[Discuss-gnuradio] Thread deadlock in GNU Radio?

[Andrew Ge]

Eric,

In my experiments, I had one transmitter and one receiver, which used 
tunnel.py for communicating with each other. Occasionally, I got the 
problem that one radio stopped receiving, but could still transmit. I 
used TX and RX printings to observe this behavior. In the receiving 
path, there is one thread to put received packets into a queue and 
another thread to read out the packets from this queue. Is it possible 
that these two threads can get deadlocked?

Once the above behavior happened, I used oprifile to see what's still 
running, here is the data:


CPU: Core 2, speed 1600 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a 
unit mask of 0x00 (Unhalted core cycles) count 50000
samples  %        image name               app name                 
symbol name
505795   36.8303  /no-vmlinux              /no-vmlinux              
/no-vmlinux
91821     6.6861  /lib/libgcc_s.so.1       /lib/libgcc_s.so.1       
/lib/libgcc_s.so.1
63582     4.6298  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gr_block_executor::run_one_iteration()
62849     4.5765  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 gr_fast_atan2f(float, 
float)
52437     3.8183  /lib/tls/i686/cmov/libm-2.11.1.so 
/lib/tls/i686/cmov/libm-2.11.1.so /lib/tls/i686/cmov/libm-2.11.1.so
41528     3.0239  /lib/tls/i686/cmov/libpthread-2.11.1.so 
/lib/tls/i686/cmov/libpthread-2.11.1.so pthread_mutex_lock
40215     2.9283  /usr/lib/libfftw3f.so.3.2.4 
/usr/lib/libfftw3f.so.3.2.4 /usr/lib/libfftw3f.so.3.2.4
32285     2.3509  /lib/tls/i686/cmov/libpthread-2.11.1.so 
/lib/tls/i686/cmov/libpthread-2.11.1.so __pthread_mutex_unlock_usercnt
27639     2.0126  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 ccomplex_dotprod_sse
25218     1.8363  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gr_clock_recovery_mm_ff::general_work(int, std::vector<int, 
std::allocator<int> >&, std::vector<void const*, std::allocator<void 
const*> >&, std::vector<void*, std::allocator<void*> >&)
24609     1.7919  /lib/tls/i686/cmov/libc-2.11.1.so 
/lib/tls/i686/cmov/libc-2.11.1.so /lib/tls/i686/cmov/libc-2.11.1.so
23391     1.7033  /usr/bin/python2.6       /usr/bin/python2.6       
/usr/bin/python2.6
22216     1.6177  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gr_fir_ccc_simd::filter(std::complex<float> const*)
19529     1.4220  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gri_fft_filter_ccc_generic::filter(int, std::complex<float> const*, 
std::complex<float>*)
19382     1.4113  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
min_available_space(gr_block_detail*, int)
17852     1.2999  [vdso] (tgid:2135 range:0x5bd000-0x5be000) 
/usr/bin/python2.6       [vdso] (tgid:2135 range:0x5bd000-0x5be000)
17703     1.2891  /lib/tls/i686/cmov/libpthread-2.11.1.so 
/lib/tls/i686/cmov/libpthread-2.11.1.so pthread_cond_signal@@GLIBC_2.3.2
17030     1.2401  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gr_freq_xlating_fir_filter_ccc::work(int, std::vector<void const*, 
std::allocator<void const*> >&, std::vector<void*, std::allocator<void*> >&)
15846     1.1539  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gr_tpb_detail::notify_downstream(gr_block_detail*)
15706     1.1437  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gr_tpb_detail::notify_upstream(gr_block_detail*)
15387     1.1204  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 float_dotprod_sse
14412     1.0494  /usr/bin/oprofiled       /usr/bin/oprofiled       
/usr/bin/oprofiled
12486     0.9092  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gr_keep_one_in_n::general_work(int, std::vector<int, std::allocator<int> 
>&, std::vector<void const*, std::allocator<void const*> >&, 
std::vector<void*, std::allocator<void*> >&)
12119     0.8825  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gr_quadrature_demod_cf::work(int, std::vector<void const*, 
std::allocator<void const*> >&, std::vector<void*, std::allocator<void*> >&)
11792     0.8587  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gr_count_bits32(unsigned int)
10476     0.7628  /usr/lib/libboost_thread.so.1.40.0 
/usr/lib/libboost_thread.so.1.40.0 /usr/lib/libboost_thread.so.1.40.0
9285      0.6761  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gr_tpb_thread_body::gr_tpb_thread_body(boost::shared_ptr<gr_block>)
9073      0.6607  /lib/tls/i686/cmov/libpthread-2.11.1.so 
/lib/tls/i686/cmov/libpthread-2.11.1.so pthread_cond_wait@@GLIBC_2.3.2
8443      0.6148  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
gri_mmse_fir_interpolator::interpolate(float const*, float) const
7698      0.5605  /usr/local/lib/libusrp2-3.3.1git.so.0.0.0 
/usr/local/lib/libusrp2-3.3.1git.so.0.0.0 
usrp2::copy_u2_16sc_to_host_32fc(unsigned int, unsigned int const*, 
std::complex<float>*)
7512      0.5470  /usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 
/usr/local/lib/libgnuradio-core-3.3.1git.so.0.0.0 __i686.get_pc_thunk.bx