From: Scott Worley Date: Wed, 26 Oct 2011 05:45:45 +0000 (-0700) Subject: FillStateTable() X-Git-Url: http://git.scottworley.com/planeteer/commitdiff_plain/e7e4bc13603972237c4d2979a60739f0764391be FillStateTable() --- diff --git a/planeteer.go b/planeteer.go index 314a3b6..456e6b3 100644 --- a/planeteer.go +++ b/planeteer.go @@ -70,7 +70,8 @@ type Planet struct { type planet_data struct { Commodities map[string]Commodity Planets map[string]Planet - pi, ci map[string]int // Generated; not read from file + p2i, c2i map[string]int // Generated; not read from file + i2p, i2c []string // Generated; not read from file } func ReadData() (data planet_data) { @@ -104,6 +105,15 @@ func ReadData() (data planet_data) { * Note that the sizes of each dimension are data driven. Many dimensions * collapse to one possible value (ie, disappear) if the corresponding * feature is not enabled. + * + * The order of the dimensions in the list of constants below determines + * their layout in RAM. The cargo-based 'dimensions' are not completely + * independent -- some combinations are illegal and not used. They are + * handled as three dimensions rather than one for simplicity. Placing + * these dimensions first causes the unused cells in the table to be + * grouped together in large blocks. This keeps them from polluting + * cache lines, and if they are large enough, prevent the memory manager + * from allocating pages for these areas at all. */ // The official list of dimensions: @@ -164,10 +174,6 @@ type State struct { funds, from int } -func NewStateTable(dims []int) []State { - return make([]State, StateTableSize(dims)) -} - func EncodeIndex(dims, addr []int) int { index := addr[0] for i := 1; i < len(dims); i++ { @@ -186,6 +192,96 @@ func DecodeIndex(dims []int, index int) []int { return addr } +func FillStateCell(data planet_data, dims []int, table []State, addr []int) { +} + +func FillStateTable2(data planet_data, dims []int, table []State, +fuel_remaining, edens_remaining int, planet string, barrier chan<- bool) { + /* The dimension nesting order up to this point is important. + * Beyond this point, it's not important. + * + * It is very important when iterating through the Hold dimension + * to visit the null commodity (empty hold) first. Visiting the + * null commodity represents selling. Visiting it first gets the + * action order correct: arrive, sell, buy, leave. Visiting the + * null commodity after another commodity would evaluate the action + * sequence: arrive, buy, sell, leave. This is a useless action + * sequence. Because we visit the null commodity first, we do not + * consider these action sequences. + */ + eden_capacity := data.Commodities["Eden Warp Units"].Limit + addr := make([]int, len(dims)) + addr[Edens] = edens_remaining + addr[Fuel] = fuel_remaining + addr[Location] = data.p2i[planet] + for addr[Hold] = 0; addr[Hold] < dims[Hold]; addr[Hold]++ { + for addr[Cloaks] = 0; addr[Cloaks] < dims[Cloaks]; addr[Cloaks]++ { + for addr[UnusedCargo] = 0; + addr[UnusedCargo] < dims[UnusedCargo]; + addr[UnusedCargo]++ { + if addr[Edens] + addr[Cloaks] + addr[UnusedCargo] <= + eden_capacity + 1 { + for addr[NeedFighters] = 0; + addr[NeedFighters] < dims[NeedFighters]; + addr[NeedFighters]++ { + for addr[NeedShields] = 0; + addr[NeedShields] < dims[NeedShields]; + addr[NeedShields]++ { + for addr[Visit] = 0; + addr[Visit] < dims[Visit]; + addr[Visit]++ { + FillStateCell(data, dims, table, addr) + } + } + } + } + } + } + } + barrier <- true +} + +/* Filling the state table is a set of nested for loops NumDimensions deep. + * We split this into two procedures: 1 and 2. #1 is the outer, slowest- + * changing indexes. #1 fires off many calls to #2 that run in parallel. + * The order of the nesting of the dimensions, the order of iteration within + * each dimension, and where the 1 / 2 split is placed are carefully chosen + * to make this arrangement safe. + * + * Outermost two layers: Go from high-energy states (lots of fuel, edens) to + * low-energy state. These must be processed sequentially and in this order + * because you travel through high-energy states to get to the low-energy + * states. + * + * Third layer: Planet. This is a good layer to parallelize on. There's + * high enough cardinality that we don't have to mess with parallelizing + * multiple layers for good utilization (on 2011 machines). Each thread + * works on one planet's states and need not synchronize with peer threads. + */ +func FillStateTable1(data planet_data, dims []int) []State { + table := make([]State, StateTableSize(dims)) + barrier := make(chan bool, len(data.Planets)) + eden_capacity := data.Commodities["Eden Warp Units"].Limit + work_units := (float64(*fuel) + 1) * (float64(eden_capacity) + 1) + work_done := 0.0 + for fuel_remaining := *fuel; fuel_remaining >= 0; fuel_remaining-- { + for edens_remaining := eden_capacity; + edens_remaining >= 0; + edens_remaining-- { + for planet := range data.Planets { + go FillStateTable2(data, dims, table, fuel_remaining, + edens_remaining, planet, barrier) + } + for _ = range data.Planets { + <-barrier + } + work_done++ + fmt.Printf("\r%3.0f%%", 100 * work_done / work_units) + } + } + return table +} + /* What is the value of hauling 'commodity' from 'from' to 'to'? * Take into account the available funds and the available cargo space. */ func TradeValue(data planet_data, @@ -221,7 +317,7 @@ func FindBestTrades(data planet_data) [][]string { // TODO: We can't cache this because this can change based on available funds. best := make([][]string, len(data.Planets)) for from := range data.Planets { - best[data.pi[from]] = make([]string, len(data.Planets)) + best[data.p2i[from]] = make([]string, len(data.Planets)) for to := range data.Planets { best_gain := 0 price_list := data.Planets[from].RelativePrices @@ -236,7 +332,7 @@ func FindBestTrades(data planet_data) [][]string { 10000000, 1) if gain > best_gain { - best[data.pi[from]][data.pi[to]] = commodity + best[data.p2i[from]][data.p2i[to]] = commodity gain = best_gain } } @@ -246,40 +342,44 @@ func FindBestTrades(data planet_data) [][]string { } // (Example of a use case for generics in Go) -func IndexPlanets(m *map[string]Planet) map[string]int { - index := make(map[string]int, len(*m)) - i := 0 +func IndexPlanets(m *map[string]Planet, start_at int) (map[string]int, []string) { + e2i := make(map[string]int, len(*m) + start_at) + i2e := make([]string, len(*m) + start_at) + i := start_at for e := range *m { - index[e] = i + e2i[e] = i + i2e[i] = e i++ } - return index + return e2i, i2e } -func IndexCommodities(m *map[string]Commodity) map[string]int { - index := make(map[string]int, len(*m)) - i := 0 +func IndexCommodities(m *map[string]Commodity, start_at int) (map[string]int, []string) { + e2i := make(map[string]int, len(*m) + start_at) + i2e := make([]string, len(*m) + start_at) + i := start_at for e := range *m { - index[e] = i + e2i[e] = i + i2e[i] = e i++ } - return index + return e2i, i2e } func main() { flag.Parse() data := ReadData() - data.pi = IndexPlanets(&data.Planets) - data.ci = IndexCommodities(&data.Commodities) + data.p2i, data.i2p = IndexPlanets(&data.Planets, 0) + data.c2i, data.i2c = IndexCommodities(&data.Commodities, 1) dims := DimensionSizes(data) - table := NewStateTable(dims) + table := FillStateTable1(data, dims) table[0] = State{1, 1} best_trades := FindBestTrades(data) for from := range data.Planets { for to := range data.Planets { best_trade := "(nothing)" - if best_trades[data.pi[from]][data.pi[to]] != "" { - best_trade = best_trades[data.pi[from]][data.pi[to]] + if best_trades[data.p2i[from]][data.p2i[to]] != "" { + best_trade = best_trades[data.p2i[from]][data.p2i[to]] } fmt.Printf("%s to %s: %s\n", from, to, best_trade) }