louisjenkinscs / chapel-data-structures Goto Github PK

Shared Memory

• Queue
• Stack
• Vector
• PriorityQueue

Distributed

• DistBag
• DistQueue
• RCUArray

I'd like to add a nice and fast 'Channel' such as the one described here: chapel-lang/chapel#12660

In essence, it will be like Golang's Channel (or like Rust's Crossbeam Channel) which enables a CSP programming style. The N-Bodies simulation seems like a very apt benchmark and example for it. It'd be a way to get my feet wet with more HPC while also allowing me to benefit the Chapel language as a whole. If I understand it right, there are two kinds of ways to implement N-Bodies: Time-Step/Epoch-Based which is entirely data-parallel (which Chapel can handle very well on its own), and then you have the Chaotic message-passing based where particles go flying everywhere! That is, a particle collides with its neighbors and sends a message, and as soon as this message is received it handles collisions with its neighbors, and so forth. Something, at a very high-level and at risk of over-simplification, will be like this...

// channelMatrix[i,j] => (send_j, recv_i) where send_j is paired with recv_j
var channelMatrix : [0..#numLocales, 0..#numLocales] (Channel, Channel);
coforall loc in Locales do on loc {
   coforall tid in 0..#here.maxTaskPar {
      var (send, recv) = select(channelMatrix[loc.id,0..#numLocales]);
      var x = recv.receive();
      for n in neighbors() do channelMatrix[loc.id, n][1].send(f(x));
   }
}