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// This test case runs concurrent 3 instances of `do_select` that
// communicate with 6 other threads doing send and receive operations.
// There are buffered and unbuffered channels - handled by one or two
// concurrend threads on the other side
fn do_select(ch1 chan int, ch2 chan int, chf1 chan f64, chf2 chan f64, sumch1 chan i64, sumch2 chan i64) {
mut sum1 := i64(0)
mut sum2 := i64(0)
f1 := 17.
f2 := 7.
for _ in 0 .. 20000 + chf1.cap / 3 {
select {
chf1 <- f1 {}
i := <-ch1 {
sum1 += i
}
j := <-ch2 {
sum2 += j
}
chf2 <- f2 {}
}
}
sumch1 <- sum1
sumch2 <- sum2
}
fn do_send_int(ch chan int, factor int) {
for i in 0 .. 10000 {
ch <- (i * factor)
}
}
fn do_rec_f64(ch chan f64, sumch chan f64) {
mut sum := 0.
for _ in 0 .. 10000 {
sum += <-ch
}
sumch <- sum
}
fn test_select() {
ch1 := chan int{cap: 3}
ch2 := chan int{}
// buffer length of chf1 mus be mutiple of 3 (# select threads)
chf1 := chan f64{cap: 30}
chf2 := chan f64{}
chsum1 := chan i64{}
chsum2 := chan i64{}
chsumf1 := chan f64{}
chsumf2 := chan f64{}
go do_send_int(ch1, 3)
go do_select(ch1, ch2, chf1, chf2, chsum1, chsum2)
go do_rec_f64(chf1, chsumf1)
go do_rec_f64(chf2, chsumf2)
go do_rec_f64(chf2, chsumf2)
go do_select(ch1, ch2, chf1, chf2, chsum1, chsum2)
go do_send_int(ch2, 7)
go do_send_int(ch2, 17)
go do_select(ch1, ch2, chf1, chf2, chsum1, chsum2)
sum1 := <-chsum1 + <-chsum1 + <-chsum1
sum2 := <-chsum2 + <-chsum2 + <-chsum2
mut sumf1 := <-chsumf1
// empty channel buffer
for _ in 0 .. chf1.cap {
sumf1 += <-chf1
}
sumf2 := <-chsumf2 + <-chsumf2
// Use Gauß' formula
expected_sum := i64(10000) * (10000 - 1) / 2
assert sum1 == 3 * expected_sum
assert sum2 == (7 + 17) * expected_sum
assert sumf1 == 17. * f64(10000 + chf1.cap)
assert sumf2 == 7. * 20000
}
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