issue #260: avoid start_transmit()/on_transmit()/stop_transmit()
Previous transmit sequence was:
Router._async_route -> Stream._send -> Broker._start_transmit ->
Broker.loop -> Stream.on_transmit -> socket.write ->
Broker.stop_transmit
New sequence, when socket buffer can hold message is:
Router._async_route -> Stream._send -> socket.write
bench/roundtrip.py
Before: 240 usec
after: 178 usec
Stat before:
5088.276050 task-clock (msec) # 0.997 CPUs utilized
185,568 context-switches # 0.036 M/sec
0 cpu-migrations # 0.000 K/sec
18,923 page-faults # 0.004 M/sec
13,063,871,501 cycles # 2.567 GHz
12,834,579,684 instructions # 0.98 insn per cycle
2,669,820,684 branches # 524.700 M/sec
107,296,033 branch-misses # 4.02% of all branches
5.105018296 seconds time elapsed
2.350970000 seconds user
0.345497000 seconds sys
Stat after:
4019.208047 task-clock (msec) # 0.998 CPUs utilized
249,471 context-switches # 0.062 M/sec
0 cpu-migrations # 0.000 K/sec
20,990 page-faults # 0.005 M/sec
10,312,535,979 cycles # 2.566 GHz
11,586,365,995 instructions # 1.12 insn per cycle
2,392,933,370 branches # 595.374 M/sec
75,432,205 branch-misses # 3.15% of all branches
4.028763347 seconds time elapsed
3.367051000 seconds user
0.652962000 seconds sys
a18a083c94
