Changes between Initial Version and Version 1 of mpich/constants

Timestamp:

Mar 26, 2008, 5:24:16 PM (18 years ago)

Author:

wade

Comment:

--

mpich/constants

@@ +1 @@
+[[PageOutline]]
+= Constants =
+Meaning of MPIs defined constants
+
+= Data types =
+Note that the Fortran types should only be used in Fortran programs, and the C types should only be used in C programs. For example, it is in error to use MPI_INT for a Fortran INTEGER. Datatypes are of type MPI_Datatype in C and of tyep INTEGER in Fortran.
+
+= C datatypes =
+
+MPI_CHAR
+    char 
+
+MPI_BYTE
+    See standard; like unsigned char 
+
+MPI_SHORT
+    short 
+
+MPI_INT
+    int 
+
+MPI_LONG
+    long 
+
+MPI_FLOAT
+    float 
+
+MPI_DOUBLE
+    double 
+
+MPI_UNSIGNED_CHAR
+    unsigned char 
+
+MPI_UNSIGNED_SHORT
+    unsigned short 
+
+MPI_UNSIGNED
+    unsigned int 
+
+MPI_UNSIGNED_LONG
+    unsigned long 
+
+MPI_LONG_DOUBLE
+    long double (some systems may not implement) 
+
+MPI_LONG_LONG_INT
+    long long (some systems may not implement) 
+
+
+
+'''The following are datatypes for the MPI functions MPI_MAXLOC and MPI_MINLOC.'''
+
+MPI_FLOAT_INT
+    struct { float, int } 
+
+MPI_LONG_INT
+    struct { long, int } 
+
+MPI_DOUBLE_INT
+    struct { double, int } 
+
+MPI_SHORT_INT
+    struct { short, int } 
+
+MPI_2INT
+    struct { int, int } 
+
+MPI_LONG_DOUBLE_INT
+    struct { long double, int }; this is an OPTIONAL type, and may be set to NULL 
+
+
+
+'''Note that there is no MPI_LONG_LONG_INT type corresponding to a struct { long long, int }.[[BR]]
+Special datatypes for C and Fortran'''
+
+MPI_PACKED
+    For MPI_Pack and MPI_Unpack 
+
+MPI_UB
+    For MPI_Type_struct; an upper-bound indicator 
+
+MPI_LB
+    For MPI_Type_struct; a lower-bound indicator 
+
+
+
+= Fortran datatypes =
+
+MPI_REAL
+    REAL 
+
+MPI_INTEGER
+    INTEGER 
+
+MPI_LOGICAL
+    LOGICAL 
+
+MPI_DOUBLE_PRECISION
+    DOUBLE PRECISION 
+
+MPI_COMPLEX
+    COMPLEX 
+
+MPI_DOUBLE_COMPLEX
+    complex*16 (or complex*32) where supported. 
+
+
+
+'''The following datatypes are optional'''
+
+MPI_INTEGER1
+    integer*1 if supported 
+
+MPI_INTEGER2
+    integer*2 if supported 
+
+MPI_INTEGER4
+    integer*4 if supported 
+
+MPI_REAL4
+    real*4 if supported 
+
+MPI_REAL8
+    real*8 if supported 
+
+
+
+'''The following are datatypes for the MPI functions MPI_MAXLOC and MPI_MINLOC. In Fortran, these datatype always consist of two elements of the same Fortran type.'''
+
+MPI_2INTEGER
+    INTEGER,INTEGER 
+
+MPI_2REAL
+    REAL, REAL 
+
+MPI_2DOUBLE_PRECISION
+    DOUBLE PRECISION, DOUBLE PRECISION 
+
+MPI_2COMPLEX
+    COMPLEX, COMPLEX 
+
+MPI_2DOUBLE_COMPLEX
+    complex*16, complex*16 
+
+
+
+= Communicators =
+Communicators are of type MPI_Comm in C and INTEGER in Fortran
+
+MPI_COMM_WORLD
+    Contains all of the processes 
+
+MPI_COMM_SELF
+    Contains only the calling process 
+
+
+
+= Groups =
+Groups are of type MPI_Group in C and INTEGER in Fortran
+
+MPI_GROUP_EMPTY
+    A group containing no members. 
+
+Results of the compare operations
+
+MPI_IDENT
+    Identical 
+
+MPI_CONGRUENT
+    (only for MPI_COMM_COMPARE) The groups are identical 
+
+MPI_SIMILAR
+    Same members, but in a different order 
+
+MPI_UNEQUAL
+    Different 
+
+
+
+= Collective operations =
+The collective combination operations (MPI_REDUCE, MPI_ALLREDUCE, MPI_REDUCE_SCATTER, and MPI_SCAN) take a combination operation. This operation is of type MPI_Op in C and of type INTEGER in Fortran. The predefined operations are
+
+MPI_MAX
+    return the maximum 
+
+MPI_MIN
+    return the minumum 
+
+MPI_SUM
+    return the sum 
+
+MPI_PROD
+    return the product 
+
+MPI_LAND
+    return the logical and 
+
+MPI_BAND
+    return the bitwise and 
+
+MPI_LOR
+    return the logical or 
+
+MPI_BOR
+    return the bitwise of 
+
+MPI_LXOR
+    return the logical exclusive or 
+
+MPI_BXOR
+    return the bitwise exclusive or 
+
+MPI_MINLOC
+    return the minimum and the location (actually, the value of the second element of the structure where the minimum of the first is found) 
+
+MPI_MAXLOC
+    return the maximum and the location 
+
+
+
+= Notes on collective operations =
+
+The reduction functions (MPI_Op) do not return an error value. As a result, if the functions detect an error, all they can do is either call MPI_Abort or silently skip the problem. Thus, if you change the error handler from MPI_ERRORS_ARE_FATAL to something else, for example, MPI_ERRORS_RETURN, then no error may be indicated.
+
+The reason for this is the performance problems in ensuring that all collective routines return the same error value.
+
+Note that not all datatypes are valid for these functions. For example, MPI_COMPLEX is not valid for MPI_MAX and MPI_MIN. In addition, the MPI 1.1 standard did not include the C types MPI_CHAR and MPI_UNSIGNED_CHAR among the lists of arithmetic types for operations like MPI_SUM. However, since the C type char is an integer type (like short), it should have been included. The MPI Forum will probably include char and unsigned char as a clarification to MPI 1.1; until then, users are advised that MPI implementations may not accept MPI_CHAR and MPI_UNSIGNED_CHAR as valid datatypes for MPI_SUM, MPI_PROD, etc. MPICH does allow these datatypes.
+
+
+
+= Permanent key values =
+These are the same in C and Fortran
+
+MPI_TAG_UB
+    Largest tag value 
+
+MPI_HOST
+    Rank of process that is host, if any 
+
+MPI_IO
+    Rank of process that can do I/O 
+
+MPI_WTIME_IS_GLOBAL
+    Has value 1 if MPI_WTIME is globally synchronized. 
+
+
+
+= Null objects =
+
+MPI_COMM_NULL
+    Null communicator 
+
+MPI_OP_NULL
+    Null operation 
+
+MPI_GROUP_NULL
+    Null group 
+
+MPI_DATATYPE_NULL
+    Null datatype 
+
+MPI_REQUEST_NULL
+    Null request 
+
+MPI_ERRHANDLER_NULL
+    Null error handler 
+
+
+
+= Predefined Constants =
+
+MPI_MAX_PROCESSOR_NAME
+    Maximum length of name returned by MPI_GET_PROCESSOR_NAME 
+
+MPI_MAX_ERROR_STRING
+    Maximum length of string return by MPI_ERROR_STRING 
+
+MPI_UNDEFINED
+    Used by many routines to indicated undefined or unknown integer value 
+
+MPI_UNDEFINED_RANK
+    Unknown rank 
+
+MPI_KEYVAL_INVALID
+    Special keyval that may be used to detect uninitialized keyvals. 
+
+MPI_BSEND_OVERHEAD
+    Add this to the size of a MPI_BSEND buffer for each outstanding message 
+
+MPI_PROC_NULL
+    This rank may be used to send or receive from no-one. 
+
+MPI_ANY_SOURCE
+    In a receive, accept a message from anyone. 
+
+MPI_ANY_TAG
+    In a receive, accept a message with any tag value. 
+
+MPI_BOTTOM
+    May be used to indicate the bottom of the address space 
+
+
+
+= Topology types =
+
+MPI_GRAPH
+    General graph 
+
+MPI_CART
+    Cartesian grid 
+
+
+
+= MPI Status =
+The MPI_Status datatype is a structure. The three elements for use by programmers are
+
+MPI_SOURCE
+    Who sent the message 
+
+MPI_TAG
+    What tag the message was sent with 
+
+MPI_ERROR
+    Any error return 
+
+
+
+= Special MPI types and functions =
+
+MPI_Aint
+    C type that holds any valid address. 
+
+MPI_Handler_function
+    C function for handling errors (see MPI_Errhandler_create) . 
+
+MPI_User_function
+    C function to combine values (see collective operations and MPI_Op_create) 
+
+MPI_Copy_function
+    Function to copy attributes (see MPI_Keyval_create) 
+
+MPI_NULL_COPY_FN
+    Predefined copy function 
+
+MPI_Delete_function
+    Function to delete attributes (see MPI_Keyval_create) 
+
+MPI_NULL_DELETE_FN
+    Predefined delete function 
+
+MPI_DUP_FN
+    Predefined duplication function 
+
+MPI_ERRORS_ARE_FATAL
+    Error handler that forces exit on error 
+
+MPI_ERRORS_RETURN
+    Error handler that returns error codes (as value of MPI routine in C and through last argument in Fortran) 
+
+
+
+= MPI Error classes =
+
+MPI_SUCCESS
+    Successful return code 
+
+MPI_ERR_BUFFER
+    Invalid buffer pointer 
+
+MPI_ERR_COUNT
+    Invalid count argument 
+
+MPI_ERR_TYPE
+    Invalid datatype argument 
+
+MPI_ERR_TAG
+    Invalid tag argument 
+
+MPI_ERR_COMM
+    Invalid communicator 
+
+MPI_ERR_RANK
+    Invalid rank 
+
+MPI_ERR_ROOT
+    Invalid root 
+
+MPI_ERR_GROUP
+    Null group passed to function 
+
+MPI_ERR_OP
+    Invalid operation 
+
+MPI_ERR_TOPOLOGY
+    Invalid topology 
+
+MPI_ERR_DIMS
+    Illegal dimension argument 
+
+MPI_ERR_ARG
+    Invalid argument 
+
+MPI_ERR_UNKNOWN
+    Unknown error 
+
+MPI_ERR_TRUNCATE
+    message truncated on receive 
+
+MPI_ERR_OTHER
+    Other error; use Error_string 
+
+MPI_ERR_INTERN
+    internal error code 
+
+MPI_ERR_IN_STATUS
+    Look in status for error value 
+
+MPI_ERR_PENDING
+    Pending request 
+
+MPI_ERR_REQUEST
+    illegal mpi_request handle 
+
+MPI_ERR_LASTCODE
+    Last error code -- always at end 
+
+Location:/home/MPI/mansrc/mpiconsts.txt
+
+from:[http://www-unix.mcs.anl.gov/mpi/www/www3/Constants.html]