谁能帮忙解释一段并发代码的诡异结果

写了一段并发代码，初始化一个10w个元素的int数组，输出这10w个数之和，我的机器是2个cpu，每个cpu包含6个核，将数组分成12分子数组，分别用12个goroutine来算出子数组的和，最后求总和。 goroutine的执行单位是calsome()函数，我在这个函数的最后故意加了个死循环，结果执行时有时能安全退出（即输出result=4999950000），有时输出了若干个from=%d, subSum=%d就夯住了（此时通过top命令看到各个cpu核使用率都几乎达到100%），哪位大神能帮忙解释这种情况？ 完整代码如下： package main import ( "fmt" "runtime" "time" ) const COUNT int = 100000 const SIZE int = 100000 var MULTICORE int func main() { var num [SIZE]int MULTICORE = runtime.NumCPU() //number of core runtime.GOMAXPROCS(MULTICORE) //running in multicore for i := 0; i < COUNT; i++ { num[i] = i } fmt.Printf("result=%d\n", calmul(num[0:])) } func calmul(num []int) int { t1 := time.Now() ch := make(chan int) fmt.Printf("with %d core\n", MULTICORE) for i := 0; i < MULTICORE; i++ { go calsome(i*COUNT/MULTICORE, (i+1)*COUNT/MULTICORE, num[0:], ch, i) } //divide into some parts result := 0; for i := 0; i < MULTICORE; i++ { temp := <-ch result += temp } //read result of some part from channel,loop will stop after all is read t2 := time.Now() fmt.Printf("multicore total time:%d\n", t2.Sub(t1)) return result } func calsome(from int, to int, num []int, ch chan int, i int) { subSum := 0 for i := from; i < to; i++ { subSum += num[i] } fmt.Printf("from=%d, subSum=%d\n", from,subSum); ch <- subSum //put result in channel j := 1; **//这里做了死循环** for j > 0{} }