Reworking forceful thread termination.

Ctrl-C now kills a thread even if it hangs at termination. And readded
a (rather long) timeout to kill threads automatically that don't
shutdown.

src/logging/WriterBackend.cc

@@ -162,9 +162,7 @@ bool WriterBackend::Init(const WriterInfo& arg_info, int arg_num_fields, const F
 	num_fields = arg_num_fields;
 	fields = arg_fields;
 
-	string name = Fmt("%s/%s", info.path.c_str(), frontend_name.c_str());
-
-	SetName(name);
+	SetName(frontend->Name());
 
 	if ( ! DoInit(arg_info, arg_num_fields, arg_fields) )
 		{

src/logging/writers/Ascii.cc

@@ -169,6 +169,7 @@ bool Ascii::DoFinish(double network_time)
 	ascii_done = true;
 
 	CloseFile(network_time);
+
 	return true;
 	}
 

src/threading/BasicThread.cc

@@ -125,7 +125,7 @@ void BasicThread::Join()
 
 	DBG_LOG(DBG_THREADING, "Joining thread %s ...", name.c_str());
 
-	if ( pthread_join(pthread, 0) != 0  )
+	if ( pthread && pthread_join(pthread, 0) != 0  )
 		reporter->FatalError("Failure joining thread %s", name.c_str());
 
 	DBG_LOG(DBG_THREADING, "Done with thread %s", name.c_str());
@@ -135,13 +135,13 @@ void BasicThread::Join()
 
 void BasicThread::Kill()
 	{
+	terminating = true;
+
 	if ( ! (started && pthread) )
 		return;
 
-	// I believe this is safe to call from a signal handler ... Not error
-	// checking so that killing doesn't bail out if we have already
-	// terminated.
-	pthread_kill(pthread, SIGKILL);
+	pthread = 0;
+	pthread_kill(pthread, SIGTERM);
 	}
 
 void* BasicThread::launcher(void *arg)

src/threading/Manager.cc

@@ -83,6 +83,14 @@ double Manager::NextTimestamp(double* network_time)
 	return -1.0;
 	}
 
+void Manager::KillThreads()
+	{
+        DBG_LOG(DBG_THREADING, "Killing threads ...");
+	
+        for ( all_thread_list::iterator i = all_threads.begin(); i != all_threads.end(); i++ )
+                (*i)->Kill();
+        }
+
 void Manager::Process()
 	{
 	bool do_beat = false;

src/threading/Manager.h

@@ -106,6 +106,13 @@ protected:
 	 */
 	virtual double NextTimestamp(double* network_time);
 
+	/**
+	 * Kills all thread immediately. Note that this may cause race conditions
+	 * if a child thread currently holds a lock that might block somebody
+	 * else.
+	 */
+	virtual void KillThreads();
+
 	/**
 	 * Part of the IOSource interface.
 	 */

src/threading/MsgThread.cc

@@ -156,6 +156,9 @@ MsgThread::MsgThread() : BasicThread()
 	thread_mgr->AddMsgThread(this);
 	}
 
+// Set by Bro's main signal handler.
+extern int signal_val;
+
 void MsgThread::OnStop()
 	{
 	if ( stopped )
@@ -164,13 +167,31 @@ void MsgThread::OnStop()
 	// Signal thread to terminate and wait until it has acknowledged.
 	SendIn(new FinishMessage(this, network_time), true);
 
+	int old_signal_val = signal_val;
+	signal_val = 0;
+
 	int cnt = 0;
+	bool aborted = 0;
+
 	while ( ! finished )
 		{
-		if ( ++cnt % 2000 == 0 ) // Insurance against broken threads ...
+                // Terminate if we get another kill signal.
+		if ( signal_val == SIGTERM || signal_val == SIGINT )
 			{
-			reporter->Warning("thread %s has not yet terminated ...", Name().c_str());
-			fprintf(stderr, "warning: thread %s has not yet terminated ...", Name().c_str());
+			// Abort all threads here so that we won't hang next
+			// on another one.
+                        fprintf(stderr, "received signal while waiting for thread %s, aborting all ...\n", Name().c_str());
+			thread_mgr->KillThreads();
+			aborted = true;
+			break;
+			}
+
+		if ( ++cnt % 10000 == 0 ) // Insurance against broken threads ...
+			{
+                        fprintf(stderr, "killing thread %s ...\n", Name().c_str());
+			Kill();
+			aborted = true;
+			break;
 			}
 
 		usleep(1000);
@@ -178,7 +199,10 @@ void MsgThread::OnStop()
 
 	Finished();
 
+	signal_val = old_signal_val;
+
 	// One more message to make sure the current queue read operation unblocks.
+	if ( ! aborted )
 		SendIn(new UnblockMessage(this), true);
 	}