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PMIX_DATA_TYPE_T(5) OpenPMIx PMIX_DATA_TYPE_T(5)

pmix_data_type_t — Identifies the type of a PMIx data value

SYNTAX

C Syntax

#include <pmix_common.h>
typedef uint16_t pmix_data_type_t;
#define PMIX_UNDEF                       0
#define PMIX_BOOL                        1  // converted to/from native true/false to uint8 for pack/unpack
#define PMIX_BYTE                        2  // a byte of data
#define PMIX_STRING                      3  // NULL-terminated string
#define PMIX_SIZE                        4  // size_t
#define PMIX_PID                         5  // OS-pid
#define PMIX_INT                         6
#define PMIX_INT8                        7
#define PMIX_INT16                       8
#define PMIX_INT32                       9
#define PMIX_INT64                      10
#define PMIX_UINT                       11
#define PMIX_UINT8                      12
#define PMIX_UINT16                     13
#define PMIX_UINT32                     14
#define PMIX_UINT64                     15
#define PMIX_FLOAT                      16
#define PMIX_DOUBLE                     17
#define PMIX_TIMEVAL                    18
#define PMIX_TIME                       19
#define PMIX_STATUS                     20
#define PMIX_VALUE                      21
#define PMIX_PROC                       22
#define PMIX_APP                        23
#define PMIX_INFO                       24
#define PMIX_PDATA                      25
// Hole left by deprecation/removal of PMIX_BUFFER
#define PMIX_BYTE_OBJECT                27
#define PMIX_KVAL                       28
// Hole left by deprecation/removal of PMIX_MODEX
#define PMIX_PERSIST                    30
#define PMIX_POINTER                    31
#define PMIX_SCOPE                      32
#define PMIX_DATA_RANGE                 33
#define PMIX_COMMAND                    34
#define PMIX_INFO_DIRECTIVES            35
#define PMIX_DATA_TYPE                  36
#define PMIX_PROC_STATE                 37
#define PMIX_PROC_INFO                  38
#define PMIX_DATA_ARRAY                 39
#define PMIX_PROC_RANK                  40
#define PMIX_QUERY                      41
// Hole left by deprecation of PMIX_COMPRESSED_STRING
#define PMIX_ALLOC_DIRECTIVE            43
// Hole left by deprecation/removal of PMIX_INFO_ARRAY
#define PMIX_IOF_CHANNEL                45
#define PMIX_ENVAR                      46
#define PMIX_COORD                      47
#define PMIX_REGATTR                    48
// Hole left by deprecation of PMIX_REGEX (use PMIX_REGEX2 instead)
#define PMIX_JOB_STATE                  50
#define PMIX_LINK_STATE                 51
#define PMIX_PROC_CPUSET                52
#define PMIX_GEOMETRY                   53
#define PMIX_DEVICE_DIST                54
#define PMIX_ENDPOINT                   55
#define PMIX_TOPO                       56
#define PMIX_DEVTYPE                    57
#define PMIX_LOCTYPE                    58
#define PMIX_COMPRESSED_BYTE_OBJECT     59
#define PMIX_PROC_NSPACE                60
#define PMIX_DATA_BUFFER                65
#define PMIX_STOR_MEDIUM                66
#define PMIX_STOR_ACCESS                67
#define PMIX_STOR_PERSIST               68
#define PMIX_STOR_ACCESS_TYPE           69
#define PMIX_DEVICE                     70
#define PMIX_RESBLOCK_DIRECTIVE         71
#define PMIX_RESOURCE_UNIT              72
#define PMIX_NODE_PID                   73
#define PMIX_REGEX2                     74
#define PMIX_ALLOC_INHERIT              75
/* define a boundary for implementers so they can add their own data types */
#define PMIX_DATA_TYPE_MAX     500


Python Syntax

from pmix import *
type = PMIX_STRING


where type is one of the PMIX_* data type constants naming the type of an associated value.

DESCRIPTION

The pmix_data_type_t is a uint16_t value that identifies the type of data carried in a PMIx value (for example, the type field of a pmix_value_t(5) <#man5-pmix-value-t>). It also drives serialization: the bfrops framework uses the data type to select the correct pack/unpack routine when placing data on, or extracting data from, the wire.

The full, authoritative list of defined data types lives in pmix_common.h; the constants copied above are reproduced from that header. The values fall into the following broad categories:

  • Intrinsic scalars — the native C scalar types, such as PMIX_BOOL, PMIX_BYTE, PMIX_SIZE, PMIX_PID, the signed and unsigned fixed-width integers (PMIX_INT8 through PMIX_UINT64), PMIX_INT/PMIX_UINT, PMIX_FLOAT, PMIX_DOUBLE, PMIX_TIMEVAL, PMIX_TIME, and PMIX_POINTER.
  • Strings — PMIX_STRING for a NULL-terminated character string. A compressed form, PMIX_COMPRESSED_STRING, is deprecated: nothing in PMIx produces one, and a value that arrives carrying that type is expanded and delivered as a PMIX_STRING. Do not tag a value with it. Compression of a collective payload is applied to the whole payload by the operation that ships it, not to individual values.
  • Enumerated / directive types — the typed PMIx enumerations and bit-mask directive types, such as PMIX_STATUS, PMIX_PERSIST, PMIX_SCOPE, PMIX_DATA_RANGE, PMIX_PROC_STATE, PMIX_INFO_DIRECTIVES, PMIX_ALLOC_DIRECTIVE, PMIX_IOF_CHANNEL, PMIX_JOB_STATE, PMIX_LINK_STATE, PMIX_DEVTYPE, PMIX_LOCTYPE, and PMIX_RESBLOCK_DIRECTIVE. PMIX_DATA_TYPE names the pmix_data_type_t value itself.
  • PMIx structures — the composite PMIx structs, each identified by its own data type, including PMIX_VALUE (pmix_value_t(5) <#man5-pmix-value-t>), PMIX_PROC (pmix_proc_t(5) <#man5-pmix-proc-t>), PMIX_INFO (pmix_info_t(5) <#man5-pmix-info-t>), PMIX_APP, PMIX_PDATA, PMIX_KVAL, PMIX_BYTE_OBJECT, PMIX_COMPRESSED_BYTE_OBJECT, PMIX_PROC_INFO, PMIX_QUERY, PMIX_ENVAR, PMIX_COORD, PMIX_REGATTR, PMIX_PROC_CPUSET, PMIX_GEOMETRY, PMIX_DEVICE_DIST, PMIX_ENDPOINT, PMIX_TOPO, PMIX_DEVICE, PMIX_PROC_NSPACE, PMIX_DATA_BUFFER, PMIX_RESOURCE_UNIT, PMIX_NODE_PID, and the storage descriptors PMIX_STOR_MEDIUM, PMIX_STOR_ACCESS, PMIX_STOR_PERSIST, and PMIX_STOR_ACCESS_TYPE.
  • Arrays — PMIX_DATA_ARRAY identifies a pmix_data_array_t(5) <#man5-pmix-data-array-t>, a self-describing array whose elements may themselves be any of the above data types. This is the mechanism by which a collection of values of a single type is carried in one PMIx value.

PMIX_UNDEF (value 0) indicates that no type has been assigned. Several numeric values are intentionally skipped (marked as holes above) where a data type was deprecated and removed; those values must never be reused, as doing so would break wire compatibility with peers built against earlier releases. PMIX_DATA_TYPE_MAX (500) establishes a boundary above which implementers are free to define their own private data types.

A human-readable string representation of a pmix_data_type_t value can be obtained from PMIx_Data_type_string(3) <#man3-pmix-data-type-string>.

See also:

PMIx_Data_type_string(3) <#man3-pmix-data-type-string>, pmix_value_t(5) <#man5-pmix-value-t>, pmix_info_t(5) <#man5-pmix-info-t>, pmix_data_array_t(5) <#man5-pmix-data-array-t>


Copyright

2014-2026, OpenPMIx Community

September 27, 2026