65 lines
1.5 KiB
V
65 lines
1.5 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 time
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import os
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fn do_rec(ch chan int, resch chan i64, n int) {
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mut sum := i64(0)
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for _ in 0 .. n {
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sum += <-ch
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}
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println(sum)
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resch <- sum
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}
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fn do_send(ch chan int, start int, end int) {
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for i in start .. end {
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ch <- 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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ch := chan int{cap: buflen}
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resch := chan i64{}
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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(ch, 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(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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sum += <-resch
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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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