#250 Id counters in UGGrid may overflow
Metadata
| Property | Value |
|---|---|
| Reported by | Oliver Sander (oliver.sander@tu-dresden.de) |
| Reported at | Feb 1, 2007 13:42 |
| Type | Bug Report |
| Version | Git (pre2.4) [autotools] |
| Operating System | Unspecified / All |
| Last edited by | Oliver Sander (oliver.sander@tu-dresden.de) |
| Last edited at | Jun 27, 2013 11:47 |
| Closed by | Oliver Sander (oliver.sander@tu-dresden.de) |
| Closed at | Jun 27, 2013 11:47 |
| Closed in version | Unknown |
| Resolution | Fixed |
| Comment |
Description
UGGrid relies on the UG object ids to implement the Global- and LocalIdSets. UG stores these ids as signed integers. A new id is created by incrementing a counter. There is one counter for each entity type in each grid. This means that after about 4 billions of, e.g., node creations, these counters start at zero again, and you will end up with two entities of the same codimension having the same id. Note that if the counter overflows you will surely get those collisions, as the entities with the very low ids exist in the level zero grid and never get removed no matter what.
A counter overflow is of course extreme rare, but it may conceivably happen when doing very long time series on large, highly adaptive meshes.