.
Thread 2 (Thread 0x7fd1da8e2700 (LWP 2442)):
#0  0x00007fd1e9a56d93 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
        resultvar = <optimized out>
        oldtype = 0
        result = <optimized out>
#1  0x00007fd1e7c3e136 in ?? ()
No symbol table info available.
#2  0x00007fd1d400a9d0 in ?? ()
No symbol table info available.
#3  0xffffffff7fffffff in ?? ()
No symbol table info available.
#4  0x0000000000000001 in ?? ()
No symbol table info available.
#5  0x00007fd1d400a980 in ?? ()
No symbol table info available.
#6  0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 1 (Thread 0x7fd1ea851700 (LWP 2434)):
#0  0x00007fd1e7c3d847 in ?? ()
No symbol table info available.
#1  0x0000000001c48af0 in ?? ()
No symbol table info available.
#2  0xffffffff023db100 in ?? ()
No symbol table info available.
#3  0x0000000000000001 in ?? ()
No symbol table info available.
#4  0x0000000001c48af0 in ?? ()
No symbol table info available.
#5  0x00000000023dca30 in ?? ()
No symbol table info available.
#6  0x0000000000000005 in ?? ()
No symbol table info available.
#7  0x0000000000000001 in ?? ()
No symbol table info available.
#8  0x0000000000000000 in ?? ()
No symbol table info available.