Little benchmark for E01HelloWorld

The E01HelloWorld tutorial is found in the user guide [4].

commonapi.ini configuration:

[default]
binding=someip

[logging]
console = true
dlt = false
level = verbose

Results for 10,000 requests:

                   1st try    2nd try     3rd try
no logging        7.17268s   7.01405s    7.11199s
print to console  10.1618s   9.34912s    9.47056s

Logging with GDB

First, let's do the same benchmark, with the client running inside gdb:

(running inside gdb)
                   1st try    2nd try     3rd try
no logging        7.53790s   7.08302s    6.87121s
print to console  9.30453s   9.80104s    9.92076s

By analyzing the source code of SOME/IP, one finds this method in routing_manager_proxy.hpp quite interesting:

void on_message(const byte_t *_data, length_t _length, endpoint *_receiver);

We make a symbol dump of the SOME/IP shared library:

readelf -s --wide $SOMEIP_PATH/lib/libvsomeip.so > readelf_libvsomeip.dump

If the library was not stripped from all its local symbols (with strip --strip-all libvsomeip.so), this symbol will be found among many others:

cat readelf_libvsomeip.dump | grep "on_message"
_ZThn4_N7vsomeip21routing_manager_proxy10on_messageEPKhjPNS_8endpointE

Let's set a breakpoint there and see the content of the arguments:

(gdb) b _ZThn4_N7vsomeip21routing_manager_proxy10on_messageEPKhjPNS_8endpointE

...and run the client (libvsomeip.so has debug symbols here):

Breakpoint 1, vsomeip::routing_manager_proxy::on_message (this=0x2d714, _data=0x756085ec "\027w\022$", _size=47, _receiver=0x2fa08)
    at /home/pi/capi/10_someip/vSomeIP/implementation/routing/src/routing_manager_proxy.cpp:515
515             endpoint *_receiver) {

The breakpoint was met and the content of the arguments is shown. Using _data and _size, we can display the content of the message:

(gdb) x/47xb 0x756085ec
0x756085ec:     0x17    0x77    0x12    0x24    0x00    0x00    0x00    0x12
0x756085f4:     0x34    0x80    0xe8    0x00    0x00    0x00    0x1c    0x11
0x756085fc:     0x2e    0x00    0x01    0x01    0x00    0x80    0x00    0x00
0x75608604:     0x00    0x00    0x10    0xef    0xbb    0xbf    0x48    0x65
0x7560860c:     0x6c    0x6c    0x6f    0x20    0x57    0x6f    0x72    0x6c
0x75608614:     0x64    0x21    0x00    0x78    0x56    0x01    0x01

As expected, it contains a special sequence of ASCII characters (starting in the 4th line above):

0x48 0x65 0x6c 0x6c 0x6f 0x20 0x57 0x6f 0x72 0x6c 0x64 0x21
   H    e    l    l    o         W    o    r    l    d    !

With the correct offest, the data can be displayed as a simple null-terminated string:

(gdb) x/s (0x756085ec+30)
0x7560860a:     "Hello World!"

Automatic breakpoint with GDB

The breapoint of the previous section can be automatized:

(gdb) set pagination off
(gdb) b _ZThn4_N7vsomeip21routing_manager_proxy10on_messageEPKhjPNS_8endpointE
(gdb) commands
Type commands for breakpoint(s) 1, one per line.
End with a line saying just "end".
>silent
>x/s $r1+30
>cont
>end

gdb will break on each message, print the content of the message with the offset calculated earlier, and continue the execution.

How fast is it for 10,000 requests?

(running inside gdb)
                   1st try    2nd try     3rd try
gdb auto. break   65.3633s   65.3735s    64.9654s

The execution is awfully slow, but there is a bonus: messages can be changed on the fly.

If we add a memory-set in the commands of the breakpoint, the client will see a different message each time:

(gdb) commands
Type commands for breakpoint(s) 1, one per line.
End with a line saying just "end".
>silent
>x/s $r1+30
>set {char}($r1+31) = 0x61
>cont
>end

Result in gdb:

0x7560860a:     "Hello World!" <- gdb break
Got message: 'Hallo World!'    <- console print from the client

References