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PMIX_DATA_BUFFER_UNLOAD(3) OpenPMIx PMIX_DATA_BUFFER_UNLOAD(3)

PMIx_Data_buffer_unload — Extract the raw byte payload from a pmix_data_buffer_t.

SYNOPSIS

#include <pmix.h>
void PMIx_Data_buffer_unload(pmix_data_buffer_t *b,


                             char **bytes, size_t *sz);


INPUT PARAMETERS

•
b: Pointer to the source pmix_data_buffer_t whose payload is to be extracted.

OUTPUT PARAMETERS

  • bytes: Address of a char * in which the pointer to the extracted payload is returned.
  • sz: Address of a size_t in which the number of extracted bytes is returned.

DESCRIPTION

Remove the packed byte payload from b and hand it to the caller. The function extracts the buffer’s contents via PMIx_Data_unload(3) <#man3-pmix-data-unload>; on success it stores the pointer to the payload in *bytes and its length in *sz.

The transfer is a move, not a copy: ownership of the underlying memory passes out of the buffer to the caller, and the buffer is left empty. No new allocation is made and no byte-copy is performed. Because the caller now owns the returned memory, it becomes responsible for eventually freeing *bytes. The emptied buffer may itself still be destructed or released as usual; doing so will not free the payload that has been handed off.

If the extraction fails, *bytes is set to NULL and *sz is set to zero.

The extracted payload is in packed (serialized) form. It may be transmitted, stored, and later reintroduced into a buffer with PMIx_Data_buffer_load(3) <#man3-pmix-data-buffer-load> for subsequent unpacking.

RETURN VALUE

PMIx_Data_buffer_unload returns no value (void). Failure is signalled by *bytes being set to NULL and *sz to zero.

NOTES

PMIx_Data_buffer_unload is an OpenPMIx convenience routine. The Standard-defined interface for this operation is the PMIX_DATA_BUFFER_UNLOAD macro, which is implemented in terms of this function.

See also:

PMIx_Data_buffer_load(3) <#man3-pmix-data-buffer-load>, PMIx_Data_buffer_create(3) <#man3-pmix-data-buffer-create>, PMIx_Data_buffer_release(3) <#man3-pmix-data-buffer-release>, PMIx_Data_unload(3) <#man3-pmix-data-unload>, pmix_data_buffer_t(5) <#man5-pmix-data-buffer-t>


Copyright

2014-2026, OpenPMIx Community

October 5, 2026