Thanks Dmitry! I am confused. I think from your reply, we could implement safe inter-process synchronization using mutex (on global memory), right? But it seems that Aaron do not agree that there are any inter-process communication?
regards, George ----- Original Message ---- From: Dmitry Grinberg <[EMAIL PROTECTED]> To: Palm Developer Forum <[email protected]> Sent: Tuesday, December 12, 2006 3:03:51 AM Subject: Re: multi-threaded application in Palm OS 5.2 there is no memory protection in palmos so if process A allocates a chunk, nothing stops process B from reading (or writing) it. there IS semaphore, mutex, mailbox and event group api, but what Aaron said stands for these as well. On 12/11/06, Lin George <[EMAIL PROTECTED]> wrote: Thanks Aaron! I want to confirm with you that, you mean each process can only have one thread, right? Other issues are, 1. are there any ways to do inter-process communication, like what we did on Linux/UNIX by using pipe/shared memory? 2. If the answer to 1 is yes, are there any inter-process synchronization control approaches, like what we did on Linux/UNIX by using mutex/lock? regards, George ----- Original Message ---- From: Aaron Ardiri <[EMAIL PROTECTED] > To: Palm Developer Forum <[email protected]> Sent: Monday, December 11, 2006 6:26:00 PM Subject: Re: multi-threaded application in Palm OS 5.2 On 12/11/06, Ben Combee <[EMAIL PROTECTED]> wrote: > On 12/10/06, Lin George <[EMAIL PROTECTED] > wrote: > > In my current understanding, Palm OS 5.2 only supports one application > > (process) one thread -- means each process could only have one thread. > > Is my understanding correct? > > You neither have multiple threads or multiple processes in standard Palm OS > programming. To switch applications, the current one ends, then the system > starts the new one. > > There is a limited background thread capability exposed through the sound > stream APIs. Also, applications can register for notifications where their > routines will be called while other programs are running. this is the official palmsource response. there is however, the ability to run true threads on palmos - the API is system use-only, however, it is really supposed to be used for small, simple tasks. how do you think your sms messages get delivered in the background? some developers may have been able to tune into this - but, its not official. i know for sure; i use it to get more accurate timing for nilEvent processing when doing animations and games. i dont know what the limitations are while using the threads - for example; you may be restricted to a certain set of API's and semaphore states in the callbacks. official answer: no un-official answer: yes, but - if you dont know how - forget it. -- // Aaron Ardiri -- For information on using the PalmSource Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/ ____________________________________________________________________________________ Cheap talk? Check out Yahoo! Messenger's low PC-to-Phone call rates. http://voice.yahoo.com -- For information on using the PalmSource Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/ -- Best Regards, Dmitry Grinberg Software Engineer, http://PalmPowerups.com (847) 226 9295 AIM: DmitryGrinberg MSN: [EMAIL PROTECTED] ICQ: 165589894 Y! IM: dmitrygr2003 -- For information on using the PalmSource Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/ ____________________________________________________________________________________ Need a quick answer? Get one in minutes from people who know. Ask your question on www.Answers.yahoo.com -- For information on using the PalmSource Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
