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2018-07-27Update copyright headers to 2018DrahtBot
2018-03-22Merge #12048: Use best-fit strategy in Arena, now O(log(n)) instead O(n)Wladimir J. van der Laan
5fbf7c4 fix nits: variable naming, typos (Martin Ankerl) 1e0ee90 Use best-fit strategy in Arena, now O(log(n)) instead O(n) (Martin Ankerl) Pull request description: This replaces the first-fit algorithm used in the Arena with a best-fit. According to "Dynamic Storage Allocation: A Survey and Critical Review", Wilson et. al. 1995, http://www.scs.stanford.edu/14wi-cs140/sched/readings/wilson.pdf, both startegies work well in practice. The advantage of using best-fit is that we can switch the O(n) allocation to O(log(n)). Additionally, some previously O(log(n)) operations are now O(1) operations by using hash maps. The end effect is that the benchmark runs about 2.5 times faster on my machine: # Benchmark, evals, iterations, total, min, max, median old: BenchLockedPool, 5, 530, 5.25749, 0.00196938, 0.00199755, 0.00198172 new: BenchLockedPool, 5, 1300, 5.11313, 0.000781493, 0.000793314, 0.00078606 I've run all unit tests and benchmarks, and increased the number of iterations so that BenchLockedPool takes about 5 seconds again. Tree-SHA512: 6551e384671f93f10c60df530a29a1954bd265cc305411f665a8756525e5afe2873a8032c797d00b6e8c07e16d9827465d0b662875433147381474a44119ccce
2018-01-03Increment MIT Licence copyright header year on files modified in 2017Akira Takizawa
2017-12-29Use best-fit strategy in Arena, now O(log(n)) instead O(n)Martin Ankerl
This replaces the first-fit algorithm used in the Arena with a best-fit. According to "Dynamic Storage Allocation: A Survey and Critical Review", Wilson et. al. 1995, http://www.scs.stanford.edu/14wi-cs140/sched/readings/wilson.pdf, both startegies work well in practice. The advantage of using best-fit is that we can switch the slow O(n) algorithm to O(log(n)) operations. Additionally, some previously O(log(n)) operations are now replaced with O(1) operations by using a hash map. The end effect is that the benchmark runs about 2.5 times faster on my machine: old: BenchLockedPool, 5, 530, 5.25749, 0.00196938, 0.00199755, 0.00198172 new: BenchLockedPool, 5, 1300, 5.11313, 0.000781493, 0.000793314, 0.00078606 I've run all unit tests and benchmarks.
2017-09-16Refactor: Modernize disallowed copy constructors/assignmentDan Raviv
Use C++11's better capability of expressing an interface of a non-copyable class by publicly deleting its copy ctor and assignment operator instead of just declaring them private.
2017-08-16Declare single-argument (non-converting) constructors "explicit"practicalswift
In order to avoid unintended implicit conversions.
2017-08-16Use nullptr instead of zero (0) as the null pointer constantpracticalswift
2016-11-28Fix some typosfsb4000
2016-11-02LockedPool: avoid quadratic-time allocationKaz Wesley
Use separate maps for used/free chunks to avoid linear scan through alloced chunks for each alloc.
2016-10-27support: Add LockedPoolWladimir J. van der Laan
Add a pool for locked memory chunks, replacing LockedPageManager. This is something I've been wanting to do for a long time. The current approach of locking objects where they happen to be on the stack or heap in-place causes a lot of mlock/munlock system call overhead, slowing down any handling of keys. Also locked memory is a limited resource on many operating systems (and using a lot of it bogs down the system), so the previous approach of locking every page that may contain any key information (but also other information) is wasteful.