[master <] Introduce a reader writer spin lock #1187
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@Josipmrden I used this to play a bit with it to understand exactly what is going on. Maybe you will find it useful, if not ignore |
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It is possible for multiple read only queries to be accessing the same squence of vertices/edges. The reader mode of the spin lock will ensure multiple threads can make progress at the same time.
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It is possible for multiple read only queries to be accessing the same sequence of vertices/edges. The reader mode of the spin lock will ensure multiple threads can make progress at the same time.
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There are situations where multiple readonly queries in parallel are contended on the same vertex lock. Take for example a highly connected supernode which is repetitively used in result values and it needs encode it to a bolt value for sending to the client.
Since
SpinLockcan only be used exclusively, it causes unnecessary blocking.RWSpinLockwould allow shared reading.Before: you can see heavy use of
__pthread_spin_lockAfter: in the same part of the profile the locks don't even appear, this is because of the
RWSpinLock[master < Task] PR
To keep docs changelog up to date, one more thing to do:
closes #1189