How to reuse variables in cgo？ - c

Question

I use GO code build a so file, and call it from go. at begin, i want to do some init job, so make sure the go call the shared library can reuse some variable. for example:
main.go
package main
import "C"
import (
"fmt"
"os"
"os/signal"
"syscall"
"time"
)
var (
globalConfig string
)
func main() {
}
//export search
func search() {
fmt.Println(globalConfig)
}
//export start
func start() {
// just keep running to keep globalConfig in RAM
go forever()
quitChannel := make(chan os.Signal, 1)
signal.Notify(quitChannel, syscall.SIGINT, syscall.SIGTERM)
<-quitChannel
}
func forever() {
v := "global value"
globalConfig = v
for {
time.Sleep(10 * time.Second)
fmt.Println(globalConfig)
}
}
and then generate the shared library.
go build -buildmode=c-shared -o libsdk.so main.go
call the shared lib.
cgo1.go
package main
/*
first step: export LD_LIBRARY_PATH="xxx sopath xxx"
*/
// #include "libsdk.h"
// #cgo LDFLAGS: -L. -lsdk
import "C"
func main() {
C.start()
// C.search()
}
cgo2.go
package main
/*
first step: export LD_LIBRARY_PATH="xxx sopath xxx"
*/
// #include "libsdk.h"
// #cgo LDFLAGS: -L. -lsdk
import "C"
func main() {
// C.start()
C.search()
}
and then the output first get the global value, the the second is null.
shouldn't shared lib share memory?