主从同步性能优化，主从同步性能测试。

kvs_array_bin.c

@@ -235,13 +235,22 @@ int kvs_array_save(iouring_ctx_t *uring, kvs_array_t *inst, const char* filename
         for (int i = 0; i < count; i++) total += lens[i];
 
         task_t *t = submit_write(uring, fd, bufs, lens, count, current_off);
+        cleanup_finished_iouring_tasks();
 
-		if (!t) { close(fd); return -4; }
+		if (!t) { 
+            perror("task init failed");
+            goto clean;
+        }
 
         
         current_off += (off_t) total;
 	}
 
+clean:
+	while (!uring_task_complete(uring)) {
+		usleep(1000);
+		cleanup_finished_iouring_tasks();
+	}
 	close(fd);
 	return 0;
 }