Re: [Discuss-gnuradio] Clarification of lock() and unlock() in Dynamic Flow-Graph Reconfiguration
Hey, We have tried just about every different combination of start,stop,wait,lock, and unlock possible Whenever we remove the stop() call, we get an error that we do not receive whenever the stop() call is in place. With the stop() call removed, the program gives us the following error at the unlock() statement: *terminate called after throwing an instance of 'boost::thread_interrupted'* *Aborted* This error does not come up if we remove the stop() statement, but the program freezes at the unlock instead. Any clues to solving the boost error or what this actually means?? From viewing the version 3.2.2 API documentationhttp://gnuradio.org/doc/doxygen/index.htmlfor the gr_top_block class, there is a note saying that the lock() and unlock() methods should not be called from a flowgraph thread or the program will be become deadlocked. In my program the lock() and unlock() are being called from the same top_block() which is instantiated when the program is started. Could this be the cause of freezing once we get to the unlock statement? Once again thanks for your help. I was extremely surprised at how quickly you guys responded :) A couple of things to try: Try removing the tb.stop() call, lock will stop the flowgraph anyway. You may need to 'disconnect' (essentially undo all the connect calls) the path before recreating it. In the first instance try the disconnect_all() method, but from memory that had some issues so you could try calling disconnect for each block which was connected. else: print Receiver Mode : USRP to Switch to Receiving Packets self.tb.stop() Don't call stop. Just call lock. -- Venkat Vinod Patcha and Ben Carroll ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Clarification of lock() and unlock() in Dynamic Flow-Graph Reconfiguration
Hello All, I am having some difficulties implementing a cognitive receiver program that involves dynamically reconfiguring the USRP between sensing the spectrum and acting as a receiver based on the results of the spectrum sensing. The program I am developing is mostly based on the usrp_spectrum_sense.py for the sensing part and benchmark_rx.py for the receiving part. The specifications for our platform are at the end of the e-mail. The general logic of my program is to run one flow graph which is connected in the same way as in the usrp_spectrum_sense program. After obtaining the results from the spectrum sensing, I wish to reconfigure the flow graph to connect the USRP to receive and demodulate a user-defined number of packets just as in the benchmark_rx program whenever we deem the spectrum to be free, after which we could revert to the configuration in the first flow graph and continue until the program is terminated. Here is some code of the most relevant parts of the program: # CODE : class my_top_block(): def __init__(self, frame_count): . self.tb = gr.top_block() self.u = usrp.source_c(fusb_block_size=options.fusb_block_size, fusb_nblocks=options.fusb_nblocks) self.tb.connect(self.u, s2v, fft, c2mag, stats) . def set_freq(self, target_freq): return self.u.tune(0, self.subdev, target_freq) def set_next_freq(self): target_freq = self.next_freq min_center_freq = self.min_center_freq max_center_freq = self.max_center_freq power_norm = self.power_norm frame_count = self.frame_count if (target_freq == self.prev_freq + self.freq_step): main_loop(self) . if self.next_freq self.max_center_freq: self.next_freq = self.min_center_freq self.prev_freq = self.min_center_freq - self.freq_step self.finished_sensing = True Make a decision on reception mode or sleep mode based on the value of avg_frame_power if target_freq == self.min_center_freq and self.finished_sensing == True: print The average power for previous frame %d : %frame_count, self.avg_frame_power frame_count += 1 self.finished_sensing = False if (self.avg_frame_power 50): print Sensing Mode : USRP in Sleep self.stats.sleep_mode(True,1000) # THIS IS OUR MODIFICATION WE USE IN gr_bin_statistics_f.cc # IN PLACE OF USING time.sleep(); WE KNOW THIS WORKS # WITH NO PROBLEMS else: print Receiver Mode : USRP to Switch to Receiving Packets self.tb.stop() self.tb.lock() # THIS IS WHERE WE WANT TO RECONFIGURE TO RECEIVE # PACKETS self.rx_path = receive_path(self.tb,self.u,self.demodulator,self.options,self.samples_per_symbol, self.decim,self.rx_subdev_spec,self.rx_freq,self.subdev) self.tb.unlock() # THIS IS WHERE THE PROGRAM FREEZES return target_freq ... class receive_path(my_top_block): def __init__(self,tb,u,demodulator,options,samples_per_symbol,decim,rx_subdev_spec,rx_freq,subdev): ... self.tb.connect(self.u,self.channel_filter, self.probe) self.tb.connect(self.channel_filter, self._demodulator) self.tb.connect(self._demodulator, self.correlator, self.framer_sink) #self._watcher = _queue_watcher_thread(self._rcvd_pktq, rx_callback) def main_loop(tb): # THIS IS WHERE WE CALCULATE THE avg_frame_power AND PRINT RESULTS TO OUTPUT FILES if __name__ == '__main__': frame_count = 1 my_tb = my_top_block(frame_count)# start executing flow graph in another thread... try: my_tb.tb.run() except KeyboardInterrupt: pass # Since I have been unable to switch from the sensing path to the receiving path with no errors, I haven't begun to deal with switching back from the receiving path to the sensing path yet. I know that the program is freezing at the unlock() statement, since I have debugged the program at execution time line-by-line using the standard pdb Python debugger. From viewing the version 3.2.2 API documentationhttp://gnuradio.org/doc/doxygen/index.htmlfor the gr_top_block class, there is a note saying that the lock() and unlock() methods should not be called from a flowgraph thread or the program will be become deadlocked. I was wondering if someone could clarify what
Re: [Discuss-gnuradio] Clarification of lock() and unlock() in Dynamic Flow-Graph Reconfiguration
Quick Question.. Is there a reason you do not want to use time.sleep(). Just curious? On Sun, Aug 29, 2010 at 8:27 PM, Venkat Vinod venkatvi...@gmail.com wrote: Hello All, I am having some difficulties implementing a cognitive receiver program that involves dynamically reconfiguring the USRP between sensing the spectrum and acting as a receiver based on the results of the spectrum sensing. The program I am developing is mostly based on the usrp_spectrum_sense.py for the sensing part and benchmark_rx.py for the receiving part. The specifications for our platform are at the end of the e-mail. The general logic of my program is to run one flow graph which is connected in the same way as in the usrp_spectrum_sense program. After obtaining the results from the spectrum sensing, I wish to reconfigure the flow graph to connect the USRP to receive and demodulate a user-defined number of packets just as in the benchmark_rx program whenever we deem the spectrum to be free, after which we could revert to the configuration in the first flow graph and continue until the program is terminated. Here is some code of the most relevant parts of the program: # CODE : class my_top_block(): def __init__(self, frame_count): . self.tb = gr.top_block() self.u = usrp.source_c(fusb_block_size=options.fusb_block_size, fusb_nblocks=options.fusb_nblocks) self.tb.connect(self.u, s2v, fft, c2mag, stats) . def set_freq(self, target_freq): return self.u.tune(0, self.subdev, target_freq) def set_next_freq(self): target_freq = self.next_freq min_center_freq = self.min_center_freq max_center_freq = self.max_center_freq power_norm = self.power_norm frame_count = self.frame_count if (target_freq == self.prev_freq + self.freq_step): main_loop(self) . if self.next_freq self.max_center_freq: self.next_freq = self.min_center_freq self.prev_freq = self.min_center_freq - self.freq_step self.finished_sensing = True Make a decision on reception mode or sleep mode based on the value of avg_frame_power if target_freq == self.min_center_freq and self.finished_sensing == True: print The average power for previous frame %d : %frame_count, self.avg_frame_power frame_count += 1 self.finished_sensing = False if (self.avg_frame_power 50): print Sensing Mode : USRP in Sleep self.stats.sleep_mode(True,1000) # THIS IS OUR MODIFICATION WE USE IN gr_bin_statistics_f.cc # IN PLACE OF USING time.sleep(); WE KNOW THIS WORKS # WITH NO PROBLEMS else: print Receiver Mode : USRP to Switch to Receiving Packets self.tb.stop() self.tb.lock() # THIS IS WHERE WE WANT TO RECONFIGURE TO RECEIVE # PACKETS self.rx_path = receive_path(self.tb,self.u,self.demodulator,self.options,self.samples_per_symbol, self.decim,self.rx_subdev_spec,self.rx_freq,self.subdev) self.tb.unlock() # THIS IS WHERE THE PROGRAM FREEZES return target_freq ... class receive_path(my_top_block): def __init__(self,tb,u,demodulator,options,samples_per_symbol,decim,rx_subdev_spec,rx_freq,subdev): ... self.tb.connect(self.u,self.channel_filter, self.probe) self.tb.connect(self.channel_filter, self._demodulator) self.tb.connect(self._demodulator, self.correlator, self.framer_sink) #self._watcher = _queue_watcher_thread(self._rcvd_pktq, rx_callback) def main_loop(tb): # THIS IS WHERE WE CALCULATE THE avg_frame_power AND PRINT RESULTS TO OUTPUT FILES if __name__ == '__main__': frame_count = 1 my_tb = my_top_block(frame_count)# start executing flow graph in another thread... try: my_tb.tb.run() except KeyboardInterrupt: pass # Since I have been unable to switch from the sensing path to the receiving path with no errors, I haven't begun to deal with switching back from the receiving path to the sensing path yet. I know that the program is freezing at the unlock() statement, since I have debugged the program at execution time line-by-line using the standard pdb Python debugger. From viewing the version 3.2.2 API
Re: [Discuss-gnuradio] Clarification of lock() and unlock() in Dynamic Flow-Graph Reconfiguration
Hi Venkat, A couple of things to try: Try removing the tb.stop() call, lock will stop the flowgraph anyway. You may need to 'disconnect' (essentially undo all the connect calls) the path before recreating it. In the first instance try the disconnect_all() method, but from memory that had some issues so you could try calling disconnect for each block which was connected. It has been awhile since I battled with the locking system of GNU Radio so I am a little rusty, hopefully it helps! Kieran On Mon, Aug 30, 2010 at 12:27 PM, Venkat Vinod venkatvi...@gmail.comwrote: Hello All, I am having some difficulties implementing a cognitive receiver program that involves dynamically reconfiguring the USRP between sensing the spectrum and acting as a receiver based on the results of the spectrum sensing. The program I am developing is mostly based on the usrp_spectrum_sense.py for the sensing part and benchmark_rx.py for the receiving part. The specifications for our platform are at the end of the e-mail. The general logic of my program is to run one flow graph which is connected in the same way as in the usrp_spectrum_sense program. After obtaining the results from the spectrum sensing, I wish to reconfigure the flow graph to connect the USRP to receive and demodulate a user-defined number of packets just as in the benchmark_rx program whenever we deem the spectrum to be free, after which we could revert to the configuration in the first flow graph and continue until the program is terminated. Here is some code of the most relevant parts of the program: # CODE : class my_top_block(): def __init__(self, frame_count): . self.tb = gr.top_block() self.u = usrp.source_c(fusb_block_size=options.fusb_block_size, fusb_nblocks=options.fusb_nblocks) self.tb.connect(self.u, s2v, fft, c2mag, stats) . def set_freq(self, target_freq): return self.u.tune(0, self.subdev, target_freq) def set_next_freq(self): target_freq = self.next_freq min_center_freq = self.min_center_freq max_center_freq = self.max_center_freq power_norm = self.power_norm frame_count = self.frame_count if (target_freq == self.prev_freq + self.freq_step): main_loop(self) . if self.next_freq self.max_center_freq: self.next_freq = self.min_center_freq self.prev_freq = self.min_center_freq - self.freq_step self.finished_sensing = True Make a decision on reception mode or sleep mode based on the value of avg_frame_power if target_freq == self.min_center_freq and self.finished_sensing == True: print The average power for previous frame %d : %frame_count, self.avg_frame_power frame_count += 1 self.finished_sensing = False if (self.avg_frame_power 50): print Sensing Mode : USRP in Sleep self.stats.sleep_mode(True,1000) # THIS IS OUR MODIFICATION WE USE IN gr_bin_statistics_f.cc # IN PLACE OF USING time.sleep(); WE KNOW THIS WORKS # WITH NO PROBLEMS else: print Receiver Mode : USRP to Switch to Receiving Packets self.tb.stop() self.tb.lock() # THIS IS WHERE WE WANT TO RECONFIGURE TO RECEIVE # PACKETS self.rx_path = receive_path(self.tb,self.u,self.demodulator,self.options,self.samples_per_symbol, self.decim,self.rx_subdev_spec,self.rx_freq,self.subdev) self.tb.unlock() # THIS IS WHERE THE PROGRAM FREEZES return target_freq ... class receive_path(my_top_block): def __init__(self,tb,u,demodulator,options,samples_per_symbol,decim,rx_subdev_spec,rx_freq,subdev): ... self.tb.connect(self.u,self.channel_filter, self.probe) self.tb.connect(self.channel_filter, self._demodulator) self.tb.connect(self._demodulator, self.correlator, self.framer_sink) #self._watcher = _queue_watcher_thread(self._rcvd_pktq, rx_callback) def main_loop(tb): # THIS IS WHERE WE CALCULATE THE avg_frame_power AND PRINT RESULTS TO OUTPUT FILES if __name__ == '__main__': frame_count = 1 my_tb = my_top_block(frame_count)# start executing flow graph in another thread... try: my_tb.tb.run() except KeyboardInterrupt: pass #
Re: [Discuss-gnuradio] Clarification of lock() and unlock() in Dynamic Flow-Graph Reconfiguration
On Sun, Aug 29, 2010 at 07:27:21PM -0500, Venkat Vinod wrote: Hello All, I am having some difficulties implementing a cognitive receiver program that involves dynamically reconfiguring the USRP between sensing the spectrum and acting as a receiver based on the results of the spectrum sensing. The program I am developing is mostly based on the usrp_spectrum_sense.py for the sensing part and benchmark_rx.py for the receiving part. The specifications for our platform are at the end of the e-mail. The general logic of my program is to run one flow graph which is connected in the same way as in the usrp_spectrum_sense program. After obtaining the results from the spectrum sensing, I wish to reconfigure the flow graph to connect the USRP to receive and demodulate a user-defined number of packets just as in the benchmark_rx program whenever we deem the spectrum to be free, after which we could revert to the configuration in the first flow graph and continue until the program is terminated. Here is some code of the most relevant parts of the program: # CODE : else: print Receiver Mode : USRP to Switch to Receiving Packets self.tb.stop() Don't call stop. Just call lock. self.tb.lock() # THIS IS WHERE WE WANT TO RECONFIGURE TO RECEIVE # PACKETS ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
