try to raise the number of file descriptors that can be opened to remove limits on number of connected clients (#193)

internal/rlimit/rlimit_unix.go

@@ -0,0 +1,29 @@
+// +build !windows
+
+package rlimit
+
+import (
+	"syscall"
+)
+
+// Raise raises the number of file descriptors that can be opened.
+func Raise() error {
+	var rlim syscall.Rlimit
+	err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlim)
+	if err != nil {
+		return err
+	}
+
+	rlim.Cur = 999999
+	err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rlim)
+	if err != nil {
+		return err
+	}
+
+	err = syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlim)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

internal/rlimit/rlimit_win.go

@@ -0,0 +1,7 @@
+// +build windows
+
+package rlimit
+
+func Raise() error {
+	return nil
+}

main.go

@@ -16,6 +16,7 @@ import (
 	"github.com/aler9/rtsp-simple-server/internal/metrics"
 	"github.com/aler9/rtsp-simple-server/internal/pathman"
 	"github.com/aler9/rtsp-simple-server/internal/pprof"
+	"github.com/aler9/rtsp-simple-server/internal/rlimit"
 	"github.com/aler9/rtsp-simple-server/internal/serverrtmp"
 	"github.com/aler9/rtsp-simple-server/internal/serverrtsp"
 	"github.com/aler9/rtsp-simple-server/internal/stats"
@@ -56,6 +57,11 @@ func newProgram(args []string) (*program, bool) {
 		os.Exit(0)
 	}
 
+	// on Linux, try to raise the number of file descriptors that can be opened
+	// to allow the maximum possible number of clients
+	// do not check for errors
+	rlimit.Raise()
+
 	p := &program{
 		confPath:  *argConfPath,
 		terminate: make(chan struct{}),