September 2010 - libdispatch-dev - lists.macosforge.org

Some questions about source handling
by cee1 11 Dec '10

11 Dec '10

Hi all, Questions: 1. How does a source's event handler accesses data returned by kevent? Data returned by kevent will finally be recorded is ds_data field in _dispatch_source_latch_and_call. The event handler will be called with ds_handler_ctxt, which shoule be do_ctxt. "do_ctxt" can be set by function dispatch_set_context. The problem is: - If a handler need to access ds_data, we have to set a proper do_ctxt (e.g. a do_ctxt of source). That's not convenient. - "ds_data" is a member of dispatch_source_t, and dispatch_source_t is an opaque struct to client code. 2. We have custom source of type DISPATCH_SOURCE_TYPE_DATA_ADD and DISPATCH_SOURCE_TYPE_DATA_OR, and can use dispatch_source_merge_data to fire custom sources. Why we don't have an 'is_level' source? An "is_level" source may not make much sense, but can be attached with cancel handler, this may be useful in some cases. -- Regards, - cee1

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Queue size
by Danilo Egea 29 Sep '10

29 Sep '10

First, sorry my english... Are possible define the queue size in GCD? Example: Define the max. number of task run simultaneous in a queue. -- Danilo Egêa Gondolfo Email/MSN - daniloegea(a)yahoo.com.br Skype - daniloegea Twitter - http://twitter.com/daniloegea Blog - http://daniloegea.wordpress.com __________________________________________________ Fale com seus amigos de graça com o novo Yahoo! Messenger http://br.messenger.yahoo.com/

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Some slides about libdispatch
by cee1 07 Sep '10

07 Sep '10

Hi all, I've written some slides about libdispatch: - http://dev.lemote.com/files/upload/people/~chenj/libdispatch/libdispatch.pdf - http://dev.lemote.com/files/upload/people/~chenj/libdispatch/libdispatch-ev… Here are odp versions: - http://dev.lemote.com/files/upload/people/~chenj/libdispatch/libdispatch.odp - http://dev.lemote.com/files/upload/people/~chenj/libdispatch/libdispatch-ev… -- Regards, - cee1

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Question about event handling in libdispatch
by cee1 02 Sep '10

02 Sep '10

Hi all, A kevent can associate with more than one source. What if: 1. A kevent of EVFILT_READ indicating that data is available to read. 2. A series of sources associating with this kevent are waken up. 3. One source handler fetches the data. 4. The rest source handlers will find there is no data available to read in monitored fd. It seems waking up more than one source doesn't make sense here? The rest source handlers will simply fail to read. -- Regards, - cee1

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Update FreeBSD information on the libdispatch page?
by Robert N. M. Watson 01 Sep '10

01 Sep '10

If someone could update the following text: > libdispatch on FreeBSD > 2009-10-21 > The libdispatch library is available in the FreeBSD ports collection for experimental use on FreeBSD 9.x. Several kqueue kernel enhancements are planned for FreeBSD 8.1 in order to allow the libdispatch port to be used on FreeBSD 8.x as well. > > Information is available on the FreeBSD wiki about installing the libdispatch, llvm-devel, and compiler-rt ports allowing full use of the blocks extension to C with libdispatch. libdispatch is now appropriate for (we think) production use as of FreeBSD 8.1; to use it, just install the libdispatch port or package and the rest should follow automatically. I've just updated the FreeBSD wiki page, wiki.freebsd.org/GCD, to reflect this as well. (If the above turns out not to work so well, I also accept bug reports!) Robert

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