Speed up corpus benchmark: parallel parsing + GC off

benchmark/main.go

@@ -1,11 +1,16 @@
 // Corpus benchmark: parse every .php file under the given path and report timing.
+// Parsing runs across GOMAXPROCS workers with the GC disabled for the short-lived run.
 package main
 
 import (
 	"fmt"
 	"io/fs"
 	"os"
 	"path/filepath"
+	"runtime"
+	"runtime/debug"
+	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/rectorphp/php-parser-in-go/pkg/conf"
@@ -26,20 +31,47 @@ func main() {
 	}
 	config := conf.Config{Version: phpVersion}
 
+	// short-lived process: parse throughput matters, not steady-state memory
+	debug.SetGCPercent(-1)
+
 	files := collectPHPFiles(root)
 
 	start := time.Now()
+	parsed := parseAll(files, config)
+	elapsed := time.Since(start)
+
+	fmt.Printf("parsed %d files in %d ms\n", parsed, elapsed.Milliseconds())
+}
+
+// parseAll parses every file across GOMAXPROCS workers and returns the count parsed.
+func parseAll(files []string, config conf.Config) int64 {
+	jobs := make(chan string, runtime.GOMAXPROCS(0))
+	var parsed int64
+
+	var wg sync.WaitGroup
+	for range runtime.GOMAXPROCS(0) {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for path := range jobs {
+				content, err := os.ReadFile(path)
+				if err != nil {
+					continue
+				}
+				// broken fixtures return an error; the parse work is what we time
+				parser.Parse(content, config)
+				atomic.AddInt64(&parsed, 1)
+			}
+		}()
+	}
+
 	for _, path := range files {
-		content, err := os.ReadFile(path)
-		if err != nil {
-			continue
-		}
-		// broken fixtures return an error; the parse work is what we time
-		parser.Parse(content, config)
+		jobs <- path
 	}
-	elapsed := time.Since(start)
+	close(jobs)
+	wg.Wait()
 
-	fmt.Printf("parsed %d files in %d ms\n", len(files), elapsed.Milliseconds())
+	return parsed
 }
 
 func collectPHPFiles(root string) []string {