lldb/source/Utility/Listener.cpp - llvm-project - Git at Google

 //===-- Listener.cpp ------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #include "lldb/Utility/Listener.h"

 #include "lldb/Utility/Broadcaster.h"
 #include "lldb/Utility/ConstString.h"
 #include "lldb/Utility/Event.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/Logging.h"

 #include "llvm/ADT/Optional.h"

 #include <algorithm>
 #include <memory>
 #include <utility>

 using namespace lldb;
 using namespace lldb_private;

 namespace {
 class BroadcasterManagerWPMatcher {
 public:
   BroadcasterManagerWPMatcher(BroadcasterManagerSP manager_sp)
       : m_manager_sp(std::move(manager_sp)) {}
   bool operator()(const BroadcasterManagerWP &input_wp) const {
     BroadcasterManagerSP input_sp = input_wp.lock();
     return (input_sp && input_sp == m_manager_sp);
   }

   BroadcasterManagerSP m_manager_sp;
 };
 } // anonymous namespace

 Listener::Listener(const char *name)
     : m_name(name), m_broadcasters(), m_broadcasters_mutex(), m_events(),
       m_events_mutex() {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OBJECT));
   if (log != nullptr)
     LLDB_LOGF(log, "%p Listener::Listener('%s')", static_cast<void *>(this),
               m_name.c_str());
 }

 Listener::~Listener() {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OBJECT));

   Clear();

   LLDB_LOGF(log, "%p Listener::%s('%s')", static_cast<void *>(this),
             __FUNCTION__, m_name.c_str());
 }

 void Listener::Clear() {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OBJECT));
   std::lock_guard<std::recursive_mutex> broadcasters_guard(
       m_broadcasters_mutex);
   broadcaster_collection::iterator pos, end = m_broadcasters.end();
   for (pos = m_broadcasters.begin(); pos != end; ++pos) {
     Broadcaster::BroadcasterImplSP broadcaster_sp(pos->first.lock());
     if (broadcaster_sp)
       broadcaster_sp->RemoveListener(this, pos->second.event_mask);
   }
   m_broadcasters.clear();

   std::lock_guard<std::mutex> events_guard(m_events_mutex);
   m_events.clear();
   size_t num_managers = m_broadcaster_managers.size();

   for (size_t i = 0; i < num_managers; i++) {
     BroadcasterManagerSP manager_sp(m_broadcaster_managers[i].lock());
     if (manager_sp)
       manager_sp->RemoveListener(this);
   }

   LLDB_LOGF(log, "%p Listener::%s('%s')", static_cast<void *>(this),
             __FUNCTION__, m_name.c_str());
 }

 uint32_t Listener::StartListeningForEvents(Broadcaster *broadcaster,
                                            uint32_t event_mask) {
   if (broadcaster) {
     // Scope for "locker"
     // Tell the broadcaster to add this object as a listener
     {
       std::lock_guard<std::recursive_mutex> broadcasters_guard(
           m_broadcasters_mutex);
       Broadcaster::BroadcasterImplWP impl_wp(broadcaster->GetBroadcasterImpl());
       m_broadcasters.insert(
           std::make_pair(impl_wp, BroadcasterInfo(event_mask)));
     }

     uint32_t acquired_mask =
         broadcaster->AddListener(this->shared_from_this(), event_mask);

     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS));
     if (log != nullptr)
       LLDB_LOGF(log,
                 "%p Listener::StartListeningForEvents (broadcaster = %p, "
                 "mask = 0x%8.8x) acquired_mask = 0x%8.8x for %s",
                 static_cast<void *>(this), static_cast<void *>(broadcaster),
                 event_mask, acquired_mask, m_name.c_str());

     return acquired_mask;
   }
   return 0;
 }

 uint32_t Listener::StartListeningForEvents(Broadcaster *broadcaster,
                                            uint32_t event_mask,
                                            HandleBroadcastCallback callback,
                                            void *callback_user_data) {
   if (broadcaster) {
     // Scope for "locker"
     // Tell the broadcaster to add this object as a listener
     {
       std::lock_guard<std::recursive_mutex> broadcasters_guard(
           m_broadcasters_mutex);
       Broadcaster::BroadcasterImplWP impl_wp(broadcaster->GetBroadcasterImpl());
       m_broadcasters.insert(std::make_pair(
           impl_wp, BroadcasterInfo(event_mask, callback, callback_user_data)));
     }

     uint32_t acquired_mask =
         broadcaster->AddListener(this->shared_from_this(), event_mask);

     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS));
     if (log != nullptr) {
       void **pointer = reinterpret_cast<void **>(&callback);
       LLDB_LOGF(log,
                 "%p Listener::StartListeningForEvents (broadcaster = %p, "
                 "mask = 0x%8.8x, callback = %p, user_data = %p) "
                 "acquired_mask = 0x%8.8x for %s",
                 static_cast<void *>(this), static_cast<void *>(broadcaster),
                 event_mask, *pointer, static_cast<void *>(callback_user_data),
                 acquired_mask, m_name.c_str());
     }

     return acquired_mask;
   }
   return 0;
 }

 bool Listener::StopListeningForEvents(Broadcaster *broadcaster,
                                       uint32_t event_mask) {
   if (broadcaster) {
     // Scope for "locker"
     {
       std::lock_guard<std::recursive_mutex> broadcasters_guard(
           m_broadcasters_mutex);
       m_broadcasters.erase(broadcaster->GetBroadcasterImpl());
     }
     // Remove the broadcaster from our set of broadcasters
     return broadcaster->RemoveListener(this->shared_from_this(), event_mask);
   }

   return false;
 }

 // Called when a Broadcaster is in its destructor. We need to remove all
 // knowledge of this broadcaster and any events that it may have queued up
 void Listener::BroadcasterWillDestruct(Broadcaster *broadcaster) {
   // Scope for "broadcasters_locker"
   {
     std::lock_guard<std::recursive_mutex> broadcasters_guard(
         m_broadcasters_mutex);
     m_broadcasters.erase(broadcaster->GetBroadcasterImpl());
   }

   // Scope for "event_locker"
   {
     std::lock_guard<std::mutex> events_guard(m_events_mutex);
     // Remove all events for this broadcaster object.
     event_collection::iterator pos = m_events.begin();
     while (pos != m_events.end()) {
       if ((*pos)->GetBroadcaster() == broadcaster)
         pos = m_events.erase(pos);
       else
         ++pos;
     }
   }
 }

 void Listener::BroadcasterManagerWillDestruct(BroadcasterManagerSP manager_sp) {
   // Just need to remove this broadcast manager from the list of managers:
   broadcaster_manager_collection::iterator iter,
       end_iter = m_broadcaster_managers.end();
   BroadcasterManagerWP manager_wp;

   BroadcasterManagerWPMatcher matcher(std::move(manager_sp));
   iter = std::find_if<broadcaster_manager_collection::iterator,
                       BroadcasterManagerWPMatcher>(
       m_broadcaster_managers.begin(), end_iter, matcher);
   if (iter != end_iter)
     m_broadcaster_managers.erase(iter);
 }

 void Listener::AddEvent(EventSP &event_sp) {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS));
   if (log != nullptr)
     LLDB_LOGF(log, "%p Listener('%s')::AddEvent (event_sp = {%p})",
               static_cast<void *>(this), m_name.c_str(),
               static_cast<void *>(event_sp.get()));

   std::lock_guard<std::mutex> guard(m_events_mutex);
   m_events.push_back(event_sp);
   m_events_condition.notify_all();
 }

 class EventBroadcasterMatches {
 public:
   EventBroadcasterMatches(Broadcaster *broadcaster)
       : m_broadcaster(broadcaster) {}

   bool operator()(const EventSP &event_sp) const {
     return event_sp->BroadcasterIs(m_broadcaster);
   }

 private:
   Broadcaster *m_broadcaster;
 };

 class EventMatcher {
 public:
   EventMatcher(Broadcaster *broadcaster, const ConstString *broadcaster_names,
                uint32_t num_broadcaster_names, uint32_t event_type_mask)
       : m_broadcaster(broadcaster), m_broadcaster_names(broadcaster_names),
         m_num_broadcaster_names(num_broadcaster_names),
         m_event_type_mask(event_type_mask) {}

   bool operator()(const EventSP &event_sp) const {
     if (m_broadcaster && !event_sp->BroadcasterIs(m_broadcaster))
       return false;

     if (m_broadcaster_names) {
       bool found_source = false;
       ConstString event_broadcaster_name =
           event_sp->GetBroadcaster()->GetBroadcasterName();
       for (uint32_t i = 0; i < m_num_broadcaster_names; ++i) {
         if (m_broadcaster_names[i] == event_broadcaster_name) {
           found_source = true;
           break;
         }
       }
       if (!found_source)
         return false;
     }

     return m_event_type_mask == 0 || m_event_type_mask & event_sp->GetType();
   }

 private:
   Broadcaster *m_broadcaster;
   const ConstString *m_broadcaster_names;
   const uint32_t m_num_broadcaster_names;
   const uint32_t m_event_type_mask;
 };

 bool Listener::FindNextEventInternal(
     std::unique_lock<std::mutex> &lock,
     Broadcaster *broadcaster,             // nullptr for any broadcaster
     const ConstString *broadcaster_names, // nullptr for any event
     uint32_t num_broadcaster_names, uint32_t event_type_mask, EventSP &event_sp,
     bool remove) {
   // NOTE: callers of this function must lock m_events_mutex using a
   // Mutex::Locker
   // and pass the locker as the first argument. m_events_mutex is no longer
   // recursive.
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS));

   if (m_events.empty())
     return false;

   Listener::event_collection::iterator pos = m_events.end();

   if (broadcaster == nullptr && broadcaster_names == nullptr &&
       event_type_mask == 0) {
     pos = m_events.begin();
   } else {
     pos = std::find_if(m_events.begin(), m_events.end(),
                        EventMatcher(broadcaster, broadcaster_names,
                                     num_broadcaster_names, event_type_mask));
   }

   if (pos != m_events.end()) {
     event_sp = *pos;

     if (log != nullptr)
       LLDB_LOGF(log,
                 "%p '%s' Listener::FindNextEventInternal(broadcaster=%p, "
                 "broadcaster_names=%p[%u], event_type_mask=0x%8.8x, "
                 "remove=%i) event %p",
                 static_cast<void *>(this), GetName(),
                 static_cast<void *>(broadcaster),
                 static_cast<const void *>(broadcaster_names),
                 num_broadcaster_names, event_type_mask, remove,
                 static_cast<void *>(event_sp.get()));

     if (remove) {
       m_events.erase(pos);
       // Unlock the event queue here.  We've removed this event and are about
       // to return it so it should be okay to get the next event off the queue
       // here - and it might be useful to do that in the "DoOnRemoval".
       lock.unlock();
       event_sp->DoOnRemoval();
     }
     return true;
   }

   event_sp.reset();
   return false;
 }

 Event *Listener::PeekAtNextEvent() {
   std::unique_lock<std::mutex> guard(m_events_mutex);
   EventSP event_sp;
   if (FindNextEventInternal(guard, nullptr, nullptr, 0, 0, event_sp, false))
     return event_sp.get();
   return nullptr;
 }

 Event *Listener::PeekAtNextEventForBroadcaster(Broadcaster *broadcaster) {
   std::unique_lock<std::mutex> guard(m_events_mutex);
   EventSP event_sp;
   if (FindNextEventInternal(guard, broadcaster, nullptr, 0, 0, event_sp, false))
     return event_sp.get();
   return nullptr;
 }

 Event *
 Listener::PeekAtNextEventForBroadcasterWithType(Broadcaster *broadcaster,
                                                 uint32_t event_type_mask) {
   std::unique_lock<std::mutex> guard(m_events_mutex);
   EventSP event_sp;
   if (FindNextEventInternal(guard, broadcaster, nullptr, 0, event_type_mask,
                             event_sp, false))
     return event_sp.get();
   return nullptr;
 }

 bool Listener::GetEventInternal(
     const Timeout<std::micro> &timeout,
     Broadcaster *broadcaster,             // nullptr for any broadcaster
     const ConstString *broadcaster_names, // nullptr for any event
     uint32_t num_broadcaster_names, uint32_t event_type_mask,
     EventSP &event_sp) {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS));
   LLDB_LOG(log, "this = {0}, timeout = {1} for {2}", this, timeout, m_name);

   std::unique_lock<std::mutex> lock(m_events_mutex);

   while (true) {
     if (FindNextEventInternal(lock, broadcaster, broadcaster_names,
                               num_broadcaster_names, event_type_mask, event_sp,
                               true)) {
       return true;
     } else {
       std::cv_status result = std::cv_status::no_timeout;
       if (!timeout)
         m_events_condition.wait(lock);
       else
         result = m_events_condition.wait_for(lock, *timeout);

       if (result == std::cv_status::timeout) {
         log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS);
         LLDB_LOGF(log, "%p Listener::GetEventInternal() timed out for %s",
                   static_cast<void *>(this), m_name.c_str());
         return false;
       } else if (result != std::cv_status::no_timeout) {
         log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS);
         LLDB_LOGF(log, "%p Listener::GetEventInternal() unknown error for %s",
                   static_cast<void *>(this), m_name.c_str());
         return false;
       }
     }
   }

   return false;
 }

 bool Listener::GetEventForBroadcasterWithType(
     Broadcaster *broadcaster, uint32_t event_type_mask, EventSP &event_sp,
     const Timeout<std::micro> &timeout) {
   return GetEventInternal(timeout, broadcaster, nullptr, 0, event_type_mask,
                           event_sp);
 }

 bool Listener::GetEventForBroadcaster(Broadcaster *broadcaster,
                                       EventSP &event_sp,
                                       const Timeout<std::micro> &timeout) {
   return GetEventInternal(timeout, broadcaster, nullptr, 0, 0, event_sp);
 }

 bool Listener::GetEvent(EventSP &event_sp, const Timeout<std::micro> &timeout) {
   return GetEventInternal(timeout, nullptr, nullptr, 0, 0, event_sp);
 }

 size_t Listener::HandleBroadcastEvent(EventSP &event_sp) {
   size_t num_handled = 0;
   std::lock_guard<std::recursive_mutex> guard(m_broadcasters_mutex);
   Broadcaster *broadcaster = event_sp->GetBroadcaster();
   if (!broadcaster)
     return 0;
   broadcaster_collection::iterator pos;
   broadcaster_collection::iterator end = m_broadcasters.end();
   Broadcaster::BroadcasterImplSP broadcaster_impl_sp(
       broadcaster->GetBroadcasterImpl());
   for (pos = m_broadcasters.find(broadcaster_impl_sp);
        pos != end && pos->first.lock() == broadcaster_impl_sp; ++pos) {
     BroadcasterInfo info = pos->second;
     if (event_sp->GetType() & info.event_mask) {
       if (info.callback != nullptr) {
         info.callback(event_sp, info.callback_user_data);
         ++num_handled;
       }
     }
   }
   return num_handled;
 }

 uint32_t
 Listener::StartListeningForEventSpec(const BroadcasterManagerSP &manager_sp,
                                      const BroadcastEventSpec &event_spec) {
   if (!manager_sp)
     return 0;

   // The BroadcasterManager mutex must be locked before m_broadcasters_mutex to
   // avoid violating the lock hierarchy (manager before broadcasters).
   std::lock_guard<std::recursive_mutex> manager_guard(
       manager_sp->m_manager_mutex);
   std::lock_guard<std::recursive_mutex> guard(m_broadcasters_mutex);

   uint32_t bits_acquired = manager_sp->RegisterListenerForEvents(
       this->shared_from_this(), event_spec);
   if (bits_acquired) {
     broadcaster_manager_collection::iterator iter,
         end_iter = m_broadcaster_managers.end();
     BroadcasterManagerWP manager_wp(manager_sp);
     BroadcasterManagerWPMatcher matcher(manager_sp);
     iter = std::find_if<broadcaster_manager_collection::iterator,
                         BroadcasterManagerWPMatcher>(
         m_broadcaster_managers.begin(), end_iter, matcher);
     if (iter == end_iter)
       m_broadcaster_managers.push_back(manager_wp);
   }

   return bits_acquired;
 }

 bool Listener::StopListeningForEventSpec(const BroadcasterManagerSP &manager_sp,
                                          const BroadcastEventSpec &event_spec) {
   if (!manager_sp)
     return false;

   std::lock_guard<std::recursive_mutex> guard(m_broadcasters_mutex);
   return manager_sp->UnregisterListenerForEvents(this->shared_from_this(),
                                                  event_spec);
 }

 ListenerSP Listener::MakeListener(const char *name) {
   return ListenerSP(new Listener(name));
 }
	//===-- Listener.cpp ------------------------------------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#include "lldb/Utility/Listener.h"

	#include "lldb/Utility/Broadcaster.h"
	#include "lldb/Utility/ConstString.h"
	#include "lldb/Utility/Event.h"
	#include "lldb/Utility/Log.h"
	#include "lldb/Utility/Logging.h"

	#include "llvm/ADT/Optional.h"

	#include <algorithm>
	#include <memory>
	#include <utility>

	using namespace lldb;
	using namespace lldb_private;

	namespace {
	class BroadcasterManagerWPMatcher {
	public:
	BroadcasterManagerWPMatcher(BroadcasterManagerSP manager_sp)
	: m_manager_sp(std::move(manager_sp)) {}
	bool operator()(const BroadcasterManagerWP &input_wp) const {
	BroadcasterManagerSP input_sp = input_wp.lock();
	return (input_sp && input_sp == m_manager_sp);
	}

	BroadcasterManagerSP m_manager_sp;
	};
	} // anonymous namespace

	Listener::Listener(const char *name)
	: m_name(name), m_broadcasters(), m_broadcasters_mutex(), m_events(),
	m_events_mutex() {
	Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OBJECT));
	if (log != nullptr)
	LLDB_LOGF(log, "%p Listener::Listener('%s')", static_cast<void *>(this),
	m_name.c_str());
	}

	Listener::~Listener() {
	Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OBJECT));

	Clear();

	LLDB_LOGF(log, "%p Listener::%s('%s')", static_cast<void *>(this),
	__FUNCTION__, m_name.c_str());
	}

	void Listener::Clear() {
	Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OBJECT));
	std::lock_guard<std::recursive_mutex> broadcasters_guard(
	m_broadcasters_mutex);
	broadcaster_collection::iterator pos, end = m_broadcasters.end();
	for (pos = m_broadcasters.begin(); pos != end; ++pos) {
	Broadcaster::BroadcasterImplSP broadcaster_sp(pos->first.lock());
	if (broadcaster_sp)
	broadcaster_sp->RemoveListener(this, pos->second.event_mask);
	}
	m_broadcasters.clear();

	std::lock_guard<std::mutex> events_guard(m_events_mutex);
	m_events.clear();
	size_t num_managers = m_broadcaster_managers.size();

	for (size_t i = 0; i < num_managers; i++) {
	BroadcasterManagerSP manager_sp(m_broadcaster_managers[i].lock());
	if (manager_sp)
	manager_sp->RemoveListener(this);
	}

	LLDB_LOGF(log, "%p Listener::%s('%s')", static_cast<void *>(this),
	__FUNCTION__, m_name.c_str());
	}

	uint32_t Listener::StartListeningForEvents(Broadcaster *broadcaster,
	uint32_t event_mask) {
	if (broadcaster) {
	// Scope for "locker"
	// Tell the broadcaster to add this object as a listener
	{
	std::lock_guard<std::recursive_mutex> broadcasters_guard(
	m_broadcasters_mutex);
	Broadcaster::BroadcasterImplWP impl_wp(broadcaster->GetBroadcasterImpl());
	m_broadcasters.insert(
	std::make_pair(impl_wp, BroadcasterInfo(event_mask)));
	}

	uint32_t acquired_mask =
	broadcaster->AddListener(this->shared_from_this(), event_mask);

	Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS));
	if (log != nullptr)
	LLDB_LOGF(log,
	"%p Listener::StartListeningForEvents (broadcaster = %p, "
	"mask = 0x%8.8x) acquired_mask = 0x%8.8x for %s",
	static_cast<void >(this), static_cast<void >(broadcaster),
	event_mask, acquired_mask, m_name.c_str());

	return acquired_mask;
	}
	return 0;
	}

	uint32_t Listener::StartListeningForEvents(Broadcaster *broadcaster,
	uint32_t event_mask,
	HandleBroadcastCallback callback,
	void *callback_user_data) {
	if (broadcaster) {
	// Scope for "locker"
	// Tell the broadcaster to add this object as a listener
	{
	std::lock_guard<std::recursive_mutex> broadcasters_guard(
	m_broadcasters_mutex);
	Broadcaster::BroadcasterImplWP impl_wp(broadcaster->GetBroadcasterImpl());
	m_broadcasters.insert(std::make_pair(
	impl_wp, BroadcasterInfo(event_mask, callback, callback_user_data)));
	}

	uint32_t acquired_mask =
	broadcaster->AddListener(this->shared_from_this(), event_mask);

	Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS));
	if (log != nullptr) {
	void pointer = reinterpret_cast<void >(&callback);
	LLDB_LOGF(log,
	"%p Listener::StartListeningForEvents (broadcaster = %p, "
	"mask = 0x%8.8x, callback = %p, user_data = %p) "
	"acquired_mask = 0x%8.8x for %s",
	static_cast<void >(this), static_cast<void >(broadcaster),
	event_mask, pointer, static_cast<void >(callback_user_data),
	acquired_mask, m_name.c_str());
	}

	return acquired_mask;
	}
	return 0;
	}

	bool Listener::StopListeningForEvents(Broadcaster *broadcaster,
	uint32_t event_mask) {
	if (broadcaster) {
	// Scope for "locker"
	{
	std::lock_guard<std::recursive_mutex> broadcasters_guard(
	m_broadcasters_mutex);
	m_broadcasters.erase(broadcaster->GetBroadcasterImpl());
	}
	// Remove the broadcaster from our set of broadcasters
	return broadcaster->RemoveListener(this->shared_from_this(), event_mask);
	}

	return false;
	}

	// Called when a Broadcaster is in its destructor. We need to remove all
	// knowledge of this broadcaster and any events that it may have queued up
	void Listener::BroadcasterWillDestruct(Broadcaster *broadcaster) {
	// Scope for "broadcasters_locker"
	{
	std::lock_guard<std::recursive_mutex> broadcasters_guard(
	m_broadcasters_mutex);
	m_broadcasters.erase(broadcaster->GetBroadcasterImpl());
	}

	// Scope for "event_locker"
	{
	std::lock_guard<std::mutex> events_guard(m_events_mutex);
	// Remove all events for this broadcaster object.
	event_collection::iterator pos = m_events.begin();
	while (pos != m_events.end()) {
	if ((*pos)->GetBroadcaster() == broadcaster)
	pos = m_events.erase(pos);
	else
	++pos;
	}
	}
	}

	void Listener::BroadcasterManagerWillDestruct(BroadcasterManagerSP manager_sp) {
	// Just need to remove this broadcast manager from the list of managers:
	broadcaster_manager_collection::iterator iter,
	end_iter = m_broadcaster_managers.end();
	BroadcasterManagerWP manager_wp;

	BroadcasterManagerWPMatcher matcher(std::move(manager_sp));
	iter = std::find_if<broadcaster_manager_collection::iterator,
	BroadcasterManagerWPMatcher>(
	m_broadcaster_managers.begin(), end_iter, matcher);
	if (iter != end_iter)
	m_broadcaster_managers.erase(iter);
	}

	void Listener::AddEvent(EventSP &event_sp) {
	Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS));
	if (log != nullptr)
	LLDB_LOGF(log, "%p Listener('%s')::AddEvent (event_sp = {%p})",
	static_cast<void *>(this), m_name.c_str(),
	static_cast<void *>(event_sp.get()));

	std::lock_guard<std::mutex> guard(m_events_mutex);
	m_events.push_back(event_sp);
	m_events_condition.notify_all();
	}

	class EventBroadcasterMatches {
	public:
	EventBroadcasterMatches(Broadcaster *broadcaster)
	: m_broadcaster(broadcaster) {}

	bool operator()(const EventSP &event_sp) const {
	return event_sp->BroadcasterIs(m_broadcaster);
	}

	private:
	Broadcaster *m_broadcaster;
	};

	class EventMatcher {
	public:
	EventMatcher(Broadcaster broadcaster, const ConstString broadcaster_names,
	uint32_t num_broadcaster_names, uint32_t event_type_mask)
	: m_broadcaster(broadcaster), m_broadcaster_names(broadcaster_names),
	m_num_broadcaster_names(num_broadcaster_names),
	m_event_type_mask(event_type_mask) {}

	bool operator()(const EventSP &event_sp) const {
	if (m_broadcaster && !event_sp->BroadcasterIs(m_broadcaster))
	return false;

	if (m_broadcaster_names) {
	bool found_source = false;
	ConstString event_broadcaster_name =
	event_sp->GetBroadcaster()->GetBroadcasterName();
	for (uint32_t i = 0; i < m_num_broadcaster_names; ++i) {
	if (m_broadcaster_names[i] == event_broadcaster_name) {
	found_source = true;
	break;
	}
	}
	if (!found_source)
	return false;
	}

	return m_event_type_mask == 0 \|\| m_event_type_mask & event_sp->GetType();
	}

	private:
	Broadcaster *m_broadcaster;
	const ConstString *m_broadcaster_names;
	const uint32_t m_num_broadcaster_names;
	const uint32_t m_event_type_mask;
	};

	bool Listener::FindNextEventInternal(
	std::unique_lock<std::mutex> &lock,
	Broadcaster *broadcaster, // nullptr for any broadcaster
	const ConstString *broadcaster_names, // nullptr for any event
	uint32_t num_broadcaster_names, uint32_t event_type_mask, EventSP &event_sp,
	bool remove) {
	// NOTE: callers of this function must lock m_events_mutex using a
	// Mutex::Locker
	// and pass the locker as the first argument. m_events_mutex is no longer
	// recursive.
	Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS));

	if (m_events.empty())
	return false;

	Listener::event_collection::iterator pos = m_events.end();

	if (broadcaster == nullptr && broadcaster_names == nullptr &&
	event_type_mask == 0) {
	pos = m_events.begin();
	} else {
	pos = std::find_if(m_events.begin(), m_events.end(),
	EventMatcher(broadcaster, broadcaster_names,
	num_broadcaster_names, event_type_mask));
	}

	if (pos != m_events.end()) {
	event_sp = *pos;

	if (log != nullptr)
	LLDB_LOGF(log,
	"%p '%s' Listener::FindNextEventInternal(broadcaster=%p, "
	"broadcaster_names=%p[%u], event_type_mask=0x%8.8x, "
	"remove=%i) event %p",
	static_cast<void *>(this), GetName(),
	static_cast<void *>(broadcaster),
	static_cast<const void *>(broadcaster_names),
	num_broadcaster_names, event_type_mask, remove,
	static_cast<void *>(event_sp.get()));

	if (remove) {
	m_events.erase(pos);
	// Unlock the event queue here. We've removed this event and are about
	// to return it so it should be okay to get the next event off the queue
	// here - and it might be useful to do that in the "DoOnRemoval".
	lock.unlock();
	event_sp->DoOnRemoval();
	}
	return true;
	}

	event_sp.reset();
	return false;
	}

	Event *Listener::PeekAtNextEvent() {
	std::unique_lock<std::mutex> guard(m_events_mutex);
	EventSP event_sp;
	if (FindNextEventInternal(guard, nullptr, nullptr, 0, 0, event_sp, false))
	return event_sp.get();
	return nullptr;
	}

	Event Listener::PeekAtNextEventForBroadcaster(Broadcaster broadcaster) {
	std::unique_lock<std::mutex> guard(m_events_mutex);
	EventSP event_sp;
	if (FindNextEventInternal(guard, broadcaster, nullptr, 0, 0, event_sp, false))
	return event_sp.get();
	return nullptr;
	}

	Event *
	Listener::PeekAtNextEventForBroadcasterWithType(Broadcaster *broadcaster,
	uint32_t event_type_mask) {
	std::unique_lock<std::mutex> guard(m_events_mutex);
	EventSP event_sp;
	if (FindNextEventInternal(guard, broadcaster, nullptr, 0, event_type_mask,
	event_sp, false))
	return event_sp.get();
	return nullptr;
	}

	bool Listener::GetEventInternal(
	const Timeout<std::micro> &timeout,
	Broadcaster *broadcaster, // nullptr for any broadcaster
	const ConstString *broadcaster_names, // nullptr for any event
	uint32_t num_broadcaster_names, uint32_t event_type_mask,
	EventSP &event_sp) {
	Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS));
	LLDB_LOG(log, "this = {0}, timeout = {1} for {2}", this, timeout, m_name);

	std::unique_lock<std::mutex> lock(m_events_mutex);

	while (true) {
	if (FindNextEventInternal(lock, broadcaster, broadcaster_names,
	num_broadcaster_names, event_type_mask, event_sp,
	true)) {
	return true;
	} else {
	std::cv_status result = std::cv_status::no_timeout;
	if (!timeout)
	m_events_condition.wait(lock);
	else
	result = m_events_condition.wait_for(lock, *timeout);

	if (result == std::cv_status::timeout) {
	log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS);
	LLDB_LOGF(log, "%p Listener::GetEventInternal() timed out for %s",
	static_cast<void *>(this), m_name.c_str());
	return false;
	} else if (result != std::cv_status::no_timeout) {
	log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EVENTS);
	LLDB_LOGF(log, "%p Listener::GetEventInternal() unknown error for %s",
	static_cast<void *>(this), m_name.c_str());
	return false;
	}
	}
	}

	return false;
	}

	bool Listener::GetEventForBroadcasterWithType(
	Broadcaster *broadcaster, uint32_t event_type_mask, EventSP &event_sp,
	const Timeout<std::micro> &timeout) {
	return GetEventInternal(timeout, broadcaster, nullptr, 0, event_type_mask,
	event_sp);
	}

	bool Listener::GetEventForBroadcaster(Broadcaster *broadcaster,
	EventSP &event_sp,
	const Timeout<std::micro> &timeout) {
	return GetEventInternal(timeout, broadcaster, nullptr, 0, 0, event_sp);
	}

	bool Listener::GetEvent(EventSP &event_sp, const Timeout<std::micro> &timeout) {
	return GetEventInternal(timeout, nullptr, nullptr, 0, 0, event_sp);
	}

	size_t Listener::HandleBroadcastEvent(EventSP &event_sp) {
	size_t num_handled = 0;
	std::lock_guard<std::recursive_mutex> guard(m_broadcasters_mutex);
	Broadcaster *broadcaster = event_sp->GetBroadcaster();
	if (!broadcaster)
	return 0;
	broadcaster_collection::iterator pos;
	broadcaster_collection::iterator end = m_broadcasters.end();
	Broadcaster::BroadcasterImplSP broadcaster_impl_sp(
	broadcaster->GetBroadcasterImpl());
	for (pos = m_broadcasters.find(broadcaster_impl_sp);
	pos != end && pos->first.lock() == broadcaster_impl_sp; ++pos) {
	BroadcasterInfo info = pos->second;
	if (event_sp->GetType() & info.event_mask) {
	if (info.callback != nullptr) {
	info.callback(event_sp, info.callback_user_data);
	++num_handled;
	}
	}
	}
	return num_handled;
	}

	uint32_t
	Listener::StartListeningForEventSpec(const BroadcasterManagerSP &manager_sp,
	const BroadcastEventSpec &event_spec) {
	if (!manager_sp)
	return 0;

	// The BroadcasterManager mutex must be locked before m_broadcasters_mutex to
	// avoid violating the lock hierarchy (manager before broadcasters).
	std::lock_guard<std::recursive_mutex> manager_guard(
	manager_sp->m_manager_mutex);
	std::lock_guard<std::recursive_mutex> guard(m_broadcasters_mutex);

	uint32_t bits_acquired = manager_sp->RegisterListenerForEvents(
	this->shared_from_this(), event_spec);
	if (bits_acquired) {
	broadcaster_manager_collection::iterator iter,
	end_iter = m_broadcaster_managers.end();
	BroadcasterManagerWP manager_wp(manager_sp);
	BroadcasterManagerWPMatcher matcher(manager_sp);
	iter = std::find_if<broadcaster_manager_collection::iterator,
	BroadcasterManagerWPMatcher>(
	m_broadcaster_managers.begin(), end_iter, matcher);
	if (iter == end_iter)
	m_broadcaster_managers.push_back(manager_wp);
	}

	return bits_acquired;
	}

	bool Listener::StopListeningForEventSpec(const BroadcasterManagerSP &manager_sp,
	const BroadcastEventSpec &event_spec) {
	if (!manager_sp)
	return false;

	std::lock_guard<std::recursive_mutex> guard(m_broadcasters_mutex);
	return manager_sp->UnregisterListenerForEvents(this->shared_from_this(),
	event_spec);
	}

	ListenerSP Listener::MakeListener(const char *name) {
	return ListenerSP(new Listener(name));
	}