From bbee34fe1638b742796b00b39c0859395a752167 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= Date: Sat, 24 Aug 2013 20:36:23 +0200 Subject: Crash on failure, don't report errors When something went wrong in a handler we used to report errors and then terminate the process normally. This doesn't work so well with links which won't detect failure. Now we still catch the error, but throw another one with more details on why it happened, including the Req object information and the stacktrace. Ranch will then print an error message with all this information. Because we crash directly, this also means that we will not hog resources unnecessarily for too long when something bad happens. --- src/cowboy_handler.erl | 86 +++++++++++++++++++++++--------------------------- 1 file changed, 40 insertions(+), 46 deletions(-) (limited to 'src/cowboy_handler.erl') diff --git a/src/cowboy_handler.erl b/src/cowboy_handler.erl index 2074b4e..fcbfe55 100644 --- a/src/cowboy_handler.erl +++ b/src/cowboy_handler.erl @@ -90,15 +90,14 @@ handler_init(Req, State, Handler, HandlerOpts) -> {upgrade, protocol, Module, Req2, HandlerOpts2} -> upgrade_protocol(Req2, State, Handler, HandlerOpts2, Module) catch Class:Reason -> - error_logger:error_msg( - "** Cowboy handler ~p terminating in ~p/~p~n" - " for the reason ~p:~p~n" - "** Options were ~p~n" - "** Request was ~p~n" - "** Stacktrace: ~p~n~n", - [Handler, init, 3, Class, Reason, HandlerOpts, - cowboy_req:to_list(Req), erlang:get_stacktrace()]), - error_terminate(Req, State) + cowboy_req:maybe_reply(500, Req), + erlang:Class([ + {reason, Reason}, + {mfa, {Handler, init, 3}}, + {stacktrace, erlang:get_stacktrace()}, + {req, cowboy_req:to_list(Req)}, + {opts, HandlerOpts} + ]) end. -spec upgrade_protocol(Req, #state{}, module(), any(), module()) @@ -121,16 +120,15 @@ handler_handle(Req, State, Handler, HandlerState) -> terminate_request(Req2, State, Handler, HandlerState2, {normal, shutdown}) catch Class:Reason -> - error_logger:error_msg( - "** Cowboy handler ~p terminating in ~p/~p~n" - " for the reason ~p:~p~n" - "** Handler state was ~p~n" - "** Request was ~p~n" - "** Stacktrace: ~p~n~n", - [Handler, handle, 2, Class, Reason, HandlerState, - cowboy_req:to_list(Req), erlang:get_stacktrace()]), + cowboy_req:maybe_reply(500, Req), handler_terminate(Req, Handler, HandlerState, Reason), - error_terminate(Req, State) + erlang:Class([ + {reason, Reason}, + {mfa, {Handler, handle, 2}}, + {stacktrace, erlang:get_stacktrace()}, + {req, cowboy_req:to_list(Req)}, + {state, HandlerState} + ]) end. %% Update the state if the response was sent in the callback. @@ -195,7 +193,8 @@ handler_loop(Req, State=#state{loop_buffer_size=NbBytes, if NbBytes2 > Threshold -> _ = handler_terminate(Req, Handler, HandlerState, {error, overflow}), - error_terminate(Req, State); + cowboy_req:maybe_reply(500, Req), + exit(normal); true -> Req2 = cowboy_req:append_buffer(Data, Req), State2 = handler_loop_timeout(State#state{ @@ -232,7 +231,8 @@ handler_loop(Req, State=#state{loop_buffer_size=NbBytes, -> {ok, Req, cowboy_middleware:env()} | {error, 500, Req} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). -handler_call(Req, State, Handler, HandlerState, Message) -> +handler_call(Req, State=#state{resp_sent=RespSent}, + Handler, HandlerState, Message) -> try Handler:info(Message, Req, HandlerState) of {ok, Req2, HandlerState2} -> handler_after_loop(Req2, State, Handler, HandlerState2, @@ -243,16 +243,19 @@ handler_call(Req, State, Handler, HandlerState, Message) -> handler_after_callback(Req2, State#state{hibernate=true}, Handler, HandlerState2) catch Class:Reason -> - error_logger:error_msg( - "** Cowboy handler ~p terminating in ~p/~p~n" - " for the reason ~p:~p~n" - "** Handler state was ~p~n" - "** Request was ~p~n" - "** Stacktrace: ~p~n~n", - [Handler, info, 3, Class, Reason, HandlerState, - cowboy_req:to_list(Req), erlang:get_stacktrace()]), + if RespSent -> + ok; + true -> + cowboy_req:maybe_reply(500, Req) + end, handler_terminate(Req, Handler, HandlerState, Reason), - error_terminate(Req, State) + erlang:Class([ + {reason, Reason}, + {mfa, {Handler, info, 3}}, + {stacktrace, erlang:get_stacktrace()}, + {req, cowboy_req:to_list(Req)}, + {state, HandlerState} + ]) end. %% It is sometimes important to make a socket passive as it was initially @@ -287,21 +290,12 @@ handler_terminate(Req, Handler, HandlerState, Reason) -> try Handler:terminate(Reason, cowboy_req:lock(Req), HandlerState) catch Class:Reason2 -> - error_logger:error_msg( - "** Cowboy handler ~p terminating in ~p/~p~n" - " for the reason ~p:~p~n" - "** Handler state was ~p~n" - "** Request was ~p~n" - "** Stacktrace: ~p~n~n", - [Handler, terminate, 3, Class, Reason2, HandlerState, - cowboy_req:to_list(Req), erlang:get_stacktrace()]) + erlang:Class([ + {reason, Reason2}, + {mfa, {Handler, terminate, 3}}, + {stacktrace, erlang:get_stacktrace()}, + {req, cowboy_req:to_list(Req)}, + {state, HandlerState}, + {terminate_reason, Reason} + ]) end. - -%% Only send an error reply if there is no resp_sent message. --spec error_terminate(Req, #state{}) - -> {error, 500, Req} | {halt, Req} when Req::cowboy_req:req(). -error_terminate(Req, #state{resp_sent=true}) -> - %% Close the connection, but do not attempt sending a reply. - {halt, cowboy_req:set([{connection, close}, {resp_state, done}], Req)}; -error_terminate(Req, _) -> - {error, 500, Req}. -- cgit v1.2.3