71 lines
1.6 KiB
V
71 lines
1.6 KiB
V
// Channel Benchmark
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//
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// `nobj` integers are sent thru a channel with queue length`buflen`
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// using `nsend` sender threads and `nrec` receiver threads.
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//
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// The receive threads add all received numbers and send them to the
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// main thread where the total sum is compare to the expected value.
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import sync
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import time
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import os
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fn do_rec(mut ch sync.Channel, mut resch sync.Channel, n int) {
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mut sum := i64(0)
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for _ in 0 .. n {
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mut a := 0
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ch.pop(&a)
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sum += a
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}
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println(sum)
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resch.push(&sum)
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}
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fn do_send(mut ch sync.Channel, start, end int) {
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for i in start .. end {
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ch.push(&i)
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}
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}
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fn main() {
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if os.args.len != 5 {
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eprintln('usage:\n\t${os.args[0]} <nsend> <nrec> <buflen> <nobj>')
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exit(1)
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}
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nsend := os.args[1].int()
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nrec := os.args[2].int()
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buflen := os.args[3].int()
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nobj := os.args[4].int()
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stopwatch := time.new_stopwatch({})
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mut ch := sync.new_channel<int>(buflen)
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mut resch := sync.new_channel<i64>(0)
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mut no := nobj
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for i in 0 .. nrec {
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n := no / (nrec - i)
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go do_rec(mut ch, mut resch, n)
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no -= n
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}
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assert no == 0
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no = nobj
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for i in 0 .. nsend {
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n := no / (nsend - i)
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end := no
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no -= n
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go do_send(mut ch, no, end)
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}
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assert no == 0
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mut sum := i64(0)
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for _ in 0 .. nrec {
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mut r := i64(0)
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resch.pop(&r)
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sum += r
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}
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elapsed := stopwatch.elapsed()
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rate := f64(nobj)/elapsed*time.microsecond
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println('$nobj objects in ${f64(elapsed)/time.second} s (${rate:.2f} objs/µs)')
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// use sum formula by Gauß to calculate the expected result
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expected_sum := i64(nobj)*(nobj-1)/2
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println('got: $sum, expected: $expected_sum')
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assert sum == expected_sum
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}
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