Hello
I found a concurrency issue with the latest http server implementation.
I'm running test_http_server with multiple threads (-t 5). If I send a
request which is delayed by a sleep and in the mean time I'm calling
"http://localhost:8080/quit"; then the server crashes during
http_send_reply call due to already freed client->conn.
Index: test/test_http_server.c
===================================================================
--- test/test_http_server.c (Revision 5141)
+++ test/test_http_server.c (working copy)
@@ -237,6 +237,9 @@
if (extra_headers != NULL)
http_header_combine(resph, extra_headers);
+ if (run)
+ gwthread_sleep(5);
+
/* return response to client */
http_send_reply(client, status, resph, reply_body);
testing with:
test/test_http_server -t 5 &
curl "http://localhost:8080"; &
sleep 1
curl "http://localhost:8080/quit";
I found a possible solution in http.c: port_remove
Index: gwlib/http.c
===================================================================
--- gwlib/http.c (Revision 5141)
+++ gwlib/http.c (working copy)
@@ -2097,8 +2097,14 @@
*/
gwlist_lock(active_connections);
l = gwlist_search_all(active_connections, &port, port_match);
- while(l != NULL && (client = gwlist_extract_first(l)) != NULL)
+ while(l != NULL && (client = gwlist_extract_first(l)) != NULL) {
conn_unregister(client->conn);
+ while (client->state == request_is_being_handled) {
+ gwthread_sleep(0.1);
+ }
+ }
gwlist_unlock(active_connections);
gwlist_destroy(l, NULL);
while((client = gwlist_search(active_connections, &port,
port_match)) != NULL)
What do you think about that solution?
David
PS: There is a typo in test_http_server help:
Index: test/test_http_server.c
===================================================================
--- test/test_http_server.c (Revision 5141)
+++ test/test_http_server.c (working copy)
@@ -288,7 +291,7 @@
info(0, " read HTTP headers from file 'filename' and add them to");
info(0, " the request for url 'url'");
info(0, "specific URIs with special functions are:");
- info(0, " /quite - shutdown the HTTP server");
+ info(0, " /quit - shutdown the HTTP server");
info(0, " /whitelist - provides the -w whitelist as response");
info(0, " /blacklist - provides the -b blacklist as response");
info(0, " /save - save a HTTP POST request body to a file
/tmp/body.<pid>.<n>");
