rfc708.txt

RFC 相关的技术文档

each format to enable the environment to automatically decode and internalize
incoming parameters should it be desired to provide this service to the
applications program.

PCPB36, For Use Between 36-Bit Machines

	Bits  0-13 Unused (zero)
	Bits 14-17 Data type
	   EMPTY  =1  INTEGER=4  LIST=7
	   BOOLEAN=2  BITSTR =5
	   INDEX  -3  CHARSTR=6
	Bits 18-20 Unused (zero)	
	Bits 21-35 Value or length N
	   EMPTY       unused (zero)
	   BOOLEAN     14 zero-bits + 1-bit value (TRUE=1/FALSE=0)
	   INDEX       unsigned value
	   INTEGER     unused (zero)
	   BITSTR      unsigned bit count N
	   CHARSTR     unsigned character count N
	   LIST        unsigned element count N
	Bits 36-   Value
	   EMPTY    unused (nonexistent)
	   BOOLEAN  unused (nonexistent)
	   INDEX    unused (nonexistent)
	   INTEGER  two's complement full-word value
	   BITSTR   bit string + zero padding to word boundary
	   CHARSTR  ASCII string + zero padding to word boundary
	   LIST     element data objects





                                    -23-





Network Working			                              James E. White
Request for Comments:  708	Elements of a Distributed Programming System
	              Appendix A:  Transmission Formats for PCP Data Objects


PCPB8, For Use Between Dissimilar Machines

	Byte    0  Data type
	   EMPTY  =1  INTEGER=4  LIST=7
	   BOOLEAN=2  BITSTR =5
	   INDEX  =3  CHARSTR=6
	Bytes 1-   Value
	   EMPTY      unused (nonexistent)
	   BOOLEAN    7 zero-bits + 1-bit value (TRUE=1/FALSE=0
	   INDEX      2 byte unsigned value
	   INTEGER    4-type two's complement value
	   BITSTR     2-byte unsigned bit count N + bit string
		       + zero padding to byte boundary
	   CHARSTR    2-byte unsigned character count N + ASCII string
	   LIST	      2-byte element count N + element data objects






























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Network Working Group					      James E. White
Request for Comments:  708	Elements of a Distributed Programming System
			   Appendix B:	The Expanded Procedure Call Protocol


                              APPENDIX B

                 THE EXPANDED PROCEDURE CALL PROTOCOL


The Protocol that results from the extensions proposed in this paper is
summarized below.  The reader should note the concise syntactic description
made possible by the underlying notion of PCP data types.

Parameter list masks have been included not only as additional parameters
of the CALL message, as proposed in the paper, but as arguments of the
TAKEPROCEDURE and SGNLPROCEDURE system procedures as well.  Throughout the
Protocol description, "MASK" is shorthand for:

	[LIST (variable [CHARSTR], ...)]

Messages

	LIST (route INDEX, opcode INDEX CALL=1, tid [INDEX],
	      pkh [INDEX], procedure CHARSTR, arguments LIST,
	      argumentlistmask MASK, resultlistmask MASK)
	LIST (route INDEX, opcode INDEX RETURN=2, tid INDEX,
	      outcome BOOLEAN, results LIST)

	   If OUTCOME is FALSE
	      RESULTS is LIST (error INDEX, diagnostic CHARSTR)

Process-Related System Procedures

	INIPROCESS (program CHARSTR,
		    credentials LIST (error CHARSTR, password CHARSTR,
				      account CHARSTR))
	ALOPORT    (-> ph INDEX, computer CHARSTR, port)
	CNNPORT    (ph INDEX, computer CHARSTR, port)
	DCNPORT    (ph INDEX)
	CRTROUTE   (mycode INDEX, oldcode [INDEX]
		    -> code INDEX, ph INDEX)
	DELROUTE   (yourcode INDEX)

Package-Related System Procedures

	OPNPACKAGE (packages LISTofCHARSTRs -> pkhs LISTofINDEXs)
	CLSPACKAGE (pkhs LISTofINDEXs)






                                      -25-



Network Working Group					      James E. White
Request for Comments:  708	Elements of a Distributed Programming System
			   Appendix B:  The Expanded Procedure Call Protocol


Variable-Related System Procedures

	CRTVARIABLE (variable CHARSTR, value)
	DELVARIABLE (variable CHARSTR)
	RDVARIABLE  (pkh INDEX, variable CHARSTR,
		     substructure [LISTofINDEXs] -> value)

Procedure-Related System Procedures

	TAKEPROCEDURE (tid INDEX, yourtid BOOLEAN, parameters LIST,
		       argumentlistmask MASK, resultlistmask MASK)
	SGNLPROCEDURE (tid INDEX, yourtid BOOLEAN, parameters LIST,
		       parameterlistmask MASK)
	HELPPROCEDURE (tid INDEX, number INDEX, information -> solution)
	NOTEPROCEDURE (tid INDEX, number INDEX, information)
	ABRTPROCEDURE (tid INDEX)































                                     -26-

Network Working Group						James E. White
Request for Comments:  708		 Elements of a Distributed Programming
					Appendix C:  Summary of RTE Primitives


                              APPENDIX C

                      SUMMARY OF RTE PRIMITIVES


The DPS primitives made available to the applications program as a result of
the Model extensions proposed in this paper are summarized below.  
Collectively, they provide the applications programmer with a powerful
and coherent set of tools for constructing distributed systems.  Some of
the primitives (for example, CRTPROCESS and DELPROCESS) are necessary elements
for a "network operating system (NOS)," into which DPS may itself one day
evolve.

	CRTPROCESS (computer, program, credentials -> PH)
	DELPROCESS (ph)
	ITDPROCESS (ph1, ph2 -> ph12, ph21, ih)
	SEPPROCESS (ih)

Packages

	OPNPACKAGE (ph, packages -> pkhs)
	CLSPACKAGE (ph, pkhs)

Variables

	CRTVARIABLE (ph, variable, value)
	DELVARIABLE (ph, variable)
	RDVARIABLE  (ph, pkh, variable, substructure -> value)
	WRTVARIABLE (ph, pkh, variable, substructure, value)

Procedures

	CALLPROCEDURE (ph, pkh, procedure, arguments, argumentlistmask,
		       resultlistmask, -> outcome, results, tid)
	LINKPROCEDURE (tid, arguments, argumentlistmask,
		       resultlistmask, -> outcome, results)
	SGNLPROCEDURE (tid, parameters, parameterlistmask)
	HELPPROCEDURE (tid, number, information -> solution)
	NOTEPROCEDURE (tid, number, information)
	ABRTPROCEDURE (tid)









                                    -27-

Network Working Group              Elements of a Distributed Programming System
Request for Comments:  708	Appendix D:  Additional Areas for Investigation


                              APPENDIX D

                  ADDITIONAL AREAS FOR INVESTIGATION


Although the expanded distributed programming system developed in this paper
and summarized in the previous appendix is already very powerful, many
additional aspects of process interaction remain, of course, to be explored.
Among the additional facilities that the Protocol must eventually enable the
environment to provide are mechanisms for:

	(1)  Queuing procedure calls for long periods of time (for
	     example, days).

	(2)  Broadcasting requests to groups of processes.

	(3)  Subcontracting work to other processes (without remaining
	     a middleman).

	(4)  Supporting brief or infrequent inter-process exchanges
	     with minimal startup overhead.

	(5)  Recovering from and restarting after system errors.

























 
                                    -28-

Network Working Group		Elements of a Distributed Programming System
Request for Comments:  708					  References


                              REFERENCES


1.  White, J. E., "A High-Level Framework for Network-Based Resource Sharing,"
    submitted for publication in the AFIPS Conference Proceedings of the 1976
    National Computer Conference.

2.  Watson, R. W., Some Thoughts on System Design to Facilitate Resource
    Sharing, ARPA Network Working Group Request for Comments 592, Augmentation
    Research Center, Stanford Research Institute, Menlo Park, California,
    November 20, 1973 (SRI-ARC Catalog Item 20391).

3.  White, J. E., DPS-10 Version 2.5 Implementor's Guide, Augmentation
    Research Center, Stanford Research Institute, Menlo Park, California,
    August 15, 1975 (SRI-ARC Catalog Item 26282).

4.  White, J. E., DPS-10 Version 2.5 Programmer's Guide, Augmentation Research
    Center, Stanford Research Institute, Menlo Park, California, August 13, 
    1975 (SRI-ARC Catalog Item 26271).

5.  White, J. E., DPS-10 Version 2.5 Source Code, Augmentation Research
    Center, Stanford Research Institute, Menlo Park, California, August 13,
    1975 (SRI-ARC Catalog Item 26267).

6.  Bobrow, D. G., Burchfiel, J. D., Murphy, D. L., Tomlinson, R. S., "TENEX,
    a paged Time Sharing System for the PDP-10," Communications of the ACM,
    Vol. 15, No. 3, pp. 135-143, March 1972.























                                    -29-
Network Working Group		Elements of a Distributed Programming System
Request for Comments:  708					 Figure List


                             FIGURE LIST


Fig. 1	Interfacing distant applications programs via their run-time
	environments and an IPC channel.

Fig. 2	Two processes that can only be introduced via a logical channel.

Fig. 3  A logical channel.












































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