Omer Frenkel has submitted this change and it was merged.
Change subject: engine: fix race in CommandAsyncTask
......................................................................
engine: fix race in CommandAsyncTask
The race was the following:
1: [thread 1] CommandAsyncTask's constructor reaches the point
"entityInfo.AttachTask(this)" while the "_multiTasksByCommandIds"
still
contains one task. After this it gets interrupted
2: [thread 2] the CommandAsyncTask.handleEndActionResult is executed in
meanwhile and issues the
"_multiTasksByCommandIds.remove(commandInfo.getCommandId());"
3: [thread 1] the first thread continues the execution and calls the
"entityInfo.AttachTask(this);"
4: [thread 1] the CommandAsyncTask.ConcreteStartPollingTask() is called. It asks
for the GetCommandMultiAsyncTasks which returns null (because thread 2 have
deleted it) and fails on NPE on the next line
Fixed by moving all the code which needs to be synchonized to the sync block.
It will not cause any deadlocks because the CommandMultiAsyncTasks.AttachTask
does not use the original _lockObject (nor directly nor indirectly).
Change-Id: Id265df1c1843b976c6f8d65729fd6717c3df3c76
Bug-Url:
https://bugzilla.redhat.com/show_bug.cgi?id=1015638
Signed-off-by: Tomas Jelinek <tjelinek(a)redhat.com>
---
M
backend/manager/modules/bll/src/main/java/org/ovirt/engine/core/bll/CommandAsyncTask.java
1 file changed, 8 insertions(+), 3 deletions(-)
Approvals:
Omer Frenkel: Verified; Looks good to me, approved
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Gerrit-MessageType: merged
Gerrit-Change-Id: Id265df1c1843b976c6f8d65729fd6717c3df3c76
Gerrit-PatchSet: 2
Gerrit-Project: ovirt-engine
Gerrit-Branch: master
Gerrit-Owner: Tomas Jelinek <tjelinek(a)redhat.com>
Gerrit-Reviewer: Arik Hadas <ahadas(a)redhat.com>
Gerrit-Reviewer: Omer Frenkel <ofrenkel(a)redhat.com>
Gerrit-Reviewer: Ravi Nori <rnori(a)redhat.com>
Gerrit-Reviewer: Roy Golan <rgolan(a)redhat.com>
Gerrit-Reviewer: Tomas Jelinek <tjelinek(a)redhat.com>
Gerrit-Reviewer: oVirt Jenkins CI Server