Hi Jeon, > What factor determines input_item size (ninput_items)?
these are two things: the input item size is the size of a single item, and ninput_items is the amount of items that your (general_)work call sees. You are referring to the second thing: Consider this flow graph: A -> B -> C A is the upstream block (e.g. USRP source), B is your block, and C is a downstream block (e.g. Vector sink). ninput_items is determined by how many samples are available. Your block B has no influence on it; whenever the upstream block A finishes doing its (general_)work, GNU Radio updates the number of items available in the buffer between A and B. It then asks B whether it wants to work on this amount of input samples. I see your forecast method, and it seems to do the right thing: If your block is in the SYNC state, to output anything, it needs 480 items. If there's no 480 input items, GNU Radio won't call your general_work, usually. You should try printing ninput_items, to see if that's correct. Now, your block has two input streams. If they are somehow related, timing and buffer sizes might actually lead to a deadlock situation. Can you give us an overview over the whole flowgraph? Best regards, Marcus On 28.08.2015 19:00, Jeon wrote: > I am testing my OOT module in various condition of different machines. > > A certain block implementing a state machine requires a certain number > of items or more. > > Thus, I've stated it in forecast(): > https://gist.github.com/gsongsong/9ba1cb974a57a0861678#file-forecast-my_block-cpp > > In general work(), the block determines how many items it should be > consume: > https://gist.github.com/gsongsong/9ba1cb974a57a0861678#file-general_work-my_block-cpp > > With these codes, it works find with my own machinie. > Ubuntu 14.04, 2 CPUs and 4 GB RAM allocated virtual machine. The host > has i7-3770 and 16 GB RAM. > > But it fails on machine that my school gave to me for educational and > research purposes. I can't tell you the exact spec. of the machine, > but it apparently has a poor CPU and a lower memory space. > > Do these difference on machines' specs affect on ninput_items? I think > they have a certain relation to each other... since GNU Radio > scheduler allocates available memory over all blocks...? If so, can it > be resolved if I manually set a larger memory/buffer size to GNU > Radio? (If my memory is correct, I remember there's a configuration > file to do it...) > > Regards, > Jeon. > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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