Question

I’m looking for the analogous of Cocoa’s

-[NSObject performSelectorOnMainThread: withObject: waitUntilDone:]

method.

So basically I have a function that does some work on a separate thread but it must perform some synchronous calls that need to be performed on the main one.

Answer 1

in cocoa, the message is added to the run loop, which is cleared as part of its iteration.

to simulate this:

• you’ll a want a run loop
• an abstract message system
• and a reference counting mechanism (in most cases)
• a way to add those messages to a run loop for scheduled execution

timers would be a nice addition

to accomplish something similar using pthread interfaces exclusively, start by reading up on conditions pthread_cond_t.

i know of no pthread interface with a 1-1 relationship for what you’re trying to accomplish. conditions also operate without run loops, so you may need to bring that to the table, if you do not reuse a run loop implementation. if you use run loops, then you just need a lock to add messages to a thread with a run loop.