1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
|
%% This library is free software; you can redistribute it and/or modify
%% it under the terms of the GNU Lesser General Public License as
%% published by the Free Software Foundation; either version 2 of the
%% License, or (at your option) any later version.
%%
%% This library is distributed in the hope that it will be useful, but
%% WITHOUT ANY WARRANTY; without even the implied warranty of
%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
%% Lesser General Public License for more details.
%%
%% You should have received a copy of the GNU Lesser General Public
%% License along with this library; if not, write to the Free Software
%% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
%% USA
%%
%% $Id$
%%
%% @author Richard Carlsson <richardc@it.uu.se>
%% @copyright 2006 Richard Carlsson
%% @private
%% @see eunit
%% @doc Test runner process tree functions
-module(eunit_proc).
-include("eunit.hrl").
-include("eunit_internal.hrl").
-export([start/4]).
%% This must be exported; see new_group_leader/1 for details.
-export([group_leader_process/1]).
-record(procstate, {ref, id, super, insulator, parent, order}).
%% Spawns test process and returns the process Pid; sends {done,
%% Reference, Pid} to caller when finished. See the function
%% wait_for_task/2 for details about the need for the reference.
%%
%% The `Super' process receives a stream of status messages; see
%% message_super/3 for details.
start(Tests, Order, Super, Reference)
when is_pid(Super), is_reference(Reference) ->
St = #procstate{ref = Reference,
id = [],
super = Super,
order = Order},
spawn_group(local, #group{tests = Tests}, St).
%% Status messages sent to the supervisor process. (A supervisor does
%% not have to act on these messages - it can e.g. just log them, or
%% even discard them.) Each status message has the following form:
%%
%% {status, Id, Info}
%%
%% where Id identifies the item that the message pertains to, and the
%% Info part can be one of:
%%
%% {progress, 'begin', {test | group, Data}}
%% indicates that the item has been entered, and what type it is;
%% Data is [{desc,binary()}, {source,Source}, {line,integer()}] for
%% a test, and [{desc,binary()}, {spawn,SpawnType},
%% {order,OrderType}] for a group.
%%
%% {progress, 'end', {Status, Data}}
%% Status = 'ok' | {error, Exception} | {skipped, Cause} | integer()
%% Data = [{time,integer()}, {output,binary()}]
%%
%% where Time is measured in milliseconds and Output is the data
%% written to the standard output stream during the test; if
%% Status is {skipped, Cause}, then Cause is a term thrown from
%% eunit_test:run_testfun/1. For a group item, the Status field is
%% the number of immediate subitems of the group; this helps the
%% collation of results. Failure for groups is always signalled
%% through a cancel message, not through the Status field.
%%
%% {cancel, Descriptor}
%% where Descriptor can be:
%% timeout a timeout occurred
%% {blame, Id} forced to terminate because of item `Id'
%% {abort, Cause} the test or group failed to execute
%% {exit, Reason} the test process terminated unexpectedly
%% {startup, Reason} failed to start a remote test process
%%
%% where Cause is a term thrown from eunit_data:enter_context/4 or
%% from eunit_data:iter_next/2, and Reason is an exit term from a
%% crashed process
%%
%% Note that due to concurrent (and possibly distributed) execution,
%% there are *no* strict ordering guarantees on the status messages,
%% with one exception: a 'begin' message will always arrive before its
%% corresponding 'end' message.
message_super(Id, Info, St) ->
St#procstate.super ! {status, Id, Info}.
%% @TODO implement synchronized mode for insulator/child execution
%% Ideas for synchronized mode:
%%
%% * At each "program point", i.e., before entering a test, entering a
%% group, or leaving a group, the child will synchronize with the
%% insulator to make sure it is ok to proceed.
%%
%% * The insulator can receive controlling messages from higher up in
%% the hierarchy, telling it to pause, resume, single-step, repeat, etc.
%%
%% * Synchronization on entering/leaving groups is necessary in order to
%% get control over things such as subprocess creation/termination and
%% setup/cleanup, making it possible to, e.g., repeat all the tests
%% within a particular subprocess without terminating and restarting it,
%% or repeating tests without repeating the setup/cleanup.
%%
%% * Some tests that depend on state will not be possible to repeat, but
%% require a fresh context setup. There is nothing that can be done
%% about this, and the many tests that are repeatable should not be
%% punished because of it. The user must decide which level to restart.
%%
%% * Question: How propagate control messages down the hierarchy
%% (preferably only to the correct insulator process)? An insulator does
%% not currenctly know whether its child process has spawned subtasks.
%% (The "supervisor" process does not know the Pids of the controlling
%% insulator processes in the tree, and it probably should not be
%% responsible for this anyway.)
%% ---------------------------------------------------------------------
%% Process tree primitives
%% A "task" consists of an insulator process and a child process which
%% handles the actual work. When the child terminates, the insulator
%% process sends {done, Reference, self()} to the process which started
%% the task (the "parent"). The child process is given a State record
%% which contains the process id:s of the parent, the insulator, and the
%% supervisor.
%% @spec (Type, (#procstate{}) -> () -> term(), #procstate{}) -> pid()
%% Type = local | {remote, Node::atom()}
start_task(Type, Fun, St0) ->
St = St0#procstate{parent = self()},
%% (note: the link here is mainly to propagate signals *downwards*,
%% so that the insulator can detect if the process that started the
%% task dies before the task is done)
F = fun () -> insulator_process(Type, Fun, St) end,
case Type of
local ->
%% we assume (at least for now) that local spawns can never
%% fail in such a way that the process does not start, so a
%% new local insulator does not need to synchronize here
spawn_link(F);
{remote, Node} ->
Pid = spawn_link(Node, F),
%% See below for the need for the {ok, Reference, Pid}
%% message.
Reference = St#procstate.ref,
Monitor = erlang:monitor(process, Pid),
%% (the DOWN message is guaranteed to arrive after any
%% messages sent by the process itself)
receive
{ok, Reference, Pid} ->
Pid;
{'DOWN', Monitor, process, Pid, Reason} ->
%% send messages as if the insulator process was
%% started, but terminated on its own accord
Msg = {startup, Reason},
message_super(St#procstate.id, {cancel, Msg}, St),
self() ! {done, Reference, Pid}
end,
erlang:demonitor(Monitor, [flush]),
Pid
end.
%% Relatively simple, and hopefully failure-proof insulator process
%% (This is cleaner than temporarily setting up the caller to trap
%% signals, and does not affect the caller's mailbox or other state.)
%%
%% We assume that nobody does a 'kill' on an insulator process - if that
%% should happen, the test framework will hang since the insulator will
%% never send a reply; see below for more.
%%
%% Note that even if the insulator process itself never fails, it is
%% still possible that it does not start properly, if it is spawned
%% remotely (e.g., if the remote node is down). Therefore, remote
%% insulators must always immediately send an {ok, Reference, self()}
%% message to the parent as soon as it is spawned.
%% @spec (Type, Fun::() -> term(), St::#procstate{}) -> ok
%% Type = local | {remote, Node::atom()}
insulator_process(Type, Fun, St0) ->
process_flag(trap_exit, true),
Parent = St0#procstate.parent,
if Type =:= local -> ok;
true -> Parent ! {ok, St0#procstate.ref, self()}
end,
St = St0#procstate{insulator = self()},
Child = spawn_link(fun () -> child_process(Fun(St), St) end),
insulator_wait(Child, Parent, [], St).
%% Normally, child processes exit with the reason 'normal' even if the
%% executed tests failed (by throwing exceptions), since the tests are
%% executed within a try-block. Child processes can terminate abnormally
%% by the following reasons:
%% 1) an error in the processing of the test descriptors (a malformed
%% descriptor, failure in a setup, cleanup or initialization, a
%% missing module or function, or a failing generator function);
%% 2) an internal error in the test running framework itself;
%% 3) receiving a non-trapped error signal as a consequence of running
%% test code.
%% Those under point 1 are "expected errors", handled specially in the
%% protocol, while the other two are unexpected errors. (Since alt. 3
%% implies that the test neither reported success nor failure, it can
%% never be considered "proper" behaviour of a test.) Abnormal
%% termination is reported to the supervisor process but otherwise does
%% not affect the insulator compared to normal termination. Child
%% processes can also be killed abruptly by their insulators, in case of
%% a timeout or if a parent process dies.
%%
%% The insulator is the group leader for the child process, and gets all
%% of its standard I/O. The output is buffered and associated with the
%% currently active test or group, and is sent along with the 'end'
%% progress message when the test or group has finished.
insulator_wait(Child, Parent, Buf, St) ->
receive
{child, Child, Id, {'begin', Type, Data}} ->
message_super(Id, {progress, 'begin', {Type, Data}}, St),
insulator_wait(Child, Parent, [[] | Buf], St);
{child, Child, Id, {'end', Status, Time}} ->
Data = [{time, Time}, {output, buffer_to_binary(hd(Buf))}],
message_super(Id, {progress, 'end', {Status, Data}}, St),
insulator_wait(Child, Parent, tl(Buf), St);
{child, Child, Id, {skipped, Reason}} ->
%% this happens when a subgroup fails to enter the context
message_super(Id, {cancel, {abort, Reason}}, St),
insulator_wait(Child, Parent, Buf, St);
{child, Child, Id, {abort, Cause}} ->
%% this happens when the child code threw an internal
%% eunit_abort; the child process has already exited
exit_messages(Id, {abort, Cause}, St),
%% no need to wait for the {'EXIT',Child,_} message
terminate_insulator(St);
{io_request, Child, ReplyAs, Req} ->
%% we only collect output from the child process itself, not
%% from secondary processes, otherwise we get race problems;
%% however, each test runs its personal group leader that
%% funnels all output - see the run_test() function
Buf1 = io_request(Child, ReplyAs, Req, hd(Buf)),
insulator_wait(Child, Parent, [Buf1 | tl(Buf)], St);
{io_request, From, ReplyAs, Req} when is_pid(From) ->
%% (this shouldn't happen anymore, but we keep it safe)
%% just ensure the sender gets a reply; ignore the data
io_request(From, ReplyAs, Req, []),
insulator_wait(Child, Parent, Buf, St);
{timeout, Child, Id} ->
exit_messages(Id, timeout, St),
kill_task(Child, St);
{'EXIT', Child, normal} ->
terminate_insulator(St);
{'EXIT', Child, Reason} ->
exit_messages(St#procstate.id, {exit, Reason}, St),
terminate_insulator(St);
{'EXIT', Parent, _} ->
%% make sure child processes are cleaned up recursively
kill_task(Child, St)
end.
kill_task(Child, St) ->
exit(Child, kill),
terminate_insulator(St).
buffer_to_binary([B]) when is_binary(B) -> B; % avoid unnecessary copying
buffer_to_binary(Buf) -> list_to_binary(lists:reverse(Buf)).
%% Unlinking before exit avoids polluting the parent process with exit
%% signals from the insulator. The child process is already dead here.
terminate_insulator(St) ->
%% messaging/unlinking is ok even if the parent is already dead
Parent = St#procstate.parent,
Parent ! {done, St#procstate.ref, self()},
unlink(Parent),
exit(normal).
%% send cancel messages for the Id of the "causing" item, and also for
%% the Id of the insulator itself, if they are different
exit_messages(Id, Cause, St) ->
%% the message for the most specific Id is always sent first
message_super(Id, {cancel, Cause}, St),
case St#procstate.id of
Id -> ok;
Id1 -> message_super(Id1, {cancel, {blame, Id}}, St)
end.
%% Child processes send all messages via the insulator to ensure proper
%% sequencing with timeouts and exit signals.
message_insulator(Data, St) ->
St#procstate.insulator ! {child, self(), St#procstate.id, Data}.
%% Timeout handling
set_timeout(Time, St) ->
erlang:send_after(Time, St#procstate.insulator,
{timeout, self(), St#procstate.id}).
clear_timeout(Ref) ->
erlang:cancel_timer(Ref).
with_timeout(undefined, Default, F, St) ->
with_timeout(Default, F, St);
with_timeout(Time, _Default, F, St) ->
with_timeout(Time, F, St).
with_timeout(infinity, F, _St) ->
%% don't start timers unnecessarily
{T0, _} = statistics(wall_clock),
Value = F(),
{T1, _} = statistics(wall_clock),
{Value, T1 - T0};
with_timeout(Time, F, St) when is_integer(Time), Time > 16#FFFFffff ->
with_timeout(16#FFFFffff, F, St);
with_timeout(Time, F, St) when is_integer(Time), Time < 0 ->
with_timeout(0, F, St);
with_timeout(Time, F, St) when is_integer(Time) ->
Ref = set_timeout(Time, St),
{T0, _} = statistics(wall_clock),
try F() of
Value ->
%% we could also read the timer, but this is simpler
{T1, _} = statistics(wall_clock),
{Value, T1 - T0}
after
clear_timeout(Ref)
end.
%% The normal behaviour of a child process is not to trap exit
%% signals. The testing framework is not dependent on this, however, so
%% the test code is allowed to enable signal trapping as it pleases.
%% Note that I/O is redirected to the insulator process.
%% @spec (() -> term(), #procstate{}) -> ok
child_process(Fun, St) ->
group_leader(St#procstate.insulator, self()),
try Fun() of
_ -> ok
catch
%% the only "normal" way for a child process to bail out (e.g,
%% when not being able to parse the test descriptor) is to throw
%% an {eunit_abort, Reason} exception; any other exception will
%% be reported as an unexpected termination of the test
{eunit_abort, Cause} ->
message_insulator({abort, Cause}, St),
exit(aborted)
end.
-ifdef(TEST).
child_test_() ->
[{"test processes do not trap exit signals",
?_assertMatch(false, process_flag(trap_exit, false))}].
-endif.
%% @throws abortException()
%% @type abortException() = {eunit_abort, Cause::term()}
abort_task(Cause) ->
throw({eunit_abort, Cause}).
%% Typically, the process that executes this code is not trapping
%% signals, but it might be - it is outside of our control, since test
%% code can enable or disable trapping at will. That we cannot rely on
%% process links here, is why the insulator process of a task must be
%% guaranteed to always send a reply before it terminates.
%%
%% The unique reference guarantees that we don't extract any message
%% from the mailbox unless it belongs to the test framework (and not to
%% the running tests) - it is not possible to use selective receive to
%% match only messages that are tagged with some pid out of a
%% dynamically varying set of pids. When the wait-loop terminates, no
%% such message should remain in the mailbox.
wait_for_task(Pid, St) ->
wait_for_tasks(sets:from_list([Pid]), St).
wait_for_tasks(PidSet, St) ->
case sets:size(PidSet) of
0 ->
ok;
_ ->
%% (note that when we receive this message for some task, we
%% are guaranteed that the insulator process of the task has
%% already informed the supervisor about any anomalies)
Reference = St#procstate.ref,
receive
{done, Reference, Pid} ->
%% (if Pid is not in the set, del_element has no
%% effect, so this is always safe)
Rest = sets:del_element(Pid, PidSet),
wait_for_tasks(Rest, St)
end
end.
%% ---------------------------------------------------------------------
%% Separate testing process
%% TODO: Ability to stop after N failures.
%% TODO: Flow control, starting new job as soon as slot is available
tests(T, St) ->
I = eunit_data:iter_init(T, St#procstate.id),
case St#procstate.order of
inorder -> tests_inorder(I, St);
inparallel -> tests_inparallel(I, 0, St);
{inparallel, N} when is_integer(N), N >= 0 ->
tests_inparallel(I, N, St)
end.
set_id(I, St) ->
St#procstate{id = eunit_data:iter_id(I)}.
tests_inorder(I, St) ->
tests_inorder(I, 0, St).
tests_inorder(I, N, St) ->
case get_next_item(I) of
{T, I1} ->
handle_item(T, set_id(I1, St)),
tests_inorder(I1, N+1, St);
none ->
N % the return status of a group is the subtest count
end.
tests_inparallel(I, K0, St) ->
tests_inparallel(I, 0, St, K0, K0, sets:new()).
tests_inparallel(I, N, St, K, K0, Children) when K =< 0, K0 > 0 ->
wait_for_tasks(Children, St),
tests_inparallel(I, N, St, K0, K0, sets:new());
tests_inparallel(I, N, St, K, K0, Children) ->
case get_next_item(I) of
{T, I1} ->
Child = spawn_item(T, set_id(I1, St)),
tests_inparallel(I1, N+1, St, K - 1, K0,
sets:add_element(Child, Children));
none ->
wait_for_tasks(Children, St),
N % the return status of a group is the subtest count
end.
%% this starts a new separate task for an inparallel-item (which might
%% be a group and in that case might cause yet another spawn in the
%% handle_group() function, but it might also be just a single test)
spawn_item(T, St0) ->
Fun = fun (St) ->
fun () -> handle_item(T, St) end
end,
%% inparallel-items are always spawned locally
start_task(local, Fun, St0).
get_next_item(I) ->
try eunit_data:iter_next(I)
catch
Term -> abort_task(Term)
end.
handle_item(T, St) ->
case T of
#test{} -> handle_test(T, St);
#group{} -> handle_group(T, St)
end.
handle_test(T, St) ->
Data = [{desc, T#test.desc}, {source, T#test.location},
{line, T#test.line}],
message_insulator({'begin', test, Data}, St),
%% each test case runs under a fresh group leader process
G0 = group_leader(),
Runner = self(),
G1 = new_group_leader(Runner),
group_leader(G1, self()),
%% run the actual test, handling timeouts and getting the total run
%% time of the test code (and nothing else)
{Status, Time} = with_timeout(T#test.timeout, ?DEFAULT_TEST_TIMEOUT,
fun () -> run_test(T) end, St),
%% restore group leader, get the collected output, and re-emit it so
%% that it all seems to come from this process, and always comes
%% before the 'end' message for this test
group_leader(G0, self()),
Output = group_leader_sync(G1),
io:put_chars(Output),
message_insulator({'end', Status, Time}, St),
ok.
%% @spec (#test{}) -> ok | {error, eunit_lib:exception()}
%% | {skipped, eunit_test:wrapperError()}
run_test(#test{f = F}) ->
try eunit_test:run_testfun(F) of
{ok, _Value} ->
%% just discard the return value
ok;
{error, Exception} ->
{error, Exception}
catch
throw:WrapperError -> {skipped, WrapperError}
end.
set_group_order(#group{order = undefined}, St) ->
St;
set_group_order(#group{order = Order}, St) ->
St#procstate{order = Order}.
handle_group(T, St0) ->
St = set_group_order(T, St0),
case T#group.spawn of
undefined ->
run_group(T, St);
Type ->
Child = spawn_group(Type, T, St),
wait_for_task(Child, St)
end.
spawn_group(Type, T, St0) ->
Fun = fun (St) ->
fun () -> run_group(T, St) end
end,
start_task(Type, Fun, St0).
run_group(T, St) ->
%% note that the setup/cleanup is outside the group timeout; if the
%% setup fails, we do not start any timers
Timeout = T#group.timeout,
Data = [{desc, T#group.desc}, {spawn, T#group.spawn},
{order, T#group.order}],
message_insulator({'begin', group, Data}, St),
F = fun (G) -> enter_group(G, Timeout, St) end,
try with_context(T, F) of
{Status, Time} ->
message_insulator({'end', Status, Time}, St)
catch
%% a throw here can come from eunit_data:enter_context/4 or from
%% get_next_item/1; for context errors, report group as aborted,
%% but continue processing tests
{context_error, Why, Trace} ->
message_insulator({skipped, {Why, Trace}}, St)
end,
ok.
enter_group(T, Timeout, St) ->
with_timeout(Timeout, ?DEFAULT_GROUP_TIMEOUT,
fun () -> tests(T, St) end, St).
with_context(#group{context = undefined, tests = T}, F) ->
F(T);
with_context(#group{context = #context{} = C, tests = I}, F) ->
eunit_data:enter_context(C, I, F).
%% Group leader process for test cases - collects I/O output requests.
new_group_leader(Runner) ->
%% We must use spawn/3 here (with explicit module and function
%% name), because the 'current function' status of the group leader
%% is used by the UNDER_EUNIT macro (in eunit.hrl). If we spawn
%% using a fun, the current function will be 'erlang:apply/2' during
%% early process startup, which will fool the macro.
spawn_link(?MODULE, group_leader_process, [Runner]).
group_leader_process(Runner) ->
group_leader_loop(Runner, infinity, []).
group_leader_loop(Runner, Wait, Buf) ->
receive
{io_request, From, ReplyAs, Req} ->
P = process_flag(priority, normal),
%% run this part under normal priority always
Buf1 = io_request(From, ReplyAs, Req, Buf),
process_flag(priority, P),
group_leader_loop(Runner, Wait, Buf1);
stop ->
%% quitting time: make a minimal pause, go low on priority,
%% set receive-timeout to zero and schedule out again
receive after 2 -> ok end,
process_flag(priority, low),
group_leader_loop(Runner, 0, Buf);
_ ->
%% discard any other messages
group_leader_loop(Runner, Wait, Buf)
after Wait ->
%% no more messages and nothing to wait for; we ought to
%% have collected all immediately pending output now
process_flag(priority, normal),
Runner ! {self(), buffer_to_binary(Buf)}
end.
group_leader_sync(G) ->
G ! stop,
receive
{G, Buf} -> Buf
end.
%% Implementation of buffering I/O for group leader processes. (Note that
%% each batch of characters is just pushed on the buffer, so it needs to
%% be reversed when it is flushed.)
io_request(From, ReplyAs, Req, Buf) ->
{Reply, Buf1} = io_request(Req, Buf),
io_reply(From, ReplyAs, Reply),
Buf1.
io_reply(From, ReplyAs, Reply) ->
From ! {io_reply, ReplyAs, Reply}.
io_request({put_chars, Chars}, Buf) ->
{ok, [Chars | Buf]};
io_request({put_chars, M, F, As}, Buf) ->
try apply(M, F, As) of
Chars -> {ok, [Chars | Buf]}
catch
C:T -> {{error, {C,T,erlang:get_stacktrace()}}, Buf}
end;
io_request({put_chars, _Enc, Chars}, Buf) ->
io_request({put_chars, Chars}, Buf);
io_request({put_chars, _Enc, Mod, Func, Args}, Buf) ->
io_request({put_chars, Mod, Func, Args}, Buf);
io_request({get_chars, _Enc, _Prompt, _N}, Buf) ->
{eof, Buf};
io_request({get_chars, _Prompt, _N}, Buf) ->
{eof, Buf};
io_request({get_line, _Prompt}, Buf) ->
{eof, Buf};
io_request({get_line, _Enc, _Prompt}, Buf) ->
{eof, Buf};
io_request({get_until, _Prompt, _M, _F, _As}, Buf) ->
{eof, Buf};
io_request({setopts, _Opts}, Buf) ->
{ok, Buf};
io_request(getopts, Buf) ->
{error, {error, enotsup}, Buf};
io_request({get_geometry,columns}, Buf) ->
{error, {error, enotsup}, Buf};
io_request({get_geometry,rows}, Buf) ->
{error, {error, enotsup}, Buf};
io_request({requests, Reqs}, Buf) ->
io_requests(Reqs, {ok, Buf});
io_request(_, Buf) ->
{{error, request}, Buf}.
io_requests([R | Rs], {ok, Buf}) ->
io_requests(Rs, io_request(R, Buf));
io_requests(_, Result) ->
Result.
|