watcher: Don't wait for running callback once watcher thread cancelled

During shutdown, waiting for callbacks might never complete, as queued
callbacks might not get executed under certain conditions. Not the clean fix,
but works good enough for now.

Seen on Windows in vici tests.

src/libstrongswan/processing/watcher.c

@@ -49,6 +49,11 @@ struct private_watcher_t {
 	 */
 	bool pending;
 
+	/**
+	 * Is watcher running?
+	 */
+	bool running;
+
 	/**
 	 * Lock to access FD list
 	 */
@@ -225,6 +230,7 @@ static void activate_all(private_watcher_t *this)
 		entry->in_callback = 0;
 	}
 	enumerator->destroy(enumerator);
+	this->running = FALSE;
 	this->condvar->broadcast(this->condvar);
 	this->mutex->unlock(this->mutex);
 }
@@ -373,6 +379,7 @@ METHOD(watcher_t, add, void,
 	this->fds->insert_last(this->fds, entry);
 	if (this->fds->get_count(this->fds) == 1)
 	{
+		this->running = TRUE;
 		lib->processor->queue_job(lib->processor,
 			(job_t*)callback_job_create_with_prio((void*)watch, this,
 				NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
@@ -400,7 +407,7 @@ METHOD(watcher_t, remove_, void,
 		{
 			if (entry->fd == fd)
 			{
-				if (entry->in_callback)
+				if (this->running && entry->in_callback)
 				{
 					is_in_callback = TRUE;
 					break;