1 //===-- Broadcaster.cpp -----------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Core/Broadcaster.h"
11 
12 // C Includes
13 // C++ Includes
14 // Other libraries and framework includes
15 // Project includes
16 #include "lldb/Core/Log.h"
17 #include "lldb/Core/Event.h"
18 #include "lldb/Core/StreamString.h"
19 #include "lldb/lldb-private-log.h"
20 
21 using namespace lldb;
22 using namespace lldb_private;
23 
Broadcaster(BroadcasterManager * manager,const char * name)24 Broadcaster::Broadcaster (BroadcasterManager *manager, const char *name) :
25     m_broadcaster_name (name),
26     m_listeners (),
27     m_listeners_mutex (Mutex::eMutexTypeRecursive),
28     m_hijacking_listeners(),
29     m_hijacking_masks(),
30     m_manager (manager)
31 {
32     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OBJECT));
33     if (log)
34         log->Printf ("%p Broadcaster::Broadcaster(\"%s\")", this, m_broadcaster_name.AsCString());
35 
36 }
37 
~Broadcaster()38 Broadcaster::~Broadcaster()
39 {
40     Log *log (lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OBJECT));
41     if (log)
42         log->Printf ("%p Broadcaster::~Broadcaster(\"%s\")", this, m_broadcaster_name.AsCString());
43 
44     Clear();
45 }
46 
47 void
CheckInWithManager()48 Broadcaster::CheckInWithManager ()
49 {
50     if (m_manager != NULL)
51     {
52         m_manager->SignUpListenersForBroadcaster(*this);
53     }
54 }
55 
56 void
Clear()57 Broadcaster::Clear()
58 {
59     Mutex::Locker listeners_locker(m_listeners_mutex);
60 
61     // Make sure the listener forgets about this broadcaster. We do
62     // this in the broadcaster in case the broadcaster object initiates
63     // the removal.
64 
65     collection::iterator pos, end = m_listeners.end();
66     for (pos = m_listeners.begin(); pos != end; ++pos)
67         pos->first->BroadcasterWillDestruct (this);
68 
69     m_listeners.clear();
70 }
71 const ConstString &
GetBroadcasterName()72 Broadcaster::GetBroadcasterName ()
73 {
74     return m_broadcaster_name;
75 }
76 
77 bool
GetEventNames(Stream & s,uint32_t event_mask,bool prefix_with_broadcaster_name) const78 Broadcaster::GetEventNames (Stream &s, uint32_t event_mask, bool prefix_with_broadcaster_name) const
79 {
80     uint32_t num_names_added = 0;
81     if (event_mask && !m_event_names.empty())
82     {
83         event_names_map::const_iterator end = m_event_names.end();
84         for (uint32_t bit=1u, mask=event_mask; mask != 0 && bit != 0; bit <<= 1, mask >>= 1)
85         {
86             if (mask & 1)
87             {
88                 event_names_map::const_iterator pos = m_event_names.find(bit);
89                 if (pos != end)
90                 {
91                     if (num_names_added > 0)
92                         s.PutCString(", ");
93 
94                     if (prefix_with_broadcaster_name)
95                     {
96                         s.PutCString (m_broadcaster_name.GetCString());
97                         s.PutChar('.');
98                     }
99                     s.PutCString(pos->second.c_str());
100                     ++num_names_added;
101                 }
102             }
103         }
104     }
105     return num_names_added > 0;
106 }
107 
108 void
AddInitialEventsToListener(Listener * listener,uint32_t requested_events)109 Broadcaster::AddInitialEventsToListener (Listener *listener, uint32_t requested_events)
110 {
111 
112 }
113 
114 uint32_t
AddListener(Listener * listener,uint32_t event_mask)115 Broadcaster::AddListener (Listener* listener, uint32_t event_mask)
116 {
117     if (listener == NULL)
118         return 0;
119 
120     Mutex::Locker locker(m_listeners_mutex);
121     collection::iterator pos, end = m_listeners.end();
122 
123     collection::iterator existing_pos = end;
124     // See if we already have this listener, and if so, update its mask
125     uint32_t taken_event_types = 0;
126     for (pos = m_listeners.begin(); pos != end; ++pos)
127     {
128         if (pos->first == listener)
129             existing_pos = pos;
130     // For now don't descriminate on who gets what
131     // FIXME: Implement "unique listener for this bit" mask
132     //  taken_event_types |= pos->second;
133     }
134 
135     // Each event bit in a Broadcaster object can only be used
136     // by one listener
137     uint32_t available_event_types = ~taken_event_types & event_mask;
138 
139     if (available_event_types)
140     {
141         // If we didn't find our listener, add it
142         if (existing_pos == end)
143         {
144             // Grant a new listener the available event bits
145             m_listeners.push_back(std::make_pair(listener, available_event_types));
146         }
147         else
148         {
149             // Grant the existing listener the available event bits
150             existing_pos->second |= available_event_types;
151         }
152 
153         // Individual broadcasters decide whether they have outstanding data when a
154         // listener attaches, and insert it into the listener with this method.
155 
156         AddInitialEventsToListener (listener, available_event_types);
157     }
158 
159     // Return the event bits that were granted to the listener
160     return available_event_types;
161 }
162 
163 bool
EventTypeHasListeners(uint32_t event_type)164 Broadcaster::EventTypeHasListeners (uint32_t event_type)
165 {
166     Mutex::Locker locker (m_listeners_mutex);
167 
168     if (m_hijacking_listeners.size() > 0 && event_type & m_hijacking_masks.back())
169         return true;
170 
171     if (m_listeners.empty())
172         return false;
173 
174     collection::iterator pos, end = m_listeners.end();
175     for (pos = m_listeners.begin(); pos != end; ++pos)
176     {
177         if (pos->second & event_type)
178             return true;
179     }
180     return false;
181 }
182 
183 bool
RemoveListener(Listener * listener,uint32_t event_mask)184 Broadcaster::RemoveListener (Listener* listener, uint32_t event_mask)
185 {
186     Mutex::Locker locker(m_listeners_mutex);
187     collection::iterator pos, end = m_listeners.end();
188     // See if we already have this listener, and if so, update its mask
189     for (pos = m_listeners.begin(); pos != end; ++pos)
190     {
191         if (pos->first == listener)
192         {
193             // Relinquish all event bits in "event_mask"
194             pos->second &= ~event_mask;
195             // If all bits have been relinquished then remove this listener
196             if (pos->second == 0)
197                 m_listeners.erase (pos);
198             return true;
199         }
200     }
201     return false;
202 }
203 
204 void
BroadcastEvent(EventSP & event_sp)205 Broadcaster::BroadcastEvent (EventSP &event_sp)
206 {
207     return PrivateBroadcastEvent (event_sp, false);
208 }
209 
210 void
BroadcastEventIfUnique(EventSP & event_sp)211 Broadcaster::BroadcastEventIfUnique (EventSP &event_sp)
212 {
213     return PrivateBroadcastEvent (event_sp, true);
214 }
215 
216 void
PrivateBroadcastEvent(EventSP & event_sp,bool unique)217 Broadcaster::PrivateBroadcastEvent (EventSP &event_sp, bool unique)
218 {
219     // Can't add a NULL event...
220     if (event_sp.get() == NULL)
221         return;
222 
223     // Update the broadcaster on this event
224     event_sp->SetBroadcaster (this);
225 
226     const uint32_t event_type = event_sp->GetType();
227 
228     Mutex::Locker event_types_locker(m_listeners_mutex);
229 
230     Listener *hijacking_listener = NULL;
231     if (!m_hijacking_listeners.empty())
232     {
233         assert (!m_hijacking_masks.empty());
234         hijacking_listener = m_hijacking_listeners.back();
235         if ((event_type & m_hijacking_masks.back()) == 0)
236             hijacking_listener = NULL;
237     }
238 
239     Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_EVENTS));
240     if (log)
241     {
242         StreamString event_description;
243         event_sp->Dump  (&event_description);
244         log->Printf ("%p Broadcaster(\"%s\")::BroadcastEvent (event_sp = {%s}, unique =%i) hijack = %p",
245                      this,
246                      m_broadcaster_name.AsCString(""),
247                      event_description.GetData(),
248                      unique,
249                      hijacking_listener);
250     }
251 
252     if (hijacking_listener)
253     {
254         if (unique && hijacking_listener->PeekAtNextEventForBroadcasterWithType (this, event_type))
255             return;
256         hijacking_listener->AddEvent (event_sp);
257     }
258     else
259     {
260         collection::iterator pos, end = m_listeners.end();
261 
262 
263         // Iterate through all listener/mask pairs
264         for (pos = m_listeners.begin(); pos != end; ++pos)
265         {
266             // If the listener's mask matches any bits that we just set, then
267             // put the new event on its event queue.
268             if (event_type & pos->second)
269             {
270                 if (unique && pos->first->PeekAtNextEventForBroadcasterWithType (this, event_type))
271                     continue;
272                 pos->first->AddEvent (event_sp);
273             }
274         }
275     }
276 }
277 
278 void
BroadcastEvent(uint32_t event_type,EventData * event_data)279 Broadcaster::BroadcastEvent (uint32_t event_type, EventData *event_data)
280 {
281     EventSP event_sp (new Event (event_type, event_data));
282     PrivateBroadcastEvent (event_sp, false);
283 }
284 
285 void
BroadcastEventIfUnique(uint32_t event_type,EventData * event_data)286 Broadcaster::BroadcastEventIfUnique (uint32_t event_type, EventData *event_data)
287 {
288     EventSP event_sp (new Event (event_type, event_data));
289     PrivateBroadcastEvent (event_sp, true);
290 }
291 
292 bool
HijackBroadcaster(Listener * listener,uint32_t event_mask)293 Broadcaster::HijackBroadcaster (Listener *listener, uint32_t event_mask)
294 {
295     Mutex::Locker event_types_locker(m_listeners_mutex);
296 
297     Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_EVENTS));
298     if (log)
299     {
300         log->Printf ("%p Broadcaster(\"%s\")::HijackBroadcaster (listener(\"%s\")=%p)",
301                      this,
302                      m_broadcaster_name.AsCString(""),
303                      listener->m_name.c_str(),
304                      listener);
305     }
306     m_hijacking_listeners.push_back(listener);
307     m_hijacking_masks.push_back(event_mask);
308     return true;
309 }
310 
311 void
RestoreBroadcaster()312 Broadcaster::RestoreBroadcaster ()
313 {
314     Mutex::Locker event_types_locker(m_listeners_mutex);
315 
316     Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_EVENTS));
317     if (log)
318     {
319         Listener *listener = m_hijacking_listeners.back();
320         log->Printf ("%p Broadcaster(\"%s\")::RestoreBroadcaster (about to pop listener(\"%s\")=%p)",
321                      this,
322                      m_broadcaster_name.AsCString(""),
323                      listener->m_name.c_str(),
324                      listener);
325     }
326     m_hijacking_listeners.pop_back();
327     m_hijacking_masks.pop_back();
328 }
329 
330 ConstString &
GetBroadcasterClass() const331 Broadcaster::GetBroadcasterClass() const
332 {
333     static ConstString class_name ("lldb.anonymous");
334     return class_name;
335 }
336 
BroadcastEventSpec(const BroadcastEventSpec & rhs)337 BroadcastEventSpec::BroadcastEventSpec (const BroadcastEventSpec &rhs) :
338     m_broadcaster_class (rhs.m_broadcaster_class),
339     m_event_bits (rhs.m_event_bits)
340 {
341 }
342 
343 bool
operator <(const BroadcastEventSpec & rhs) const344 BroadcastEventSpec::operator< (const BroadcastEventSpec &rhs) const
345 {
346     if (GetBroadcasterClass() == rhs.GetBroadcasterClass())
347     {
348         return GetEventBits() < rhs.GetEventBits();
349     }
350     else
351     {
352         return GetBroadcasterClass() < rhs.GetBroadcasterClass();
353     }
354 }
355 
356 const BroadcastEventSpec &
operator =(const BroadcastEventSpec & rhs)357 BroadcastEventSpec::operator= (const BroadcastEventSpec &rhs)
358 {
359     m_broadcaster_class = rhs.m_broadcaster_class;
360     m_event_bits = rhs.m_event_bits;
361     return *this;
362 }
363 
BroadcasterManager()364 BroadcasterManager::BroadcasterManager() :
365     m_manager_mutex(Mutex::eMutexTypeRecursive)
366 {
367 
368 }
369 
370 uint32_t
RegisterListenerForEvents(Listener & listener,BroadcastEventSpec event_spec)371 BroadcasterManager::RegisterListenerForEvents (Listener &listener, BroadcastEventSpec event_spec)
372 {
373     Mutex::Locker locker(m_manager_mutex);
374 
375     collection::iterator iter = m_event_map.begin(), end_iter = m_event_map.end();
376     uint32_t available_bits = event_spec.GetEventBits();
377 
378     while (iter != end_iter
379            && (iter = find_if (iter, end_iter, BroadcasterClassMatches(event_spec.GetBroadcasterClass()))) != end_iter)
380     {
381         available_bits &= ~((*iter).first.GetEventBits());
382         iter++;
383     }
384 
385     if (available_bits != 0)
386     {
387         m_event_map.insert (event_listener_key (BroadcastEventSpec (event_spec.GetBroadcasterClass(), available_bits), &listener));
388         m_listeners.insert(&listener);
389     }
390 
391     return available_bits;
392 }
393 
394 bool
UnregisterListenerForEvents(Listener & listener,BroadcastEventSpec event_spec)395 BroadcasterManager::UnregisterListenerForEvents (Listener &listener, BroadcastEventSpec event_spec)
396 {
397     Mutex::Locker locker(m_manager_mutex);
398     bool removed_some = false;
399 
400     if (m_listeners.erase(&listener) == 0)
401         return false;
402 
403     ListenerMatchesAndSharedBits predicate (event_spec, listener);
404     std::vector<BroadcastEventSpec> to_be_readded;
405     uint32_t event_bits_to_remove = event_spec.GetEventBits();
406 
407     // Go through the map and delete the exact matches, and build a list of matches that weren't exact to re-add:
408     while (1)
409     {
410         collection::iterator iter, end_iter = m_event_map.end();
411         iter = find_if (m_event_map.begin(), end_iter, predicate);
412         if (iter == end_iter)
413         {
414             break;
415         }
416         else
417         {
418             uint32_t iter_event_bits = (*iter).first.GetEventBits();
419             removed_some = true;
420 
421             if (event_bits_to_remove != iter_event_bits)
422             {
423                 uint32_t new_event_bits = iter_event_bits & ~event_bits_to_remove;
424                 to_be_readded.push_back(BroadcastEventSpec (event_spec.GetBroadcasterClass(), new_event_bits));
425             }
426             m_event_map.erase (iter);
427         }
428     }
429 
430     // Okay now add back the bits that weren't completely removed:
431     for (size_t i = 0; i < to_be_readded.size(); i++)
432     {
433         m_event_map.insert (event_listener_key (to_be_readded[i], &listener));
434     }
435 
436     return removed_some;
437 }
438 
439 Listener *
GetListenerForEventSpec(BroadcastEventSpec event_spec) const440 BroadcasterManager::GetListenerForEventSpec (BroadcastEventSpec event_spec) const
441 {
442     Mutex::Locker locker(*(const_cast<Mutex *> (&m_manager_mutex)));
443 
444     collection::const_iterator iter, end_iter = m_event_map.end();
445     iter = find_if (m_event_map.begin(), end_iter, BroadcastEventSpecMatches (event_spec));
446     if (iter != end_iter)
447         return (*iter).second;
448     else
449         return NULL;
450 }
451 
452 void
RemoveListener(Listener & listener)453 BroadcasterManager::RemoveListener (Listener &listener)
454 {
455     Mutex::Locker locker(m_manager_mutex);
456     ListenerMatches predicate (listener);
457 
458 
459     if (m_listeners.erase (&listener) == 0)
460         return;
461 
462     while (1)
463     {
464         collection::iterator iter, end_iter = m_event_map.end();
465         iter = find_if (m_event_map.begin(), end_iter, predicate);
466         if (iter == end_iter)
467             break;
468         else
469             m_event_map.erase(iter);
470     }
471 }
472 
473 void
SignUpListenersForBroadcaster(Broadcaster & broadcaster)474 BroadcasterManager::SignUpListenersForBroadcaster (Broadcaster &broadcaster)
475 {
476     Mutex::Locker locker(m_manager_mutex);
477 
478     collection::iterator iter = m_event_map.begin(), end_iter = m_event_map.end();
479 
480     while (iter != end_iter
481            && (iter = find_if (iter, end_iter, BroadcasterClassMatches(broadcaster.GetBroadcasterClass()))) != end_iter)
482     {
483         (*iter).second->StartListeningForEvents (&broadcaster, (*iter).first.GetEventBits());
484         iter++;
485     }
486 }
487 
488 void
Clear()489 BroadcasterManager::Clear ()
490 {
491     Mutex::Locker locker(m_manager_mutex);
492     listener_collection::iterator end_iter = m_listeners.end();
493 
494     for (listener_collection::iterator iter = m_listeners.begin(); iter != end_iter; iter++)
495         (*iter)->BroadcasterManagerWillDestruct(this);
496     m_listeners.clear();
497     m_event_map.clear();
498 
499 }
500