18.2.127. PMIx_Info_persistent

PMIx_Info_persistent — Mark a pmix_info_t(5) as persistent

18.2.127.1. SYNOPSIS

#include <pmix.h>

void PMIx_Info_persistent(pmix_info_t *p);

18.2.127.1.1. Python Syntax

No Python equivalent

18.2.127.2. INPUT PARAMETERS

p: Pointer to the pmix_info_t(5) structure to be marked persistent.

18.2.127.3. DESCRIPTION

The PMIx_Info_persistent function sets the PMIX_INFO_PERSISTENT directive bit in the info structure’s flags field. A persistent info is understood not to own the pmix_value_t(5) payload it carries, so the library will not release that value on the info’s behalf.

This flag changes the behavior of the info lifecycle routines:

PMIx_Info_destruct(3) and PMIx_Info_free(3) leave the contained value untouched instead of releasing it.
PMIx_Info_xfer(3) copies the value by shallow structure assignment (the destination shares the source’s underlying value memory) rather than deep-copying it.

Use this flag when the value memory is owned elsewhere and must outlive the info structure, to avoid a double free. Whether an info is currently persistent can be tested with PMIx_Info_is_persistent(3).

18.2.127.4. RETURN VALUE

PMIx_Info_persistent returns no value (void).

18.2.127.5. NOTES

PMIx_Info_persistent is the OpenPMIx routine underlying the historical PMIX_INFO_SET_PERSISTENT macro. That macro is retained in pmix_deprecated.h for backward compatibility and simply expands to a call to this function.

Info structures default to non-persistent at construction, which the surrounding source notes is retained “for historical reasons”: the library owns and releases the contained value unless this flag is explicitly set.