g_file_copy, g_file_move - остановка операции на время

#define _POSIX_C_SOURCE 2

#include <gtk/gtk.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <signal.h>

void callback(goffset a, goffset b, gpointer c) { printf("%li %li\n", a, b); }

int main(int argc, char **argv)
{
	gtk_init(&argc, &argv);

	pid_t p;
	char flag = 1;

	if ((p = fork()) > 0) {
		puts("parent");
		for (;;) {
			sleep(4);
			if (flag)
				kill(p, SIGSTOP), puts("stopped");
			else
				kill(p, SIGCONT), puts("started");
			flag ^= 1;
		}
	}
	else {
		if (p < 0) { puts("fork failed"); return 1; }
		puts("child");

		GError *e = NULL;
		GFile *s = g_file_new_for_path("/mnt/111");
		GFile *d = g_file_new_for_path("/mnt/222");

		g_file_copy(s, d,
			G_FILE_COPY_NOFOLLOW_SYMLINKS | G_FILE_COPY_ALL_METADATA,
			NULL, callback, NULL, &e);
	}

	return 0;
}