[9fans] Go testing and resource exhaustion

[Skip Tavakkolian <skip.tavakkolian@gmail.com>]

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This is just an FYI.

I'm seeing something that looks to me like a resource exhaustion of some
sort. When running the standard test (i.e. go test std), some tests are
broken (see below); but test of each "broken" package/cmd/etc, passes
correctly.

I thought it might be related to semaphores, but the attached program
didn't fail at all; in fact running 100 simultaneously caused nothing more
than several temporary "Fault" states, but none broken.

partial output of ps:

fst           83379    0:00   0:00      240K Await    run.rc -e ./run.rc
--no-rebuild
fst           83385    0:00   0:00       48K Await    time go test std
-short -timeout 120s
fst           83386    0:04   0:07   797488K Semacqui go test std -short
-timeout 120s
fst           83387    0:00   0:00   797488K Semacqui go
fst           83388    0:00   0:00   797488K Tsemacqu go
fst           83389    0:00   0:00   797488K Semacqui go
fst           83399    0:00   0:00   797488K Pread    go
fst           83401    0:00   0:00   797488K Pread    go
fst           83403    0:00   0:01   797488K Semacqui go
fst           83404    0:00   0:00   797488K Pread    go
fst           83405    0:00   0:00   797488K Semacqui go
fst           83406    0:00   0:01   797488K Pread    go
fst           83407    0:00   0:00   797488K Semacqui go
fst           83426    0:00   0:00   797488K Semacqui go
fst           83437    0:00   0:00   794320K Sleep    api.test
fst           83453    0:00   0:00   794528K Broken   tar.test
fst           83497    0:00   0:00   793628K Sleep    bzip2.test
fst           83499    0:00   0:00   793628K Broken   bzip2.test
fst           83532    0:00   0:00   794328K Sleep    lzw.test
fst           83533    0:00   0:00   794328K Broken   lzw.test
fst           84100    0:00   0:00   795204K Sleep    template.test
fst           84101    0:00   0:00   795204K Semacqui template.test
fst           84102    0:00   0:00   795204K Broken   template.test

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[-- Attachment #2: goroutines.go --]
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package main

import (
	"fmt"
	"math/rand"
)

func produce(ch chan<- int, n int) {
	for i := 0; i < n; i++ {
		ch <- i
	}

}

func consume(ch <-chan int) {
	for i := range ch {
		if i % 100 == 0 {
			fmt.Println(i)
		}
	}
}

func busywork(n int, done chan<- bool) {
	ch := make(chan int)
	go produce(ch, n)
	consume(ch)
	done <- true
}

const N = 1000

func main() {
	r := rand.New(rand.NewSource(1000000))
	done := make(chan bool)
	for i := 0; i < N; i++ {
		go busywork(r.Int(), done)
	}
	for i := 0; i < N; i++ {
		<-done
	}
}