1 //===-- Broadcaster.cpp ---------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "lldb/Utility/Broadcaster.h" 10 #include "lldb/Utility/Event.h" 11 #include "lldb/Utility/LLDBLog.h" 12 #include "lldb/Utility/Listener.h" 13 #include "lldb/Utility/Stream.h" 14 #include "lldb/Utility/StreamString.h" 15 16 #include <algorithm> 17 #include <memory> 18 #include <utility> 19 20 #include <cassert> 21 #include <cstddef> 22 23 using namespace lldb; 24 using namespace lldb_private; 25 26 Broadcaster::Broadcaster(BroadcasterManagerSP manager_sp, const char *name) 27 : m_broadcaster_sp(std::make_shared<BroadcasterImpl>(*this)), 28 m_manager_sp(std::move(manager_sp)), m_broadcaster_name(name) { 29 Log *log = GetLog(LLDBLog::Object); 30 LLDB_LOG(log, "{0} Broadcaster::Broadcaster(\"{1}\")", 31 static_cast<void *>(this), GetBroadcasterName()); 32 } 33 34 Broadcaster::BroadcasterImpl::BroadcasterImpl(Broadcaster &broadcaster) 35 : m_broadcaster(broadcaster), m_listeners(), m_listeners_mutex(), 36 m_hijacking_listeners(), m_hijacking_masks() {} 37 38 Broadcaster::~Broadcaster() { 39 Log *log = GetLog(LLDBLog::Object); 40 LLDB_LOG(log, "{0} Broadcaster::~Broadcaster(\"{1}\")", 41 static_cast<void *>(this), GetBroadcasterName()); 42 43 Clear(); 44 } 45 46 void Broadcaster::CheckInWithManager() { 47 if (m_manager_sp) { 48 m_manager_sp->SignUpListenersForBroadcaster(*this); 49 } 50 } 51 52 llvm::SmallVector<std::pair<ListenerSP, uint32_t &>, 4> 53 Broadcaster::BroadcasterImpl::GetListeners() { 54 llvm::SmallVector<std::pair<ListenerSP, uint32_t &>, 4> listeners; 55 listeners.reserve(m_listeners.size()); 56 57 for (auto it = m_listeners.begin(); it != m_listeners.end();) { 58 lldb::ListenerSP curr_listener_sp(it->first.lock()); 59 if (curr_listener_sp && it->second) { 60 listeners.emplace_back(std::move(curr_listener_sp), it->second); 61 ++it; 62 } else 63 it = m_listeners.erase(it); 64 } 65 66 return listeners; 67 } 68 69 void Broadcaster::BroadcasterImpl::Clear() { 70 std::lock_guard<std::recursive_mutex> guard(m_listeners_mutex); 71 72 // Make sure the listener forgets about this broadcaster. We do this in the 73 // broadcaster in case the broadcaster object initiates the removal. 74 for (auto &pair : GetListeners()) 75 pair.first->BroadcasterWillDestruct(&m_broadcaster); 76 77 m_listeners.clear(); 78 } 79 80 Broadcaster *Broadcaster::BroadcasterImpl::GetBroadcaster() { 81 return &m_broadcaster; 82 } 83 84 bool Broadcaster::BroadcasterImpl::GetEventNames( 85 Stream &s, uint32_t event_mask, bool prefix_with_broadcaster_name) const { 86 uint32_t num_names_added = 0; 87 if (event_mask && !m_event_names.empty()) { 88 event_names_map::const_iterator end = m_event_names.end(); 89 for (uint32_t bit = 1u, mask = event_mask; mask != 0 && bit != 0; 90 bit <<= 1, mask >>= 1) { 91 if (mask & 1) { 92 event_names_map::const_iterator pos = m_event_names.find(bit); 93 if (pos != end) { 94 if (num_names_added > 0) 95 s.PutCString(", "); 96 97 if (prefix_with_broadcaster_name) { 98 s.PutCString(GetBroadcasterName()); 99 s.PutChar('.'); 100 } 101 s.PutCString(pos->second); 102 ++num_names_added; 103 } 104 } 105 } 106 } 107 return num_names_added > 0; 108 } 109 110 void Broadcaster::AddInitialEventsToListener( 111 const lldb::ListenerSP &listener_sp, uint32_t requested_events) {} 112 113 uint32_t 114 Broadcaster::BroadcasterImpl::AddListener(const lldb::ListenerSP &listener_sp, 115 uint32_t event_mask) { 116 if (!listener_sp) 117 return 0; 118 119 std::lock_guard<std::recursive_mutex> guard(m_listeners_mutex); 120 121 // See if we already have this listener, and if so, update its mask 122 123 bool handled = false; 124 125 for (auto &pair : GetListeners()) { 126 if (pair.first == listener_sp) { 127 handled = true; 128 pair.second |= event_mask; 129 m_broadcaster.AddInitialEventsToListener(listener_sp, event_mask); 130 break; 131 } 132 } 133 134 if (!handled) { 135 // Grant a new listener the available event bits 136 m_listeners.push_back( 137 std::make_pair(lldb::ListenerWP(listener_sp), event_mask)); 138 139 // Individual broadcasters decide whether they have outstanding data when a 140 // listener attaches, and insert it into the listener with this method. 141 m_broadcaster.AddInitialEventsToListener(listener_sp, event_mask); 142 } 143 144 // Return the event bits that were granted to the listener 145 return event_mask; 146 } 147 148 bool Broadcaster::BroadcasterImpl::EventTypeHasListeners(uint32_t event_type) { 149 std::lock_guard<std::recursive_mutex> guard(m_listeners_mutex); 150 151 if (!m_hijacking_listeners.empty() && event_type & m_hijacking_masks.back()) 152 return true; 153 154 for (auto &pair : GetListeners()) { 155 if (pair.second & event_type) 156 return true; 157 } 158 return false; 159 } 160 161 bool Broadcaster::BroadcasterImpl::RemoveListener( 162 lldb_private::Listener *listener, uint32_t event_mask) { 163 if (!listener) 164 return false; 165 166 std::lock_guard<std::recursive_mutex> guard(m_listeners_mutex); 167 for (auto &pair : GetListeners()) { 168 if (pair.first.get() == listener) { 169 pair.second &= ~event_mask; 170 return true; 171 } 172 } 173 return false; 174 } 175 176 bool Broadcaster::BroadcasterImpl::RemoveListener( 177 const lldb::ListenerSP &listener_sp, uint32_t event_mask) { 178 return RemoveListener(listener_sp.get(), event_mask); 179 } 180 181 void Broadcaster::BroadcasterImpl::BroadcastEvent(EventSP &event_sp) { 182 return PrivateBroadcastEvent(event_sp, false); 183 } 184 185 void Broadcaster::BroadcasterImpl::BroadcastEventIfUnique(EventSP &event_sp) { 186 return PrivateBroadcastEvent(event_sp, true); 187 } 188 189 void Broadcaster::BroadcasterImpl::PrivateBroadcastEvent(EventSP &event_sp, 190 bool unique) { 191 // Can't add a nullptr event... 192 if (!event_sp) 193 return; 194 195 // Update the broadcaster on this event 196 event_sp->SetBroadcaster(&m_broadcaster); 197 198 const uint32_t event_type = event_sp->GetType(); 199 200 std::lock_guard<std::recursive_mutex> guard(m_listeners_mutex); 201 202 ListenerSP hijacking_listener_sp; 203 204 if (!m_hijacking_listeners.empty()) { 205 assert(!m_hijacking_masks.empty()); 206 hijacking_listener_sp = m_hijacking_listeners.back(); 207 if ((event_type & m_hijacking_masks.back()) == 0) 208 hijacking_listener_sp.reset(); 209 } 210 211 Log *log = GetLog(LLDBLog::Events); 212 if (!log && event_sp->GetData()) 213 log = event_sp->GetData()->GetLogChannel(); 214 215 if (log) { 216 StreamString event_description; 217 event_sp->Dump(&event_description); 218 LLDB_LOGF(log, 219 "%p Broadcaster(\"%s\")::BroadcastEvent (event_sp = {%s}, " 220 "unique =%i) hijack = %p", 221 static_cast<void *>(this), GetBroadcasterName(), 222 event_description.GetData(), unique, 223 static_cast<void *>(hijacking_listener_sp.get())); 224 } 225 226 if (hijacking_listener_sp) { 227 if (unique && hijacking_listener_sp->PeekAtNextEventForBroadcasterWithType( 228 &m_broadcaster, event_type)) 229 return; 230 hijacking_listener_sp->AddEvent(event_sp); 231 } else { 232 for (auto &pair : GetListeners()) { 233 if (!(pair.second & event_type)) 234 continue; 235 if (unique && pair.first->PeekAtNextEventForBroadcasterWithType( 236 &m_broadcaster, event_type)) 237 continue; 238 239 pair.first->AddEvent(event_sp); 240 } 241 } 242 } 243 244 void Broadcaster::BroadcasterImpl::BroadcastEvent(uint32_t event_type, 245 EventData *event_data) { 246 auto event_sp = std::make_shared<Event>(event_type, event_data); 247 PrivateBroadcastEvent(event_sp, false); 248 } 249 250 void Broadcaster::BroadcasterImpl::BroadcastEvent( 251 uint32_t event_type, const lldb::EventDataSP &event_data_sp) { 252 auto event_sp = std::make_shared<Event>(event_type, event_data_sp); 253 PrivateBroadcastEvent(event_sp, false); 254 } 255 256 void Broadcaster::BroadcasterImpl::BroadcastEventIfUnique( 257 uint32_t event_type, EventData *event_data) { 258 auto event_sp = std::make_shared<Event>(event_type, event_data); 259 PrivateBroadcastEvent(event_sp, true); 260 } 261 262 bool Broadcaster::BroadcasterImpl::HijackBroadcaster( 263 const lldb::ListenerSP &listener_sp, uint32_t event_mask) { 264 std::lock_guard<std::recursive_mutex> guard(m_listeners_mutex); 265 266 Log *log = GetLog(LLDBLog::Events); 267 LLDB_LOG( 268 log, 269 "{0} Broadcaster(\"{1}\")::HijackBroadcaster (listener(\"{2}\")={3})", 270 static_cast<void *>(this), GetBroadcasterName(), 271 listener_sp->m_name.c_str(), static_cast<void *>(listener_sp.get())); 272 m_hijacking_listeners.push_back(listener_sp); 273 m_hijacking_masks.push_back(event_mask); 274 return true; 275 } 276 277 bool Broadcaster::BroadcasterImpl::IsHijackedForEvent(uint32_t event_mask) { 278 std::lock_guard<std::recursive_mutex> guard(m_listeners_mutex); 279 280 if (!m_hijacking_listeners.empty()) 281 return (event_mask & m_hijacking_masks.back()) != 0; 282 return false; 283 } 284 285 const char *Broadcaster::BroadcasterImpl::GetHijackingListenerName() { 286 if (m_hijacking_listeners.size()) { 287 return m_hijacking_listeners.back()->GetName(); 288 } 289 return nullptr; 290 } 291 292 void Broadcaster::BroadcasterImpl::RestoreBroadcaster() { 293 std::lock_guard<std::recursive_mutex> guard(m_listeners_mutex); 294 295 if (!m_hijacking_listeners.empty()) { 296 ListenerSP listener_sp = m_hijacking_listeners.back(); 297 Log *log = GetLog(LLDBLog::Events); 298 LLDB_LOG(log, 299 "{0} Broadcaster(\"{1}\")::RestoreBroadcaster (about to pop " 300 "listener(\"{2}\")={3})", 301 static_cast<void *>(this), GetBroadcasterName(), 302 listener_sp->m_name.c_str(), 303 static_cast<void *>(listener_sp.get())); 304 m_hijacking_listeners.pop_back(); 305 } 306 if (!m_hijacking_masks.empty()) 307 m_hijacking_masks.pop_back(); 308 } 309 310 ConstString &Broadcaster::GetBroadcasterClass() const { 311 static ConstString class_name("lldb.anonymous"); 312 return class_name; 313 } 314 315 bool BroadcastEventSpec::operator<(const BroadcastEventSpec &rhs) const { 316 if (GetBroadcasterClass() == rhs.GetBroadcasterClass()) { 317 return GetEventBits() < rhs.GetEventBits(); 318 } 319 return GetBroadcasterClass() < rhs.GetBroadcasterClass(); 320 } 321 322 BroadcasterManager::BroadcasterManager() : m_manager_mutex() {} 323 324 lldb::BroadcasterManagerSP BroadcasterManager::MakeBroadcasterManager() { 325 return lldb::BroadcasterManagerSP(new BroadcasterManager()); 326 } 327 328 uint32_t BroadcasterManager::RegisterListenerForEvents( 329 const lldb::ListenerSP &listener_sp, const BroadcastEventSpec &event_spec) { 330 std::lock_guard<std::recursive_mutex> guard(m_manager_mutex); 331 332 collection::iterator iter = m_event_map.begin(), end_iter = m_event_map.end(); 333 uint32_t available_bits = event_spec.GetEventBits(); 334 335 while (iter != end_iter && 336 (iter = find_if(iter, end_iter, 337 BroadcasterClassMatches( 338 event_spec.GetBroadcasterClass()))) != end_iter) { 339 available_bits &= ~((*iter).first.GetEventBits()); 340 iter++; 341 } 342 343 if (available_bits != 0) { 344 m_event_map.insert(event_listener_key( 345 BroadcastEventSpec(event_spec.GetBroadcasterClass(), available_bits), 346 listener_sp)); 347 m_listeners.insert(listener_sp); 348 } 349 350 return available_bits; 351 } 352 353 bool BroadcasterManager::UnregisterListenerForEvents( 354 const lldb::ListenerSP &listener_sp, const BroadcastEventSpec &event_spec) { 355 std::lock_guard<std::recursive_mutex> guard(m_manager_mutex); 356 bool removed_some = false; 357 358 if (m_listeners.erase(listener_sp) == 0) 359 return false; 360 361 ListenerMatchesAndSharedBits predicate(event_spec, listener_sp); 362 std::vector<BroadcastEventSpec> to_be_readded; 363 uint32_t event_bits_to_remove = event_spec.GetEventBits(); 364 365 // Go through the map and delete the exact matches, and build a list of 366 // matches that weren't exact to re-add: 367 while (true) { 368 collection::iterator iter, end_iter = m_event_map.end(); 369 iter = find_if(m_event_map.begin(), end_iter, predicate); 370 if (iter == end_iter) { 371 break; 372 } 373 uint32_t iter_event_bits = (*iter).first.GetEventBits(); 374 removed_some = true; 375 376 if (event_bits_to_remove != iter_event_bits) { 377 uint32_t new_event_bits = iter_event_bits & ~event_bits_to_remove; 378 to_be_readded.emplace_back(event_spec.GetBroadcasterClass(), 379 new_event_bits); 380 } 381 m_event_map.erase(iter); 382 } 383 384 // Okay now add back the bits that weren't completely removed: 385 for (size_t i = 0; i < to_be_readded.size(); i++) { 386 m_event_map.insert(event_listener_key(to_be_readded[i], listener_sp)); 387 } 388 389 return removed_some; 390 } 391 392 ListenerSP BroadcasterManager::GetListenerForEventSpec( 393 const BroadcastEventSpec &event_spec) const { 394 std::lock_guard<std::recursive_mutex> guard(m_manager_mutex); 395 396 collection::const_iterator iter, end_iter = m_event_map.end(); 397 iter = find_if(m_event_map.begin(), end_iter, 398 BroadcastEventSpecMatches(event_spec)); 399 if (iter != end_iter) 400 return (*iter).second; 401 402 return nullptr; 403 } 404 405 void BroadcasterManager::RemoveListener(Listener *listener) { 406 std::lock_guard<std::recursive_mutex> guard(m_manager_mutex); 407 ListenerMatchesPointer predicate(listener); 408 listener_collection::iterator iter = m_listeners.begin(), 409 end_iter = m_listeners.end(); 410 411 iter = std::find_if(iter, end_iter, predicate); 412 if (iter != end_iter) 413 m_listeners.erase(iter); 414 415 while (true) { 416 collection::iterator iter, end_iter = m_event_map.end(); 417 iter = find_if(m_event_map.begin(), end_iter, predicate); 418 if (iter == end_iter) 419 break; 420 421 m_event_map.erase(iter); 422 } 423 } 424 425 void BroadcasterManager::RemoveListener(const lldb::ListenerSP &listener_sp) { 426 std::lock_guard<std::recursive_mutex> guard(m_manager_mutex); 427 ListenerMatches predicate(listener_sp); 428 429 if (m_listeners.erase(listener_sp) == 0) 430 return; 431 432 while (true) { 433 collection::iterator iter, end_iter = m_event_map.end(); 434 iter = find_if(m_event_map.begin(), end_iter, predicate); 435 if (iter == end_iter) 436 break; 437 438 m_event_map.erase(iter); 439 } 440 } 441 442 void BroadcasterManager::SignUpListenersForBroadcaster( 443 Broadcaster &broadcaster) { 444 std::lock_guard<std::recursive_mutex> guard(m_manager_mutex); 445 446 collection::iterator iter = m_event_map.begin(), end_iter = m_event_map.end(); 447 448 while (iter != end_iter && 449 (iter = find_if(iter, end_iter, 450 BroadcasterClassMatches( 451 broadcaster.GetBroadcasterClass()))) != end_iter) { 452 (*iter).second->StartListeningForEvents(&broadcaster, 453 (*iter).first.GetEventBits()); 454 iter++; 455 } 456 } 457 458 void BroadcasterManager::Clear() { 459 std::lock_guard<std::recursive_mutex> guard(m_manager_mutex); 460 listener_collection::iterator end_iter = m_listeners.end(); 461 462 for (listener_collection::iterator iter = m_listeners.begin(); 463 iter != end_iter; iter++) 464 (*iter)->BroadcasterManagerWillDestruct(this->shared_from_this()); 465 m_listeners.clear(); 466 m_event_map.clear(); 467 } 468