Integrated Parallel Macros User's Guide
Contents
1. IN none OUT none Discussion IPM_HOST returns the process rank of the host process Even if this value is often set to 0 the user should always use the IPM_HOST function in communication routines Example c c receive initial value from host c integer initv is it il IPM RECV IPM HOST IPM ANYTAG IPM INTEGER 1 initv is it il 29 IPM 2 3 IPM_HOST_STATUS function Synopsis IPM_HOST_STATUS Arguments IN none OUT none Discussion The IPM_HOST_STATUS returns the current status of the host process in the virtual topology as defined by the IPM_CREATE routines IPM_HOST_I host active IPM_HOST_O host passive See also IPM_CREATE_TORUS IPM_CREATE_GRAPH Example c cx some social considerations c if IPM_HOST_STATUS eq IPM_HOST_O then write 6 master is sleeping while the slaves are working endif c 30 IPM 2 3 IPM_INIT subroutine Synopsis IPM_INIT Arguments IN none OUT none Discussion IPM_INIT is a first attempt to MPI like interface Its allows full SPMD pro gramming model by automatically checking if the call is done from the host or node program and then starting IPM BEGIN_HOST or IPM_BEGIN_NODE Example program spmd c include ipm h c IPM_DECLAR IPM_INIT if IPM RANK eq IPM_HOST then write 6 It is great to wake up and to discover that write 6 you are the master endif c IPM_END end 31 IPM 2 3 IPM_LIBRARY function Synopsis IPM_LIB2. OPTIONS c f 5 User Interface 5 1 Naming Conventions All of the macros start with IPM prefix and are written in upper case letters No blanks or carriage returns are permitted in the macro interface Cc correct IPM_GET_RANK coords rank c incorrect IPM_GET_RANK coords rank IPM_GET_RANK coords rank 5 2 Behavior of Macros Calls Some macros behave like subroutine calls and others as functions calls For example IPM_GET_RANK coords rank behaves as a subroutine call where rank is an output argument of the subroutine and neigh IPM_RANK 1 behaves as a function call Note that there is no overhead when functions such as IPM_RANK are called several times and it would be against IPM s philosophy to store this value elsewhere 5 3 List of Macros Process management IPM_ABORT IPM_BARRIER IPM_BEGIN_HOST IPM_BEGIN_NODE IPM_DECLAR IPM_END 8 IPM 2 3 IPM_INIT IPM GBARRIER Logical topology IPM_CREATE_GRAPH IPM_CREATE_TORUS Communication features IPM_MCAST IPM_NRECV IPM_PROBE IPM_RECV IPM_SEND Global tree IPM_DADDY IPM_MAXSONS IPM_NB_SONS IPM_ROOT IPM_SONS Inquiry functions IPM_GET_ALL_COORDS IPM_GET_COORDS IPM_GET_RANK IPM_HOST IPM_HOST_STATUS IPM_LIBRARY IPM_MSG_RECV IPM_MSG_SEND IPM_NBRECV 9 IPM 2 3 IPM_NBSEND IPM_NB_NEIGHBORS IPM_NEIGHBORS IPM_NODES IPM_RANK IPM_SIZE IPM_ TOPO IPM TORDIM IPM_TORSIZE IPM_TYPE_LENGH IP
3. LOCAL_ROOT 1ib libfpvm3 a PCSLIBA PCSLIBF PCSLIBC lsocket lnsl LDCSFL L LOCAL_ROOT 1ib lrms lew lelan PCS PCSLIBA LDCSFL RUNPCS HOME COMPILATION t CMD main OBJS obj1 0 obj2 o SUFFIXES o f F all ipm h expand CMD ipm h echo You must select a message passing style expand mkdir expand t PWM pvm OK pvm all F77 LFLAGS o CMD 0BJS PVM mv CMD RUNPVM OK pvm ln s IPM ipm h pvm ipm h ln s PVM_ROOT include fpvm3 h fpvm3 h touch OK pvm PVM CS 2 pvmcs OK pvmcs all 58 IPM 2 3 F77 LFLAGS o CMD OBJS PCS OK pvmcs ln s IPM ipm h pvm ipm h ln s opt MEIKOcs2 include PVM fpvm3 h fpvm3 h touch K pvmcs PARMACS 6 0 pm6 OK pm6 all F77 LFLAGS o CMD OBJS PM6 OK pm6 ln s INCLUDE DIR pm inc pm inc ln s IPM ipm h pm6 ipm h touch K pm6 Compilations CMD OBJS f 0 F77 CFFLAGS c f F o M4DIR F egrep v M4FILTER gt f F77 CFFLAGS c f mv f expand c 0 CC CFLAGS c c clean rm f CMD rm f 0 rm f ipm h fpvm3 h pm inc rm f OK rm r expand 59 IPM 2 3
4. 2 IPM 2 3 Contents Acknowledgements 1 Introduction 2 Conventions 2 1 IPM Programming Models 2 2 Process Identifier 2 3 Logical Topologies 2 4 Communications 3 Obtaining IPM 4 Compiling IPM Applications 5 User Interface 5 1 Naming Conventions 5 2 Behavior of Macros Calls 5 3 List of Macros 0202 2 6 Advanced Features 6 1 Datatypes 6 2 Encoding flag inipm h pyvm 6 3 Internal integer type in ipm h pvm 7 Warnings and Bugs Reference pages for IPM 2 3 macros An example of generic makefile N DDD Or WH mm 11 11 11 12 13 55 IPM 2 3 Acknowledgements Some important contributions to the definition and the continuing development of IPM have come from researchers who do not formally belong to the FunParTools Corpo ration We would like to thank the following persons for their help and suggestions Norman Barth UCSD Frederic Carbonnell CERFACS Tuomo Kauranne University of Joensuu Finland Jean Latour CRAY FRANCE Michael Rudgyard CERFACS Sami Saarinen CSC Finland Philip Hariss FEGS Cambridge 4 IPM 2 3 1 Introduction This guide contains a brief overview of the information required to implement parallel code using message passing with IPM 2 3 A dominant characteristic of the Integrated Parallel Macros is that they are integrated macros and are therefore easy to use at least in ou
5. c the shortest IPM program c IPM_DECLAR IPM_INIT write 6 I am the process IPM_RANK IPM_END end 23 IPM 2 3 IPM_END subroutine Synopsis IPM_END Arguments IN none OUT none Discussion IPM_END exits from the parallel application but doesn t kill the process Example program TheEnd c include ipm h c IPM_DECLAR IPM_END end 24 IPM 2 3 IPM_GBARRIER subroutine Synopsis IPM_GBARRIER msgtag Arguments IN bartag integer barrier identifier supplied by the user Should be in the same range than message tag It allows the user to distinguish between two barriers OUT none Discussion The IPM_GBARRIER call synchronizes all the processes including the host pro cess It is recommended to do not use the same tag number in two consecutive barriers See also IPM_BARRIER Example c integer bartag c bartag 10 IPM_BARRIER bartag IPM GBARRIER bartag 10 c 25 IPM 2 3 IPM_GET_ALL_COORDS subroutine Synopsis IPM_GET_ALL_COORDS coords Arguments IN none OUT coords vector of integers containing coordinates of all the active processes Discussion IPM_GET_ALL_COORDS returns a vector of integers filled with the coordinates of all the processes ordered by their rank number in a torus topology If host is active in the topology coords contains IPM_SIZE IPM_TORDIM elements IPM_NODE IPM_TORDIM otherwise See also IPM_SIZE IPM_TORDIM IPM_GET_COORDS Example integer xy 2 co
6. requested tag of the expected message integer OUT recvrank rank of the effective sending process if any integer recvtag tag of the received message if any integer arrived integer which specifies if the requested message has arrived 1 or not 0 Discussion IPM_PROBE checks if a message from the regrank process with a regtag tag identifier has arrived or not If such a message has arrived recvrank and recvtag return the rank of the sending process and the tag of the message This allows use of wildcards IPM_ANYSND and IPM_ANYTAG for the first arguments See also IPM_ANYSND IPM_ANYTAG Example c Probe if I have received any letter from daddy IPM_PROBE IPM_DADDY IPM_ANYTAG is it iok if iok eg 0 then write 6 Daddy has probably lost my address endif 43 IPM 2 3 IPM_RANK function Synopsis IPM_RANK Arguments IN none OUT none Discussion IPM_RANK returns the logical identifier of the calling process Processes are numbered from 0 up to IPM_SIZE 1 These values are used is communications and probe functions Example write 6 my rank IPM RANK 44 IPM 2 3 IPM_RECV subroutine Synopsis IPM_RECV reqrank reqtag type len buffer recvrank recvtag recvlen Arguments IN reqrank requested rank of the sending process integer regtag requested tag of the expected message integer type data type expected integer len number of elements expected integer buffer
7. starting address of the receive buffer handle OUT recvrank rank of the effective sending process integer recvtag tag of the received message integer recvlen lengh in bytes of the received message integer Discussion IPM RECV is used for asynchronous message passing between any two active processes The calling process is blocked until an appropriate message has been received Wildcards IPM_ANYSND and IPM_ANYTAG can be used in place of the first two arguments matching for any sender or any tag See also IPM_SEND for the list of datatypes IPM_ANYSND IPM_ANYTAG IPM_TYPE_LENGTH Example cx receive from host basic dimensions of Kim Basinger integer dim 3 c IPM_RECV IPM_HOST IPM_ANYTAG IPM_INTEGER 3 dim is it il if dim 1 1t 90 or dim 2 gt 68 or dim 3 1t 85 then write 6 I received incoherent initial values write 6 for the modelisation of Kim Basinger s body IPM_ABORT endif 45 IPM 2 3 IPM_ROOT function Synopsis IPM_ROOT Arguments IN none OUT none Discussion IPM_ROOT returns the rank of the root process in the global tree provided by IPM for global operations See also IPM_DADDY IPM_NB_SONS IPM_SONS Example write 6 root IPM_ROOT 46 IPM 2 3 IPM_SEND subroutine Synopsis IPM_SEND rank msgtag type len buffer Arguments IN rank rank identifier of destination integer msgtag message tag identifier integer type date type integer len l
8. Integrated Parallel Macros User s Guide Luc Giraud Pascale Noyret Eric Sevault Vincent Van Kemenade January 1995 TR PA 95 01 IPM 2 3 User s Guide and Reference Manual January 1995 english Integrated Parallel Macros french Inutile Paquet de Macros Abstract This user s guide describes the features of the set of m4 macros provided by IPM Integrated Paralell Macros Those macros allow the users to easily imple ment a portable distributed programme based on the message passing paradigm using a hidden message passing library like PVM PARMACS or a subset of MPI The choice of the hidden message passing library is made only at the compilaton time The purpose of this set of macros is not to provide the user with a new message passing library IPM is not even a library but only to provide the user with a simple message passing interface Some IPM macros give an easy access to relevant message passing data while avoiding a deep technical knowledge of the hidden message passing library We made the choice of a set of macros although the drawback of some possible border effects instead of a library mainly because it allows the advanced users to have access to the expanded code for tuning some communication according to his knowledge of both the target architecture and the hidden message passing library L Giraud P Noyret E Sevault V Van Kemenade CERFACS 42 avenue Coriolis 31 057 TOULOUSE cedex
9. L_SUN4 0 FL_CRAY 01 FL_MCS2 g FFLAGS FL PVM ARCH t Flags when linking 56 IPM 2 3 LF_RS6K LSP LF_SUN4 LF_CRAY LF_MCS2 g LFLAGS LF PVM ARCH m4 location M4_RS6K usr bin m4 M4_SUN4 usr bin m4 M4_CRAY usr bin m4 M4_MCS2 usr ccs bin m4 M4DIR M4_ PVM_ARCH M4FILTER egrep 0 9 a z A Z Message passing librairies i PARMACS 6 0 4 1 Meiko CS 2 PP MCS2 meiko PR MCS2 cs2 PD MCS2 opt MEIKOcs2 parmacs 2 Cluster IBM s PP_RS6K ws PR_RS6K RS6K PD_RS6K usr parmacs PARALLEL_PLATFORM PARALLEL_RESOURCE PARMACS_DIR PP_ PVM_ARCH PR_ PVM_ARCH PD_ PVM_ARCH INCLUDE_DIR PARMACS_DIR include PARALLEL_PLATFORM LIB_DIR PARMACS_DIR 1ib PARALLEL_PLATFORM PARALLEL_RESOURCE PM6_SYS1 L opt MEIKOcs2 1ib PM6_SYS2 lrms lsocket lnsl lew lelan SYS_MCS2 PM6_SYS1 PM6_SYS2 SYS_RS6K lrpcsvc PM6LIBC LIB DIR libpm6 a PM6LIBF PM6 PM6LIBF PM6LIBC SYS_ PVM_ARCH RUNPM6 HOME ipm example 57 IPM 2 3 PVM standart PVMLIBC PVM_ROOT 1ib PVM_ARCH libpvm3 a PVMLIBF PVM_ROOT 1ib PVM_ARCH libfpvm3 a PVM PVMLIBF PVMLIBC RUNPVM HOME pvm3 bin PVM ARCH t PVM amp 7 amp CS 2 LOCAL_ROOT opt MEIKOcs2 PCSLIBC LOCAL_ROOT 1ib libpvm3 a PCSLIBF
10. M_VERSION Defined Constants IPM_ANYSND IPM_ANYTAG IPM GRAPH IPM_HOST_I IPM_HOST_O IPM_NO_DADDY IPM_NONE IPM PARMACS IPM_PVM IPM_TORUS Generic Data types IPM COMPLEX IPM_DBLE IPM_INTEGER IPM_REAL Specific Data types IPM_BYTE IPM_CHARACTER 10 IPM 2 3 IPM_COMPLEX8 IPM_COMPLEX16 IPM_INT2 IPM_INT4 IPM_INTS IPM_REAL4 IPM_REAL8 We refer to the appendix for a complete description of those macros 6 Advanced Features 6 1 Data types In order to run on computers with different intrinsic data representation types one can edit the ipm h file and modify the generic data types for 4 bytes reals Sun4s IBM RS6000s IEEE arithmetic define IPM_REAL REAL4 for 8 bytes reals Crays define IPM_REAL REAL8 The sources of the application itself need not be changed if generic data types are used in communication macros 6 2 Encoding flag in ipm h pvm The PVM encoding scheme when initializing send buffers is defined in an internal macro of the ipm h pvm file which may be edited and modified Initsend Buffer Flag Customized define IPM_INITFLAG PVMRAW The PVMINPLACE option is not available with PVM 3 2 6 3 Internal integer type in ipm h pvm IPM uses and exchanges integers to store process identifiers current topology trees information etc In order to keep a maximum of flexibility no specific type had been defined for these integers An integer is then defined by
11. RARY Arguments IN none OUT none Discussion IPM_LIBRARY returns the running parallel library defined by one of the follow ing integer values IPM_PARMACS IPM_PVM Example ox parvm or p macs if IPM_LIBRARY eq IPM_PARMACS then write 6 the FunParTools advice try PVM else write 6 the FunParTools advice try PARMACS endif 32 IPM 2 3 IPM_MCAST subroutine Synopsis IPM_MCAST nb _dests dests msgtag type lenmsg buffer Arguments IN nb_dests number of recipients of the message integer dests vector of integers containing the ranks of recipients processes msgtag integer message tag identifier type data type integer lenmsg lengh in elements of the message integer buffer buffer containing the message OUT none Discussion The multicasting call allows the user to send the same message to various pro cesses See also IPM_SEND for the list of datatypes Example integer dests 3 buff dests 1 4 dests 2 IPM_HOST dests 3 7 IPM_MCAST 3 dests 1 IPM_INTEGER 1 buff 33 IPM 2 3 IPM_MSG_RECV Synopsis IPM_MSG_RECV Arguments IN none OUT none Discussion function IPM_MSG_RECV returns the number of messages already received by the calling process Example c to be or not to be a parallel program C if IPM_MSG_RECV eq 0 then write 6 Hey are you sure to run a parallel program endif 34 IPM 2 3 IPM_MSG_SEND functi
12. REATE_GRAPH macros which define a logical topology for node processes In many cases the host may be excluded from this logical topology and therefore does not partici pate in the computational part of the execution Note that the IPM_BARRIER macro provides the user with a barrier that synchronizes all the node processes e With the SPMD model each process runs the same program Since IPM is built on top of parallel libraries where one process is in charge of the creation of the others there is always a host process even if this is hidden from the user As a result the work to be performed in some macros is only defined at execution time 1m4 is the standard Unix macro language processor 2Geist et al Oak Ridge National Laboratory 3Hempel et al Institute fur Methodische Grundlagen and GMD 5 IPM 2 3 For example the IPM_INIT macro performs functions of IPM BEGIN_HOST or IPM_BEGIN_NODE depending on the nature host node of the calling process For the same reason the IPM_CREATE instructions are ignored when running on a node process The host process is supposed to be a formal member of the logical topology and has an effective part of the computational work The IPM_GBARRIER synchronizes both host and node processes 2 2 Process Identifier All the processes are identified by an integer rank starting from 0 up to size 1 where size is the total number of processes In most cases one can distin
13. also IPM_GBARRIER Example c cx first barrier IPM_BARRIER 101 c cx second barrier IPM_BARRIER 102 17 IPM 2 3 IPM_BEGIN_HOST subroutine Synopsis IPM_BEGIN_HOST Arguments IN none OUT none Discussion IPM_BEGIN_HOST is the first macro invoked before any other IPM call in the host program It performs first initial set up of basic enquiry functions See also IPM_INIT Example program host c include ipm h c IPM_DECLAR c IPM_BEGIN_HOST c write 6 size IPM_SIZE write 6 nodes IPM_NODES c IPM_END end 18 IPM 2 3 IPM BEGIN NODE subroutine Synopsis IPM_BEGIN_NODE Arguments IN none OUT none Discussion IPM_BEGIN_NODE is equivalent to IPM_BEGIN_HOST in the node program It performs all the initializations needed for any other IPM call See also IPM_INIT Example program node c include ipm h c IPM_DECLAR IPM_BEGIN_NODE write 6 All these values are available IPM_RANK IPM_HOST IPM_DADDY IPM_ROOT IPM TOPO IPM_NB_SONS IPM NB NEIGHBORS 7and so on IPM_END end 19 IPM 2 3 IPM_CREATE_GRAPH subroutine Synopsis IPM_CREATE_GRAPH name _exe nb_nodes index neighbors host_status numc Arguments IN name exe character string that contains the name of the exe cutable to be spawned nb_nodes number of nodes in the graph index vector of integers containing indices in neighbors neighbors vector of integers containing neighbo
14. aypes can be setted by explicit changes in the ipm h file before com pilation By default IPM_INTEGER is IPM_INT4 IPM_REAL is IPM_REAL4 and IPM_COMPLEX is IPM_COMPLEX8 Example if IPM TYPE LENGTH IPM REAL eq 8 then write 6 Double precision is implicit endif 53 IPM 2 3 IPM_VERSION Synopsis IPM_VERSION Arguments IN none OUT none Discussion function IPM_VERSION returns a real number which specifies the current version of the IPM package Example c some wishes C write 6 Is it possible to have a IPM VERSION 0 1 IPM version without so many bugs 54 IPM 2 3 Appendix II An example of generic makefile using IPM 55 IPM 2 3 Makefile for programs under IPM c Eric Sevault Vinvent Van Kemenade CERFACS This makefile should be Ok for these computers RS6K IBM RS6000 SUN4 Sparc workstation CRAY C90 CRAY 2 MCS2 MEIKO CS 2 have fun With these message passing librairies PVM PVM 3 2 x or 3 3 x make pvm PCS PVM Meiko CS 2 make pvmcs PM6 PARMACS 6 0 make pm6 ipm location HH HHH RH HOH HOH HOF FH OH OH OF OF IPM HOME ipm include t 4 C Compiler if needed t CC RS6K c89 CC SUN4 gcc CC_CRAY cc CC MCS2 cc CC CC PVM ARCH t 4 Fortan Compiler t FF_RS6K xlf FF SUN4 usr lang f77 FF_CRAY cf77 FF_MCS2 177 F77 FF _ PVM_ARCH Flags when compiling FL_RS6K 0 F
15. e Discussion The IPM_ABORT macro kills all existing processes except itself and exits from the parallel application The calling process is not killed Example cx Check for incorrect value of IPM_RANK if IPM_RANK 1t 0 then IPM_ABORT stop endif 14 IPM 2 3 IPM_ANYSND constant Synopsis IPM_ANYSND Arguments IN none OUT none Discussion Using IPM_ANYSND in place of the sender s rank in receive and probe functions matches any process rank Example c cx Check if a specified tagged message has arrived c integer msgtag is it arrived c msgtag 101 IPM_PROBE IPM_ANYSND msgtag is it arrived 15 IPM 2 3 IPM_ANYTAG constant Synopsis IPM_ANYTAG Arguments IN none OUT none Discussion Using IPM_ANYTAG in place of the tag argument in receive and probe functions matches any tag number Example c cx Check if any kind of message has arrived c integer is it arrived c IPM_PROBE IPM_ANYSND IPM_ANYTAG is it arrived 16 IPM 2 3 IPM_BARRIER subroutine Synopsis IPM BARRIER bartag Arguments IN bartag integer barrier identifier supplied by the user Should be in the same range than message tag It allows the user to distinguish between two barriers OUT none Discussion IPM_BARRIER synchronizes all the node processes If called from the host program the barrier call is ignored Node processes have to use the same barrier identifier otherwise a deadlock will occur See
16. engh of the message in elements integer buffer starting address of the message handle OUT none Discussion IPM_SEND is used for asynchronous message passing between any two active processes The calling process continues as soon as the message is safely on its way One could use generic datatypes such as IPM_CHARACTER IPM_BYTE IPM_INTEGER IPM_REAL IPM_DBLE IPM_COMPLEX or specific datatypes IPM_INT2 IPM_INT4 IPM INT8 IPM_REAL4 IPM_REAL8 IPM_COMPLEX8 IPM_COMPLEX16 See also IPM_RECV IPM_TYPE_LENGTH Example cx nothing to send integer null null 0 c IPM_SEND IPM_HOST 1 IPM_INTEGER 1 nu11 47 IPM 2 3 IPM_SIZE function Synopsis IPM_SIZE Arguments IN none OUT none Discussion IPM_SIZE returns the total number of processes in the application including host process Users should be aware that this value is not dynamically updated if a process leaves the application See also IPM_NODES Example if IPM SIZE eg 1 then write 6 application not yet started endif 48 IPM 2 3 IPM_SONS function Synopsis IPM_SONS num Arguments IN num num th son of the calling process integer OUT none Discussion The IPM_SONS function returns the rank of the num th son of the calling process in the global tree num varies from 1 up to IPM_NB_SONS See also IPM_ROOT IPM_DADDY IPM_NB_SONS Example c first day of the month it s time for allowance c integer 1 allowance all
17. er an uncompress and a tar xvf ipm tar one can re trieve the following directory doc ipmdoc ps gridsum makefile sum F ring makefile host F node F spmd F include dico ipm h pm6 ipm h pym mpi Readme makefile mpif h mpiipm F The file ipm include dico contains the list of all the macros defined in the include files The mpi directory contains a subset of MPI functions built on top of IPM See the Readme file of this directory for more information 4 Compiling IPM Applications Before compiling an application written with IPM the user has to select an available parallel library for the target machine A symbolic link must then be defined between the local ipm h file and the corresponding IPM include file For example if the library to be used is PVM the following link should be created ln s HOME ipm include ipm h pvm ipm h The user should also link with the specific include files of the chosen library such as fpvm3 h PVM or pm inc PARMACS 6 0 Files with IPM calls must contain one and only one m4 include instruction at the beginning of the file include ipm h c subroutine subvoid c fortran code T IPM 2 3 These files should be expanded before compilation using the m4 pre processor in the makefile an example of a generic makefile using IPM is given in appendix II F o m4 F egrep v gt f F77
18. guish host process with rank 0 and node processes with ranks from up to number_of_nodes These logical values are the only ones recognized by IPM The underlying task identifiers tid PVM or process identifiers pid PARMACS are no longer required and are completely hidden from the user 2 3 Logical Topologies As well as MPI and PARMACS IPM provides two main topologies a torus of up to four dimension and a customized graph As these features are not available with PVM they are completely emulated by IPM A binary tree is also provided for global reduction or scatter operations across the nodes 2 4 Communications Processes exchange data through tagged messages IPM provides asynchronous send and blocking or non blocking receive functions as well as multi cast and probe func tions These communication routines allow the user to communicate contiguous data in the memory no packing is assumed and the user may need to define intermediate buffer arrays before using these functions A message is defined by its datatype and the number of elements sent or received previous releases of IPM only needed the length in bytes Processes ranks are used to specify the destination or the origin of messages 6 IPM 2 3 3 Obtaining IPM The IPM package is available by anonymous ftp from orion cerfacs fr 138 63 200 33 on pub algo softw ipm The file is available in a tar compressed or gzipped format ipm tar Z or ipm tar gz Aft
19. nd 38 IPM 2 3 IPM_NB_SONS function Synopsis IPM_NB_SONS Arguments IN none OUT none Discussion The IPM_NB_SONS function returns the number of sons of the calling process in the global tree This value is less than or equal to IPM _ MAXSONS See also IPM_ROOT IPM_DADDY IPM_SONS Example c Sweet family if IPM_NB_SONS eq 0 and IPM_DADDY eq IPM_NO_DADDY then write 6 Hey is there someone here write 6 I am the lonesome process endif 39 IPM 2 3 IPM_NEIGHBORS function Synopsis IPM_NEIGHBORS num Arguments IN num num th neighbor of the calling process integer OUT none Discussion The IPM_NEIGHBORS function returns the num th neighbor of the calling pro cess in the logical graph topology num varies from 1 up to IPM_NB_NEIGHBORS See also IPM_ CREATE_GRAPH IPM_NB_NEIGHBORS Example integer htime invitation c the party will start at 18h30 invitation 1 htime 1830 do 100 i 1 IPM NB NEIGHBORS IPM_SEND IPM_NEIGHBORS 1 invitation IPM INTEGER 1 htime 100 continue 40 IPM 2 3 IPM_NODES function Synopsis IPM_NODES Arguments IN none OUT none Discussion IPM_NODES returns the number of nodes that have been created by one of the IPM_CREATE functions 0 otherwise See also IPM_SIZE Example if IPM_NODES eq 0 then write 6 it is not St Tropez here endif 4 IPM 2 3 IPM_NRECV subroutine Synopsis IPM_NRECV reqrank reqtag t
20. on Synopsis IPM_MSG_SEND Arguments IN none OUT none Discussion IPM_MSG_SEND returns the number of messages already sent by the calling process Example cx looking for White snow c if IPM_MSG_SEND eq 0 then write 6 i am the grumpy dwarf endif 35 IPM 2 3 IPM_NBRECV function Synopsis IPM_NBRECV Arguments IN none OUT none Discussion IPM NBRECV returns the number of bytes already received by the calling pro cess Example c the FunParTools process c if IPM_NBRECV eq 0 then write 6 Good thanks God there is nothing to do yet endif 36 IPM 2 3 IPM_NBSEND function Synopsis IPM_NBSEND Arguments IN none OUT none Discussion IPM_NBSEND returns the number of bytes already received by the calling pro cess Example c a good load balance c if IPM_NBRECV gt IPM_NBSEND then IPM_SEND IPM_HOST 1 IPM_BYTE IPM_NBRECV IPM_NBSEND ibuff if IPM NBRECV ne IPM NBSEND then write 6 Another bug in IPM endif endif 37 IPM 2 3 IPM_NB_NEIGHBORS function Synopsis IPM_NB_NEIGHBORS Arguments IN none OUT none Discussion If a graph topology has been defined IPM _NB_NEIGHBORS returns the number of neighbors of the calling process If there is no graph defined this value is set to 0 See also IPM_CREATE_GRAPH IPM_TOPO IPM_NEIGHBORS Example c suspicious process write 6 I have IPM NB NEIGHBORS guys hanging arou
21. ords 12 c cx in a 3 2 torus c IPM_GET_ALL_COORDS coords IPM_GET_COORDS 6 xy if xy 1 ne coords 11 or xy 2 ne coords 12 then write 6 error in IPM coords functions abort end 26 IPM 2 3 IPM_GET_COORDS subroutine Synopsis IPM_GET_COORDS rank coords Arguments IN rank logical rank of the process OUT coords vector of integers containing the coordinates of the rank th process Discussion Coordinates in direction k start from 0 up to IPM_ TORSIZE amp 1 The last dimension varies first In a 2 2 grid for example we have process 0 0 0 process 0 1 process 2 1 0 process 3 1 1 See also IPM_GET_ALL_COORDS IPM_GET_RANK Example integer coords 2 IPM_GET_COORDS 1 coords if coords 1 coords 2 ne 0 then write 6 host is active in the torus endif 27 IPM 2 3 IPM GET RANK subroutine Synopsis IPM_GET_RANK coords rank Arguments IN coords vector of integers containing coordinates of a process OUT rank logical rank of the process associated to the specified coordinates Discussion IPM_GET_RANK translates the process coordinates to process ranks as they are used in communications routines Example integer coords 2 rank c IPM_GET_COORDS 1 coords IPM_GET_RANK coords rank c if rank ne 1 then write 6 error in IPM COORDS lt gt RANK routines abort endif 28 IPM 2 3 IPM_HOST function Synopsis IPM_HOST Arguments
22. owance 1000 IPM_NB_SONS c do 100 i 1 IPM_NB_SONS IPM_SEND IPM_SONS i 1 IPM_INT4 1 allowance 100 continue 49 IPM 2 3 IPM_TOPO function Synopsis IPM_TOPO Arguments IN none OUT none Discussion IPM_TOPO returns the active topology which can be one the following prede fined integer values IPM_NONE IPM_TORUS IPM_GRAPH Example if IPM_TOPO eq IPM_NONE then write 6 no mapping defined endif 50 IPM 2 3 IPM_TORDIM function Synopsis IPM TORDIM Arguments IN none OUT none Discussion IPM_TORDIM returns the torus dimension Even if the active topology is not a torus a logical one dimensional torus is always provided and all IPM cartesian functions are allowed See also IPM CREATE_TORUS IPM_TORSIZE Example write 6 dimension of the torus IPM_TORDIM 51 IPM 2 3 IPM_TORSIZE function Synopsis IPM_TORSIZE num Arguments IN num integer which specifies a direction of the torus OUT none Discussion The IPM_TORSIZE function returns the dimension of the torus in num th direc tion See also IPM_ CREATE_TORUS IPM_TORDIM Example do 100 1 1 IPM TORDIM write 6 Size in direction i IPM TORSIZE i 100 continue 52 IPM 2 3 IPM_TYPE_LENGTH function Synopsis IPM_TYPE_LENGTH datatype Arguments IN datatype specified datatype OUT none Discussion IPM_TYPE_LENGTH returns the length in bytes of the specified datatype Generic dat
23. r opinion The user may then avoid many of the technical aspects of the parallel implementation and concentrate on the application itself IPM is not a new message passing library Not even a library It is just a package of m4 macros built on top of existing message passing libraries such as PVM 3 2 x or 3 3 x or PARMACS 6 0 It allows the user to choose between parallel libraries at compilation time although he retains a single source code it therefore reduces development costs while permitting the use of libraries that may be better suited for a particular hardware configuration New releases of these libraries are hidden from the user because of the compact IPM interface For advanced features the user can easily alter parts of the macros or modify the expanded source code before compilation IPM has been designed keeping in mind the specifications for MPI Converting appli cations from IPM to MPI should not be difficult indeed this will not be necessary as soon as an IPM interface to MPI is available An MPI subset built on top of IPM calls is provided with the IPM package 2 Conventions 2 1 IPM Programming Models IPM supports both Host Node and SPMD programming models e For a Host Node scheme the user can explicitly define the environment through the IPM_BEGIN_HOST or the IPM_BEGIN_NODE calls All others macros can be invoked from the host or node program The nodes are created using the IPM CREATE_TORUS or IPM_C
24. rs for all graph nodes host_status integer which specifies if the host is included in the graph or not OUT nume integer equal to the number of created nodes Discussion The mapping function IPM CREATE GRAPH allows the user to define a cus tomized graph for its processes index starts from 0 if host_status is set to 1 and starts at 1 otherwise The last value of index must point to the position just after the last element of neighbors Neighbors of node number k are neigh bors index k up to neighbors index k 1 1 See also IPM_HOST_STATUS IPM_NB_NEIGHBORS IPM_NEIGHBORS Example c host a 3 nodes graph integer index 4 neighbors 4 c index 1 1 neighbors 1 2 neighbors 2 3 index 2 3 neighbors 3 1 index 3 4 neighbors 4 1 index 4 5 IPM_CREATE_GRAPH node 3 index neighbors IPM_HOST_O numc 20 IPM 2 3 IPM_CREATE_TORUS subroutine Synopsis IPM_CREATE_TORUS name _exe dim ndims host_status numc Arguments IN name_exe character string that contains the name of the exe cutable to be spawned dim integer which specifies the dimension of the torus ndims vector of integers containing the size of the torus in each direction host_status integer which specifies if the host is included in the torus or not OUT nume integer equal to the number of created nodes Discussion The mapping function IPM_CREATE_TORUS defines a cartesian topology where each process is associated
25. to dim coordinates If host_status is equal to 1 the host process is included in the torus topology and its coordinates are 0 0 In this case the number of nodes created nume is equal to the product of the ndims entries minus 1 The vector ndims should contain at least dim elements with dim inferior or equal to 4 See also IPM_HOST_STATUS IPM_TOPO IPM_TORDIM IPM_TORSIZE IPM_GET_COORDS Example cx 3 2 torus integer dim ndims 2 c dim 2 ndims 1 3 ndims 2 2 IPM_CREATE node dim ndims IPM_HOST_I numc c numc should be equal to 5 21 IPM 2 3 IPM_DADDY function Synopsis IPM_DADDY Arguments IN none OUT none Discussion IPM_DADDY is the rank process of the logical father of the calling process in the global binary tree Host and root processes don t have any father process thus IPM_DADDY is set to IPM_NO_DADDY See also IPM_ROOT IPM_NB_SONS IPM_SONS Example c if IPM_DADDY eq IPM_NO_DADDY then write 6 I am probably the host process if IPM RANK eq IPM_ROOT then write 6 bouuhh I am only root else write 6 yeaahh I am the master endif endif c 22 IPM 2 3 IPM_DECLAR subroutine Synopsis IPM_DECLAR Arguments IN none OUT none Discussion IPM_DECLAR should be included in user s declarations in each routine which invokes IPM functions or subroutines It contains internal declarations Example program short c include ipm h c
26. two IPM internal macros an internal type and the number of internals needed to constitute an integer The default values are 11 IPM 2 3 Internal Integer Type and Basic unit Customized define IPM_INTERNAL INTEGER4 define IPM_INTBUNIT 1 which defines the internal integer used by IPM to be a single INTEGER4 If the user wishes to run on a CRAY T3D or other machines where 8 bytes integers are default he should define define IPM_INTERNAL BYTE1 define IPM_INTBUNIT 8 7 Warnings and Bugs A customized graph which includes the host process as an active process is not possible using PARMACS 6 0 The only way of running such an application is to define an un derlying one dimensional torus with PARMACS and then to emulate the customized graph If the current mapping is a torus and the host process is not included in this topology then calling IPM_GET_COORDS with the host process rank returns the point of ori gin However IPM_GET_RANK with the same coordinates returns 1 which is clearly not the rank of the host process It happens on the Meiko CS 2 machine that an executable is unable to spwan itself No definitive reason has been found for this problem A solution is to duplicate the executable The user should not use message tags greater than 16000000 12 IPM 2 3 Appendix I Reference pages for IPM 2 3 macros 13 IPM 2 3 IPM_ABORT subroutine Synopsis IPM_ABORT Arguments IN none OUT non
27. ype len buffer recvrank recvtag recvlen arrived Arguments IN reqrank requested rank of the sending process integer regtag requested tag of the expected message integer type data type expected integer len number of elements expected integer buffer starting address of the receive buffer handle OUT recvrank rank of the effective sending process integer recvtag tag of the received message integer recvlen lengh in bytes of the received message integer arrived integer which specifies if the requested message has arrived 1 or not 0 Discussion IPM NRECV is used for asynchronous message passing between any two active proces ses It performs a non blocking receive the calling process checks if a message with reqtag tag from reqrank is arrived or not and returns immediately Wildcards IPM_ANYSND and IPM_ANYTAG can be used in place of the first two arguments matching for any sender or any tag See also IPM_SEND for the list of datatypes IPM_ANYSND IPM_ANYTAG IPM_RECV IPM_TYPE_LENGTH Example c c 100 looking for a job continue IPM_NRECV IPM_ANYSND 1 IPM_INTEGER 1 ijob is it il iok if iok eq 0 no job available ip sleep 60 go to 100 else have a big nap before working ip sleep 7200 endif 42 IPM 2 3 IPM_PROBE subroutine Synopsis IPM_PROBE reqrank reqtag recvrank recvtag arrived Arguments IN reqrank requested rank of the sending process integer regtag
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