Example: IOSchedulerJob
private int count_children (File file, Cancellable? cancellable = null) throws Error {
FileEnumerator enumerator = file.enumerate_children (
"standard::*",
FileQueryInfoFlags.NOFOLLOW_SYMLINKS,
cancellable);
FileInfo info = null;
int counter = 0;
while (cancellable.is_cancelled () == false && ((info = enumerator.next_file (cancellable)) != null)) {
if (info.get_file_type () == FileType.DIRECTORY) {
File subdir = file.resolve_relative_path (info.get_name ());
counter += count_children (subdir, cancellable);
}
counter++;
}
if (cancellable.is_cancelled ()) {
throw new IOError.CANCELLED ("Operation was cancelled");
}
return counter;
}
public async int count_children_async (File file, Cancellable? cancellable = null) throws Error {
Error e = null;
int result = -1;
// Job runs in a new thread:
IOSchedulerJob.push ((job, cancellable) => {
try {
result = count_children (file, cancellable);
} catch (Error err) {
e = err;
}
// Run the user-callback in the thread that the job was started from:
job.send_to_mainloop (() => {
print ("user-callback, start\n");
count_children_async.callback ();
print ("user-callback, end\n");
return false;
});
return false;
}, Priority.DEFAULT, cancellable);
yield;
if (e != null) {
throw e;
}
return result;
}
public static int main (string[] args) {
Cancellable cancellable = new Cancellable ();
MainLoop loop = new MainLoop ();
if (args.length != 2) {
print ("%s [DIRECTORY]\n", args[0]);
return 0;
}
// Output:
// ``user-callback, start``
// ``120``
// ``user-callback, end``
count_children_async.begin (File.new_for_commandline_arg (args[1]), cancellable, (obj, res) => {
try {
int i = count_children_async.end (res);
print ("%d\n", i);
} catch (Error e) {
print ("Error: %s\n", e.message);
}
loop.quit ();
});
loop.run ();
return 0;
}
valac --pkg gio-2.0 GLib.IOSchedulerJob.vala
See:
