On 08/12/2010 08:38 AM, salk31 wrote: > Don't you have to count the async returning and then do yet another > callback? > > So hook into the callback of all your commands and then when the last > one is done do the callback?
Extending salk31's logic: Put your execute() inside a loop, inside an IncrementalCommand. Your execute() routine implements a mutex. The loop terminates per salk31's observation. The execute() routine sets the mutex before the async call, and clears it in OnResponseReceived(), OnError(). The loop checks that mutex and immediately returns to the IncrementalCommand if set. In FF 3.6, I found it was too easy to overload the server (resulting in response timeouts) w/o serializing the calls via a mutex. IOW, simply allowing the brower's RPC queue to serialize (i.e. clear the execute() queue as fast as possible) resulted in dropped calls. I believe the above will work w/ Java RPC. If there are many list elements, you might want a timer that controls a "loading..." message. Also, you might want to evaluate at the Dictionary class to see if that's a better fit for the problem you're trying to solve. > > On Aug 12, 3:30 pm, Kevin Qiu <[email protected]> wrote: >> I don't know if the title makes sense but working with gwt for about 2 >> years, I often find myself in the position to mix both asynchronous and >> synchronous (blocking) apis. It's easy to transform a synchronous call to >> asynchronous, but the other way around is not immediately obvious to me, >> especially in the context of the single-threaded browser environment. >> >> Imagine I the following: >> >> abstract class GetList<T> { >> abstract void execute(AsyncCallback<List<T>> callback); >> >> } >> >> class GetContactList extends GetList<Contact> { >> void execute(AsyncCallback<List<Contact>> callback) { /* implementation */ >> >> } >> } >> >> class GetAddressList extends GetList<Address> { >> void execute(AsyncCallback<List<Address>> callback) { /* implementation */ >> >> } >> } >> >> class GetPhoneList extends GetList<Phone> { >> void execute(AsyncCallback<List<Phone>> callback) { /* implementation */ } >> >> } >> >> now imagine I keep a list of GetList objects: >> List<GetList> commands = Arrays.asList(new GetContactList(), new >> GetAddressList(), new GetPhoneList()); >> >> and I have an executor that executes these commands: >> >> class Executor { >> List<? extends GetList<?>> commands; >> Executor(List<? extends GetList<?>> commands) { >> this.commands = commands; >> } >> void execute() { >> // XXX: >> } >> >> } >> >> Now, for whatever reason, I need my execute() method to be a blocking call >> (synchronous). It should terminate after all GetList calls are returned. How >> can I achieve this? > -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
