Re: [Libvir] [PATCH] avoid virsh hang due to missing virDomainFree(dom) call
On Wed, Jan 30, 2008 at 06:25:19PM +0100, Jim Meyering wrote:
Without the following patch, this command would hang
printf 'domuuid fc4\ndomstate fc4\n' \
| ./virsh --connect test://$PWD/../docs/testnode.xml
with this stack trace:
__lll_lock_wait ...
_L_lock_105 ...
__pthread_mutex_lock ...
virUnrefDomain (domain=0x6a8b30) at hash.c:884
virDomainFree (domain=0x6a8b30) at libvirt.c:1211
cmdDomstate (ctl=0x7fffea723390, cmd=0x6a8b10) at virsh.c:677
vshCommandRun (ctl=0x7fffea723390, cmd=0x6a8b10) at virsh.c:4033
main (argc=3, argv=0x7fffea7234e8) at virsh.c:501
The problem is that cmdDomuuid didn't call virDomainFree(dom), so
cmdDomstate hangs trying to do the Unref.
I don't understand why it would hang simply because it forgot to free
an object. Surely it ought to just be a memory leak not hang ? Each
individual libvirt API must always have a matched lock & unlock pair
in all codepaths, so a hang should only occur if an unlock is missing
in some codepath.
Dan.
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