Add first cut at a pool

master/runexpress.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"io"
 	"log"
 	"os"
@@ -10,43 +11,45 @@ import (
 	"time"
 )
 
-func runExpress(changes <-chan FileChange) {
-	var currentProcess *exec.Cmd
+func runExpress(changes <-chan FileChange, numProcesses int, basePort int, pool *WorkerPool) {
+	var currentProcesses []*exec.Cmd
 	var mu sync.Mutex
 
-	// Helper to start the express process
-	startExpress := func() *exec.Cmd {
-		cmd := exec.Command("../express/run.sh")
+	// Helper to start an express process on a specific port
+	startExpress := func(port int) *exec.Cmd {
+		listenAddr := fmt.Sprintf("127.0.0.1:%d", port)
+		cmd := exec.Command("../express/run.sh", "--listen", listenAddr)
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
 
 		if err := cmd.Start(); err != nil {
-			log.Printf("[express] Failed to start: %v", err)
+			log.Printf("[express:%d] Failed to start: %v", port, err)
 			return nil
 		}
 
-		log.Printf("[express] Started (pid %d)", cmd.Process.Pid)
+		log.Printf("[express:%d] Started (pid %d)", port, cmd.Process.Pid)
 
 		// Monitor the process in background
-		go func() {
+		go func(p int) {
 			err := cmd.Wait()
 			if err != nil {
-				log.Printf("[express] Process exited: %v", err)
+				log.Printf("[express:%d] Process exited: %v", p, err)
 			} else {
-				log.Printf("[express] Process exited normally")
+				log.Printf("[express:%d] Process exited normally", p)
 			}
-		}()
+		}(port)
 
 		return cmd
 	}
 
-	// Helper to stop the express process
+	// Helper to stop an express process
 	stopExpress := func(cmd *exec.Cmd) {
 		if cmd == nil || cmd.Process == nil {
 			return
 		}
 
-		log.Printf("[express] Stopping (pid %d)", cmd.Process.Pid)
+		pid := cmd.Process.Pid
+		log.Printf("[express] Stopping (pid %d)", pid)
 		cmd.Process.Signal(syscall.SIGTERM)
 
 		// Wait briefly for graceful shutdown
@@ -58,13 +61,38 @@ func runExpress(changes <-chan FileChange) {
 
 		select {
 		case <-done:
-			log.Printf("[express] Stopped gracefully")
+			log.Printf("[express] Stopped gracefully (pid %d)", pid)
 		case <-time.After(5 * time.Second):
-			log.Printf("[express] Force killing")
+			log.Printf("[express] Force killing (pid %d)", pid)
 			cmd.Process.Kill()
 		}
 	}
 
+	// Helper to stop all express processes
+	stopAllExpress := func(processes []*exec.Cmd) {
+		for _, cmd := range processes {
+			stopExpress(cmd)
+		}
+	}
+
+	// Helper to start all express processes and update the worker pool
+	startAllExpress := func() []*exec.Cmd {
+		processes := make([]*exec.Cmd, 0, numProcesses)
+		addresses := make([]string, 0, numProcesses)
+		for i := 0; i < numProcesses; i++ {
+			port := basePort + i
+			addr := fmt.Sprintf("127.0.0.1:%d", port)
+			cmd := startExpress(port)
+			if cmd != nil {
+				processes = append(processes, cmd)
+				addresses = append(addresses, addr)
+			}
+		}
+		// Update the worker pool with new worker addresses
+		pool.SetWorkers(addresses)
+		return processes
+	}
+
 	// Helper to run the build
 	runBuild := func() bool {
 		log.Printf("[build] Starting ncc build...")
@@ -97,6 +125,14 @@ func runExpress(changes <-chan FileChange) {
 	var debounceTimer *time.Timer
 	const debounceDelay = 100 * time.Millisecond
 
+	// Initial build and start
+	log.Printf("[master] Initial build...")
+	if runBuild() {
+		currentProcesses = startAllExpress()
+	} else {
+		log.Printf("[master] Initial build failed")
+	}
+
 	for change := range changes {
 		log.Printf("[watch] %s: %s", change.Operation, change.Path)
 
@@ -107,18 +143,18 @@ func runExpress(changes <-chan FileChange) {
 
 		debounceTimer = time.AfterFunc(debounceDelay, func() {
 			if !runBuild() {
-				log.Printf("[master] Build failed, keeping current process")
+				log.Printf("[master] Build failed, keeping current processes")
 				return
 			}
 
 			mu.Lock()
 			defer mu.Unlock()
 
-			// Stop old process
-			stopExpress(currentProcess)
+			// Stop all old processes
+			stopAllExpress(currentProcesses)
 
-			// Start new process
-			currentProcess = startExpress()
+			// Start all new processes
+			currentProcesses = startAllExpress()
 		})
 	}
 }