主从同步性能优化，主从同步性能测试。

diskuring/diskuring.h

@@ -18,7 +18,6 @@ typedef struct task {
     int fd;
     off_t off;
 
-    int refcount;
     int res;          // cqe->res
     int done;         // 0/1
 
@@ -49,7 +48,6 @@ typedef struct {
     pthread_mutex_t lock;
 } destroy_queue_t;
 
-int iouring_register_fd(iouring_ctx_t *ctx, int fd);
 
 void task_init(task_t *t);
 void task_finish(task_t *t, int res);
@@ -61,6 +59,7 @@ int iouring_init(iouring_ctx_t *ctx, unsigned entries);
 void iouring_shutdown(iouring_ctx_t *ctx);
 
 task_t* submit_write(iouring_ctx_t *ctx, int fd, void **bufs, size_t *lens, int count, off_t off);
+int uring_task_complete(iouring_ctx_t *ctx);
 
 void cleanup_finished_iouring_tasks();