diff --git a/tlog.c b/tlog.c
index 6a3cfce..354a130 100644
--- a/tlog.c
+++ b/tlog.c
@@ -78,6 +78,8 @@ struct tlog_log {
 
     time_t last_try;
     time_t last_waitpid;
+    mode_t file_perm;
+    mode_t archive_perm;
 
     int waiters;
     int is_exit;
@@ -304,6 +306,12 @@ void tlog_set_maxline_size(struct tlog_log *log, int size)
     log->max_line_size = size;
 }
 
+void tlog_set_permission(struct tlog_log *log, unsigned int file, unsigned int archive)
+{
+    log->file_perm = file;
+    log->archive_perm = archive;
+}
+
 int tlog_localtime(struct tlog_time *tm)
 {
     return _tlog_gettime(tm);
@@ -684,6 +692,8 @@ static int _tlog_rename_logfile(struct tlog_log *log, const char *log_file)
         return -1;
     }
 
+    chmod(archive_file, log->archive_perm);
+
     return 0;
 }
 
@@ -1123,7 +1133,7 @@ static int _tlog_write(struct tlog_log *log, const char *buff, int bufflen)
         }
         snprintf(logfile, sizeof(logfile), "%s/%s", log->logdir, log->logname);
         log->filesize = 0;
-        log->fd = open(logfile, O_APPEND | O_CREAT | O_WRONLY | O_CLOEXEC, 0640);
+        log->fd = open(logfile, O_APPEND | O_CREAT | O_WRONLY | O_CLOEXEC, log->file_perm);
         if (log->fd < 0) {
             if (print_errmsg == 0) {
                 return -1;
@@ -1608,6 +1618,8 @@ tlog_log *tlog_open(const char *logfile, int maxlogsize, int maxlogcount, int bu
     log->segment_log = ((flag & TLOG_SEGMENT) == 0) ? 0 : 1;
     log->max_line_size = TLOG_MAX_LINE_LEN;
     log->output_func = _tlog_write;
+    log->file_perm = S_IRUSR | S_IWUSR | S_IRGRP;
+    log->archive_perm = S_IRUSR | S_IRGRP;
 
     tlog_rename_logfile(log, logfile);
     if (log->nocompress) {
diff --git a/tlog.h b/tlog.h
index c58530b..e07fd8c 100644
--- a/tlog.h
+++ b/tlog.h
@@ -1,12 +1,13 @@
 /*
  * tinylog
- * Copyright (C) 2018-2020 Ruilin Peng (Nick) <pymumu@gmail.com>
+ * Copyright (C) 2018-2021 Ruilin Peng (Nick) <pymumu@gmail.com>
  * https://github.com/pymumu/tinylog
  */
 
 #ifndef TLOG_H
 #define TLOG_H
 #include <stdarg.h>
+#include <sys/stat.h>
 
 #ifdef __cplusplus
 #include <functional>
@@ -196,57 +197,75 @@ extern int tlog_localtime(struct tlog_time *tm);
 /* set max line size */
 extern void tlog_set_maxline_size(struct tlog_log *log, int size);
 
+/*
+Function: set log file and archive permission
+log: log stream
+file: log file permission, default is 640
+archive: archive file permission, default is 440
+*/
+
+extern void tlog_set_permission(struct  tlog_log *log, mode_t file, mode_t archive);
+
 #ifdef __cplusplus
 class Tlog {
-    using Stream = std::ostringstream;
-    using Buffer = std::unique_ptr<Stream, std::function<void(Stream *)>>;
-
 public:
-    Tlog() { }
-    ~Tlog() { }
+    Tlog(tlog_level level, const char *file, int line, const char *func, void *userptr)
+    {
+        level_ = level;
+        file_ = file;
+        line_ = line;
+        func_ = func;
+        userptr_ = userptr;
+    }
 
-    static Tlog &Instance()
+    ~Tlog()
     {
-        static Tlog logger;
-        return logger;
+        tlog_ext(level_, file_, line_, func_, userptr_, "%s", msg_.str().c_str());
     }
 
-    Buffer LogStream(tlog_level level, const char *file, int line, const char *func, void *userptr)
+    std::ostream &Stream()
     {
-        return Buffer(new Stream, [=](Stream *st) {
-            tlog_ext(level, file, line, func, userptr, "%s", st->str().c_str());
-            delete st;
-        });
+        return msg_;
     }
+
+private:
+    tlog_level level_;
+    const char *file_;
+    int line_;
+    const char *func_;
+    void *userptr_;
+    std::ostringstream msg_;
 };
 
 class TlogOut {
-    using Stream = std::ostringstream;
-    using Buffer = std::unique_ptr<Stream, std::function<void(Stream *)>>;
-
 public:
-    TlogOut() { }
-    ~TlogOut() { }
+    TlogOut(tlog_log *log)
+    {
+        log_ = log;
+    }
 
-    static TlogOut &Instance()
+    ~TlogOut()
     {
-        static TlogOut logger;
-        return logger;
+        if (log_ == nullptr) {
+            return;
+        }
+
+        tlog_printf(log_, "%s", msg_.str().c_str());
     }
 
-    Buffer Out(tlog_log *log)
+    std::ostream &Stream()
     {
-        return Buffer(new Stream, [=](Stream *st) {
-            tlog_printf(log, "%s", st->str().c_str());
-            delete st;
-        });
+        return msg_;
     }
+
+private:
+    tlog_log *log_;
+    std::ostringstream msg_;
 };
 
-#define Tlog_logger (Tlog::Instance())
 #define Tlog_stream(level)        \
     if (tlog_getlevel() <= level) \
-    *Tlog_logger.LogStream(level, BASE_FILE_NAME, __LINE__, __func__, NULL)
+    Tlog(level, BASE_FILE_NAME, __LINE__, __func__, NULL).Stream()
 #define tlog_debug Tlog_stream(TLOG_DEBUG)
 #define tlog_info Tlog_stream(TLOG_INFO)
 #define tlog_notice Tlog_stream(TLOG_NOTICE)
@@ -254,8 +273,7 @@ class TlogOut {
 #define tlog_error Tlog_stream(TLOG_ERROR)
 #define tlog_fatal Tlog_stream(TLOG_FATAL)
 
-#define Tlog_out_logger (TlogOut::Instance())
-#define tlog_out(stream) (*Tlog_out_logger.Out(stream))
+#define tlog_out(stream) TlogOut(stream).Stream()
 
 } /*__cplusplus */
 #else