code refactor

[JimyMa]

SLIME_QP_NUM=1 MASTER_ADDR=127.0.0.1 MASTER_PORT=7000 RANK=1 WORLD_SIZE=2 python bench/python/sendrecv_bench.py --num-concurrency 8
SLIME_QP_NUM=1 MASTER_ADDR=127.0.0.1 MASTER_PORT=7000 RANK=0 WORLD_SIZE=2 python bench/python/sendrecv_bench.py --num-concurrency 8

Benchmark Results:
+------------------------+---------------------------+---------------+---------------+
|   Message Size (bytes) |   Total Transport (bytes) | Avg Latency   | Bandwidth     |
+========================+===========================+===============+===============+
|                   2048 |                     16384 | 267.47 ms     | 0.77 MB/s     |
+------------------------+---------------------------+---------------+---------------+
|                   4096 |                     32768 | 244.23 ms     | 1.68 MB/s     |
+------------------------+---------------------------+---------------+---------------+
|                   8192 |                     65536 | 238.73 ms     | 3.43 MB/s     |
+------------------------+---------------------------+---------------+---------------+
|                  16384 |                    131072 | 218.42 ms     | 7.50 MB/s     |
+------------------------+---------------------------+---------------+---------------+
|                  32768 |                    262144 | 215.98 ms     | 15.17 MB/s    |
+------------------------+---------------------------+---------------+---------------+
|                  65536 |                    524288 | 224.38 ms     | 29.21 MB/s    |
+------------------------+---------------------------+---------------+---------------+
|                 131072 |                   1048576 | 223.36 ms     | 58.68 MB/s    |
+------------------------+---------------------------+---------------+---------------+
|                 262144 |                   2097152 | 228.55 ms     | 114.70 MB/s   |
+------------------------+---------------------------+---------------+---------------+
|                 524288 |                   4194304 | 232.80 ms     | 225.21 MB/s   |
+------------------------+---------------------------+---------------+---------------+
|                1048576 |                   8388608 | 221.25 ms     | 473.94 MB/s   |
+------------------------+---------------------------+---------------+---------------+
|                2097152 |                  16777216 | 247.58 ms     | 847.07 MB/s   |
+------------------------+---------------------------+---------------+---------------+
|                4194304 |                  33554432 | 248.27 ms     | 1689.42 MB/s  |
+------------------------+---------------------------+---------------+---------------+
|                8388608 |                  67108864 | 233.03 ms     | 3599.86 MB/s  |
+------------------------+---------------------------+---------------+---------------+
|               16777216 |                 134217728 | 260.41 ms     | 6442.51 MB/s  |
+------------------------+---------------------------+---------------+---------------+
|               33554432 |                 268435456 | 339.35 ms     | 9887.88 MB/s  |
+------------------------+---------------------------+---------------+---------------+
|               67108864 |                 536870912 | 441.75 ms     | 15191.47 MB/s |
+------------------------+---------------------------+---------------+---------------+
|              134217728 |                1073741824 | 693.08 ms     | 19365.40 MB/s |
+------------------------+---------------------------+---------------+---------------+