run.go: add a way to profile program's cpu usage

set the flag `cpuprofile` to a file where the cpu profiling output
should be saved. the output can then be read using:
  `go tool pprof math-optim <profiling output file`.

ref: https://go.dev/blog/pprof

run.go

@@ -6,6 +6,8 @@ package main
 import (
 	"flag"
 	"log"
+	"os"
+	"runtime/pprof"
 	"sync"
 
 	"git.dotya.ml/wanderer/math-optim/algo"
@@ -15,6 +17,8 @@ import (
 var version = "development"
 
 var (
+	cpuprofile = flag.String("cpuprofile", "", "write cpu profile to file")
+
 	doPrint  = flag.Bool("printreport", true, "print report.tex to console")
 	generate = flag.Bool("generate", true, "run algos and generate plot pics/statistical tables (anew)")
 	rS       = flag.Bool("randomsearch", false, "run Random Search algorithm")
@@ -34,6 +38,20 @@ func run() {
 
 	flag.Parse()
 
+	if *cpuprofile != "" {
+		f, err := os.Create(*cpuprofile)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		err = pprof.StartCPUProfile(f)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		defer pprof.StopCPUProfile()
+	}
+
 	if *generate {
 		if !*jDE && !*c2jDE && !*c2SOMAT3A && !*sHC && !*rS {
 			log.Println("at least one algo needs to be specified, exiting...")