#cgo LDFLAGS: -pthread
extern int RunSigThread();
extern int CheckBlocked();
*/
import "C"
import (
	"os"
	"os/signal"
	"syscall"
	"testing"
)

var blocked bool

//export IntoGoAndBack
func IntoGoAndBack() {
	// Verify that SIGIO stays blocked on the C thread
	// even when unblocked for signal.Notify().
	signal.Notify(make(chan os.Signal), syscall.SIGIO)
	blocked = C.CheckBlocked() != 0
}

#include <stdio.h>
#include <time.h>
#include <unistd.h>

extern void IntoGoAndBack();

int CheckBlocked() {
	sigset_t mask;
	sigprocmask(SIG_BLOCK, NULL, &mask);
	return sigismember(&mask, SIGIO);
}

static void* sigthreadfunc(void* unused) {
	sigset_t mask;
	sigemptyset(&mask);
	sigaddset(&mask, SIGIO);
	sigprocmask(SIG_BLOCK, &mask, NULL);
	IntoGoAndBack();
	return NULL;
}

int RunSigThread() {
	int tries;