parmatrix.nim

## Example of using linalg library with ref-counting GC.  If *just* have ptr DMatrix64, then
## it will get GC'd since the DMatrix64 is a ref to an object - the GC doesn't keep track of ptrs (duh)
## so this will be collected on the next cycle.
##
## Solution is as the example in the manual for the string in the 'Data' tuple.  Ideal solution would be
## automatically-managed memory container with destructor that deallocates the matrix, but the Matrix
## definition might have to be managed to support that.
import linalg
import threadpool

type ThreadSafeMatrixContainer = object
  matrix: DMatrix64


var resultMatrix : ptr ThreadSafeMatrixContainer

proc createThreadSafeMatrixContainer(rows, cols: int): ptr ThreadSafeMatrixContainer =
  result = createShared(ThreadSafeMatrixContainer)
  result.matrix = zeros(rows, cols)
  GC_ref(result.matrix)

proc calcMatrixSlice(chunk: Slice[int]) =
  for i in chunk:
    let v = randomVector(500)
    for j in 0 .. <500:
      resultMatrix[].matrix[i, j] = v[j]


proc main()   =
  let NUM_CHUNKS = 3

  let (nrow, ncol) = (300, 500)
  resultMatrix = createThreadSafeMatrixContainer(nrow, ncol)

  echo repr(resultMatrix)
  echo repr(resultMatrix[])

  echo resultMatrix[]

  for i in 0 .. <NUM_CHUNKS:
    let starting = 100 * i
    let ending = (100 * (i + 1)) - 1
    spawn calcMatrixSlice(starting .. ending)
    GC_fullCollect()

  sync()

  echo isNil(resultMatrix)
  echo repr(resultMatrix)
  echo "Result Matrix: \n" & $resultMatrix[]


  GC_unref(resultMatrix.matrix)
  deallocShared(resultMatrix)

when isMainModule:
  main()