Crash when using SetParallelUnzip

ROOT
1

Hello,

I tried to play with the new features of ROOT 5.30, in particular the asynchronous prefetch.
Basically I just adedd
myTree->SetParallelUnzip(true) to my analysis code.
With this activated, it ends up crashing when accessing the first entry of the TChain.
I must confess that my code is quite complicated (TChain, with a friend that is filled when the main tree is read, and some TTreeFormulas in the middle), and that I could not find a minimal example that triggers the crash.

But I put the backtrace here in case you have some ideas about where the problem comes from.

Cheers,
Nicolas

===========================================================
There was a crash.
This is the entire stack trace of all threads:

Thread 3 (Thread 0x415d5940 (LWP 1133)):
#0 0x0000003b9280ae00 in pthread_cond_timedwait

GLIBC_2.3.2 ()
from /lib64/libpthread.so.0
#1 0x00002b10e32d0be1 in TPosixCondition::TimedWait ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libThread.so
#2 0x00002b10e32cc057 in TCondition::TimedWait ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libThread.so
#3 0x00002b10e32cc192 in TCondition::TimedWaitRelative ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libThread.so
#4 0x00002b10e18684d3 in TTreeCacheUnzip::UnzipLoop ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libTree.so
#5 0x00002b10e32ce1b6 in TThread::Function ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libThread.so
#6 0x0000003b928064a7 in start_thread () from /lib64/libpthread.so.0
#7 0x0000003b91cd3c2d in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x4267a940 (LWP 1134)):
#0 0x0000003b9280ae00 in pthread_cond_timedwait

GLIBC_2.3.2 ()
from /lib64/libpthread.so.0
#1 0x00002b10e32d0be1 in TPosixCondition::TimedWait ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libThread.so
#2 0x00002b10e32cc057 in TCondition::TimedWait ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libThread.so
#3 0x00002b10e32cc192 in TCondition::TimedWaitRelative ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libThread.so
#4 0x00002b10e18684d3 in TTreeCacheUnzip::UnzipLoop ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libTree.so
#5 0x00002b10e32ce1b6 in TThread::Function ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libThread.so
#6 0x0000003b928064a7 in start_thread () from /lib64/libpthread.so.0
#7 0x0000003b91cd3c2d in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x2b10e74dab90 (LWP 1131)):
#0 0x0000003b91c99cbf in waitpid () from /lib64/libc.so.6
#1 0x0000003b91c3c331 in do_system () from /lib64/libc.so.6
#2 0x0000003b91c3c687 in system () from /lib64/libc.so.6
#3 0x00002b10e3761d23 in TUnixSystem::StackTrace ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libCore.so
#4 0x00002b10e375ea0a in TUnixSystem::DispatchSignals ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libCore.so
#5
#6 0x0000003b91c7be91 in memcpy () from /lib64/libc.so.6
#7 0x00002b10e186635a in TTreeCacheUnzip::UnzipBuffer ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libTree.so
#8 0x00002b10e1868035 in TTreeCacheUnzip::GetUnzipBuffer ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libTree.so
#9 0x00002b10e1818196 in TBasket::ReadBasketBuffers ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libTree.so
#10 0x00002b10e181ef75 in TBranch::GetBasket ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libTree.so
#11 0x00002b10e181fb2a in TBranch::GetEntry ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libTree.so
#12 0x00002b10e187c46e in TTree::GetEntry ()
from /home/manip/mnt/atlas/software/root_v5.30.00//lib/libTree.so
#13 0x00002b10dfa39fe8 in ZeeJetsAnalysis::Loop ()
from /home/usr202/mnt/nmorange/Atlas/AnalysisWZ/lib/libAnalysisWZ.so.0.0
#14 0x0000000000402696 in main ()

2

Hi,

Cheers,
Philippe