Cannot delete a ring with halcmd

[ArcEye]

Issue by cdsteinkuehler
Fri Oct 14 00:11:52 2016
Originally opened as machinekit/machinekit#1076

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I'm not sure I completely understand the syntax, but if I'm not confused it doesn't look like you can delete a ring with halcmd once it's created:

machinekit@beaglebone:~$ halcmd newring test 1024
machinekit@beaglebone:~$ halcmd show ring
Rings:
Name           Size       Type   Rdr Wrt Ref Flags
test           1024       record 0/0 0/0 0   recmax:1008

machinekit@beaglebone:~$ halcmd delring test
delring NIY: ring='test'
machinekit@beaglebone:~$ halcmd show ring
Rings:
Name           Size       Type   Rdr Wrt Ref Flags
test           1024       record 0/0 0/0 0   recmax:1008

machinekit@beaglebone:~$ halcmd newring test 1024
<commandline>:0: newring: failed to create new ring test: File exists
machinekit@beaglebone:~$

[ArcEye]

Comment by cdsteinkuehler
Fri Oct 14 00:14:53 2016

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It looks like "NIY" means Not Implemented Yet. I guess this is a feature request and not a bug...here's the code:

int do_delring_cmd(char *ring)
{
    halcmd_output("delring NIY: ring='%s'\n", ring);
    // return halpr_group_delete(group);
    return 0;
}

[ArcEye]

Comment by mhaberler
Fri Oct 14 08:30:04 2016

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A ringbuffer is a toplevel HAL object (=independent of any other) and there is no dependency tracking of which comps reference a ringbuffer - deleting a ringbuffer which happens to be referenced by a comp will likely lead to a crash

so it is best to consider a ringbuffer "eternal" (for HAL session lifetime)

the delring command is implemented in the last version I worked on 13 months ago but I do not recommend it except after all comps are unloaded

[ArcEye]

Comment by luminize
Thu May 18 15:40:29 2017

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@cdsteinkuehler do you want to keep this issue open?