Skip to main content

Sasa v0.10 Released

I just uploaded v0.10 of Sasa, my open source class libraries. This release features a few small bugfixes and enhancements to MIME parsing, and some useful new concurrency features. .NET 4.0 binaries are now also provided.

Bugixes

  • bugfix: added some runtime fixes due to semantic changes in .NET 4.0 base class libraries
  • bugfix: multipart/alternative MIME messages are now parsed into the containing message's alternate views
  • bugfix: set a MailMessage reply's From property if a source address is available
  • bugfix: ThreadScoped now properly reclaims data across threads
  • bugfix: more efficient and safer Lazy initializer

New

  • new: provided builds for .NET 4.0
  • new: added Atomics.Read and Atomics.Write thread-safe read/write operations that perform atomic reads larger-than-word structs without locks [1]
  • new: added simple load-linked/store-conditional operations, under Atomics.LoadLinked/StoreCondition, and Sasa.Concurrency.LLSC
  • new: added a LockSet object which takes locks in hashcode order to avoid deadlocks
  • new: added Pad64 and Pad128 structs which place 64 bytes, and 128 bytes of padding after a value in order to address false sharing
Labels:

Comments

Post a Comment

Popular posts from this blog

Blue-eyed Islander Puzzle - an analysis

Many people find themselves stumped by the so-called Blue-Eyed Islanders puzzle . There is also much controversy over its supposed solution. I'm going to analyze the problem and the solution, and in the process, explain why the solution works. To begin, let's modify the problem slightly and say that there's only 1 blue-eyed islander. When the foreigner makes his pronouncement, the blue-eyed islander looks around and sees no other blue eyes, and being logical, correctly deduces that his own eyes must be blue in order for the foreigner's statement to make sense. The lone blue-eyed islander thus commits suicide the following day at noon. Now comes the tricky part, and the source of much confusion. Let's say there are 2 blue-eyed islanders, Mort and Bob. When the foreigner makes his pronouncement, Mort and Bob look around and see only each other. Mort and Bob thus both temporarily assume that the other will commit suicide the following day at noon. Imagine their chagrin...
40 comments
Read more

Easy Reverse Mode Automatic Differentiation in C#

Continuing from my last post on implementing forward-mode automatic differentiation (AD) using C# operator overloading , this is just a quick follow-up showing how easy reverse mode is to achieve, and why it's important. Why Reverse Mode Automatic Differentiation? As explained in the last post, the vector representation of forward-mode AD can compute the derivatives of all parameter simultaneously, but it does so with considerable space cost: each operation creates a vector computing the derivative of each parameter. So N parameters with M operations would allocation O(N*M) space. It turns out, this is unnecessary! Reverse mode AD allocates only O(N+M) space to compute the derivatives of N parameters across M operations. In general, forward mode AD is best suited to differentiating functions of type: R → R N That is, functions of 1 parameter that compute multiple outputs. Reverse mode AD is suited to the dual scenario: R N → R That is, functions of many parameters t...
18 comments
Read more

Extensible, Statically Typed Pratt Parser in C#

I just completed a statically typed Pratt-style single-state extensible lexer+parser, otherwise known as a top-down operator precedence parser, for the Sasa library . The implementation is available in the Sasa.Parsing dll, under Sasa.Parsing.Pratt . Two simple arithmetic calculators are available in the unit tests . This implementation is novel in two ways: Aside from an alleged implementation in Ada , this is the only statically typed Pratt parser I'm aware of. Pratt parsers typically require a pre-tokenized input before parsing semantic tokens, but I've eliminated this step by using the symbol definitions to drive a longest-match priority-based lexer. Symbols by default match themselves, but you can optionally provide a scanning function used to match arbitrary string patterns. The symbol selected for the current position of the input is the symbol that matches the longest substring. If two symbols match equally, then the symbol with higher precedence is selected. The design...
12 comments
Read more