The rsm_memseg_export_create(), rsm_memseg_export_destroy(), and rsm_memseg_export_rebind() functions provide for allocation and management of resources supporting export memory segments. Exporting a memory segment involves the application
allocating memory in its virtual address space through the System V shared memory interface or normal operating system memory allocation functions. This is followed by the calls to create the export segment and bind physical pages to back to allocated virtual address space.
The rsm_memseg_export_create() creates a new memory segment. Physical memory pages are allocated and are associated with the segment. The segment lifetime is the same as the lifetime of the creating process or until a destroy operation is performed. The controller
argument is the controller handle obtained from a prior call to rsm_get_controller(3RSM). The export memory segment handle is obtained through the memseg
argument for use in subsequent operations. The vaddr argument specifies the process virtual address for the segment. It must be aligned according to the controller page size attribute. The length argument specifies the size of the segment in bytes and must
be in multiples of the controller page size. The flags argument is a bitmask of flags. The RSM_ALLOW_REBIND flag indicates that unbind and rebind is allowed on the segment during its lifetime. The RSM_LOCK_OPS flag indicates that this segment can be used for lock operations.
The rsm_memseg_export_destroy() function deallocates the physical memory pages associated with the segment and disconnects all importers of the segment. The memseg argument is the export memory segment handle obtained by a call to rsm_memseg_export_create().
The rsm_memseg_export_rebind() function releases the current backing pages associated with the segment and allocates new physical memory pages. This operation is transparent to the importers of the segment. It is the responsibility of the application to prevent data access to
the export segment until the rebind operation has completed. Segment data access during rebind does not cause a system failure but data content results are undefined. The memseg argument is the export segment handle pointer obtained from rsm_memseg_export_create().
The vaddr argument must be aligned with respect to the page size attribute of the controller. The length argument modulo controller page size must be 0. The off argument is currently unused.