.TH Constants 3 "11/21/2018" " " "MPI"
.SH NAME
Constants \-  Meaning of MPI's defined constants 
.SH 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 
.I MPI_INT
for a Fortran INTEGER.
Datatypes are of type 
.I MPI_Datatype
in C, type 
.I INTEGER
in Fortran,
and 
.I Type(MPI_Datatype)
in Fortran08

.SH C DATATYPES
MPI_CHAR - char
.PD 0
.TP
.B MPI_SIGNED_CHAR 
- signed char
.PD 1
.PD 0
.TP
.B MPI_UNSIGNED_CHAR 
- unsigned char
.PD 1
.PD 0
.TP
.B MPI_BYTE 
- See standard; like unsigned char
.PD 1
.PD 0
.TP
.B MPI_WCHAR 
- wide character (wchar_t)
.PD 1
.PD 0
.TP
.B MPI_SHORT 
- short
.PD 1
.PD 0
.TP
.B MPI_UNSIGNED_SHORT 
- unsigned short
.PD 1
.PD 0
.TP
.B MPI_INT   
- int
.PD 1
.PD 0
.TP
.B MPI_UNSIGNED 
- unsigned int
.PD 1
.PD 0
.TP
.B MPI_LONG 
- long
.PD 1
.PD 0
.TP
.B MPI_UNSIGNED_LONG 
- unsigned long
.PD 1
.PD 0
.TP
.B MPI_LONG_LONG_INT 
- long long
.PD 1
.PD 0
.TP
.B MPI_LONG_LONG 
- synonyn for 
.I MPI_LONG_LONG_INT

.PD 1
.PD 0
.TP
.B MPI_UNSIGNED_LONG_LONG 
- unsigned long long
.PD 1
.PD 0
.TP
.B MPI_FLOAT 
- float
.PD 1
.PD 0
.TP
.B MPI_DOUBLE 
- double
.PD 1
.PD 0
.TP
.B MPI_LONG_DOUBLE  
- long double (some systems may not implement this)
.PD 1
.PD 0
.TP
.B MPI_INT8_T  
- int8_t
.PD 1
.PD 0
.TP
.B MPI_INT16_T 
- int16_t
.PD 1
.PD 0
.TP
.B MPI_INT32_T 
- int32_t
.PD 1
.PD 0
.TP
.B MPI_INT64_T 
- int64_t
.PD 1
.PD 0
.TP
.B MPI_UINT8_T  
- uint8_t
.PD 1
.PD 0
.TP
.B MPI_UINT16_T 
- uint16_t
.PD 1
.PD 0
.TP
.B MPI_UINT32_T 
- uint32_t
.PD 1
.PD 0
.TP
.B MPI_UINT64_T 
- uint64_t
.PD 1
.PD 0
.TP
.B MPI_C_BOOL 
- _Bool
.PD 1
.PD 0
.TP
.B MPI_C_FLOAT_COMPLEX 
- float _Complex
.PD 1
.PD 0
.TP
.B MPI_C_COMPLEX 
- float _Complex
.PD 1
.PD 0
.TP
.B MPI_C_DOUBLE_COMPLEX 
- double _Complex
.PD 1
.PD 0
.TP
.B MPI_C_LONG_DOUBLE_COMPLEX 
- long double _Complex
.PD 1


The following are datatypes for the MPI functions 
.I MPI_MAXLOC
and
.I MPI_MINLOC
\&.

MPI_FLOAT_INT - 
.I struct { float, int }

.PD 0
.TP
.B MPI_LONG_INT  
- 
.I struct { long, int }

.PD 1
.PD 0
.TP
.B MPI_DOUBLE_INT 
- 
.I struct { double, int }

.PD 1
.PD 0
.TP
.B MPI_SHORT_INT  
- 
.I struct { short, int }

.PD 1
.PD 0
.TP
.B MPI_2INT       
- 
.I struct { int, int }

.PD 1
.PD 0
.TP
.B MPI_LONG_DOUBLE_INT 
- 
.I struct { long double, int }
; this
is an 
.B optional
type, and may be set to 
.I MPI_DATATYPE_NULL

.PD 1


Special datatypes for C and Fortran
MPI_PACKED - For 
.I MPI_Pack
and 
.I MPI_Unpack

.PD 0
.TP
.B MPI_UB 
- For 
.I MPI_Type_struct
; an upper-bound indicator.  Removed in MPI 3
.PD 1
.PD 0
.TP
.B MPI_LB 
- For 
.I MPI_Type_struct
; a lower-bound indicator. Removed in MPI 3
.PD 1

.SH FORTRAN DATATYPES
MPI_REAL - 
.I REAL

.PD 0
.TP
.B MPI_INTEGER 
- 
.I INTEGER

.PD 1
.PD 0
.TP
.B MPI_LOGICAL 
- 
.I LOGICAL

.PD 1
.PD 0
.TP
.B MPI_DOUBLE_PRECISION 
- 
.I DOUBLE PRECISION

.PD 1
.PD 0
.TP
.B MPI_COMPLEX 
- 
.I COMPLEX

.PD 1
.PD 0
.TP
.B MPI_DOUBLE_COMPLEX 
- 
.I complex*16
(or 
.I complex*32
) where supported.
.PD 1

The following datatypes are optional
MPI_INTEGER1  - 
.I integer*1
if supported
.PD 0
.TP
.B MPI_INTEGER2  
- 
.I integer*2
if supported
.PD 1
.PD 0
.TP
.B MPI_INTEGER4  
- 
.I integer*4
if supported
.PD 1
.PD 0
.TP
.B MPI_INTEGER8  
- 
.I integer*8
if supported
.PD 1
.PD 0
.TP
.B MPI_INTEGER16 
- 
.I integer*16
if supported
.PD 1
.PD 0
.TP
.B MPI_REAL4     
- 
.I real*4
if supported
.PD 1
.PD 0
.TP
.B MPI_REAL8     
- 
.I real*8
if supported
.PD 1
.PD 0
.TP
.B MPI_REAL16    
- 
.I real*16
if supported
.PD 1
.PD 0
.TP
.B MPI_COMPLEX8  
- 
.I complex*8
if supported
.PD 1
.PD 0
.TP
.B MPI_COMPLEX16 
- 
.I complex*16
if supported
.PD 1
.PD 0
.TP
.B MPI_COMPLEX32 
- 
.I complex*32
if supported
.PD 1

The following are datatypes for the MPI functions 
.I MPI_MAXLOC
and
.I MPI_MINLOC
\&.
In Fortran, these datatype always consist of
two elements of the same Fortran type.
MPI_2INTEGER - 
.I INTEGER,INTEGER

.PD 0
.TP
.B MPI_2REAL    
- 
.I REAL, REAL

.PD 1
.PD 0
.TP
.B MPI_2DOUBLE_PRECISION 
- 
.I DOUBLE PRECISION, DOUBLE PRECISION

.PD 1

MPI Datatypes for MPI Types
MPI_AINT - Datatype for an 
.I MPI_Aint

.PD 0
.TP
.B MPI_OFFSET 
- Datatype for an 
.I MPI_Offset

.PD 1
.PD 0
.TP
.B MPI_COUNT 
- Datatype for an 
.I MPI_Count

.PD 1

.SH MPI DATATYPE COMBINER NAMES
MPI_COMBINER_NAMED            - a named predefined datatype
.PD 0
.TP
.B MPI_COMBINER_DUP              
- MPI_TYPE_DUP
.PD 1
.PD 0
.TP
.B MPI_COMBINER_CONTIGUOUS       
- MPI_TYPE_CONTIGUOUS
.PD 1
.PD 0
.TP
.B MPI_COMBINER_VECTOR           
- MPI_TYPE_VECTOR
.PD 1
.PD 0
.TP
.B MPI_COMBINER_HVECTOR_INTEGER  
- Removed in MPI-3
.PD 1
.PD 0
.TP
.B MPI_COMBINER_HVECTOR          
- MPI_TYPE_CREATE_HVECTOR
.PD 1
.PD 0
.TP
.B MPI_COMBINER_INDEXED          
- MPI_TYPE_INDEXED
.PD 1
.PD 0
.TP
.B MPI_COMBINER_HINDEXED_INTEGER 
- Removed in MPI-3
.PD 1
.PD 0
.TP
.B MPI_COMBINER_HINDEXED         
- MPI_TYPE_CREATE_HINDEXED
.PD 1
.PD 0
.TP
.B MPI_COMBINER_INDEXED_BLOCK    
- MPI_TYPE_CREATE_INDEXED_BLOCK
.PD 1
.PD 0
.TP
.B MPI_COMBINER_STRUCT_INTEGER   
- Removed in MPI-3
.PD 1
.PD 0
.TP
.B MPI_COMBINER_STRUCT           
- MPI_TYPE_CREATE_STRUCT
.PD 1
.PD 0
.TP
.B MPI_COMBINER_SUBARRAY         
- MPI_TYPE_CREATE_SUBARRAY
.PD 1
.PD 0
.TP
.B MPI_COMBINER_DARRAY           
- MPI_TYPE_CREATE_DARRAY
.PD 1
.PD 0
.TP
.B MPI_COMBINER_F90_REAL         
- MPI_TYPE_CREATE_F90_REAL
.PD 1
.PD 0
.TP
.B MPI_COMBINER_F90_COMPLEX      
- MPI_TYPE_CREATE_F90_COMPLEX
.PD 1
.PD 0
.TP
.B MPI_COMBINER_F90_INTEGER      
- MPI_TYPE_CREATE_F90_INTEGER
.PD 1
.PD 0
.TP
.B MPI_COMBINER_RESIZED          
- MPI_TYPE_CREATE_RESIZED
.PD 1
.PD 0
.TP
.B MPI_COMBINER_HINDEXED_BLOCK   
- MPI_TYPE_CREATE_HINDEXED_BLOCK
.PD 1

.SH MPI DATATYPE TYPE CLASSES
MPI Type classes used with routines to return Fortran types with defined
precision and range
MPI_TYPECLASS_REAL    - 
.I REAL

.PD 0
.TP
.B MPI_TYPECLASS_INTEGER 
- 
.I INTEGER

.PD 1
.PD 0
.TP
.B MPI_TYPECLASS_COMPLEX 
- 
.I COMPLEX

.PD 1

.SH MPI DARRAY AND SUBARRAY VALUES
These values are used to create a datatype with the 
.I DARRAY
and 
.I SUBARRAY
constructors.
MPI_ORDER_C              - Row-major order (as used by C)
.PD 0
.TP
.B MPI_ORDER_FORTRAN        
- Column-major order (as used by Fortran)
.PD 1
.PD 0
.TP
.B MPI_DISTRIBUTE_BLOCK     
- Block distribution
.PD 1
.PD 0
.TP
.B MPI_DISTRIBUTE_CYCLIC    
- Cyclic distribution
.PD 1
.PD 0
.TP
.B MPI_DISTRIBUTE_NONE      
- This dimension is not distributed
.PD 1
.PD 0
.TP
.B MPI_DISTRIBUTE_DFLT_DARG 
- Use the default distribution
.PD 1

.SH COMMUNICATORS
Communicators are of type 
.I MPI_Comm
in C, 
.I INTEGER
in Fortran, and
.I Type(MPI_Comm)
in Fortran08
MPI_COMM_WORLD - Contains all of the processes
.PD 0
.TP
.B MPI_COMM_SELF 
- Contains only the calling process
.PD 1

.SH KIND OF COMMUNICATOR FOR 'MPI_COMM_SPLIT_TYPE'
MPI_COMM_TYPE_SHARED - All processes that can share memory are grouped into
the same communicator.

.SH GROUPS
Groups are of type 
.I MPI_Group
in C, 
.I INTEGER
in Fortran,
and 
.I Type(MPI_Group)
in Fortran08

MPI_GROUP_EMPTY - A group containing no members.

.SH RESULTS OF THE COMPARE OPERATIONS ON GROUPS AND COMMUNICATORS
MPI_IDENT - Identical
.PD 0
.TP
.B MPI_CONGRUENT  
- (only for 
.I MPI_COMM_COMPARE
) The groups are identical
.PD 1
.PD 0
.TP
.B MPI_SIMILAR 
- Same members, but in a different order
.PD 1
.PD 0
.TP
.B MPI_UNEQUAL 
- Different
.PD 1


.SH COLLECTIVE OPERATIONS
The collective combination operations (e.g., 
.I MPI_REDUCE
, 
.I MPI_ALLREDUCE
,
.I MPI_REDUCE_SCATTER
, and 
.I MPI_SCAN
) take a combination operation.
This operation is of type 
.I MPI_Op
in C and of type 
.I INTEGER
in Fortran.
The predefined operations are

MPI_MAX - return the maximum
.PD 0
.TP
.B MPI_MIN 
- return the minumum
.PD 1
.PD 0
.TP
.B MPI_SUM 
- return the sum
.PD 1
.PD 0
.TP
.B MPI_PROD 
- return the product
.PD 1
.PD 0
.TP
.B MPI_LAND 
- return the logical and
.PD 1
.PD 0
.TP
.B MPI_BAND 
- return the bitwise and
.PD 1
.PD 0
.TP
.B MPI_LOR 
- return the logical or
.PD 1
.PD 0
.TP
.B MPI_BOR 
- return the bitwise of
.PD 1
.PD 0
.TP
.B MPI_LXOR 
- return the logical exclusive or
.PD 1
.PD 0
.TP
.B MPI_BXOR 
- return the bitwise exclusive or
.PD 1
.PD 0
.TP
.B 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)
.PD 1
.PD 0
.TP
.B MPI_MAXLOC 
- return the maximum and the location
.PD 1
.PD 0
.TP
.B MPI_REPLACE 
- replace b with a
.PD 1
.PD 0
.TP
.B MPI_NO_OP 
- perform no operation
.PD 1

.SH NOTES ON COLLECTIVE OPERATIONS

The reduction functions (
.I MPI_Op
) do not return an error value.  As a result,
if the functions detect an error, all they can do is either call 
.I MPI_Abort
or silently skip the problem.  Thus, if you change the error handler from
.I MPI_ERRORS_ARE_FATAL
to something else, for example, 
.I 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,
.I MPI_COMPLEX
is not valid for 
.I MPI_MAX
and 
.I MPI_MIN
\&.
In addition, the MPI
1.1 standard did not include the C types 
.I MPI_CHAR
and 
.I MPI_UNSIGNED_CHAR
among the lists of arithmetic types for operations like 
.I MPI_SUM
\&.
However,
since the C type 
.I char
is an integer type (like 
.I short
), it should have been
included.  The MPI Forum will probably include 
.I char
and 
.I unsigned char
as a clarification to MPI 1.1; until then, users are advised that MPI
implementations may not accept 
.I MPI_CHAR
and 
.I MPI_UNSIGNED_CHAR
as valid
datatypes for 
.I MPI_SUM
, 
.I MPI_PROD
, etc.  MPICH does allow these datatypes.

.SH PERMANENT KEY VALUES
These are the same in C and Fortran

MPI_TAG_UB - Largest tag value
.PD 0
.TP
.B MPI_HOST 
- Rank of process that is host, if any
.PD 1
.PD 0
.TP
.B MPI_IO 
- Rank of process that can do I/O
.PD 1
.PD 0
.TP
.B MPI_WTIME_IS_GLOBAL 
- Has value 1 if 
.I MPI_WTIME
is globally synchronized.
.PD 1
.PD 0
.TP
.B MPI_UNIVERSE_SIZE 
- Number of available processes.  See the standard for
a description of limitations on this value
.PD 1
.PD 0
.TP
.B MPI_LASTUSEDCODE 
- Last used MPI error code (check - code or class?)
.PD 1
.PD 0
.TP
.B MPI_APPNUM 
- Application number, starting from 0.  See the standard for
.I MPI_COMM_SPAWN_MULTIPLE
and 
.I mpiexec
for details
.PD 1

.SH NULL OBJECTS
MPI_COMM_NULL          - Null communicator
.PD 0
.TP
.B MPI_OP_NULL            
- Null operation
.PD 1
.PD 0
.TP
.B MPI_GROUP_NULL         
- Null group
.PD 1
.PD 0
.TP
.B MPI_DATATYPE_NULL      
- Null datatype
.PD 1
.PD 0
.TP
.B MPI_REQUEST_NULL       
- Null request
.PD 1
.PD 0
.TP
.B MPI_ERRHANDLER_NULL    
- Null error handler
.PD 1
.PD 0
.TP
.B MPI_WIN_NULL           
- Null window handle
.PD 1
.PD 0
.TP
.B MPI_FILE_NULL          
- Null file handle
.PD 1
.PD 0
.TP
.B MPI_INFO_NULL          
- Null info handle
.PD 1
.PD 0
.TP
.B MPI_MESSAGE_NULL       
- Null message handle
.PD 1
.PD 0
.TP
.B MPI_ARGV_NULL          
- Empty ARGV value for spawn commands
.PD 1
.PD 0
.TP
.B MPI_ARGVS_NULL         
- Empty ARGV array for spawn-multiple command
.PD 1
.PD 0
.TP
.B MPI_T_ENUM_NULL        
- Null MPI_T enum
.PD 1
.PD 0
.TP
.B MPI_T_CVAR_HANDLE_NULL 
- Null MPI_T control variable handle
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_HANDLE_NULL 
- Null MPI_T performance variable handle
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_SESSION_NULL
- Null MPI_T performance variable session handle
.PD 1

.SH PREDEFINED CONSTANTS
MPI_MAX_PROCESSOR_NAME         - Maximum length of name returned by
.I MPI_GET_PROCESSOR_NAME

.PD 0
.TP
.B MPI_MAX_ERROR_STRING           
- Maximum length of string return by
.I MPI_ERROR_STRING

.PD 1
.PD 0
.TP
.B MPI_MAX_LIBRARY_VERSION_STRING 
- Maximum length of string returned by
.I MPI_GET_LIBRARY_VERSION_STRING
???
.PD 1
.PD 0
.TP
.B MPI_MAX_PORT_NAME              
- Maximum length of a port
.PD 1
.PD 0
.TP
.B MPI_MAX_OBJECT_NAME            
- Maximum length of an object (?)
.PD 1
.PD 0
.TP
.B MPI_MAX_INFO_KEY               
- Maximum length of an info key
.PD 1
.PD 0
.TP
.B MPI_MAX_INFO_VAL               
- Maximum length of an info value
.PD 1
.PD 0
.TP
.B MPI_UNDEFINED                  
- Used by many routines to indicated
undefined or unknown integer value
.PD 1
.PD 0
.TP
.B MPI_UNDEFINED_RANK             
- Unknown rank
.PD 1
.PD 0
.TP
.B MPI_KEYVAL_INVALID             
- Special keyval that may be used to detect
uninitialized keyvals.
.PD 1
.PD 0
.TP
.B MPI_BSEND_OVERHEAD             
- Add this to the size of a 
.I MPI_BSEND
buffer for each outstanding message
.PD 1
.PD 0
.TP
.B MPI_PROC_NULL                  
- This rank may be used to send or receive from no-one.
.PD 1
.PD 0
.TP
.B MPI_ANY_SOURCE                 
- In a receive, accept a message from anyone.
.PD 1
.PD 0
.TP
.B MPI_ANY_TAG                    
- In a receive, accept a message with any tag value.
.PD 1
.PD 0
.TP
.B MPI_BOTTOM                     
- May be used to indicate the bottom of the address space
.PD 1
.PD 0
.TP
.B MPI_IN_PLACE                   
- Special location for buffer in some
collective communication routines
.PD 1
.PD 0
.TP
.B MPI_VERSION                    
- Numeric value of MPI version (e.g., 3)
.PD 1
.PD 0
.TP
.B MPI_SUBVERSION                 
- Numeric value of MPI subversion (e.g., 1)
.PD 1

.SH TOPOLOGY TYPES
MPI_CART       - Cartesian grid
.PD 0
.TP
.B MPI_GRAPH      
- General graph
.PD 1
.PD 0
.TP
.B MPI_DIST_GRAPH 
- General distributed graph
.PD 1

.SH SPECIAL VALUES FOR DISTRIBUTED GRAPH
MPI_UNWEIGHTED    - Indicates that the edges are unweighted
.PD 0
.TP
.B MPI_WEIGHTS_EMPTY 
- Special address that indicates no array of weights
information
.PD 1

.SH FILE MODES
MPI_MODE_RDONLY          - Read only
.PD 0
.TP
.B MPI_MODE_RDWR            
- Read and write
.PD 1
.PD 0
.TP
.B MPI_MODE_WRONLY          
- Write only
.PD 1
.PD 0
.TP
.B MPI_MODE_CREATE          
- Create the file if it does not exist
.PD 1
.PD 0
.TP
.B MPI_MODE_EXCL            
- It is an error if creating a file that already
exists
.PD 1
.PD 0
.TP
.B MPI_MODE_DELETE_ON_CLOSE 
- Delete the file on close
.PD 1
.PD 0
.TP
.B MPI_MODE_UNIQUE_OPEN     
- The file will not be concurrently opened elsewhere
.PD 1
.PD 0
.TP
.B MPI_MODE_APPEND          
- The initial position of all file pointers is at
the end of the file
.PD 1
.PD 0
.TP
.B MPI_MODE_SEQUENTIAL      
- File will only be accessed sequentially
.PD 1

.SH FILE DISPLACEMENT
MPI_DISPLACEMENT_CURRENT - Use with files opened with mode
.I MPI_MODE_SEQUENTIAL
in calls to 
.I MPI_FILE_SET_VIEW


.SH FILE POSITIONING
MPI_SEEK_SET             - Set the pointer to 
.I offset

.PD 0
.TP
.B MPI_SEEK_CUR             
- Set the pointer to the current position plus 
.I offset

.PD 1
.PD 0
.TP
.B MPI_SEEK_END             
- Set the pointer to the end of the file plus 
.I offset

.PD 1

.SH WINDOW ATTRIBUTES
MPI_WIN_BASE - window base address.
.PD 0
.TP
.B MPI_WIN_SIZE 
- window size, in bytes
.PD 1
.PD 0
.TP
.B MPI_WIN_DISP_UNIT 
- displacement unit associated with the window
.PD 1
.PD 0
.TP
.B MPI_WIN_CREATE_FLAVOR 
- how the window was created
.PD 1
.PD 0
.TP
.B MPI_WIN_MODEL 
- memory model for window
.PD 1

.SH WINDOW FLAVORS
MPI_WIN_FLAVOR_CREATE   - Window was created with MPI_WIN_CREATE.
.PD 0
.TP
.B MPI_WIN_FLAVOR_ALLOCATE 
- Window was created with MPI_WIN_ALLOCATE.
.PD 1
.PD 0
.TP
.B MPI_WIN_FLAVOR_DYNAMIC  
- Window was created with MPI_WIN_CREATE_DYNAMIC.
.PD 1
.PD 0
.TP
.B MPI_WIN_FLAVOR_SHARED   
- Window was created with MPI_WIN_ALLOCATE_SHARED.
.PD 1

.SH WINDOW MEMORY MODEL
MPI_WIN_SEPARATE - Separate public and private copies of window memory
.PD 0
.TP
.B MPI_WIN_UNIFIED 
- The publich and private copies are identical (by which
we mean that updates are eventually observed without additional RMA operations)
.PD 1

.SH WINDOW LOCK TYPES
MPI_LOCK_EXCLUSIVE - Only one process at a time will execute accesses
within the lock
.PD 0
.TP
.B MPI_LOCK_SHARED 
- Not exclusive; multiple processes may execute accesses
within the lock
.PD 1

.SH WINDOW ASSERTIONS
See section 11.5 in MPI 3.1 for a detailed description of each of these
assertion values.
MPI_MODE_NOCHECK      - The matching calls to MPI_WIN_POST or MPI_WIN_START
have already completed, or no process holds or will attempt to acquire, a
conflicting lock.
.PD 0
.TP
.B MPI_MODE_NOSTORE      
- The local window has not been updated by stores
since the last synchronization
.PD 1
.PD 0
.TP
.B MPI_MODE_NOPUT        
- The local window will not be updated by put or
accumulate until the next synchronization
.PD 1
.PD 0
.TP
.B MPI_MODE_NOPRECEDE    
- The fence does not complete any locally issued RMA
calls
.PD 1
.PD 0
.TP
.B MPI_MODE_NOSUCCEED    
- The fence does not start any locally issued RMA calls
.PD 1

.SH PREDEFINED INFO OBJECT
MPI_INFO_ENV - Contains the execution environment

.SH MPI STATUS
The 
.I MPI_Status
datatype is a structure in C.  The three elements for use
by programmers are
MPI_SOURCE - Who sent the message
.PD 0
.TP
.B MPI_TAG 
- What tag the message was sent with
.PD 1
.PD 0
.TP
.B MPI_ERROR 
- Any error return (only when the error returned by the routine
has error class 
.I MPI_ERR_IN_STATUS
)
.PD 1

MPI_STATUS_IGNORE   - Ignore a single 
.I MPI_Status
argument
.PD 0
.TP
.B MPI_STATUSES_IGNORE 
- Ignore an array of 
.I MPI_Status

.PD 1

.SH SPECIAL VALUE FOR ERROR CODES ARRAY
MPI_ERRCODES_IGNORE - Ignore an array of error codes

.SH MPI_T CONSTANTS
MPI_T_VERBOSITY_USER_BASIC     - Basic information of interest to users
.PD 0
.TP
.B MPI_T_VERBOSITY_USER_DETAIL    
- Detailed information of interest to users
.PD 1
.PD 0
.TP
.B MPI_T_VERBOSITY_USER_ALL       
- All remaining information of interest to users
.PD 1
.PD 0
.TP
.B MPI_T_VERBOSITY_TUNER_BASIC    
- Basic information required for tuning
.PD 1
.PD 0
.TP
.B MPI_T_VERBOSITY_TUNER_DETAIL   
- Detailed information required for tuning
.PD 1
.PD 0
.TP
.B MPI_T_VERBOSITY_TUNER_ALL      
- All remaining information required for tuning
.PD 1
.PD 0
.TP
.B MPI_T_VERBOSITY_MPIDEV_BASIC   
- Basic information for MPI implementors
.PD 1


.PD 0
.TP
.B MPI_T_VERBOSITY_MPIDEV_DETAIL  
- Detailed information for MPI implementors
.PD 1
.PD 0
.TP
.B MPI_T_VERBOSITY_MPIDEV_ALL     
- All remaining information for MPI implementors
.PD 1
.PD 0
.TP
.B MPI_T_BIND_NO_OBJECT           
- Applies globally to entire MPI process
.PD 1
.PD 0
.TP
.B MPI_T_BIND_MPI_COMM            
- MPI communicators
.PD 1
.PD 0
.TP
.B MPI_T_BIND_MPI_DATATYPE        
- MPI datatypes
.PD 1
.PD 0
.TP
.B MPI_T_BIND_MPI_ERRHANDLER      
- MPI error handlers
.PD 1
.PD 0
.TP
.B MPI_T_BIND_MPI_FILE            
- MPI file handles
.PD 1
.PD 0
.TP
.B MPI_T_BIND_MPI_GROUP           
- MPI groups
.PD 1
.PD 0
.TP
.B MPI_T_BIND_MPI_OP              
- MPI reduction operators
.PD 1
.PD 0
.TP
.B MPI_T_BIND_MPI_REQUEST         
- MPI requests
.PD 1
.PD 0
.TP
.B MPI_T_BIND_MPI_WIN             
- MPI windows for one-sided communication
.PD 1
.PD 0
.TP
.B MPI_T_BIND_MPI_MESSAGE         
- MPI message object
.PD 1
.PD 0
.TP
.B MPI_T_BIND_MPI_INFO            
- MPI info object
.PD 1
.PD 0
.TP
.B MPI_T_SCOPE_CONSTANT           
- read-only, value is constant
.PD 1
.PD 0
.TP
.B MPI_T_SCOPE_READONLY           
- read-only, cannot be written, but can
change
.PD 1
.PD 0
.TP
.B MPI_T_SCOPE_LOCAL              
- may be writeable, writing is a local
operation
.PD 1
.PD 0
.TP
.B MPI_T_SCOPE_GROUP              
- may be writeable, must be done to a
group of processes, all processes in a group must be set to consistent values
.PD 1
.PD 0
.TP
.B MPI_T_SCOPE_GROUP_EQ           
- may be writeable, must be done to a
group of processes, all processes in a group must be set to the same value
.PD 1
.PD 0
.TP
.B MPI_T_SCOPE_ALL                
- may be writeable, must be done to all
processes, all connected processes must be set to consistent values
.PD 1
.PD 0
.TP
.B MPI_T_SCOPE_ALL_EQ             
- may be writeable, must be done to all
processes, all connected processes must be set to the same value
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_CLASS_STATE         
- set of discrete states (MPI_INT)
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_CLASS_LEVEL         
- utilization level of a resource
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_CLASS_SIZE          
- size of a resource
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_CLASS_PERCENTAGE    
- percentage utilization of a resource
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_CLASS_HIGHWATERMARK 
- high watermark of a resource
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_CLASS_LOWWATERMARK  
- low watermark of a resource
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_CLASS_COUNTER       
- number of occurances of an event
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_CLASS_AGGREGATE     
- aggregate value over an event (e.g.,
sum of all memory allocations)
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_CLASS_TIMER         
- aggretate time spent executing event
.PD 1
.PD 0
.TP
.B MPI_T_PVAR_CLASS_GENERIC       
- used for any other time of performance
variable
.PD 1

.SH THREAD LEVELS
MPI_THREAD_SINGLE     - Only one thread executes
.PD 0
.TP
.B MPI_THREAD_FUNNELED   
- Only the main thread makes MPI calls
.PD 1
.PD 0
.TP
.B MPI_THREAD_SERIALIZED 
- Only one thread at a time makes MPI calls
.PD 1
.PD 0
.TP
.B MPI_THREAD_MULTIPLE   
- Multiple threads may make MPI calls
.PD 1

.SH SPECIAL MPI TYPES AND FUNCTIONS

MPI_Aint   - C type that holds any valid address.
.PD 0
.TP
.B MPI_Count  
- C type that holds any valid count.
.PD 1
.PD 0
.TP
.B MPI_Offset 
- C type that holds any valid file offset.
.PD 1
.PD 0
.TP
.B MPI_Handler_function 
- C function for handling errors (see
.I MPI_Errhandler_create
) .
.PD 1
.PD 0
.TP
.B MPI_User_function 
- C function to combine values (see collective operations
and 
.I MPI_Op_create
)
.PD 1
.PD 0
.TP
.B MPI_Copy_function 
- Function to copy attributes (see 
.I MPI_Keyval_create
)
.PD 1
.PD 0
.TP
.B MPI_Delete_function 
- Function to delete attributes (see 
.I MPI_Keyval_create
)
.PD 1
.PD 0
.TP
.B MPI_ERRORS_ARE_FATAL 
- Error handler that forces exit on error
.PD 1
.PD 0
.TP
.B MPI_ERRORS_RETURN 
- Error handler that returns error codes (as value of
MPI routine in C and through last argument in Fortran)
.PD 1

.SH MPI ATTRIBUTE DEFAULT FUNCTIONS
MPI_COMM_NULL_COPY_FN - Predefined attribute copy function for communicators
.PD 0
.TP
.B MPI_COMM_NULL_DELETE_FN 
- Predefined attribute delete function for communicators
.PD 1
.PD 0
.TP
.B MPI_COMM_DUP_FN  
- Predefined attribute duplicate function for communicators
.PD 1
.PD 0
.TP
.B MPI_WIN_NULL_COPY_FN 
- Predefined attribute copy function for windows
.PD 1
.PD 0
.TP
.B MPI_WIN_NULL_DELETE_FN 
- Predefined attribute delete function for windows
.PD 1
.PD 0
.TP
.B MPI_WIN_DUP_FN   
- Predefined attribute duplicate function for windows
.PD 1
.PD 0
.TP
.B MPI_TYPE_NULL_COPY_FN 
- Predefined attribute copy function for datatypes
.PD 1
.PD 0
.TP
.B MPI_TYPE_NULL_DELETE_FN 
- Predefined attribute delete function for datatypes
.PD 1
.PD 0
.TP
.B MPI_TYPE_DUP_FN 
- Predefined attribute duplicate function for datatypes
.PD 1

.SH MPI-1 ATTRIBUTE DEFAULT FUNCTIONS
MPI_NULL_COPY_FN - Predefined copy function
.PD 0
.TP
.B MPI_NULL_DELETE_FN 
- Predefined delete function
.PD 1
.PD 0
.TP
.B MPI_DUP_FN 
- Predefined duplication function
.PD 1

.SH MPI ERROR CLASSES
MPI_SUCCESS               - Successful return code
.PD 0
.TP
.B MPI_ERR_BUFFER            
- Invalid buffer pointer
.PD 1
.PD 0
.TP
.B MPI_ERR_COUNT             
- Invalid count argument
.PD 1
.PD 0
.TP
.B MPI_ERR_TYPE              
- Invalid datatype argument
.PD 1
.PD 0
.TP
.B MPI_ERR_TAG               
- Invalid tag argument
.PD 1
.PD 0
.TP
.B MPI_ERR_COMM              
- Invalid communicator
.PD 1
.PD 0
.TP
.B MPI_ERR_RANK              
- Invalid rank
.PD 1
.PD 0
.TP
.B MPI_ERR_ROOT              
- Invalid root
.PD 1
.PD 0
.TP
.B MPI_ERR_GROUP             
- Null group passed to function
.PD 1
.PD 0
.TP
.B MPI_ERR_OP                
- Invalid operation
.PD 1
.PD 0
.TP
.B MPI_ERR_TOPOLOGY          
- Invalid topology
.PD 1
.PD 0
.TP
.B MPI_ERR_DIMS              
- Illegal dimension argument
.PD 1
.PD 0
.TP
.B MPI_ERR_ARG               
- Invalid argument
.PD 1
.PD 0
.TP
.B MPI_ERR_UNKNOWN           
- Unknown error
.PD 1
.PD 0
.TP
.B MPI_ERR_TRUNCATE          
- Message truncated on receive
.PD 1
.PD 0
.TP
.B MPI_ERR_OTHER             
- Other error; use Error_string
.PD 1
.PD 0
.TP
.B MPI_ERR_INTERN            
- Internal error code
.PD 1
.PD 0
.TP
.B MPI_ERR_IN_STATUS         
- Look in status for error value
.PD 1
.PD 0
.TP
.B MPI_ERR_PENDING           
- Pending request
.PD 1
.PD 0
.TP
.B MPI_ERR_REQUEST           
- Invalid mpi_request handle
.PD 1
.PD 0
.TP
.B MPI_ERR_ACCESS            
- Permission denied
.PD 1
.PD 0
.TP
.B MPI_ERR_AMODE             
- Error related to the amode passed to
.I MPI_FILE_OPEN

.PD 1
.PD 0
.TP
.B MPI_ERR_BAD_FILE          
- Invalid file name (e.g., path name too long)
.PD 1
.PD 0
.TP
.B MPI_ERR_CONVERSION        
- An error occurred in a user supplied data
conversion function
.PD 1
.PD 0
.TP
.B MPI_ERR_DUP_DATAREP       
- Conversion functions could not be registered
because a data representation identifier that was already defined was passed
to 
.I MPI_REGISTER_DATAREP

.PD 1
.PD 0
.TP
.B MPI_ERR_FILE_EXISTS       
- File exists
.PD 1
.PD 0
.TP
.B MPI_ERR_FILE_IN_USE       
- File operation could not be completed, as
the file is currently open by some process
.PD 1
.PD 0
.TP
.B MPI_ERR_FILE              
- Invalid file handle
.PD 1
.PD 0
.TP
.B MPI_ERR_IO                
- Other I/O error
.PD 1
.PD 0
.TP
.B MPI_ERR_NO_SPACE          
- Not enough space
.PD 1
.PD 0
.TP
.B MPI_ERR_NO_SUCH_FILE      
- File does not exist
.PD 1
.PD 0
.TP
.B MPI_ERR_READ_ONLY         
- Read-only file or file system
.PD 1
.PD 0
.TP
.B MPI_ERR_UNSUPPORTED_DATAREP 
- Unsupported datarep passed to
.I MPI_FILE_SET_VIEW

.PD 1
.PD 0
.TP
.B MPI_ERR_INFO              
- Invalid info argument
.PD 1
.PD 0
.TP
.B MPI_ERR_INFO_KEY          
- Key longer than MPI_MAX_INFO_KEY
.PD 1
.PD 0
.TP
.B MPI_ERR_INFO_VALUE        
- Value longer than MPI_MAX_INFO_VAL
.PD 1
.PD 0
.TP
.B MPI_ERR_INFO_NOKEY        
- Invalid key passed to MPI_INFO_DELETE
.PD 1
.PD 0
.TP
.B MPI_ERR_NAME              
- Invalid service name passed to MPI_LOOKUP_NAME
.PD 1
.PD 0
.TP
.B MPI_ERR_NO_MEM            
- Alloc_mem could not allocate memory
.PD 1
.PD 0
.TP
.B MPI_ERR_NOT_SAME          
- Collective argument not identical on all
processes, or collective routines called in a different order by different
processes
.PD 1
.PD 0
.TP
.B MPI_ERR_PORT              
- Invalid port name passed to MPI_COMM_CONNECT
.PD 1
.PD 0
.TP
.B MPI_ERR_QUOTA             
- Quota exceeded
.PD 1
.PD 0
.TP
.B MPI_ERR_SERVICE           
- Invalid service name passed to MPI_UNPUBLISH_NAME
.PD 1
.PD 0
.TP
.B MPI_ERR_SPAWN             
- Error in spawning processes
.PD 1
.PD 0
.TP
.B MPI_ERR_UNSUPPORTED_OPERATION 
- Unsupported operation, such as seeking on
a file which supports sequential access only
.PD 1
.PD 0
.TP
.B MPI_ERR_WIN               
- Invalid win argument
.PD 1
.PD 0
.TP
.B MPI_ERR_BASE              
- Invalid base passed to MPI_FREE_MEM
.PD 1
.PD 0
.TP
.B MPI_ERR_LOCKTYPE          
- Invalid locktype argument
.PD 1
.PD 0
.TP
.B MPI_ERR_KEYVAL            
- Erroneous attribute key
.PD 1
.PD 0
.TP
.B MPI_ERR_RMA_CONFLICT      
- Conflicting accesses to window
.PD 1
.PD 0
.TP
.B MPI_ERR_RMA_SYNC          
- Wrong synchronization of RMA calls
.PD 1
.PD 0
.TP
.B MPI_ERR_SIZE              
- Invalid size argument
.PD 1
.PD 0
.TP
.B MPI_ERR_DISP              
- Invalid disp argument
.PD 1
.PD 0
.TP
.B MPI_ERR_ASSERT            
- Invalid assert argument
.PD 1
.PD 0
.TP
.B MPI_ERR_RMA_RANGE         
- Target memory is not part of the window (in
the case of a window created with MPI_WIN_CREATE_DYNAMIC, target memory is
not attached)
.PD 1
.PD 0
.TP
.B MPI_ERR_RMA_ATTACH        
- Memory cannot be attached (e.g., because of
resource exhaustion)
.PD 1
.PD 0
.TP
.B MPI_ERR_RMA_SHARED        
- Memory cannot be shared (e.g., some process in
the group of the specified communicator cannot expose shared memory)
.PD 1
.PD 0
.TP
.B MPI_ERR_RMA_FLAVOR        
- Passed window has the wrong flavor for the
called function
.PD 1
.PD 0
.TP
.B MPI_ERR_LASTCODE          
- Last error code -- always at end
.PD 1

.SH ERROR CODES FOR MPI_T

MPI_T_ERR_MEMORY            - Out of memory
.PD 0
.TP
.B MPI_T_ERR_NOT_INITIALIZED   
- Interface not initialized
.PD 1
.PD 0
.TP
.B MPI_T_ERR_CANNOT_INIT       
- Interface not in the state to be initialized
.PD 1
.PD 0
.TP
.B MPI_T_ERR_INVALID_INDEX     
- The index is invalid or has been deleted
.PD 1
.PD 0
.TP
.B MPI_T_ERR_INVALID_ITEM      
- Item index queried is out of range
.PD 1
.PD 0
.TP
.B MPI_T_ERR_INVALID_HANDLE    
- The handle is invalid
.PD 1
.PD 0
.TP
.B MPI_T_ERR_OUT_OF_HANDLES    
- No more handles available
.PD 1
.PD 0
.TP
.B MPI_T_ERR_OUT_OF_SESSIONS   
- No more sessions available
.PD 1
.PD 0
.TP
.B MPI_T_ERR_INVALID_SESSION   
- Session argument is not valid
.PD 1
.PD 0
.TP
.B MPI_T_ERR_CVAR_SET_NOT_NOW  
- Cvar can't be set at this moment
.PD 1
.PD 0
.TP
.B MPI_T_ERR_CVAR_SET_NEVER    
- Cvar can't be set until end of execution
.PD 1
.PD 0
.TP
.B MPI_T_ERR_PVAR_NO_STARTSTOP 
- Pvar can't be started or stopped
.PD 1
.PD 0
.TP
.B MPI_T_ERR_PVAR_NO_WRITE     
- Pvar can't be written or reset
.PD 1
.PD 0
.TP
.B MPI_T_ERR_PVAR_NO_ATOMIC    
- Pvar can't be R/W atomically
.PD 1
.PD 0
.TP
.B MPI_T_ERR_INVALID_NAME      
- Name doesn't match
.PD 1
.PD 0
.TP
.B MPI_T_ERR_INVALID           
- Invalid use of the interface or bad parameter
values(s)
.PD 1