Since it is critical to understand how the buffer is currently being used when a new buffered send does not find enough free space to proceed, the
error message contains all information about free space, active and completed messages and the corresponding memory ranges. Memory ranges are given using the [
] notation where the
is not part of the memory range. For convenience the number of bytes in each range is also printed. For messages this includes the
, so even empty messages have a non-zero size.