Merge remote-tracking branch 'origin/topic/robin/thread-cleanup' into topic/seth/exec-module

scripts/base/frameworks/logging/main.bro

@@ -189,6 +189,15 @@ export {
 	## .. bro:see:: Log::add_default_filter Log::remove_default_filter
 	global create_stream: function(id: ID, stream: Stream) : bool;
 
+	## Removes a logging stream completely, stopping all the threads.
+	##
+	## id: The ID enum to be associated with the new logging stream.
+	##
+	## Returns: True if a new stream was successfully removed.
+	##
+	## .. bro:see:: Log:create_stream
+	global remove_stream: function(id: ID) : bool;
+
 	## Enables a previously disabled logging stream.  Disabled streams
 	## will not be written to until they are enabled again.  New streams
 	## are enabled by default.
@@ -442,6 +451,13 @@ function create_stream(id: ID, stream: Stream) : bool
 	return add_default_filter(id);
 	}
 
+function remove_stream(id: ID) : bool
+	{
+	delete active_streams[id];
+
+	return __remove_stream(id);
+	}
+
 function disable_stream(id: ID) : bool
 	{
 	delete active_streams[id];

src/logging.bif

@@ -18,6 +18,12 @@ function Log::__create_stream%(id: Log::ID, stream: Log::Stream%) : bool
 	return new Val(result, TYPE_BOOL);
 	%}
 
+function Log::__remove_stream%(id: Log::ID%) : bool
+	%{
+	bool result = log_mgr->RemoveStream(id->AsEnumVal());
+	return new Val(result, TYPE_BOOL);
+	%}
+
 function Log::__enable_stream%(id: Log::ID%) : bool
 	%{
 	bool result = log_mgr->EnableStream(id->AsEnumVal());

src/logging/Manager.cc

@@ -374,6 +374,38 @@ bool Manager::CreateStream(EnumVal* id, RecordVal* sval)
 	return true;
 	}
 
+bool Manager::RemoveStream(EnumVal* id)
+	{
+	unsigned int idx = id->AsEnum();
+
+	if ( idx >= streams.size() || ! streams[idx] )
+		return false;
+
+	Stream* stream = streams[idx];
+
+	if ( ! stream )
+		return false;
+
+	for ( Stream::WriterMap::iterator i = stream->writers.begin(); i != stream->writers.end(); i++ )
+		{
+		WriterInfo* winfo = i->second;
+
+		DBG_LOG(DBG_LOGGING, "Removed writer '%s' from stream '%s'",
+			winfo->writer->Name(), stream->name.c_str());
+
+		winfo->writer->Stop();
+		delete winfo->writer;
+		delete winfo;
+		}
+
+	stream->writers.clear();
+	delete stream;
+	streams[idx] = 0;
+
+	DBG_LOG(DBG_LOGGING, "Removed logging stream '%s'", stream->name.c_str());
+	return true;
+	}
+
 bool Manager::EnableStream(EnumVal* id)
 	{
 	Stream* stream = FindStream(id);

src/logging/Manager.h

@@ -47,6 +47,16 @@ public:
 	 */
 	bool CreateStream(EnumVal* id, RecordVal* stream);
 
+	/**
+	 * Remove a log stream, stopping all threads.
+	 *
+	 * @param id  The enum value corresponding the log stream.
+	 *
+	 * This methods corresponds directly to the internal BiF defined in
+	 * logging.bif, which just forwards here.
+	 */
+	bool RemoveStream(EnumVal* id);
+
 	/**
 	 * Enables a log log stream.
 	 *

src/logging/WriterFrontend.cc

@@ -138,6 +138,12 @@ void WriterFrontend::Stop()
 	{
 	FlushWriteBuffer();
 	SetDisable();
+
+	if ( backend )
+		{
+		backend->SignalStop();
+		backend = 0; // Thread manager will clean it up once it finishes.
+		}
 	}
 
 void WriterFrontend::Init(int arg_num_fields, const Field* const * arg_fields)

src/logging/WriterFrontend.h

@@ -54,7 +54,8 @@ public:
 
 	/**
 	 * Stops all output to this writer. Calling this methods disables all
-	 * message forwarding to the backend.
+	 * message forwarding to the backend and will eventually remove the
+	 * backend thread.
 	 *
 	 * This method must only be called from the main thread.
 	 */

src/threading/BasicThread.cc

@@ -117,20 +117,7 @@ void BasicThread::Start()
 	OnStart();
 	}
 
-void BasicThread::PrepareStop()
-	{
-	if ( ! started )
-		return;
-
-	if ( terminating )
-		return;
-
-	DBG_LOG(DBG_THREADING, "Preparing thread %s to terminate ...", name);
-
-	OnPrepareStop();
-	}
-
-void BasicThread::Stop()
+void BasicThread::SignalStop()
 	{
 	if ( ! started )
 		return;
@@ -140,7 +127,20 @@ void BasicThread::Stop()
 
 	DBG_LOG(DBG_THREADING, "Signaling thread %s to terminate ...", name);
 
-	OnStop();
+	OnSignalStop();
+	}
+
+void BasicThread::WaitForStop()
+	{
+	if ( ! started )
+		return;
+
+	if ( terminating )
+		return;
+
+	DBG_LOG(DBG_THREADING, "Waiting for thread %s to terminate ...", name);
+
+	OnWaitForStop();
 
 	terminating = true;
 	}
@@ -150,11 +150,12 @@ void BasicThread::Join()
 	if ( ! started )
 		return;
 
+	if ( ! pthread )
+		return;
+
 	assert(terminating);
 
-	DBG_LOG(DBG_THREADING, "Joining thread %s ...", name);
-
-	if ( pthread && pthread_join(pthread, 0) != 0  )
+	if ( pthread_join(pthread, 0) != 0  )
 		reporter->FatalError("Failure joining thread %s", name);
 
 	DBG_LOG(DBG_THREADING, "Joined with thread %s", name);

src/threading/BasicThread.h

@@ -71,32 +71,33 @@ public:
 	void Start();
 
 	/**
-	 * Signals the thread to prepare for stopping. This must be called
-	 * before Stop() and allows the thread to trigger shutting down
-	 * without yet blocking for doing so.
+	 * Signals the thread to prepare for stopping, but doesn't block to
+	 * wait for that to happen. Use WaitForStop() for that.
+	 *
+	 * The method lets Terminating() now return true, it does however not
+	 * force the thread to terminate. It's up to the Run() method to to
+	 * query Terminating() and exit eventually.
 	 * 
 	 * Calling this method has no effect if Start() hasn't been executed
 	 * yet.
 	 *
 	 * Only Bro's main thread must call this method.
 	 */
-	void PrepareStop();
+	void SignalStop();
 
 	/**
-	 * Signals the thread to stop. The method lets Terminating() now
-	 * return true. It does however not force the thread to terminate.
-	 * It's up to the Run() method to to query Terminating() and exit
-	 * eventually.
+	 * Waits until a thread has stopped after receiving SignalStop().
 	 *
 	 * Calling this method has no effect if Start() hasn't been executed
-	 * yet.
+	 * yet. If this is executed without calling SignalStop() first,
+	 * results are undefined.
 	 *
 	 * Only Bro's main thread must call this method.
 	 */
-	void Stop();
+	void WaitForStop();
 
 	/**
-	 * Returns true if Stop() has been called.
+	 * Returns true if WaitForStop() has been called and finished.
 	 *
 	 * This method is safe to call from any thread.
 	 */
@@ -145,18 +146,19 @@ protected:
 	virtual void OnStart()	{}
 
 	/**
-	 * Executed with PrepareStop() (and before OnStop()). This is a hook
-	 * into preparing the thread for stopping. It will be called from
-	 * Bro's main thread before the thread has been signaled to stop.
+	 * Executed with SignalStop(). This is a hook into preparing the
+	 * thread for stopping. It will be called from Bro's main thread
+	 * before the thread has been signaled to stop.
 	 */
-	virtual void OnPrepareStop()	{}
+	virtual void OnSignalStop()	{}
 
 	/**
-	 * Executed with Stop() (and after OnPrepareStop()). This is a hook
-	 * into stopping the thread. It will be called from Bro's main thread
-	 * after the thread has been signaled to stop.
+	 * Executed with WaitForStop(). This is a hook into waiting for the
+	 * thread to stop. It must be overridden by derived classes and only
+	 * return once the thread has indeed finished processing. The method
+	 * will be called from Bro's main thread.
 	 */
-	virtual void OnStop()	{}
+	virtual void OnWaitForStop() = 0;
 
 	/**
 	 * Executed with Kill(). This is a hook into killing the thread.

src/threading/Manager.cc

@@ -32,10 +32,10 @@ void Manager::Terminate()
 	// Signal all to stop.
 
 	for ( all_thread_list::iterator i = all_threads.begin(); i != all_threads.end(); i++ )
-		(*i)->PrepareStop();
+		(*i)->SignalStop();
 
 	for ( all_thread_list::iterator i = all_threads.begin(); i != all_threads.end(); i++ )
-		(*i)->Stop();
+		(*i)->WaitForStop();
 
 	// Then join them all.
 	for ( all_thread_list::iterator i = all_threads.begin(); i != all_threads.end(); i++ )
@@ -141,13 +141,40 @@ void Manager::Process()
 			else
 				{
 				reporter->Error("%s failed, terminating thread", msg->Name());
-				t->Stop();
+				t->SignalStop();
 				}
 
 			delete msg;
 			}
 		}
 
+	all_thread_list to_delete;
+
+	for ( all_thread_list::iterator i = all_threads.begin(); i != all_threads.end(); i++ )
+		{
+		BasicThread* t = *i;
+
+		if ( ! t->Killed() )
+			continue;
+
+		to_delete.push_back(t);
+		}
+
+	for ( all_thread_list::iterator i = to_delete.begin(); i != to_delete.end(); i++ )
+		{
+		BasicThread* t = *i;
+
+		all_threads.remove(t);
+
+		MsgThread* mt = dynamic_cast<MsgThread *>(t);
+
+		if ( mt )
+			msg_threads.remove(mt);
+
+		t->Join();
+		delete t;
+		}
+
 //	fprintf(stderr, "P %.6f %.6f do_beat=%d did_process=%d next_next=%.6f\n", network_time, timer_mgr->Time(), do_beat, (int)did_process, next_beat);
 	}
 

src/threading/MsgThread.cc

@@ -161,16 +161,16 @@ MsgThread::MsgThread() : BasicThread(), queue_in(this, 0), queue_out(0, this)
 // Set by Bro's main signal handler.
 extern int signal_val;
 
-void MsgThread::OnPrepareStop()
+void MsgThread::OnSignalStop()
 	{
 	if ( finished || Killed() )
 		return;
 
-	// Signal thread to terminate and wait until it has acknowledged.
+	// Signal thread to terminate.
 	SendIn(new FinishMessage(this, network_time), true);
 	}
 
-void MsgThread::OnStop()
+void MsgThread::OnWaitForStop()
 	{
 	int signal_count = 0;
 	int old_signal_val = signal_val;

src/threading/MsgThread.h

@@ -228,8 +228,8 @@ protected:
 	 *
 	 */
 	virtual void Run();
-	virtual void OnStop();
-	virtual void OnPrepareStop();
+	virtual void OnWaitForStop();
+	virtual void OnSignalStop();
 	virtual void OnKill();
 
 private: