diff --git a/include/nng/nng.h b/include/nng/nng.h
index 2730c39ec..4a6d8190f 100644
--- a/include/nng/nng.h
+++ b/include/nng/nng.h
@@ -1344,6 +1344,10 @@ NNG_DECL bool nng_lmq_empty(nng_lmq *);
 typedef struct conn_param        conn_param;
 typedef struct pub_packet_struct pub_packet_struct;
 typedef struct pipe_db           nano_pipe_db;
+
+NNG_DECL int nng_access(const char* name, int flag);
+
+// NANOMQ MQTT API ends
 // UDP operations.  These are provided for convenience,
 // and should be considered somewhat experimental.
 
diff --git a/include/nng/supplemental/util/platform.h b/include/nng/supplemental/util/platform.h
index 330824c99..c20ceee9e 100644
--- a/include/nng/supplemental/util/platform.h
+++ b/include/nng/supplemental/util/platform.h
@@ -29,6 +29,8 @@
 extern "C" {
 #endif
 
+// Return unix timestamp (milliseconds) .
+NNG_DECL nng_time nng_timestamp(void);
 
 // Get current process Id.
 NNG_DECL int nng_getpid();
diff --git a/src/core/platform.h b/src/core/platform.h
index 4225d612b..57dc94748 100644
--- a/src/core/platform.h
+++ b/src/core/platform.h
@@ -582,6 +582,8 @@ extern int nni_plat_getpid(void);
 // nni_plat_file_size get file size.
 extern int nni_plat_file_size(const char *, size_t *);
 
+// nni_access check accessibility of path
+extern int nni_plat_access(const char* name, int flag);
 //
 // Actual platforms we support.  This is included up front so that we can
 // get the specific types that are supplied by the platform.
diff --git a/src/nng.c b/src/nng.c
index ceb233ada..43c7a469d 100644
--- a/src/nng.c
+++ b/src/nng.c
@@ -2478,7 +2478,7 @@ conn_param_set_username(conn_param *cparam, const char *username)
 void
 conn_param_set_password(conn_param *cparam, const char *password)
 {
-	cparam->password.body = nng_strdup(password);
+	cparam->password.body = (uint8_t *)nng_strdup(password);
 	cparam->password.len  = strlen(password) + 1;
 }
 
@@ -2555,6 +2555,12 @@ nng_file_is_dir(const char *path)
 	return nni_file_is_dir(path);
 }
 
+int nng_access(const char* name, int flag)
+{
+    return nni_plat_access(name, flag);
+}
+// Ends of NANOMQ API
+
 void
 nng_init_set_parameter(nng_init_parameter p, uint64_t value)
 {
diff --git a/src/platform/posix/posix_file.c b/src/platform/posix/posix_file.c
index 29b495997..95f77781c 100644
--- a/src/platform/posix/posix_file.c
+++ b/src/platform/posix/posix_file.c
@@ -356,4 +356,8 @@ nni_plat_file_size(const char *path, size_t *size)
 	return (0);
 }
 
+int nni_plat_access(const char* name, int flag)
+{
+    return access(name, flag);
+}
 #endif // NNG_PLATFORM_POSIX
diff --git a/src/platform/windows/win_file.c b/src/platform/windows/win_file.c
index 98f64bfbf..f3b6eb02a 100644
--- a/src/platform/windows/win_file.c
+++ b/src/platform/windows/win_file.c
@@ -388,4 +388,8 @@ nni_plat_file_size(const char *path, size_t *size)
 	return (rv);
 }
 
+int nni_plat_access(const char* name, int flag)
+{
+    return _access(name, flag);
+}
 #endif // NNG_PLATFORM_WINDOWS
diff --git a/src/supplemental/mqtt/mqtt_msg.c b/src/supplemental/mqtt/mqtt_msg.c
index a1dccb435..f630f3d95 100644
--- a/src/supplemental/mqtt/mqtt_msg.c
+++ b/src/supplemental/mqtt/mqtt_msg.c
@@ -1024,7 +1024,7 @@ mqtt_close_unack_aio_cb(void *key, void *val)
 	nni_aio * aio = val;
 
 	if (aio) {
-		nni_aio_finish_error(aio, NNG_ECLOSED);
+		nni_aio_finish_sync(aio, NNG_ECLOSED, 0);
 		nni_msg_free(nni_aio_get_msg(aio));
 		nni_aio_set_msg(aio, NULL);
 		nni_aio_set_prov_data(aio, NULL);
diff --git a/src/supplemental/mqtt/mqtt_public.c b/src/supplemental/mqtt/mqtt_public.c
index 326d3e2f2..4655bb32f 100644
--- a/src/supplemental/mqtt/mqtt_public.c
+++ b/src/supplemental/mqtt/mqtt_public.c
@@ -725,7 +725,8 @@ mqtt_property_free(property *prop)
 void
 mqtt_property_foreach(property *prop, void (*cb)(property *))
 {
-	return property_foreach(prop, cb);
+	property_foreach(prop, cb);
+	return;
 }
 
 int
@@ -809,7 +810,8 @@ mqtt_property_get_value(property *prop, uint8_t prop_id)
 void
 mqtt_property_append(property *prop_list, property *last)
 {
-	return property_append(prop_list, last);
+	property_append(prop_list, last);
+	return;
 }
 
 
@@ -839,11 +841,14 @@ nng_mqtt_client_send_cb(void* arg)
 {
 	nng_mqtt_client *client = (nng_mqtt_client *) arg;
 	nng_aio *        aio    = client->send_aio;
-	nng_msg *        msg    = nng_aio_get_msg(aio);
 	nng_msg *        tmsg   = NULL;
 
 	nni_lmq * lmq = (nni_lmq *)client->msgq;
+	// in case of data conention while fini pipes
+	if (nng_aio_result(aio) == NNG_ECLOSED)
+		return;
 
+	nng_msg *        msg    = nng_aio_get_msg(aio);
 	if (msg == NULL || nng_aio_result(aio) != 0) {
 		client->cb(client, NULL, client->obj);
 		return;
diff --git a/src/supplemental/nanolib/log.c b/src/supplemental/nanolib/log.c
index ba2222678..8abc855ff 100644
--- a/src/supplemental/nanolib/log.c
+++ b/src/supplemental/nanolib/log.c
@@ -98,6 +98,18 @@ file_callback(log_event *ev)
 #else
 	pid_t pid = syscall(__NR_gettid);
 #endif
+#ifndef NNG_PLATFORM_WINDOWS
+	if (nng_access(ev->config->dir, W_OK) < 0) {
+		fprintf(stderr, "open path %s failed! close file!\n",
+				ev->config->dir);
+		if (ev->config->fp != NULL)
+			fclose(ev->config->fp);
+		ev->config->fp = NULL;
+		return;
+	}
+#endif
+	if (ev->config->fp == NULL)
+		ev->config->fp = fopen(ev->config->abs_path, "a");
 	FILE *fp = ev->config->fp;
 	buf[strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", &ev->time)] = '\0';
 	fprintf(fp, "%s [%i] %-5s %s:%d: ", buf, pid,
@@ -300,8 +312,7 @@ log_clear_callback()
 static void
 file_rotation(FILE *fp, conf_log *config)
 {
-	// Note : do not call log_xxx() in this function, it will cause dead
-	// lock
+	// Note : do not call log_xxx() in this function, it will cause dead lock
 	size_t sz = 0;
 	int    rv;
 	if ((rv = nni_plat_file_size(config->abs_path, &sz)) != 0) {
@@ -309,10 +320,23 @@ file_rotation(FILE *fp, conf_log *config)
 		    config->abs_path, nng_strerror(rv));
 		if (!nni_plat_file_exists(config->abs_path)) {
 			// file missing, recreate one
-			fclose(fp);
-			if (nng_file_put(config->abs_path, "\n", 1) != 0)
-				fprintf(stderr, "create file %s failed: %s\n",
+			if (fp)
+				fclose(fp);
+#ifndef NNG_PLATFORM_WINDOWS
+			if (nng_access(config->dir, W_OK) < 0) {
+				fprintf(stderr, "open path %s failed\n",
+						config->dir);
+				config->fp = NULL;
+				return;
+			}
+#endif
+			if (nng_file_put(config->abs_path, "\n", 1) != 0) {
+				fprintf(stderr, "write to file %s failed: %s\n",
 				    config->abs_path, nng_strerror(rv));
+				config->fp = NULL;
+				return;
+			}
+
 			config->fp = fopen(config->abs_path, "a");
 			fp             = config->fp;
 		}
@@ -342,13 +366,21 @@ file_rotation(FILE *fp, conf_log *config)
 		    log_name, log_name_len, "%s.%lu", config->file, index);
 		char *backup_log_path =
 		    nano_concat_path(config->dir, log_name);
-		fclose(fp);
+		if (fp)
+			fclose(fp);
 		fp = NULL;
 		remove(backup_log_path);
 		rename(config->abs_path, backup_log_path);
 		nni_free(log_name, log_name_len);
 		nni_strfree(backup_log_path);
-
+#ifndef NNG_PLATFORM_WINDOWS
+		if (nng_access(config->dir, W_OK) < 0) {
+			fprintf(stderr, "open path %s failed\n",
+					config->dir);
+			config->fp = NULL;
+			return;
+		}
+#endif
 		fp           = fopen(config->abs_path, "a");
 		config->fp   = fp;
 		char num[20] = { 0 };