style-guide-ification
authorPaul Davis <paul@linuxaudiosystems.com>
Fri, 4 Jun 2010 12:02:00 +0000 (12:02 +0000)
committerPaul Davis <paul@linuxaudiosystems.com>
Fri, 4 Jun 2010 12:02:00 +0000 (12:02 +0000)
git-svn-id: svn://localhost/ardour2/branches/3.0@7230 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/ardour/graph.cc

index bd4a5fab3138948e9345aaf04410dbf7192f6e79..b998884ad024d25ee97925cb780f124c0d08b9f6 100644 (file)
@@ -1,22 +1,33 @@
 /*
-    Copyright (C) 2010 Paul Davis
+  Copyright (C) 2010 Paul Davis
+  Author: Torben Hohn
 
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
 
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
 
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
 */
 
+#ifdef __linux__
+#include <unistd.h>
+#elif defined(__APPLE__) || defined(__FreeBSD__)
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#endif
+
+#include <stdio.h>
+#include <cmath>
+
 #include "pbd/compose.h"
 
 #include "ardour/debug.h"
 
 #include <jack/thread.h>
 
-#ifdef __linux__
-#include <unistd.h>
-#elif defined(__APPLE__) || defined(__FreeBSD__)
-#include <sys/types.h>
-#include <sys/sysctl.h>
-#endif
-
-
-
-#include <stdio.h>
-#include <cmath>
+#include "i18n.h"
 
 using namespace ARDOUR;
 using namespace PBD;
 
-static    unsigned int hardware_concurrency()
-    {
+static unsigned int 
+hardware_concurrency()
+{
 #if defined(PTW32_VERSION) || defined(__hpux)
         return pthread_num_processors_np();
 #elif defined(__APPLE__) || defined(__FreeBSD__)
@@ -58,464 +60,447 @@ static    unsigned int hardware_concurrency()
 #else
         return 0;
 #endif
-    }
-// ========================================== Graph
+}
 
-Graph::Graph( Session & session 
-    : SessionHandleRef( session 
+Graph::Graph (Session & session
+        : SessionHandleRef (session
 {
-    pthread_mutex_init( &_trigger_mutex, NULL );
-    sem_init( &_execution_sem, 0, 0 );
-
-    sem_init( &_callback_start_sem, 0, 0 );
-    sem_init( &_callback_done_sem,  0, 0 );
-
-    _execution_tokens = 0;
-
-    pthread_mutex_init( &_swap_mutex, NULL );
-    _current_chain = 0;
-    _pending_chain = 0;
-    _setup_chain   = 1;
-    _quit_threads = false;
-    _graph_empty = true;
-
-    int num_cpu = hardware_concurrency();
-    DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("Using %1 CPUs via %1 threads\n", num_cpu));
-    _thread_list.push_back( Glib::Thread::create( sigc::mem_fun( *this, &Graph::main_thread ), 100000, true, true, Glib::THREAD_PRIORITY_NORMAL ) );
-    for (int i=1; i<num_cpu; i++)
-        _thread_list.push_back( Glib::Thread::create( sigc::mem_fun( *this, &Graph::helper_thread ), 100000, true, true, Glib::THREAD_PRIORITY_NORMAL ) );
+        pthread_mutex_init( &_trigger_mutex, NULL);
+        sem_init( &_execution_sem, 0, 0 );
+
+        sem_init( &_callback_start_sem, 0, 0 );
+        sem_init( &_callback_done_sem,  0, 0 );
+
+        _execution_tokens = 0;
+
+        pthread_mutex_init (&_swap_mutex, NULL);
+        _current_chain = 0;
+        _pending_chain = 0;
+        _setup_chain   = 1;
+        _quit_threads = false;
+        _graph_empty = true;
+
+        int num_cpu = hardware_concurrency();
+        info << string_compose (_("Using %1 CPUs via %1 threads\n"), num_cpu) << endmsg;
+        _thread_list.push_back( Glib::Thread::create( sigc::mem_fun( *this, &Graph::main_thread), 100000, true, true, Glib::THREAD_PRIORITY_NORMAL) );
+        for (int i=1; i<num_cpu; i++)
+                _thread_list.push_back( Glib::Thread::create( sigc::mem_fun( *this, &Graph::helper_thread), 100000, true, true, Glib::THREAD_PRIORITY_NORMAL) );
 }
 
 void
 Graph::session_going_away()
 {
-    _quit_threads = true;
+        _quit_threads = true;
 
-    for (unsigned int i=0; i<_thread_list.size(); i++)
-        sem_post( &_execution_sem );
+        for (unsigned int i=0; i<_thread_list.size(); i++) {
+                sem_post( &_execution_sem);
+        }
 
-    sem_post( &_callback_start_sem );
+        sem_post( &_callback_start_sem);
 
-    for (std::list<Glib::Thread *>::iterator i=_thread_list.begin(); i!=_thread_list.end(); i++)
-    {
-        (*i)->join();
-    }
+        for (std::list<Glib::Thread *>::iterator i=_thread_list.begin(); i!=_thread_list.end(); i++) {
+                (*i)->join();
+        }
 
-    // now drop all references on the nodes.
-    _nodes.clear();
-    _nodes_rt[0].clear();
-    _nodes_rt[1].clear();
-    _init_trigger_list[0].clear();
-    _init_trigger_list[1].clear();
-    _trigger_queue.clear();
+        // now drop all references on the nodes.
+        _nodes.clear();
+        _nodes_rt[0].clear();
+        _nodes_rt[1].clear();
+        _init_trigger_list[0].clear();
+        _init_trigger_list[1].clear();
+        _trigger_queue.clear();
 }
 
 void
 Graph::prep()
 {
-    node_list_t::iterator i;
-    int chain;
-
-    if (pthread_mutex_trylock (&_swap_mutex) == 0)
-    {
-       // we got the swap mutex.
-       if (_current_chain != _pending_chain)
-       {
-           //printf ("chain swap ! %d -> %d\n", _current_chain, _pending_chain );
-           _setup_chain = _current_chain;
-           _current_chain = _pending_chain;
-       }
-       pthread_mutex_unlock (&_swap_mutex);
-    }
-
-    chain = _current_chain;
-
-    _graph_empty = true;
-    for (i=_nodes_rt[chain].begin(); i!=_nodes_rt[chain].end(); i++)
-    {
-       (*i)->prep( chain );
-        _graph_empty = false;
-    }
-    _finished_refcount = _init_finished_refcount[chain];
-
-    for (i=_init_trigger_list[chain].begin(); i!=_init_trigger_list[chain].end(); i++)
-       this->trigger( i->get() );
+        node_list_t::iterator i;
+        int chain;
+
+        if (pthread_mutex_trylock (&_swap_mutex) == 0) {
+                // we got the swap mutex.
+                if (_current_chain != _pending_chain)
+                {
+                        //printf ("chain swap ! %d -> %d\n", _current_chain, _pending_chain);
+                        _setup_chain = _current_chain;
+                        _current_chain = _pending_chain;
+                }
+                pthread_mutex_unlock (&_swap_mutex);
+        }
+
+        chain = _current_chain;
+
+        _graph_empty = true;
+        for (i=_nodes_rt[chain].begin(); i!=_nodes_rt[chain].end(); i++) {
+                (*i)->prep( chain);
+                _graph_empty = false;
+        }
+        _finished_refcount = _init_finished_refcount[chain];
+
+        for (i=_init_trigger_list[chain].begin(); i!=_init_trigger_list[chain].end(); i++) {
+                this->trigger( i->get() );
+        }
 }
 
 void
-Graph::trigger( GraphNode * n )
+Graph::trigger (GraphNode * n)
 {
-    pthread_mutex_lock( &_trigger_mutex );
-    _trigger_queue.push_back( n );
-    pthread_mutex_unlock( &_trigger_mutex );
+        pthread_mutex_lock (&_trigger_mutex);
+        _trigger_queue.push_back( n);
+        pthread_mutex_unlock (&_trigger_mutex);
 }
 
 void
 Graph::dec_ref()
 {
-    if (g_atomic_int_dec_and_test( &_finished_refcount ))
-    {
-       // ok... this cycle is finished now.
-       // we are the only thread alive.
-       
-       this->restart_cycle();
+        if (g_atomic_int_dec_and_test (&_finished_refcount)) {
 
-    }
+                // ok... this cycle is finished now.
+                // we are the only thread alive.
+       
+                this->restart_cycle();
+        }
 }
 
 void
 Graph::restart_cycle()
 {
-    //printf( "cycle_done chain: %d\n", _current_chain );
+        //printf( "cycle_done chain: %d\n", _current_chain);
 
-    // we are through. wakeup our caller.
-again:
-    sem_post( &_callback_done_sem );
+        // we are through. wakeup our caller.
+  again:
+        sem_post( &_callback_done_sem);
 
-    // block until we are triggered.
-    sem_wait( &_callback_start_sem );
-    if (_quit_threads)
-        return;
+        // block until we are triggered.
+        sem_wait( &_callback_start_sem);
+        if (_quit_threads)
+                return;
 
-    //printf( "cycle_start\n" );
+        //printf( "cycle_start\n" );
 
-    this->prep();
-    if (_graph_empty)
-        goto again;
-    //printf( "cycle_start chain: %d\n", _current_chain );
+        this->prep();
+        if (_graph_empty)
+                goto again;
+        //printf( "cycle_start chain: %d\n", _current_chain);
 
-    // returning will restart the cycle.
-    //  starting with waking up the others.
+        // returning will restart the cycle.
+        //  starting with waking up the others.
 }
 
 static bool
-is_feedback( boost::shared_ptr<RouteList> routelist, Route * from, boost::shared_ptr<Route> to )
+is_feedback (boost::shared_ptr<RouteList> routelist, Route * from, boost::shared_ptr<Route> to)
 {
-    for (RouteList::iterator ri=routelist->begin(); ri!=routelist->end(); ri++)
-    {
-       if ((*ri).get() == from)
-           return false;
-       if ((*ri) == to)
-           return true;
-    }
-    assert(0);
-    return false;
+        for (RouteList::iterator ri=routelist->begin(); ri!=routelist->end(); ri++) {
+                if ((*ri).get() == from)
+                        return false;
+                if ((*ri) == to)
+                        return true;
+        }
+        assert(0);
+        return false;
 }
 
 static bool
-is_feedback( boost::shared_ptr<RouteList> routelist, boost::shared_ptr<Route> from, Route * to )
+is_feedback (boost::shared_ptr<RouteList> routelist, boost::shared_ptr<Route> from, Route * to)
 {
-    for (RouteList::iterator ri=routelist->begin(); ri!=routelist->end(); ri++)
-    {
-       if ((*ri).get() == to)
-           return true;
-       if ((*ri) == from)
-           return false;
-    }
-    assert(0);
-    return false;
+        for (RouteList::iterator ri=routelist->begin(); ri!=routelist->end(); ri++) {
+                if ((*ri).get() == to)
+                        return true;
+                if ((*ri) == from)
+                        return false;
+        }
+        assert(0);
+        return false;
 }
 
 void
-Graph::rechain( boost::shared_ptr<RouteList> routelist )
+Graph::rechain (boost::shared_ptr<RouteList> routelist)
 {
-    node_list_t::iterator ni;
+        node_list_t::iterator ni;
 
-    pthread_mutex_lock (&_swap_mutex);
-    int chain = _setup_chain;
-    printf( "============== setup %d\n", chain );
-    // set all refcounts to 0;
+        pthread_mutex_lock (&_swap_mutex);
+        int chain = _setup_chain;
+        printf ("============== setup %d\n", chain);
+        // set all refcounts to 0;
 
-    _init_finished_refcount[chain] = 0;
-    _init_trigger_list[chain].clear();
+        _init_finished_refcount[chain] = 0;
+        _init_trigger_list[chain].clear();
 
-    _nodes_rt[chain].clear();
+        _nodes_rt[chain].clear();
 
-    for (RouteList::iterator ri=routelist->begin(); ri!=routelist->end(); ri++)
-    {
-       node_ptr_t n = boost::dynamic_pointer_cast<GraphNode> (*ri);
+        for (RouteList::iterator ri=routelist->begin(); ri!=routelist->end(); ri++) {
+                node_ptr_t n = boost::dynamic_pointer_cast<GraphNode> (*ri);
 
-       n->_init_refcount[chain] = 0;
-       n->_activation_set[chain].clear();
-       _nodes_rt[chain].push_back(n);
-    }
+                n->_init_refcount[chain] = 0;
+                n->_activation_set[chain].clear();
+                _nodes_rt[chain].push_back(n);
+        }
 
-    // now add refs for the connections.
+        // now add refs for the connections.
 
-    for (ni=_nodes_rt[chain].begin(); ni!=_nodes_rt[chain].end(); ni++)
-    {
-       bool has_input  = false;
-       bool has_output = false;
+        for (ni=_nodes_rt[chain].begin(); ni!=_nodes_rt[chain].end(); ni++) {
+                bool has_input  = false;
+                bool has_output = false;
 
-       boost::shared_ptr<Route> rp = boost::dynamic_pointer_cast<Route>( *ni );
+                boost::shared_ptr<Route> rp = boost::dynamic_pointer_cast<Route>( *ni);
 
-       for (RouteList::iterator ri=routelist->begin(); ri!=routelist->end(); ri++)
-       {
-           if (rp->direct_feeds( *ri ))
-           {
-               if (is_feedback( routelist, rp.get(), *ri ))
-                  continue; 
+                for (RouteList::iterator ri=routelist->begin(); ri!=routelist->end(); ri++)
+                {
+                        if (rp->direct_feeds (*ri))
+                        {
+                                if (is_feedback (routelist, rp.get(), *ri))
+                                        continue; 
                    
-               has_output = true;
-               (*ni)->_activation_set[chain].insert( boost::dynamic_pointer_cast<GraphNode> (*ri) );
-           }
-       }
-
-       for (Route::FedBy::iterator fi=rp->fed_by().begin(); fi!=rp->fed_by().end(); fi++)
-       {
-           if (boost::shared_ptr<Route> r = fi->r.lock())
-               if (!is_feedback( routelist, r, rp.get() ))
-                   has_input = true;
-       }
-
-       for (node_set_t::iterator ai=(*ni)->_activation_set[chain].begin(); ai!=(*ni)->_activation_set[chain].end(); ai++)
-       {
-           (*ai)->_init_refcount[chain] += 1;
-       }
-
-       if (!has_input)
-           _init_trigger_list[chain].push_back( *ni );
-
-       if (!has_output)
-           _init_finished_refcount[chain] += 1;
-    } 
-
-    _pending_chain = chain;
-    dump(chain);
-    pthread_mutex_unlock (&_swap_mutex);
+                                has_output = true;
+                                (*ni)->_activation_set[chain].insert (boost::dynamic_pointer_cast<GraphNode> (*ri) );
+                        }
+                }
+
+                for (Route::FedBy::iterator fi=rp->fed_by().begin(); fi!=rp->fed_by().end(); fi++)
+                {
+                        if (boost::shared_ptr<Route> r = fi->r.lock())
+                                if (!is_feedback (routelist, r, rp.get() ))
+                                        has_input = true;
+                }
+
+                for (node_set_t::iterator ai=(*ni)->_activation_set[chain].begin(); ai!=(*ni)->_activation_set[chain].end(); ai++)
+                {
+                        (*ai)->_init_refcount[chain] += 1;
+                }
+
+                if (!has_input)
+                        _init_trigger_list[chain].push_back (*ni);
+
+                if (!has_output)
+                        _init_finished_refcount[chain] += 1;
+        
+
+        _pending_chain = chain;
+        dump(chain);
+        pthread_mutex_unlock (&_swap_mutex);
 }
 
 
 bool
 Graph::run_one()
 {
-    GraphNode * to_run;
-
-    pthread_mutex_lock( &_trigger_mutex );
-    if (_trigger_queue.size()) {
-       to_run = _trigger_queue.back();
-       _trigger_queue.pop_back();
-    }
-    else
-       to_run = 0;
-
-    int wakeup = std::min( (int) _execution_tokens, (int) _trigger_queue.size() );
-    _execution_tokens -= wakeup;
-
-    for( int i=0; i<wakeup; i++ )
-       sem_post( &_execution_sem );
-
-    while (to_run == 0)
-    {
-       _execution_tokens += 1;
-       pthread_mutex_unlock( &_trigger_mutex );
-        DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("%1 goes to sleep\n", pthread_self()));
-       sem_wait( &_execution_sem );
-        if (_quit_threads)
-            return true;
-        DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("%1 is awake\n", pthread_self()));
-       pthread_mutex_lock( &_trigger_mutex );
-       if (_trigger_queue.size())
-       {
-           to_run = _trigger_queue.back();
-           _trigger_queue.pop_back();
-       }
-    }
-    pthread_mutex_unlock( &_trigger_mutex );
-
-    to_run->process();
-    to_run->finish( _current_chain );
-
-    return false;
+        GraphNode * to_run;
+
+        pthread_mutex_lock (&_trigger_mutex);
+        if (_trigger_queue.size()) {
+                to_run = _trigger_queue.back();
+                _trigger_queue.pop_back();
+        }
+        else
+                to_run = 0;
+
+        int wakeup = std::min ((int) _execution_tokens, (int) _trigger_queue.size() );
+        _execution_tokens -= wakeup;
+
+        for (int i=0; i<wakeup; i++ )
+                sem_post (&_execution_sem);
+
+        while (to_run == 0) {
+                _execution_tokens += 1;
+                pthread_mutex_unlock (&_trigger_mutex);
+                DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("%1 goes to sleep\n", pthread_self()));
+                sem_wait (&_execution_sem);
+                if (_quit_threads)
+                        return true;
+                DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("%1 is awake\n", pthread_self()));
+                pthread_mutex_lock (&_trigger_mutex);
+                if (_trigger_queue.size()) {
+                        to_run = _trigger_queue.back();
+                        _trigger_queue.pop_back();
+                }
+        }
+        pthread_mutex_unlock (&_trigger_mutex);
+
+        to_run->process();
+        to_run->finish (_current_chain);
+
+        return false;
 }
 
 static void get_rt()
 {
-    int priority = jack_client_real_time_priority( AudioEngine::instance()->jack() );
+        int priority = jack_client_real_time_priority (AudioEngine::instance()->jack());
 
-    if (priority)
-    {
-       struct sched_param rtparam;
+        if (priority) {
+                struct sched_param rtparam;
        
-       memset (&rtparam, 0, sizeof (rtparam));
-       rtparam.sched_priority = priority;
+                memset (&rtparam, 0, sizeof (rtparam));
+                rtparam.sched_priority = priority;
        
-       pthread_setschedparam (pthread_self(), SCHED_FIFO, &rtparam);
-    }
+                pthread_setschedparam (pthread_self(), SCHED_FIFO, &rtparam);
+        }
 }
 
 void
 Graph::helper_thread()
 {
-    ProcessThread *pt = new ProcessThread;
+        ProcessThread *pt = new ProcessThread;
 
-    pt->get_buffers();
-    get_rt();
+        pt->get_buffers();
+        get_rt();
 
 
-    while(1)
-    {
-       if (run_one())
-            break;
-    }
-    pt->drop_buffers();
+        while(1) {
+                if (run_one())
+                        break;
+        }
+        pt->drop_buffers();
 }
 
 void
 Graph::main_thread()
 {
-    ProcessThread *pt = new ProcessThread;
+        ProcessThread *pt = new ProcessThread;
 
-    pt->get_buffers();
-    get_rt();
+        pt->get_buffers();
+        get_rt();
 
-again:
-    sem_wait( &_callback_start_sem );
+  again:
+        sem_wait (&_callback_start_sem);
 
-    this->prep();
+        this->prep();
 
-    if (_graph_empty) {
-        sem_post( &_callback_done_sem );
-        goto again;
-    }
+        if (_graph_empty) {
+                sem_post (&_callback_done_sem);
+                goto again;
+        }
 
-    while(1)
-    {
-       if (run_one())
-            break;
-    }
-    pt->drop_buffers();
+        while(1) {
+                if (run_one())
+                        break;
+        }
+        pt->drop_buffers();
 }
 
 void
-Graph::dump( int chain )
+Graph::dump (int chain)
 {
 #ifndef NDEBUG
-    node_list_t::iterator ni;
-    node_set_t::iterator ai;
-
-    chain = _pending_chain;
-
-    printf( "--------------------------------------------Graph dump:\n" );
-    for (ni=_nodes_rt[chain].begin(); ni!=_nodes_rt[chain].end(); ni++)
-    {
-       boost::shared_ptr<Route> rp = boost::dynamic_pointer_cast<Route>( *ni );
-       printf( "GraphNode: %s  refcount: %d\n", rp->name().c_str(), (*ni)->_init_refcount[chain] );
-       for (ai=(*ni)->_activation_set[chain].begin(); ai!=(*ni)->_activation_set[chain].end(); ai++)
-       {
-           printf( "  triggers: %s\n", boost::dynamic_pointer_cast<Route>(*ai)->name().c_str() );
-       }
-    }
-
-    printf( "------------- trigger list:\n" );
-    for (ni=_init_trigger_list[chain].begin(); ni!=_init_trigger_list[chain].end(); ni++)
-    {
-       printf( "GraphNode: %s  refcount: %d\n", boost::dynamic_pointer_cast<Route>(*ni)->name().c_str(), (*ni)->_init_refcount[chain] );
-    }
-
-    printf( "final activation refcount: %d\n", _init_finished_refcount[chain] );
+        node_list_t::iterator ni;
+        node_set_t::iterator ai;
+
+        chain = _pending_chain;
+
+        printf ("--------------------------------------------Graph dump:\n" );
+        for (ni=_nodes_rt[chain].begin(); ni!=_nodes_rt[chain].end(); ni++) {
+                boost::shared_ptr<Route> rp = boost::dynamic_pointer_cast<Route>( *ni);
+                printf ("GraphNode: %s  refcount: %d\n", rp->name().c_str(), (*ni)->_init_refcount[chain] );
+                for (ai=(*ni)->_activation_set[chain].begin(); ai!=(*ni)->_activation_set[chain].end(); ai++) {
+                        printf ("  triggers: %s\n", boost::dynamic_pointer_cast<Route>(*ai)->name().c_str() );
+                }
+        }
+
+        printf ("------------- trigger list:\n" );
+        for (ni=_init_trigger_list[chain].begin(); ni!=_init_trigger_list[chain].end(); ni++) {
+                printf ("GraphNode: %s  refcount: %d\n", boost::dynamic_pointer_cast<Route>(*ni)->name().c_str(), (*ni)->_init_refcount[chain] );
+        }
+
+        printf ("final activation refcount: %d\n", _init_finished_refcount[chain] );
 #endif
 }
 
 int
 Graph::silent_process_routes (nframes_t nframes, sframes_t start_frame, sframes_t end_frame,
-                   bool can_record, bool rec_monitors_input, bool& need_butler )
+                              bool can_record, bool rec_monitors_input, bool& need_butler)
 {
-    _process_nframes = nframes;
-    _process_start_frame = start_frame;
-    _process_end_frame = end_frame;
-    _process_can_record = can_record;
-    _process_rec_monitors_input = rec_monitors_input;
-
-    _process_silent = true;
-    _process_noroll = false;
-    _process_retval = 0;
-    _process_need_butler = false;
-
-    if (!_graph_empty) 
-    {
-        sem_post( &_callback_start_sem );
-        sem_wait( &_callback_done_sem );
-    }
-
-    need_butler = _process_need_butler;
-
-    return _process_retval;
+        _process_nframes = nframes;
+        _process_start_frame = start_frame;
+        _process_end_frame = end_frame;
+        _process_can_record = can_record;
+        _process_rec_monitors_input = rec_monitors_input;
+
+        _process_silent = true;
+        _process_noroll = false;
+        _process_retval = 0;
+        _process_need_butler = false;
+
+        if (!_graph_empty) {
+                sem_post (&_callback_start_sem);
+                sem_wait (&_callback_done_sem);
+        }
+
+        need_butler = _process_need_butler;
+
+        return _process_retval;
 }
 
 int
 Graph::process_routes (nframes_t nframes, sframes_t start_frame, sframes_t end_frame, int declick,
-                   bool can_record, bool rec_monitors_input, bool& need_butler )
+                       bool can_record, bool rec_monitors_input, bool& need_butler)
 {
-    _process_nframes = nframes;
-    _process_start_frame = start_frame;
-    _process_end_frame = end_frame;
-    _process_can_record = can_record;
-    _process_rec_monitors_input = rec_monitors_input;
-    _process_declick = declick;
+        _process_nframes = nframes;
+        _process_start_frame = start_frame;
+        _process_end_frame = end_frame;
+        _process_can_record = can_record;
+        _process_rec_monitors_input = rec_monitors_input;
+        _process_declick = declick;
 
-    _process_silent = false;
-    _process_noroll = false;
-    _process_retval = 0;
-    _process_need_butler = false;
+        _process_silent = false;
+        _process_noroll = false;
+        _process_retval = 0;
+        _process_need_butler = false;
 
-    sem_post( &_callback_start_sem );
-    sem_wait( &_callback_done_sem );
+        sem_post (&_callback_start_sem);
+        sem_wait (&_callback_done_sem);
 
-    need_butler = _process_need_butler;
+        need_butler = _process_need_butler;
 
-    return _process_retval;
+        return _process_retval;
 }
 
 int
 Graph::routes_no_roll (nframes_t nframes, sframes_t start_frame, sframes_t end_frame, 
-                   bool non_rt_pending, bool can_record, int declick)
+                       bool non_rt_pending, bool can_record, int declick)
 {
-    _process_nframes = nframes;
-    _process_start_frame = start_frame;
-    _process_end_frame = end_frame;
-    _process_can_record = can_record;
-    _process_declick = declick;
-    _process_non_rt_pending = non_rt_pending;
-
-    _process_silent = false;
-    _process_noroll = true;
-    _process_retval = 0;
-    _process_need_butler = false;
-
-    sem_post( &_callback_start_sem );
-    sem_wait( &_callback_done_sem );
-
-    return _process_retval;
+        _process_nframes = nframes;
+        _process_start_frame = start_frame;
+        _process_end_frame = end_frame;
+        _process_can_record = can_record;
+        _process_declick = declick;
+        _process_non_rt_pending = non_rt_pending;
+
+        _process_silent = false;
+        _process_noroll = true;
+        _process_retval = 0;
+        _process_need_butler = false;
+
+        sem_post (&_callback_start_sem);
+        sem_wait (&_callback_done_sem);
+
+        return _process_retval;
 }
 void
-Graph::process_one_route( Route * route )
+Graph::process_one_route (Route * route)
 {
-    bool need_butler = false;
-    int retval;
-
-    assert( route );
-
-    DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("%1 runs route %2\n", pthread_self(), route->name()));
-
-    if (_process_silent)
-       retval = route->silent_roll (_process_nframes, _process_start_frame, _process_end_frame, _process_can_record, _process_rec_monitors_input, need_butler);
-    else if (_process_noroll)
-    {
-       route->set_pending_declick (_process_declick);
-       retval = route->no_roll (_process_nframes, _process_start_frame, _process_end_frame, _process_non_rt_pending, _process_can_record, _process_declick);
-    }
-    else
-    {
-       route->set_pending_declick (_process_declick);
-       retval = route->roll (_process_nframes, _process_start_frame, _process_end_frame, _process_declick, _process_can_record, _process_rec_monitors_input, need_butler);
-    }
-
-    if (retval)
-       _process_retval = retval;
+        bool need_butler = false;
+        int retval;
+
+        assert (route);
+
+        DEBUG_TRACE (DEBUG::ProcessThreads, string_compose ("%1 runs route %2\n", pthread_self(), route->name()));
+
+        if (_process_silent) {
+                retval = route->silent_roll (_process_nframes, _process_start_frame, _process_end_frame, _process_can_record, _process_rec_monitors_input, need_butler);
+        } else if (_process_noroll) {
+                route->set_pending_declick (_process_declick);
+                retval = route->no_roll (_process_nframes, _process_start_frame, _process_end_frame, _process_non_rt_pending, _process_can_record, _process_declick);
+        } else {
+                route->set_pending_declick (_process_declick);
+                retval = route->roll (_process_nframes, _process_start_frame, _process_end_frame, _process_declick, _process_can_record, _process_rec_monitors_input, need_butler);
+        }
+
+        if (retval) {
+                _process_retval = retval;
+        }
     
-    if (need_butler)
-       _process_need_butler = true;
+        if (need_butler) {
+                _process_need_butler = true;
+        }
 }