edg-l/ddnet
1
0
Fork 0
mirror of https://github.com/ddnet/ddnet.git synced 2024-11-09 09:38:19 +00:00
Code Issues Packages Projects Releases Wiki Activity

Fix race conditions in job state handling

Browse source 
We want to change the state of the job from `STATE_QUEUED` to
`STATE_RUNNING`, but not from `STATE_ABORTED`. Previously, the code
usedd `exchange` to change the state and compared non-atomically
afterwards. This led to `STATE_ABORTED` being replaced by
`STATE_RUNNING` in a race. With `compare_exchange_strong`, this can no
longer happen.

Fixes #8044.
This commit is contained in:
heinrich5991 2024-03-05 20:55:44 +01:00
parent 44bf0134f0
commit e7717f2265
1 changed files with 8 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
src/engine/shared/jobs.cpp
View file

@ -83,9 +83,8 @@ void CJobPool::RunLoop()
if(pJob) if(pJob)
{ {
// do the job if we have one IJob::EJobState OldStateQueued = IJob::STATE_QUEUED;
const IJob::EJobState OldStateQueued = pJob->m_State.exchange(IJob::STATE_RUNNING); if(!pJob->m_State.compare_exchange_strong(OldStateQueued, IJob::STATE_RUNNING))
if(OldStateQueued != IJob::STATE_QUEUED)
{ {
if(OldStateQueued == IJob::STATE_ABORTED) if(OldStateQueued == IJob::STATE_ABORTED)
{ {
@ -109,10 +108,13 @@ void CJobPool::RunLoop()
} }
// do not change state to done if job was not completed successfully // do not change state to done if job was not completed successfully
const IJob::EJobState OldStateRunning = pJob->m_State.exchange(IJob::STATE_DONE); IJob::EJobState OldStateRunning = IJob::STATE_RUNNING;
if(OldStateRunning != IJob::STATE_RUNNING) if(!pJob->m_State.compare_exchange_strong(OldStateRunning, IJob::STATE_DONE))
{ {
pJob->m_State = OldStateRunning; if(OldStateRunning != IJob::STATE_ABORTED)
{
dbg_assert(false, "Job state invalid, must be either running or aborted");
}
} }
} }
else if(m_Shutdown) else if(m_Shutdown)