From 48083e54b502afb2768066394074d29423162dc8 Mon Sep 17 00:00:00 2001 From: Lukas Larsson Date: Thu, 26 Jun 2014 18:55:47 +0200 Subject: kernel,ssh: Add synchronous user_drv protocol Added a put_chars_sync to the protocol that can be used to talk to user_drv and made group use it. This is needed in order to guarantee that bytes has been pushed to the tty port when doing something like this: io:format("halting\n"),erlang:halt(0). Before this change the halting message could be lost in the message queue of the user_drv process, this is no longer possible. This commit also fixes ssh_cli as that plugs itself in as a user_drv process. OTP-12240 --- lib/kernel/src/group.erl | 148 +++++++++++++++++++++++++++++------------------ 1 file changed, 93 insertions(+), 55 deletions(-) (limited to 'lib/kernel/src/group.erl') diff --git a/lib/kernel/src/group.erl b/lib/kernel/src/group.erl index b36dbf33dd..046885f885 100644 --- a/lib/kernel/src/group.erl +++ b/lib/kernel/src/group.erl @@ -111,8 +111,13 @@ start_shell1(Fun) -> server_loop(Drv, Shell, Buf0) -> receive {io_request,From,ReplyAs,Req} when is_pid(From) -> - Buf = io_request(Req, From, ReplyAs, Drv, Buf0), - server_loop(Drv, Shell, Buf); + %% This io_request may cause a transition to a couple of + %% selective receive loops elsewhere in this module. + Buf = io_request(Req, From, ReplyAs, Drv, Buf0), + server_loop(Drv, Shell, Buf); + {reply,{{From,ReplyAs},Reply}} -> + io_reply(From, ReplyAs, Reply), + server_loop(Drv, Shell, Buf0); {driver_id,ReplyTo} -> ReplyTo ! {self(),driver_id,Drv}, server_loop(Drv, Shell, Buf0); @@ -172,10 +177,13 @@ set_unicode_state(Drv,Bool) -> io_request(Req, From, ReplyAs, Drv, Buf0) -> - case io_request(Req, Drv, Buf0) of + case io_request(Req, Drv, {From,ReplyAs}, Buf0) of {ok,Reply,Buf} -> io_reply(From, ReplyAs, Reply), Buf; + {noreply,Buf} -> + %% We expect a {reply,_} message from the Drv when request is done + Buf; {error,Reply,Buf} -> io_reply(From, ReplyAs, Reply), Buf; @@ -196,78 +204,85 @@ io_request(Req, From, ReplyAs, Drv, Buf0) -> %% io_request({put_chars,unicode,Binary}, Drv, Buf) when is_binary(Binary) -> %% send_drv(Drv, {put_chars,Binary}), %% {ok,ok,Buf}; -io_request({put_chars,unicode,Chars}, Drv, Buf) -> +%% +%% These put requests have to be synchronous to the driver as otherwise +%% there is no guarantee that the data has actually been printed. +io_request({put_chars,unicode,Chars}, Drv, From, Buf) -> case catch unicode:characters_to_binary(Chars,utf8) of Binary when is_binary(Binary) -> - send_drv(Drv, {put_chars, unicode, Binary}), - {ok,ok,Buf}; + send_drv(Drv, {put_chars_sync, unicode, Binary, {From,ok}}), + {noreply,Buf}; _ -> {error,{error,{put_chars, unicode,Chars}},Buf} end; -io_request({put_chars,unicode,M,F,As}, Drv, Buf) -> +io_request({put_chars,unicode,M,F,As}, Drv, From, Buf) -> case catch apply(M, F, As) of Binary when is_binary(Binary) -> - send_drv(Drv, {put_chars, unicode,Binary}), - {ok,ok,Buf}; + send_drv(Drv, {put_chars_sync, unicode, Binary, {From,ok}}), + {noreply,Buf}; Chars -> case catch unicode:characters_to_binary(Chars,utf8) of B when is_binary(B) -> - send_drv(Drv, {put_chars, unicode,B}), - {ok,ok,Buf}; + send_drv(Drv, {put_chars_sync, unicode, B, {From,ok}}), + {noreply,Buf}; _ -> {error,{error,F},Buf} end end; -io_request({put_chars,latin1,Binary}, Drv, Buf) when is_binary(Binary) -> - send_drv(Drv, {put_chars, unicode,unicode:characters_to_binary(Binary,latin1)}), - {ok,ok,Buf}; -io_request({put_chars,latin1,Chars}, Drv, Buf) -> +io_request({put_chars,latin1,Binary}, Drv, From, Buf) when is_binary(Binary) -> + send_drv(Drv, {put_chars_sync, unicode, + unicode:characters_to_binary(Binary,latin1), + {From,ok}}), + {noreply,Buf}; +io_request({put_chars,latin1,Chars}, Drv, From, Buf) -> case catch unicode:characters_to_binary(Chars,latin1) of Binary when is_binary(Binary) -> - send_drv(Drv, {put_chars, unicode,Binary}), - {ok,ok,Buf}; + send_drv(Drv, {put_chars_sync, unicode, Binary, {From,ok}}), + {noreply,Buf}; _ -> {error,{error,{put_chars,latin1,Chars}},Buf} end; -io_request({put_chars,latin1,M,F,As}, Drv, Buf) -> +io_request({put_chars,latin1,M,F,As}, Drv, From, Buf) -> case catch apply(M, F, As) of Binary when is_binary(Binary) -> - send_drv(Drv, {put_chars, unicode,unicode:characters_to_binary(Binary,latin1)}), - {ok,ok,Buf}; + send_drv(Drv, {put_chars_sync, unicode, + unicode:characters_to_binary(Binary,latin1), + {From,ok}}), + {noreply,Buf}; Chars -> case catch unicode:characters_to_binary(Chars,latin1) of B when is_binary(B) -> - send_drv(Drv, {put_chars, unicode,B}), - {ok,ok,Buf}; + send_drv(Drv, {put_chars_sync, unicode, B, {From,ok}}), + {noreply,Buf}; _ -> {error,{error,F},Buf} end end; -io_request({get_chars,Encoding,Prompt,N}, Drv, Buf) -> +io_request({get_chars,Encoding,Prompt,N}, Drv, _From, Buf) -> get_chars(Prompt, io_lib, collect_chars, N, Drv, Buf, Encoding); -io_request({get_line,Encoding,Prompt}, Drv, Buf) -> +io_request({get_line,Encoding,Prompt}, Drv, _From, Buf) -> get_chars(Prompt, io_lib, collect_line, [], Drv, Buf, Encoding); -io_request({get_until,Encoding, Prompt,M,F,As}, Drv, Buf) -> +io_request({get_until,Encoding, Prompt,M,F,As}, Drv, _From, Buf) -> get_chars(Prompt, io_lib, get_until, {M,F,As}, Drv, Buf, Encoding); -io_request({get_password,_Encoding},Drv,Buf) -> +io_request({get_password,_Encoding},Drv,_From,Buf) -> get_password_chars(Drv, Buf); -io_request({setopts,Opts}, Drv, Buf) when is_list(Opts) -> +io_request({setopts,Opts}, Drv, _From, Buf) when is_list(Opts) -> setopts(Opts, Drv, Buf); -io_request(getopts, Drv, Buf) -> +io_request(getopts, Drv, _From, Buf) -> getopts(Drv, Buf); -io_request({requests,Reqs}, Drv, Buf) -> - io_requests(Reqs, {ok,ok,Buf}, Drv); +io_request({requests,Reqs}, Drv, From, Buf) -> + io_requests(Reqs, {ok,ok,Buf}, From, Drv); %% New in R12 -io_request({get_geometry,columns},Drv,Buf) -> +io_request({get_geometry,columns},Drv,_From,Buf) -> case get_tty_geometry(Drv) of {W,_H} -> {ok,W,Buf}; _ -> {error,{error,enotsup},Buf} end; -io_request({get_geometry,rows},Drv,Buf) -> +io_request({get_geometry,rows},Drv,_From,Buf) -> case get_tty_geometry(Drv) of {_W,H} -> {ok,H,Buf}; @@ -276,38 +291,49 @@ io_request({get_geometry,rows},Drv,Buf) -> end; %% BC with pre-R13 -io_request({put_chars,Chars}, Drv, Buf) -> - io_request({put_chars,latin1,Chars}, Drv, Buf); -io_request({put_chars,M,F,As}, Drv, Buf) -> - io_request({put_chars,latin1,M,F,As}, Drv, Buf); -io_request({get_chars,Prompt,N}, Drv, Buf) -> - io_request({get_chars,latin1,Prompt,N}, Drv, Buf); -io_request({get_line,Prompt}, Drv, Buf) -> - io_request({get_line,latin1,Prompt}, Drv, Buf); -io_request({get_until, Prompt,M,F,As}, Drv, Buf) -> - io_request({get_until,latin1, Prompt,M,F,As}, Drv, Buf); -io_request(get_password,Drv,Buf) -> - io_request({get_password,latin1},Drv,Buf); - - - -io_request(_, _Drv, Buf) -> +io_request({put_chars,Chars}, Drv, From, Buf) -> + io_request({put_chars,latin1,Chars}, Drv, From, Buf); +io_request({put_chars,M,F,As}, Drv, From, Buf) -> + io_request({put_chars,latin1,M,F,As}, Drv, From, Buf); +io_request({get_chars,Prompt,N}, Drv, From, Buf) -> + io_request({get_chars,latin1,Prompt,N}, Drv, From, Buf); +io_request({get_line,Prompt}, Drv, From, Buf) -> + io_request({get_line,latin1,Prompt}, Drv, From, Buf); +io_request({get_until, Prompt,M,F,As}, Drv, From, Buf) -> + io_request({get_until,latin1, Prompt,M,F,As}, Drv, From, Buf); +io_request(get_password,Drv,From,Buf) -> + io_request({get_password,latin1},Drv,From,Buf); + + + +io_request(_, _Drv, _From, Buf) -> {error,{error,request},Buf}. -%% Status = io_requests(RequestList, PrevStat, Drv) -%% Process a list of output requests as long as the previous status is 'ok'. - -io_requests([R|Rs], {ok,ok,Buf}, Drv) -> - io_requests(Rs, io_request(R, Drv, Buf), Drv); -io_requests([_|_], Error, _Drv) -> +%% Status = io_requests(RequestList, PrevStat, From, Drv) +%% Process a list of output requests as long as +%% the previous status is 'ok' or noreply. +%% +%% We use undefined as the From for all but the last request +%% in order to discards acknowledgements from those requests. +%% +io_requests([R|Rs], {noreply,Buf}, From, Drv) -> + ReqFrom = if Rs =:= [] -> From; true -> undefined end, + io_requests(Rs, io_request(R, Drv, ReqFrom, Buf), From, Drv); +io_requests([R|Rs], {ok,ok,Buf}, From, Drv) -> + ReqFrom = if Rs =:= [] -> From; true -> undefined end, + io_requests(Rs, io_request(R, Drv, ReqFrom, Buf), From, Drv); +io_requests([_|_], Error, _From, _Drv) -> Error; -io_requests([], Stat, _) -> +io_requests([], Stat, _From, _) -> Stat. %% io_reply(From, ReplyAs, Reply) %% The function for sending i/o command acknowledgement. %% The ACK contains the return value. +io_reply(undefined, _ReplyAs, _Reply) -> + %% Ignore these replies as they are generated from io_requests/4. + ok; io_reply(From, ReplyAs, Reply) -> From ! {io_reply,ReplyAs,Reply}, ok. @@ -619,6 +645,10 @@ more_data(What, Cont0, Drv, Ls, Encoding) -> io_request(Req, From, ReplyAs, Drv, []), %WRONG!!! send_drv_reqs(Drv, edlin:redraw_line(Cont)), get_line1({more_chars,Cont,[]}, Drv, Ls, Encoding); + {reply,{{From,ReplyAs},Reply}} -> + %% We take care of replies from puts here as well + io_reply(From, ReplyAs, Reply), + more_data(What, Cont0, Drv, Ls, Encoding); {'EXIT',Drv,interrupt} -> interrupted; {'EXIT',Drv,_} -> @@ -641,6 +671,10 @@ get_line_echo_off1({Chars,[]}, Drv) -> {io_request,From,ReplyAs,Req} when is_pid(From) -> io_request(Req, From, ReplyAs, Drv, []), get_line_echo_off1({Chars,[]}, Drv); + {reply,{{From,ReplyAs},Reply}} when From =/= undefined -> + %% We take care of replies from puts here as well + io_reply(From, ReplyAs, Reply), + get_line_echo_off1({Chars,[]},Drv); {'EXIT',Drv,interrupt} -> interrupted; {'EXIT',Drv,_} -> @@ -790,6 +824,10 @@ get_password1({Chars,[]}, Drv) -> %% set to []. But do we expect anything but plain output? get_password1({Chars, []}, Drv); + {reply,{{From,ReplyAs},Reply}} -> + %% We take care of replies from puts here as well + io_reply(From, ReplyAs, Reply), + get_password1({Chars, []},Drv); {'EXIT',Drv,interrupt} -> interrupted; {'EXIT',Drv,_} -> -- cgit v1.2.3