public static async Task <IList <TSource> > Sort <TSource>(IList <TSource> items,
int begin, int end, int insertionSortCount, int threadCount, IComparer <TSource> comparer)
{
int insertionSortActionsCount = (int)Math.Ceiling((end - begin) / (double)insertionSortCount);
int depth = (int)Math.Ceiling(Math.Log(insertionSortActionsCount, 2));
int donesCount = 0;
IList <bool> dones = new bool[2 * insertionSortActionsCount + depth];
Queue <Action> queue = new Queue <Action>();
for (int i = begin; i < end; i += insertionSortCount)
{
int index = donesCount++;
int insertionBegin = i;
int insertionEnd = Math.Min(i + insertionSortCount, end);
queue.Enqueue(() => InsertionSort(index, insertionBegin, insertionEnd));
}
IList <TSource> items1 = items;
IList <TSource> items2 = new TSource[items.Count];
for (int range = insertionSortCount; range < end - begin; range *= 2)
{
int lastActionsCount = (int)Math.Ceiling((end - begin) / (double)range);
int lastActionsBegin = queue.Count - lastActionsCount;
int currentRange = range;
IList <TSource> src = items1, dest = items2;
for (int j = 0, rangeBegin = begin; rangeBegin < end; j++, rangeBegin += range * 2)
{
int leftNodeIndex = lastActionsBegin + j * 2;
int rightNodeIndex = lastActionsBegin + Math.Min(j * 2 + 1, lastActionsCount);
int index = donesCount++;
int currentBegin = rangeBegin;
queue.Enqueue(() => Merge(leftNodeIndex, rightNodeIndex, index, src, dest, currentBegin, currentRange));
}
StdUtils.Swap(ref items1, ref items2);
}
await AsyncUtils.ParallelForEach(queue, threadCount);
return(items1);
void InsertionSort(int thisIndex, int insertionSortBegin, int insertionSortEnd)
{
Linq.Sort.InsertionSort.Sort(items, insertionSortBegin, insertionSortEnd, comparer);
lock (dones)
{
dones[thisIndex] = true;
Monitor.PulseAll(dones);
}
}
void Merge(int leftIndex, int rightIndex, int thisIndex,
IList <TSource> mergeSrc, IList <TSource> mergeDest, int mergeBegin, int size)
{
lock (dones)
{
while (!dones[leftIndex])
{
Monitor.Wait(dones);
}
while (!dones[rightIndex])
{
Monitor.Wait(dones);
}
}
MergeSort.Merge(mergeSrc, mergeDest, mergeBegin, size, end, comparer);
lock (dones)
{
dones[thisIndex] = true;
Monitor.PulseAll(dones);
}
}
}
