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author | Joey Hess <joeyh@joeyh.name> | 2016-04-18 14:04:20 -0400 |
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committer | Joey Hess <joeyh@joeyh.name> | 2016-04-18 14:04:50 -0400 |
commit | 71f7e6a178b9b5e694975729f276548fc5461c21 (patch) | |
tree | 6645ff0c45230878ed227f40fad5660ea87ed608 /Assistant/TransferQueue.hs | |
parent | c6d028f5e85e8cf3dcc2c15cf2e9d40a6ad16b81 (diff) |
fix drop hang reported by musicmatze
Fix hang when dropping content needs to lock the content on a ssh remote,
which occurred when the remote has git-annex version 5.20151019 or newer.
Analysis: `race` runs 2 threads at once, and the hGetLine finishes first.
So, it tries to cancel the waitForProcess, but unfortunately that is making
a foreign call and so cannot be canceled. The remote git-annex-shell
is waiting for a line on stdin before it will exit. Deadlock.
This only occurred sometimes; I reproduced it going from darkstar to
elephant, but not from darkstar to darkstar. Not sure how that fits into
the above analysis -- perhaps a race condition is also involved?
Fixed by not using `race`; now the hGetLine will fail with an exception
if the remote git-annex-shell exits without any output.
Diffstat (limited to 'Assistant/TransferQueue.hs')
0 files changed, 0 insertions, 0 deletions