我正在做一个测试：比较cgo和pure Go功能的卓越时间每次运行1亿次.与Golang功能相比,cgo功能需要更长的时间,我对此结果感到困惑.我的测试代码是：
package main
import (
"fmt"
"time"
)
/*
#include
#include
#include
void show() {
}
*/
// #cgo LDFLAGS: -lstdc++
import "C"
//import "fmt"
func show() {
}
func main() {
now := time.Now()
for i := 0; i < 100000000; i = i + 1 {
C.show()
}
end_time := time.Now()
var dur_time time.Duration = end_time.Sub(now)
var elapsed_min float64 = dur_time.Minutes()
var elapsed_sec float64 = dur_time.Seconds()
var elapsed_nano int64 = dur_time.Nanoseconds()
fmt.Printf("cgo show function elasped %f minutes or \nelapsed %f seconds or \nelapsed %d nanoseconds\n",elapsed_min,elapsed_sec,elapsed_nano)
now = time.Now()
for i := 0; i < 100000000; i = i + 1 {
show()
}
end_time = time.Now()
dur_time = end_time.Sub(now)
elapsed_min = dur_time.Minutes()
elapsed_sec = dur_time.Seconds()
elapsed_nano = dur_time.Nanoseconds()
fmt.Printf("go show function elasped %f minutes or \nelapsed %f seconds or \nelapsed %d nanoseconds\n",elapsed_nano)
var input string
fmt.Scanln(&input)
}
结果是：
cgo show function elasped 0.368096 minutes or
elapsed 22.085756 seconds or
elapsed 22085755775 nanoseconds
go show function elasped 0.000654 minutes or
elapsed 0.039257 seconds or
elapsed 39257120 nanoseconds
结果表明,调用C函数比Go函数慢.我的测试代码有什么问题吗？
我的系统是：mac OS X 10.9.4(13E28)
