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work: Fix race condition

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When a user changes their destination station or checks into a new train
while work is updating data for their in_transit entry, values for no longer
valid database entrie would be entered.
This commit is contained in:
Daniel Friesel 2020-01-23 17:14:01 +01:00
parent cda8e53b34
commit 75363c35cc
1 changed files with 17 additions and 2 deletions
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19
lib/Travelynx/Command/work.pm
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@ -47,6 +47,10 @@ sub run {
die("could not find train $train_id at $dep\n");
}
# selecting on user_id and train_no avoids a race condition when
# a user checks into a new train while we are fetching data for
# their previous journey. In this case, the new train would
# receive data from the previous journey.
$db->update(
'in_transit',
{
@ -61,7 +65,10 @@ sub run {
]
),
},
{ user_id => $uid }
{
user_id => $uid,
train_no => $train->train_no
}
);
$self->app->add_route_timestamps( $uid, $train, 1 );
}
@ -102,6 +109,10 @@ sub run {
return;
}
# selecting on user_id, train_no and checkout_station_id avoids a
# race condition when a user checks into a new train or changes
# their destination station while we are fetching times based on no
# longer valid database entries.
$db->update(
'in_transit',
{
@ -117,7 +128,11 @@ sub run {
]
),
},
{ user_id => $uid }
{
user_id => $uid,
train_no => $train->train_no,
checkout_station_id => $arr
}
);
$self->app->add_route_timestamps( $uid, $train, 0 );
}