我應該叫evhttp_request_free釋放http服務器中的資源嗎？

Question

我用libevent2.1.1來編寫一個簡單的http服務器，我想我應該在http_server_callback中發佈evhttp_request與evhttp_request_free。但是當我運行它時，發生錯誤。請告訴我爲什麼，以及我該怎麼做。

void http_server_callback (struct evhttp_request *req, void *arg) 
{ 
    evhttp_send_reply (req, HTTP_OK, "OK", NULL); 

    evhttp_request_free(req); 
} 

int http_server_run (void) 
{ 
    struct event_base *base; 
    struct evhttp *http; 
    struct evhttp_bound_socket *handle; 

    base = event_base_new(); 
    if (! base) 
    { 
     fprintf (stderr, "Couldn't create an event_base: exiting\n"); 
     return 1; 
    } 

    http = evhttp_new (base); 
    if (! http) 
    { 
     fprintf (stderr, "couldn't create evhttp. Exiting.\n"); 
     return 1; 
    } 

    evhttp_set_gencb (http, http_server_callback, NULL); 

    handle = evhttp_bind_socket_with_handle (http, "127.0.0.1", 8888); 
    if (! handle) 
    { 
     fprintf (stderr, "couldn't bind to port 8888. Exiting.\n"); 
     return 1; 
    } 

    event_base_dispatch (base); 

    return 0; 
} 

int main (void) 
{ 
    WSADATA WSAData; 
    WSAStartup (0x101, &WSAData); 

    http_server_run(); 

    return 0; 
} 

在此先感謝

Answer 1

的req將在回調函數evhttp_send_done當服務器寫完被釋放。所以它會導致雙倍免費。
中的libevent的源代碼：

static void 
evhttp_send_done(struct evhttp_connection *evcon, void *arg) 
{ 
    int need_close; 
    struct evhttp_request *req = TAILQ_FIRST(&evcon->requests); 
    TAILQ_REMOVE(&evcon->requests, req, next); 

    need_close = 
     (REQ_VERSION_BEFORE(req, 1, 1) && 
     !evhttp_is_connection_keepalive(req->input_headers))|| 
     evhttp_is_connection_close(req->flags, req->input_headers) || 
     evhttp_is_connection_close(req->flags, req->output_headers); 

    EVUTIL_ASSERT(req->flags & EVHTTP_REQ_OWN_CONNECTION); 
    evhttp_request_free(req); 
    ... 
}