf, and passed off to NIT, which then allocates a STREAMS message ....

Sun Microsystems Inc. NIT(4P); SunOS 4.1.1 Reference Manual. Mountain View, CA, Oct. 1990. Part Number: 8005480 -10.

....system code module fl fl Appropriate system services for system code modules fl Avoidance of infinite system service usage fl 6 Discussions The comparisons with previous work is summarized in Table 5. Recent UNIX variants implement the Loadable Kernel Module (LKM) mechanism [Sun Microsystems91, NetBSD project94] which allows fragments of low level system code to be installed into an executing UNIX kernel. Although this approach makes dynamic changes possible, it is an ad hoc solution in that it does not guarantee the safe execution of a running system. For example, it is possible to ....

Sun Microsystems. SunOS 4.1.3 Reference Manual, 1991.

....and maintainers of software to detect and solve network problems. They can also be used to monitor performance of communication software. To build such tools, the kernel must provide user programs access to unprocessed network traffic efficiently. Tcpdump [JLM89] Arpwatch [Ler92] and Sun s NIT [nit90] are examples of tools that use a packet filtering mechanism. User level protocols: As has already been mentioned, it is difficult to implement protocols in the kernel, as kernel resident code is typically difficult to write, maintain, and debug. Thus it is desirable to implement protocols in ....

.... for dynamic multipoint(DMP) applications [Sch94] Such applications are abundant, spanning diverse domains including satellite communication systems, network management systems, real time market data analysis systems, on line news services, distributed systems, and active databases [isi94, Bra88, nit90, MRA87, GJS94] These applications display many characteristics which call for solutions involving packet filters: a high volume of messages; signalling events generated in real time by suppliers; complex message formats containing a number of header fields; a number of consumers, each interested ....

Sun Microsystems Inc. Mountain View, CA, NIT(4P); SunOS 4.11 Reference Manual, Oct. 1990.

....domain. Recently, thread libraries have become a common element of new languages and operating systems for shared memory multiprocessor and uniprocessors to support concurrent programming. Mach Cthreads[6, 16] the University of Washington threads[15, 2] POSIX Pthreads[7] SunOS LWP and threads[12, 13, 20], are a few popular lightweight thread implementations. We have implemented a portable user level thread package 1 [16] on several multiprocessor platforms such as BBN Butterfly parallel processor, Kendall Square Research parallel processor, Sequent Symmetry multiprocessor, Silicon Graphics ....

Sun Microsystem Inc. Sun OS 4.0 Reference Manual, November 1987. Section 3L.

....realtime guarantee of its execution. 6 Related Work Sony s NEWS OS 4.0[Sony Corporation92] supports dynamic loading of device drivers using command devattach. NEWS OS 6.0[Sony Corporation94] SVR4.2 variants) also supports the same functionality. LKM (Loadable Kernel Module) implemented on SunOS[Sun Microsystems91] and NetBSD[NetBSD project94] enables kernel modules to be dynamically loaded using command modload. In these systems, a module loaded into the kernel is actually relocated and linked into the kernel memory space. Entry points to the module will be attached by modifying kernel memory space ....

Sun Microsystems. SunOS 4.1.3 Reference Manual, 1991.

....bits. To ensure that the method works, shell scripts and C code were written and executed on Sun Unix 4.0. The two files that are setuid root are required so that TP i can change from a group that can read CDI i Gamma1 to a group that can execute TP i 1 . Some versions of Unix, such as Sun 4. 0 [8], provide a command that allows a program to change its group identity. Either method requires more trusted code, but the setuid root method is particularly dangerous because if any of the n Gamma 1 setuid root files are compromised, the entire system is compromised. The method shown in Figure 3 ....

Sun Microsystems, Inc. Sun 4.0 Reference Manuals, November 1987.

....in TPVM are hosted within regular PVM tasks and form the units of parallelism and scheduling. In other words, a collection of TPVM threads that comprise an application are created and execute within the context of a (usually smaller) number of regular processes or pods (as in, e.g. SunOS LWP [16]) TPVM exploits multiple CPU SMMP s by concurrently executing threads, but is also very beneficial in single CPU systems in terms of program asynchrony and latency hiding. The TPVM model requires that host processes be instantiated prior to the active computational entities, i.e. the threads, ....

.... over the Rex [6] thread system, which operates in user space, is non preemptive, does not support true concurrent thread execution, and performs scheduling only at the request of the user (via a yield( operation) ffl We also implemented the thread interface over the Solaris threads library [16], a POSIX compliant package which provides kernel supported, preemptive threads which will operate with true concurrency on a multiprocessor. ffl We also ported the thread interface to use the Cthreads package developed at the Georgia Institute of Technology [14] This thread system is ....

Sun Microsystems, Mountain View, CA. SunOS 5.3 Reference Manual, 1993.

....events through these older mechanisms, the runtime library supporting your threads facility should convert them into more appropriate mechanisms. See, for example, the design of the Topaz system calls [11] or the exception and trapping machinery included with Sun s lightweight process library [14,15]. If your program is interacting with a human user, you will usually want it to be responsive even while it is working on some request. This is particularly true of windoworiented interfaces. It is particularly infuriating to the user if the interactive display goes dumb just because the database ....

Sun Microsystems Inc. Sun OS 4.0 Reference Manual, Nov. 1987, section 3L.

....than non optimized execution. 7 Table 5: Costs of network protocol handlers on m System (in sec) metaoperation Apertos ICMP echo echoreply roundtrip 3466.0 ICMP echo echoreply roundtrip(optimized) 362.3 6 Discussions Recent UNIX variants implement the Loadable Kernel Module (LKM) mechanism [Sun Microsystems91, NetBSD project94] which allows fragments of low level system code to be installed into an executing UNIX kernel. Although this approach makes dynamic changes possible, it is an ad hoc solution in that it does not guarantee the safe execution of a running system. For example, it is possible to ....

Sun Microsystems. SunOS 4.1.3 Reference Manual, 1991.

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