View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0007029 | GNUnet | DHT service | public | 2021-10-05 20:45 | 2022-02-26 23:10 |
| Reporter | md | Assigned To | Christian Grothoff | ||
| Priority | normal | Severity | crash | Reproducibility | sometimes |
| Status | closed | Resolution | reopened | ||
| Platform | GNU/Linux | OS | Guix System | OS Version | v??? |
| Product Version | 0.13.1 | ||||
| Target Version | 0.16.0 | Fixed in Version | 0.16.0 | ||
| Summary | 0007029: Assertion failure in get_target_peers (when allocating rtargets) | ||||
| Description | When testing the "http://localhost:8089/search-dht" form of Scheme-GNUnet, gnunet-service-dht crashed with the following message: okt 05 20:07:27-878394 dht-25189 ERROR Assertion failed at gnunet-service-dht_neighbours.c:1181. Aborting. Looking at gnunet-service-dht_neighbours.c:1181, that's rtargets = GNUNET_new_array (ret, struct PeerInfo *); so maybe 'ret' was to large? 'ret' is assigned by: ret = get_forward_count (hop_count, target_replication); so maybe get_forward_count returns a too large result? Curiously, the crash only happens if the replication level is zero, and not if it is one. Also note that that the network size (according to $GNUB/gnunet-nse) is 1: 1633458666879901 1,000000 0,000000 -nan and ‘target_value’ is: target_value = 1 + (target_replication - 1.0) / (GDS_NSE_get () + ((float) (target_replication - 1.0) * hop_count)); So for target_replication=0, target_value = 1 - 1/(0 + (1 - 1) * hop_count) = 1 - 1/0 = some kind of infinity (or NaN?). (GDS_NSE_get() is (an approximation of) the logarithm of the network size, so it is approx. equal to 0 here). So target_value becomes infinity (or, allowing for numerical issues, at least very large in magnitude). Then the forward count is set to forward_count = (uint32_t) target_value I don't know what is the result of casting an infinity or NaN to an integral type, but I wouldn't recommend it. Maybe it can be very large? | ||||
| Steps To Reproduce | For developing/testing Scheme-GNUnet, I run the following services: dht, statistics, core, nse and peerinfo (no ARM!). | ||||
| Tags | No tags attached. | ||||
|
|
My calculation for target_replication=0 and GDS_NSE_get()=0 is bogus, it should be target_value = 1 - 1/(0 + -1* hop_count)= 1 + 1/hop_count. However, an infinity is still possible if hop_count = 0. I don't know if that can happen though. |
|
|
Seems likely. Still, how did you end up with a target_replication of 0? |
|
|
Fix committed to master branch. |
|
|
e173017ed..6ef071b8c fixes the crash by forcing the target_replication to be in a 'sane' range. Still wonder how 0 appeared, but at least the crash should be fixed now. |
|
|
The example mini-application I'm writing allows choosing any replication level, including 0. I'll look into making the minimum level 1! Unfortunately, Mantis doesn't allow commenting on resolves issues, so I had to reopen the issue. |
|
|
I see. Ok, that explains it then. reopening: no problem. I'll consider this resolved then. |
|
|
0.16.0 released |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2021-10-05 20:45 | md | New Issue | |
| 2021-10-06 12:19 | Christian Grothoff | Assigned To | => Christian Grothoff |
| 2021-10-06 12:19 | Christian Grothoff | Status | new => assigned |
| 2021-10-06 16:36 | md | Note Added: 0018428 | |
| 2021-10-06 18:51 | Christian Grothoff | Note Added: 0018429 | |
| 2021-10-06 18:53 | Christian Grothoff | Changeset attached | => gnunet master 6ef071b8 |
| 2021-10-06 18:53 | Christian Grothoff | Note Added: 0018430 | |
| 2021-10-06 18:53 | Christian Grothoff | Status | assigned => resolved |
| 2021-10-06 18:53 | Christian Grothoff | Resolution | open => fixed |
| 2021-10-06 18:54 | Christian Grothoff | Note Added: 0018431 | |
| 2021-10-06 19:02 | md | Status | resolved => feedback |
| 2021-10-06 19:02 | md | Resolution | fixed => reopened |
| 2021-10-06 19:02 | md | Note Added: 0018432 | |
| 2021-10-06 19:07 | Christian Grothoff | Note Added: 0018433 | |
| 2021-10-06 19:07 | Christian Grothoff | Status | feedback => resolved |
| 2021-10-06 19:07 | Christian Grothoff | Fixed in Version | => 0.15.4 |
| 2021-10-10 20:17 | schanzen | Target Version | => 0.15.4 |
| 2021-12-31 09:26 | schanzen | Target Version | 0.15.4 => 0.16.0 |
| 2022-02-22 23:06 | schanzen | Fixed in Version | => 0.16.0 |
| 2022-02-26 23:10 | schanzen | Note Added: 0018729 | |
| 2022-02-26 23:10 | schanzen | Status | resolved => closed |
