Allocate and return a new empty message block of size span_size mimicking parameters of mb.
This function allocates a new aligned message block using the same allocators and flags as found in mb. The size of the new message block is at least span_size; the size may be adjusted up in order to accomodate alignment requirements and still fit span_size bytes into the aligned buffer.
- Parameters
-
mb | message block whose parameters should be mimicked |
span_size | size of the new message block (will be adjusted for proper alignment) |
- Returns
- an aligned message block with rd_ptr sitting at correct alignment spot, 0 on failure