uv_req_t — Base request

uv_req_t is the base type for all libuv request types.

Structures are aligned so that any libuv request can be cast to uv_req_t. All API functions defined here work with any request type.

Data types

uv_req_t

The base libuv request structure.

uv_any_req

Union of all request types.

Public members

void* uv_req_t.data

Space for user-defined arbitrary data. libuv does not use this field.

uv_req_type uv_req_t.type

Indicated the type of request. Readonly.

typedef enum {
    UV_UNKNOWN_REQ = 0,
    UV_REQ,
    UV_CONNECT,
    UV_WRITE,
    UV_SHUTDOWN,
    UV_UDP_SEND,
    UV_FS,
    UV_WORK,
    UV_GETADDRINFO,
    UV_GETNAMEINFO,
    UV_REQ_TYPE_PRIVATE,
    UV_REQ_TYPE_MAX,
} uv_req_type;

API

int uv_cancel(uv_req_t* req)

Cancel a pending request. Fails if the request is executing or has finished executing.

Returns 0 on success, or an error code < 0 on failure.

Only cancellation of uv_fs_t, uv_getaddrinfo_t, uv_getnameinfo_t and uv_work_t requests is currently supported.

Cancelled requests have their callbacks invoked some time in the future. It’s not safe to free the memory associated with the request until the callback is called.

Here is how cancellation is reported to the callback:

• A uv_fs_t request has its req->result field set to UV_ECANCELED.
• A uv_work_t, uv_getaddrinfo_t or c:type:uv_getnameinfo_t request has its callback invoked with status == UV_ECANCELED.

size_t uv_req_size(uv_req_type type)

Returns the size of the given request type. Useful for FFI binding writers who don’t want to know the structure layout.