systhread_mutex_lock vs systhread_mutex_trylock

Hello,

AFAIK :

- with mutex_lock the thread sleeps until the mutex is released (and the thread waked up) ;
- with mutex_trylock it just abort.

instead of mutex_trylock i use something like that …

if (ATOMIC_INCREMENT (&x->lock) == 1) {
ATOMIC_DECREMENT (&x->lock) ;
} else {
ATOMIC_DECREMENT (&x->lock) ;
}

… but i’m not sure it is best ;-)

http://cycling74.com/forums/topic.php?id=25554

Hello,

i use ATOMIC for anything i can delay (like GUI) …

if not busy :
do the stuff
else :
try later

… in kind of custom event poll loop but that is my 2 cents ;-)

ATOMIC seems to be more efficient than tryLock :

http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/Multithreading/ThreadSafety/ThreadSafety.html%23//apple_ref/doc/uid/10000057i-CH8-SW1

Hello,

i code this trick mainly for GUI :

I use bit mask to set flags NEED_TO_DRAW_THAT, NEED_TO_DRAW_THIS etc … i create a clockTask polling every 40 ms (for instance) and copy data according to bit set (then ask jbox_redraw to do the job). Of course it slows the drawing rate, but i don’t really care. It’s to isolate the paint method.

For now, it’s a little bit messy, but seems efficient ; next step is to encapsulate the process in a library in a cleaner way (code is on github anyway).