Hi Ranga, either you're seriously astray or I don't understand what you want.This is C++ running on an operating system with segmentation. There are *no* globally visibly objects, there is only calls to the operating systems / IPC to communicate with other processes and objects that live within your own process that you can directly address. Ok, there's shared memory, but you can't move a uhd_source to shared pages; that doesn't make sense.
When you're in the same process, it's easy just to pass pointers around. They are objects as everything else. Let's assume you construct a flowgraph like
top_block->connect(uhd_source, processing, mac, sink)
then you can just do
mac->set_uhd_src_pointer(uhd_source)
which would be something like
mymac::set_uhd_src_pointer(uhd_source::sptr src)
{
_uhd_src_sptr = src;
}
which enables you to just
_uhd_src_sptr->set_center_frequency(20000);
inside your class.
Greetings,
Marcus
On 14.11.2013 16:53, M. Ranganathan wrote:
Marcus,Looking around I don't see where the pointer to the block is made globally visible. I am inclined to add some code to the make method to register the shared pointer in a global variable when the method is called. Since my application has only a single USRP block (source and sink), there's no danger of overwriting something.My problem is this:I have python code that creates the blocks and strings them together etc. but I want to actually access the created block from c++ code (in the mac block implementation).Let me know if I am seriously astray. Thanks again for your help.On Thu, Nov 14, 2013 at 9:52 AM, Marcus Müller <mar...@hostalia.de <mailto:mar...@hostalia.de>> wrote:In GR 3.7, the shared pointer is usually blockname::sptr; I can't really point you to a very good example, but when you call top_block.connect(src, sink) in C++, you're giving it spointers :) As I said, whenever you make a block, you actually get a shared pointer to that instance, and not the object itself. On 14.11.2013 15:39, M. Ranganathan wrote:Marcus, Thanks for your reply. What will the shared pointer be called. I see stuff like this in the code: GR_SWIG_BLOCK_MAGIC2(uhd, usrp_source) GR_SWIG_BLOCK_MAGIC2(uhd, usrp_sink) GR_SWIG_BLOCK_MAGIC2(uhd, amsg_source) Presumably, that generates a structure that is registered as a global pointer. So in my mac, I want something like extern .... At the risk of asking for too much help, can you give me some guidance or point me to a fragment of code somewhere that does this sort of thing. Thanks, Ranga On Thu, Nov 14, 2013 at 4:06 AM, Marcus Müller <mar...@hostalia.de <mailto:mar...@hostalia.de>> wrote: Hi Ranga, that's what pointers are for, after all. Just do it! Thanks to the make()-magic you basically always have a smart shared pointer instead of an block object (unless you really try to break the system ;) ). Just a quick note though: MAC is usually timing-relevant. Timed commands might not work as you expect, so please be aware that calling set_command_time on your source might break functionality since there is no out-of-order execution. Greetings, Marcus On 14.11.2013 01:26, M. Ranganathan wrote:Hello all! I want to write a block that can directly access the uhd_usrp_source. This block is a mac block hence it is up on the food chain and far away from uhd_usrp_source in terms of its processing function. What is a good way of passing it a handle to the usrp_source ? I can think of some hacks (such as a static global pointer where the uhd_usrp_source C++ object registers itself) but it seems ugly to me to take that route. Is there a better way to access global objects from within a block implementation. Thanks in advance for any help. Regards, Ranga-- M. Ranganathan_______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org <mailto:Discuss-gnuradio@gnu.org> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio_______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org <mailto:Discuss-gnuradio@gnu.org> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio-- M. Ranganathan-- M. Ranganathan
_______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
