refactor(fd/socket/udp): Flatten deeply nested if chains by reordering

[fogti]

I found this code segment very hard to reach, so I switched the if and else parts including conditions around in a few places.

I haven't measured the performance impact yet.

[github-actions]

Benchmark Results

Details

Benchmark	Current: 1cccf6c	Previous: 2e23902	Performance Ratio
startup_benchmark Build Time	95.10 s	80.34 s	1.18 ❗
startup_benchmark File Size	0.75 MB	0.80 MB	0.94 ❗
Startup Time - 1 core	0.74 s (±0.02 s)	0.75 s (±0.02 s)	0.99
Startup Time - 2 cores	0.75 s (±0.01 s)	0.74 s (±0.02 s)	1.02
Startup Time - 4 cores	0.76 s (±0.02 s)	0.74 s (±0.02 s)	1.02
multithreaded_benchmark Build Time	95.24 s	82.11 s	1.16 ❗
multithreaded_benchmark File Size	0.88 MB	0.86 MB	1.03 ❗
Multithreaded Pi Efficiency - 2 Threads	66.40 % (±6.09 %)	85.89 % (±6.61 %)	0.77 ❗
Multithreaded Pi Efficiency - 4 Threads	40.75 % (±3.21 %)	43.43 % (±2.56 %)	0.94
Multithreaded Pi Efficiency - 8 Threads	20.01 % (±1.89 %)	25.76 % (±1.53 %)	0.78 ❗
micro_benchmarks Build Time	215.82 s	80.40 s	2.68 ❗
micro_benchmarks File Size	0.89 MB	0.86 MB	1.03 ❗
Scheduling time - 1 thread	180.97 ticks (±40.78 ticks)	62.65 ticks (±4.06 ticks)	2.89 ❗
Scheduling time - 2 threads	104.77 ticks (±23.38 ticks)	34.08 ticks (±4.10 ticks)	3.07 ❗
Micro - Time for syscall (getpid)	9.38 ticks (±5.65 ticks)	3.45 ticks (±0.58 ticks)	2.72 ❗
Memcpy speed - (built_in) block size 4096	57485.43 MByte/s (±40365.65 MByte/s)	82448.38 MByte/s (±56997.13 MByte/s)	0.70
Memcpy speed - (built_in) block size 1048576	13690.45 MByte/s (±11085.20 MByte/s)	30585.98 MByte/s (±24707.84 MByte/s)	0.45
Memcpy speed - (built_in) block size 16777216	11773.95 MByte/s (±9826.59 MByte/s)	26340.06 MByte/s (±21720.96 MByte/s)	0.45
Memset speed - (built_in) block size 4096	57504.49 MByte/s (±40378.34 MByte/s)	82292.76 MByte/s (±56891.50 MByte/s)	0.70
Memset speed - (built_in) block size 1048576	14015.97 MByte/s (±11271.80 MByte/s)	31323.85 MByte/s (±25145.86 MByte/s)	0.45
Memset speed - (built_in) block size 16777216	12073.63 MByte/s (±9991.43 MByte/s)	27104.68 MByte/s (±22209.94 MByte/s)	0.45
Memcpy speed - (rust) block size 4096	52342.83 MByte/s (±37822.26 MByte/s)	74097.96 MByte/s (±51811.44 MByte/s)	0.71
Memcpy speed - (rust) block size 1048576	13998.10 MByte/s (±12058.52 MByte/s)	30361.60 MByte/s (±24602.37 MByte/s)	0.46
Memcpy speed - (rust) block size 16777216	11722.06 MByte/s (±9755.45 MByte/s)	27625.34 MByte/s (±22806.88 MByte/s)	0.42
Memset speed - (rust) block size 4096	52709.68 MByte/s (±38072.86 MByte/s)	74373.47 MByte/s (±51976.48 MByte/s)	0.71
Memset speed - (rust) block size 1048576	14365.20 MByte/s (±12278.23 MByte/s)	31110.89 MByte/s (±25033.24 MByte/s)	0.46
Memset speed - (rust) block size 16777216	11983.43 MByte/s (±9890.80 MByte/s)	28386.93 MByte/s (±23265.03 MByte/s)	0.42
alloc_benchmarks Build Time	212.32 s	74.76 s	2.84 ❗
alloc_benchmarks File Size	0.82 MB	0.87 MB	0.94 ❗
Allocations - Allocation success	91.38 %	91.31 %	1.00 ❗
Allocations - Deallocation success	100.00 %	100.00 %	1
Allocations - Pre-fail Allocations	61.60 %	61.44 %	1.00 ❗
Allocations - Average Allocation time	24512.81 Ticks (±1527.92 Ticks)	5860.58 Ticks (±98.43 Ticks)	4.18 ❗
Allocations - Average Allocation time (no fail)	25825.27 Ticks (±1848.23 Ticks)	6554.81 Ticks (±92.86 Ticks)	3.94 ❗
Allocations - Average Deallocation time	8284.34 Ticks (±1778.33 Ticks)	1805.01 Ticks (±250.35 Ticks)	4.59 ❗
mutex_benchmark Build Time	218.25 s	79.82 s	2.73 ❗
mutex_benchmark File Size	0.89 MB	0.86 MB	1.03 ❗
Mutex Stress Test Average Time per Iteration - 1 Threads	36.18 ns (±8.04 ns)	12.10 ns (±0.41 ns)	2.99 ❗
Mutex Stress Test Average Time per Iteration - 2 Threads	33.46 ns (±10.37 ns)	40.26 ns (±1.68 ns)	0.83

This comment was automatically generated by workflow using github-action-benchmark.

[mkroening]

Good idea. 👍 Do you still want to pursue this? :)

[fogti]

Yes. Do we have any benchmarks one could mod for this? afaik the existing benchmarks (e.g. in uhyve) only use TCP…

[mkroening]

This is only a trivial refactor, right? I don't expect any performance changes here. Or am I missing any changes that you expect to be difficult to optimize?

[mkroening]

Thanks! :)

I prefer early returns, so I adjusted the code accordingly. :)