DecoderStack: Fixed thread dead-lock
[pulseview.git] / pv / data / decoderstack.cpp
1 /*
2  * This file is part of the PulseView project.
3  *
4  * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
19  */
20
21 #include <libsigrokdecode/libsigrokdecode.h>
22
23 #include <stdexcept>
24
25 #include <QDebug>
26
27 #include "decoderstack.h"
28
29 #include <pv/data/logic.h>
30 #include <pv/data/logicsnapshot.h>
31 #include <pv/data/decode/decoder.h>
32 #include <pv/data/decode/annotation.h>
33 #include <pv/sigsession.h>
34 #include <pv/view/logicsignal.h>
35
36 using std::lock_guard;
37 using std::mutex;
38 using boost::optional;
39 using std::unique_lock;
40 using std::deque;
41 using std::make_pair;
42 using std::max;
43 using std::min;
44 using std::list;
45 using std::map;
46 using std::pair;
47 using std::shared_ptr;
48 using std::vector;
49
50 using namespace pv::data::decode;
51
52 namespace pv {
53 namespace data {
54
55 const double DecoderStack::DecodeMargin = 1.0;
56 const double DecoderStack::DecodeThreshold = 0.2;
57 const int64_t DecoderStack::DecodeChunkLength = 4096;
58 const unsigned int DecoderStack::DecodeNotifyPeriod = 65536;
59
60 mutex DecoderStack::_global_decode_mutex;
61
62 DecoderStack::DecoderStack(pv::SigSession &session,
63         const srd_decoder *const dec) :
64         _session(session),
65         _sample_count(0),
66         _frame_complete(false),
67         _samples_decoded(0)
68 {
69         connect(&_session, SIGNAL(frame_began()),
70                 this, SLOT(on_new_frame()));
71         connect(&_session, SIGNAL(data_received()),
72                 this, SLOT(on_data_received()));
73         connect(&_session, SIGNAL(frame_ended()),
74                 this, SLOT(on_frame_ended()));
75
76         _stack.push_back(shared_ptr<decode::Decoder>(
77                 new decode::Decoder(dec)));
78 }
79
80 DecoderStack::~DecoderStack()
81 {
82         if (_decode_thread.joinable()) {
83                 _interrupt = true;
84                 _input_cond.notify_one();
85                 _decode_thread.join();
86         }
87 }
88
89 const std::list< std::shared_ptr<decode::Decoder> >&
90 DecoderStack::stack() const
91 {
92         return _stack;
93 }
94
95 void DecoderStack::push(std::shared_ptr<decode::Decoder> decoder)
96 {
97         assert(decoder);
98         _stack.push_back(decoder);
99 }
100
101 void DecoderStack::remove(int index)
102 {
103         assert(index >= 0);
104         assert(index < (int)_stack.size());
105
106         // Find the decoder in the stack
107         auto iter = _stack.begin();
108         for(int i = 0; i < index; i++, iter++)
109                 assert(iter != _stack.end());
110
111         // Delete the element
112         _stack.erase(iter);
113 }
114
115 int64_t DecoderStack::samples_decoded() const
116 {
117         lock_guard<mutex> decode_lock(_output_mutex);
118         return _samples_decoded;
119 }
120
121 std::vector<Row> DecoderStack::get_visible_rows() const
122 {
123         lock_guard<mutex> lock(_output_mutex);
124
125         vector<Row> rows;
126
127         for (const shared_ptr<decode::Decoder> &dec : _stack)
128         {
129                 assert(dec);
130                 if (!dec->shown())
131                         continue;
132
133                 const srd_decoder *const decc = dec->decoder();
134                 assert(dec->decoder());
135
136                 // Add a row for the decoder if it doesn't have a row list
137                 if (!decc->annotation_rows)
138                         rows.push_back(Row(decc));
139
140                 // Add the decoder rows
141                 for (const GSList *l = decc->annotation_rows; l; l = l->next)
142                 {
143                         const srd_decoder_annotation_row *const ann_row =
144                                 (srd_decoder_annotation_row *)l->data;
145                         assert(ann_row);
146                         rows.push_back(Row(decc, ann_row));
147                 }
148         }
149
150         return rows;
151 }
152
153 void DecoderStack::get_annotation_subset(
154         std::vector<pv::data::decode::Annotation> &dest,
155         const Row &row, uint64_t start_sample,
156         uint64_t end_sample) const
157 {
158         lock_guard<mutex> lock(_output_mutex);
159
160         const auto iter = _rows.find(row);
161         if (iter != _rows.end())
162                 (*iter).second.get_annotation_subset(dest,
163                         start_sample, end_sample);
164 }
165
166 QString DecoderStack::error_message()
167 {
168         lock_guard<mutex> lock(_output_mutex);
169         return _error_message;
170 }
171
172 void DecoderStack::clear()
173 {
174         _sample_count = 0;
175         _frame_complete = false;
176         _samples_decoded = 0;
177         _error_message = QString();
178         _rows.clear();
179         _class_rows.clear();
180 }
181
182 void DecoderStack::begin_decode()
183 {
184         shared_ptr<pv::view::LogicSignal> logic_signal;
185         shared_ptr<pv::data::Logic> data;
186
187         if (_decode_thread.joinable()) {
188                 _interrupt = true;
189                 _input_cond.notify_one();
190                 _decode_thread.join();
191         }
192
193         clear();
194
195         // Check that all decoders have the required channels
196         for (const shared_ptr<decode::Decoder> &dec : _stack)
197                 if (!dec->have_required_probes()) {
198                         _error_message = tr("One or more required channels "
199                                 "have not been specified");
200                         return;
201                 }
202
203         // Add classes
204         for (const shared_ptr<decode::Decoder> &dec : _stack)
205         {
206                 assert(dec);
207                 const srd_decoder *const decc = dec->decoder();
208                 assert(dec->decoder());
209
210                 // Add a row for the decoder if it doesn't have a row list
211                 if (!decc->annotation_rows)
212                         _rows[Row(decc)] = decode::RowData();
213
214                 // Add the decoder rows
215                 for (const GSList *l = decc->annotation_rows; l; l = l->next)
216                 {
217                         const srd_decoder_annotation_row *const ann_row =
218                                 (srd_decoder_annotation_row *)l->data;
219                         assert(ann_row);
220
221                         const Row row(decc, ann_row);
222
223                         // Add a new empty row data object
224                         _rows[row] = decode::RowData();
225
226                         // Map out all the classes
227                         for (const GSList *ll = ann_row->ann_classes;
228                                 ll; ll = ll->next)
229                                 _class_rows[make_pair(decc,
230                                         GPOINTER_TO_INT(ll->data))] = row;
231                 }
232         }
233
234         // We get the logic data of the first channel in the list.
235         // This works because we are currently assuming all
236         // LogicSignals have the same data/snapshot
237         for (const shared_ptr<decode::Decoder> &dec : _stack)
238                 if (dec && !dec->channels().empty() &&
239                         ((logic_signal = (*dec->channels().begin()).second)) &&
240                         ((data = logic_signal->logic_data())))
241                         break;
242
243         if (!data)
244                 return;
245
246         // Check we have a snapshot of data
247         const deque< shared_ptr<pv::data::LogicSnapshot> > &snapshots =
248                 data->get_snapshots();
249         if (snapshots.empty())
250                 return;
251         _snapshot = snapshots.front();
252
253         // Get the samplerate and start time
254         _start_time = data->get_start_time();
255         _samplerate = data->samplerate();
256         if (_samplerate == 0.0)
257                 _samplerate = 1.0;
258
259         _interrupt = false;
260         _decode_thread = std::thread(&DecoderStack::decode_proc, this);
261 }
262
263 uint64_t DecoderStack::get_max_sample_count() const
264 {
265         uint64_t max_sample_count = 0;
266
267         for (auto i = _rows.cbegin(); i != _rows.end(); i++)
268                 max_sample_count = max(max_sample_count,
269                         (*i).second.get_max_sample());
270
271         return max_sample_count;
272 }
273
274 optional<int64_t> DecoderStack::wait_for_data() const
275 {
276         unique_lock<mutex> input_lock(_input_mutex);
277         while(!_interrupt && !_frame_complete &&
278                 _samples_decoded >= _sample_count)
279                 _input_cond.wait(input_lock);
280         return boost::make_optional(!_interrupt &&
281                 (_samples_decoded < _sample_count || !_frame_complete),
282                 _sample_count);
283 }
284
285 void DecoderStack::decode_data(
286         const int64_t sample_count, const unsigned int unit_size,
287         srd_session *const session)
288 {
289         uint8_t chunk[DecodeChunkLength];
290
291         const unsigned int chunk_sample_count =
292                 DecodeChunkLength / _snapshot->unit_size();
293
294         for (int64_t i = 0; !_interrupt && i < sample_count;
295                 i += chunk_sample_count)
296         {
297                 lock_guard<mutex> decode_lock(_global_decode_mutex);
298
299                 const int64_t chunk_end = min(
300                         i + chunk_sample_count, sample_count);
301                 _snapshot->get_samples(chunk, i, chunk_end);
302
303                 if (srd_session_send(session, i, i + sample_count, chunk,
304                                 (chunk_end - i) * unit_size) != SRD_OK) {
305                         _error_message = tr("Decoder reported an error");
306                         break;
307                 }
308
309                 {
310                         lock_guard<mutex> lock(_output_mutex);
311                         _samples_decoded = chunk_end;
312                 }
313
314                 if (i % DecodeNotifyPeriod == 0)
315                         new_decode_data();
316         }
317
318         new_decode_data();
319 }
320
321 void DecoderStack::decode_proc()
322 {
323         optional<int64_t> sample_count;
324         srd_session *session;
325         srd_decoder_inst *prev_di = NULL;
326
327         assert(_snapshot);
328
329         // Create the session
330         srd_session_new(&session);
331         assert(session);
332
333         // Create the decoders
334         const unsigned int unit_size = _snapshot->unit_size();
335
336         for (const shared_ptr<decode::Decoder> &dec : _stack)
337         {
338                 srd_decoder_inst *const di = dec->create_decoder_inst(session, unit_size);
339
340                 if (!di)
341                 {
342                         _error_message = tr("Failed to create decoder instance");
343                         srd_session_destroy(session);
344                         return;
345                 }
346
347                 if (prev_di)
348                         srd_inst_stack (session, prev_di, di);
349
350                 prev_di = di;
351         }
352
353         // Get the intial sample count
354         {
355                 unique_lock<mutex> input_lock(_input_mutex);
356                 sample_count = _sample_count = _snapshot->get_sample_count();
357         }
358
359         // Start the session
360         srd_session_metadata_set(session, SRD_CONF_SAMPLERATE,
361                 g_variant_new_uint64((uint64_t)_samplerate));
362
363         srd_pd_output_callback_add(session, SRD_OUTPUT_ANN,
364                 DecoderStack::annotation_callback, this);
365
366         srd_session_start(session);
367
368         do {
369                 decode_data(*sample_count, unit_size, session);
370         } while(_error_message.isEmpty() && (sample_count = wait_for_data()));
371
372         // Destroy the session
373         srd_session_destroy(session);
374 }
375
376 void DecoderStack::annotation_callback(srd_proto_data *pdata, void *decoder)
377 {
378         assert(pdata);
379         assert(decoder);
380
381         DecoderStack *const d = (DecoderStack*)decoder;
382         assert(d);
383
384         lock_guard<mutex> lock(d->_output_mutex);
385
386         const Annotation a(pdata);
387
388         // Find the row
389         assert(pdata->pdo);
390         assert(pdata->pdo->di);
391         const srd_decoder *const decc = pdata->pdo->di->decoder;
392         assert(decc);
393
394         auto row_iter = d->_rows.end();
395         
396         // Try looking up the sub-row of this class
397         const auto r = d->_class_rows.find(make_pair(decc, a.format()));
398         if (r != d->_class_rows.end())
399                 row_iter = d->_rows.find((*r).second);
400         else
401         {
402                 // Failing that, use the decoder as a key
403                 row_iter = d->_rows.find(Row(decc));    
404         }
405
406         assert(row_iter != d->_rows.end());
407         if (row_iter == d->_rows.end()) {
408                 qDebug() << "Unexpected annotation: decoder = " << decc <<
409                         ", format = " << a.format();
410                 assert(0);
411                 return;
412         }
413
414         // Add the annotation
415         (*row_iter).second.push_annotation(a);
416 }
417
418 void DecoderStack::on_new_frame()
419 {
420         begin_decode();
421 }
422
423 void DecoderStack::on_data_received()
424 {
425         {
426                 unique_lock<mutex> lock(_input_mutex);
427                 if (_snapshot)
428                         _sample_count = _snapshot->get_sample_count();
429         }
430         _input_cond.notify_one();
431 }
432
433 void DecoderStack::on_frame_ended()
434 {
435         {
436                 unique_lock<mutex> lock(_input_mutex);
437                 if (_snapshot)
438                         _frame_complete = true;
439         }
440         _input_cond.notify_one();
441 }
442
443 } // namespace data
444 } // namespace pv