[Progress Communities] [Progress OpenEdge ABL] Forum Post: RE: How the Database Storage Manager Uses Semaphores

[George Potemkin]

Thanks, Gus. Can you reveal the secret of the queued latches (USR and SCH/SCC)? How these latches work together with the semaphores? Both semaphores and latches are the locks – slow locks and fast locks. Does process use, for example, a user semaphore to put itself in the queue to access the USR latch? I can generate the high activity on the USR latch but I don’t see the related activity on the semaphores. I can catch the process when it holds the USR latch but I don’t see any changes of its semaphore status.

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