[client] Optmize process check time (#3938)

This PR optimizes the process check time by updating the implementation of getRunningProcesses and introducing new benchmark tests.

Updated getRunningProcesses to use process.Pids() instead of process.Processes()
Added benchmark tests for both the new and the legacy implementations

Benchmark: https://github.com/netbirdio/netbird/actions/runs/15512741612

todo: evaluate windows optmizations and caching risks

client/system/process.go

@@ -11,16 +11,18 @@ import (
 
 // getRunningProcesses returns a list of running process paths.
 func getRunningProcesses() ([]string, error) {
-	processes, err := process.Processes()
+	processIDs, err := process.Pids()
 	if err != nil {
 		return nil, err
 	}
 
 	processMap := make(map[string]bool)
-	for _, p := range processes {
+	for _, pID := range processIDs {
+		p := &process.Process{Pid: pID}
+
 		path, _ := p.Exe()
 		if path != "" {
-			processMap[path] = true
+			processMap[path] = false
 		}
 	}
 

client/system/process_test.go

@@ -0,0 +1,58 @@
+package system
+
+import (
+	"testing"
+
+	"github.com/shirou/gopsutil/v3/process"
+)
+
+func Benchmark_getRunningProcesses(b *testing.B) {
+	b.Run("getRunningProcesses new", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			ps, err := getRunningProcesses()
+			if err != nil {
+				b.Fatalf("unexpected error: %v", err)
+			}
+			if len(ps) == 0 {
+				b.Fatalf("expected non-empty process list, got empty")
+			}
+		}
+	})
+	b.Run("getRunningProcesses old", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			ps, err := getRunningProcessesOld()
+			if err != nil {
+				b.Fatalf("unexpected error: %v", err)
+			}
+			if len(ps) == 0 {
+				b.Fatalf("expected non-empty process list, got empty")
+			}
+		}
+	})
+	s, _ := getRunningProcesses()
+	b.Logf("getRunningProcesses returned %d processes", len(s))
+	s, _ = getRunningProcessesOld()
+	b.Logf("getRunningProcessesOld returned %d processes", len(s))
+}
+
+func getRunningProcessesOld() ([]string, error) {
+	processes, err := process.Processes()
+	if err != nil {
+		return nil, err
+	}
+
+	processMap := make(map[string]bool)
+	for _, p := range processes {
+		path, _ := p.Exe()
+		if path != "" {
+			processMap[path] = true
+		}
+	}
+
+	uniqueProcesses := make([]string, 0, len(processMap))
+	for p := range processMap {
+		uniqueProcesses = append(uniqueProcesses, p)
+	}
+
+	return uniqueProcesses, nil
+}