Start writes p.version and p.apiPort (via refreshVersion/refreshAPIPort) after
flipping the process to running, while GetXrayVersion and GetAPIPort read them
lock-free from the status and traffic poll goroutines. The struct mutex
deliberately excluded these fields, so a restart racing a poll was a real data
race — a torn read of the version string header can crash. Extend the mutex to
cover version and apiPort, doing the blocking version probe before taking the
lock.
Minor refactors across the codebase to improve readability and use more efficient APIs: replace fmt.Sprintf+base64 encoding with fmt.Appendf when building Shadowsocks userInfo; compute elapsed using max(now-prev.at, window) to simplify logic; use strings.SplitSeq for splitting in two places; simplify test and goroutine loops to range-based iterations and use errgroup's Go helper; and align/clean up struct field formatting and test map literals. Mostly stylistic/efficiency changes with no intended behavior changes.
The process cmd, done and exitErr fields were written by Start/startCommand and
the waitForCommand goroutine while IsRunning/GetErr/GetResult/Stop read them
concurrently from other goroutines (the status endpoint and the check-xray
job) — a data race. Guard them with a RWMutex: writers take the write lock;
readers snapshot under the read lock and run any blocking syscall
(Wait/Signal/Kill) on the local copy without holding it. IsRunning now uses the
done channel as the exit signal instead of reading cmd.ProcessState, which
races with cmd.Wait. Adds a -race regression test.
MHSanaei