18.2.137. PMIx_Data_array_construct

PMIx_Data_array_construct — Initialize a caller-provided pmix_data_array_t(5) and allocate its element storage.

18.2.137.1. SYNOPSIS

#include <pmix.h>

void PMIx_Data_array_construct(pmix_data_array_t *p,
                               size_t num, pmix_data_type_t type);

18.2.137.1.1. Python Syntax

No Python equivalent

18.2.137.2. INPUT PARAMETERS

p: Pointer to the pmix_data_array_t(5) structure to be initialized. The storage for the structure itself must already exist — it is supplied by the caller.
num: Number of elements to allocate in the backing array.
type: The pmix_data_type_t(5) of the elements.

18.2.137.3. DESCRIPTION

Initialize a pmix_data_array_t and, when num is greater than zero, allocate and initialize a backing array of num elements of the given type. The type and size fields are set accordingly and the array field is set to point at the newly allocated element storage.

The allocation is type-aware: for complex PMIx types (for example PMIX_INFO, PMIX_PROC, PMIX_VALUE, PMIX_APP, PMIX_ENVAR, and many others) the elements are created and constructed using the appropriate per-type routine; for scalar types (for example PMIX_INT, PMIX_SIZE, PMIX_BOOL, PMIX_STRING) an array of the corresponding C type is allocated and zeroed. If num is zero, no element storage is allocated and array is set to NULL. If type is not recognized, array is set to NULL and size is reset to zero.

18.2.137.4. RETURN VALUE

PMIx_Data_array_construct returns no value (void).

18.2.137.5. NOTES

Because PMIx_Data_array_construct operates on caller-provided structure storage but allocates the element array, it must be paired with PMIx_Data_array_destruct(3), which releases the element storage (and any per-element payload) without freeing the pmix_data_array_t structure itself. To also allocate the structure, use PMIx_Data_array_create(3). To initialize the fields without allocating element storage, use PMIx_Data_array_init(3).

18.2.137.6. EXAMPLES

Construct an array of four pmix_info_t(5) elements:

pmix_data_array_t darray;

PMIx_Data_array_construct(&darray, 4, PMIX_INFO);
/* ... populate darray.array[0..3] ... */
PMIx_Data_array_destruct(&darray);