I am digging somewhat into Clojure internals for a talk I'm doing. Now I've reached the LockingTransaction class, and have a few questions, I hope someone can answer.
In some of the Clojure presentations it says that "Readers never impede writers/readers, writers never impede readers". What does the word "impede" mean in this context? At first, before reading the code, I thought it meant that, e.g., a read-only transaction, R, can never be retried, even if a concurrent writing transaction, W, changes a ref that is read later by the R. But that is not the case; see e.g., http://groups.google.com/group/clojure/browse_frm/thread/e9b56115929fd199/f3ae6306214a0b0d I see that LockingTransaction.doGet may mark a fault and retry. So what exactly *is* meant by "never impedes"? 2) All the refs in a program are controlled by the same STM system. Suppose you have two disjoint sets of refs, A and B, in a program, and suppose that all transactions only touches either A or B. Would there be any value in having two STM instances controlling A and B, e.g., by labling each ref with 'A' or 'B.' It would mean that transactions are sourcing readPoints from distict sources and thus less synchronization (although the overhead for AtomicLong is pretty low, this might matter for many-core situations). /Karl --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
