]> git.tdb.fi Git - r2c2.git/commitdiff
Restructure ArduControl driver into more manageable units
authorMikko Rasa <tdb@tdb.fi>
Fri, 8 Nov 2013 13:06:30 +0000 (15:06 +0200)
committerMikko Rasa <tdb@tdb.fi>
Fri, 8 Nov 2013 17:27:59 +0000 (19:27 +0200)
The control thread main function was getting a bit unwieldy at over 200
lines.

source/libr2c2/arducontrol.cpp
source/libr2c2/arducontrol.h

index 7111f53012b5ec177e23f718dcf5fdc607286307..d18dc97590ee0a4af0a7ed1ab71e0aa59321087a 100644 (file)
@@ -27,7 +27,7 @@ ArduControl::ArduControl(const string &dev):
        next_mfx_address(1),
        thread(*this)
 {
-       QueuedCommand cmd;
+       PendingCommand cmd;
        cmd.command[0] = READ_POWER_STATE;
        cmd.length = 1;
        push_command(cmd);
@@ -50,7 +50,7 @@ void ArduControl::set_power(bool p)
 {
        if(power.set(p))
        {
-               QueuedCommand cmd(POWER);
+               PendingCommand cmd(POWER);
                cmd.tag.serial = power.serial;
                cmd.command[0] = (p ? POWER_ON : POWER_OFF);
                cmd.length = 1;
@@ -117,7 +117,7 @@ void ArduControl::set_loco_speed(unsigned id, unsigned speed)
 
        if(loco.speed.set(speed))
        {
-               QueuedCommand cmd(loco, Locomotive::SPEED);
+               PendingCommand cmd(loco, Locomotive::SPEED);
                push_command(cmd);
 
                add_loco_to_refresh(loco);
@@ -129,7 +129,7 @@ void ArduControl::set_loco_reverse(unsigned id, bool rev)
        Locomotive &loco = get_item(locomotives, id);
        if(loco.reverse.set(rev))
        {
-               QueuedCommand cmd(loco, Locomotive::REVERSE);
+               PendingCommand cmd(loco, Locomotive::REVERSE);
                push_command(cmd);
 
                add_loco_to_refresh(loco);
@@ -147,7 +147,7 @@ void ArduControl::set_loco_function(unsigned id, unsigned func, bool state)
        {
                if(func>0 || loco.proto!=MM)
                {
-                       QueuedCommand cmd(loco, Locomotive::FUNCTIONS, func);
+                       PendingCommand cmd(loco, Locomotive::FUNCTIONS, func);
                        push_command(cmd);
                }
 
@@ -421,7 +421,7 @@ void ArduControl::tick()
                        unsigned i;
                        for(i=0; (lowest_bit>>i)>1; ++i) ;
                        acc.state.set(acc.state^lowest_bit);
-                       QueuedCommand cmd(acc, Accessory::ACTIVATE, i);
+                       PendingCommand cmd(acc, Accessory::ACTIVATE, i);
                        push_command(cmd);
                }
                else
@@ -434,7 +434,7 @@ void ArduControl::tick()
                if(t>off_timeout)
                {
                        off_timeout = Time::TimeStamp();
-                       QueuedCommand cmd(*active_accessory, Accessory::DEACTIVATE);
+                       PendingCommand cmd(*active_accessory, Accessory::DEACTIVATE);
                        push_command(cmd);
                }
        }
@@ -444,13 +444,13 @@ void ArduControl::flush()
 {
 }
 
-void ArduControl::push_command(const QueuedCommand &cmd)
+void ArduControl::push_command(const PendingCommand &cmd)
 {
        MutexLock lock(mutex);
        command_queue.push_back(cmd);
 }
 
-bool ArduControl::pop_command(QueuedCommand &cmd)
+bool ArduControl::pop_command(PendingCommand &cmd)
 {
        MutexLock lock(mutex);
        if(command_queue.empty())
@@ -583,296 +583,379 @@ ArduControl::Sensor::Sensor(unsigned a):
 { }
 
 
-ArduControl::ControlThread::ControlThread(ArduControl &c):
-       control(c),
-       done(false)
+ArduControl::PendingCommand::PendingCommand():
+       length(0),
+       repeat_count(1)
+{ }
+
+ArduControl::PendingCommand::PendingCommand(GeneralCommand cmd):
+       length(0),
+       repeat_count(1)
 {
-       launch();
+       tag.type = Tag::GENERAL;
+       tag.command = cmd;
 }
 
-void ArduControl::ControlThread::exit()
+ArduControl::PendingCommand::PendingCommand(Locomotive &loco, Locomotive::Command cmd, unsigned index):
+       repeat_count(8)
 {
-       done = true;
-       join();
+       tag.type = Tag::LOCOMOTIVE;
+       tag.command = cmd;
+       tag.id = loco.id;
+       if(cmd==Locomotive::SPEED)
+       {
+               tag.serial = loco.speed.serial;
+               length = loco.create_speed_dir_command(command);
+       }
+       else if(cmd==Locomotive::REVERSE)
+       {
+               tag.serial = loco.reverse.serial;
+               length = loco.create_speed_dir_command(command);
+       }
+       else if(cmd==Locomotive::FUNCTIONS)
+       {
+               tag.serial = loco.funcs.serial;
+               length = loco.create_speed_func_command(index, command);
+       }
+       else
+               throw invalid_argument("PendingCommand");
 }
 
-void ArduControl::ControlThread::main()
+ArduControl::PendingCommand::PendingCommand(Accessory &acc, Accessory::Command cmd, unsigned index):
+       repeat_count(1)
 {
-       char command[15];
-       unsigned length = 0;
-       unsigned repeat_count = 0;
-       Tag tag;
-       Locomotive *loco = 0;
-       unsigned phase = 0;
-       unsigned s88_octets_remaining = 0;
+       tag.type = Tag::ACCESSORY;
+       tag.command = cmd;
+       tag.id = acc.address;
+       if(cmd==Accessory::ACTIVATE || cmd==Accessory::DEACTIVATE)
+       {
+               tag.serial = acc.state.serial;
+               length = acc.create_state_command(index, (cmd==Accessory::ACTIVATE), command);
+       }
+       else
+               throw invalid_argument("PendingCommand");
+}
 
-       Msp::Time::TimeStamp next_mfx_announce;
-       unsigned mfx_search_size = 0;
-       unsigned mfx_search_bits = 0;
-       Msp::Time::TimeStamp next_mfx_search;
 
-       while(!done)
+ArduControl::RefreshTask::RefreshTask(ArduControl &c):
+       control(c),
+       loco(0),
+       phase(0)
+{ }
+
+bool ArduControl::RefreshTask::get_work(PendingCommand &cmd)
+{
+       if(loco && loco->proto==MM && phase==0)
        {
-               Time::TimeStamp t = Time::now();
+               cmd.length = loco->create_speed_func_command(control.refresh_counter%4+1, cmd.command);
+               cmd.repeat_count = 2;
+               ++phase;
+               return true;
+       }
 
-               if(!repeat_count)
-               {
-                       tag = Tag();
-                       length = 0;
-                       repeat_count = 1;
-                       QueuedCommand qcmd;
-                       if(control.pop_command(qcmd))
-                       {
-                               length = qcmd.length;
-                               copy(qcmd.command, qcmd.command+length, command);
-                               if(qcmd.tag.type==Tag::LOCOMOTIVE)
-                                       repeat_count = 8;
-                               tag = qcmd.tag;
-                       }
-                       else if(loco && phase==0)
-                       {
-                               length = loco->create_speed_func_command(control.refresh_counter%4+1, command);
-                               repeat_count = 2;
-                               ++phase;
-                       }
-                       else if(t>=next_mfx_announce)
-                       {
-                               command[0] = MFX_ANNOUNCE;
-                               command[1] = control.mfx_announce_serial>>8;
-                               command[2] = control.mfx_announce_serial;
-                               length = 3;
-                               next_mfx_announce = t+400*Time::msec;
-                       }
-                       else if(t>=next_mfx_search)
-                       {
-                               command[0] = MFX_SEARCH;
-                               for(unsigned i=0; i<4; ++i)
-                                       command[1+i] = mfx_search_bits>>(24-i*8);
-                               command[5] = mfx_search_size;
-                               length = 6;
-                               next_mfx_search = t+200*Time::msec;
-                               if(control.debug>=1)
-                                       IO::print("Search %08X/%d\n", mfx_search_bits, mfx_search_size);
-                       }
-                       else if(!s88_octets_remaining && control.n_s88_octets)
-                       {
-                               command[0] = S88_READ;
-                               command[1] = control.n_s88_octets;
-                               length = 2;
-                               s88_octets_remaining = control.n_s88_octets;
-                       }
-                       else if((loco = control.get_loco_to_refresh()))
-                       {
-                               if(loco->proto==MM)
-                               {
-                                       length = loco->create_speed_dir_command(command);
-                                       repeat_count = 2;
-                                       phase = 0;
-                               }
-                               else if(loco->proto==MFX)
-                               {
-                                       length = loco->create_speed_func_command(0, command);
-                                       phase = 1;
-                               }
-                       }
-                       else
-                       {
-                               // Send an idle packet for the MM protocol
-                               command[0] = MOTOROLA_SPEED;
-                               command[1] = 80;
-                               command[2] = 0;
-                               command[3] = 0;
-                               length = 4;
-                       }
-               }
+       loco = control.get_loco_to_refresh();
+       if(!loco)
+               return false;
 
-               if(control.debug>=2)
+       phase = 0;
+       if(loco->proto==MM)
+       {
+               cmd.length = loco->create_speed_dir_command(cmd.command);
+               cmd.repeat_count = 2;
+       }
+       else if(loco->proto==MFX)
+               cmd.length = loco->create_speed_func_command(0, cmd.command);
+       else
+               return false;
+
+       return true;
+}
+
+
+ArduControl::S88Task::S88Task(ArduControl &c):
+       control(c),
+       octets_remaining(0)
+{ }
+
+bool ArduControl::S88Task::get_work(PendingCommand &cmd)
+{
+       if(octets_remaining || !control.n_s88_octets)
+               return false;
+
+       cmd.command[0] = S88_READ;
+       cmd.command[1] = control.n_s88_octets;
+       cmd.length = 2;
+       octets_remaining = control.n_s88_octets;
+
+       return true;
+}
+
+void ArduControl::S88Task::process_reply(const char *reply, unsigned length)
+{
+       unsigned char type = reply[0];
+       if(type==S88_DATA && length>2)
+       {
+               unsigned offset = static_cast<unsigned char>(reply[1]);
+               unsigned count = length-2;
+
+               SensorMap::iterator begin = control.sensors.lower_bound(offset*8+1);
+               SensorMap::iterator end = control.sensors.upper_bound((offset+count)*8);
+               for(SensorMap::iterator i=begin; i!=end; ++i)
                {
-                       string cmd_hex;
-                       for(unsigned i=0; i<length; ++i)
-                               cmd_hex += format(" %02X", static_cast<unsigned char>(command[i]));
-                       IO::print("< %02X%s\n", length^0xFF, cmd_hex);
+                       unsigned bit_index = i->first-1-offset*8;
+                       bool state = (reply[2+bit_index/8]>>(7-bit_index%8))&1;
+                       i->second.state.set(state);
+
+                       Tag tag;
+                       tag.type = Tag::SENSOR;
+                       tag.command = Sensor::STATE;
+                       tag.serial = i->second.state.serial;
+                       tag.id = i->first;
+                       control.push_completed_tag(tag);
                }
 
-               control.serial.put(length^0xFF);
-               control.serial.write(command, length);
-               --repeat_count;
+               if(count>octets_remaining)
+                       octets_remaining = 0;
+               else
+                       octets_remaining -= count;
+       }
+}
 
-               bool got_reply = false;
-               bool got_data = false;
-               while(!got_reply || got_data)
-               {
-                       if(got_reply)
-                               got_data = IO::poll(control.serial, IO::P_INPUT, Time::zero);
-                       else
-                               got_data = IO::poll(control.serial, IO::P_INPUT);
 
-                       if(got_data)
-                       {
-                               unsigned rlength = control.serial.get()^0xFF;
-                               if(rlength>15)
-                               {
-                                       IO::print("Invalid length %02X\n", rlength);
-                                       continue;
-                               }
+ArduControl::MfxAnnounceTask::MfxAnnounceTask(ArduControl &c):
+       control(c)
+{ }
 
-                               char reply[15];
-                               unsigned pos = 0;
-                               while(pos<rlength)
-                                       pos += control.serial.read(reply+pos, rlength-pos);
+bool ArduControl::MfxAnnounceTask::get_work(PendingCommand &cmd)
+{
+       Time::TimeStamp t = Time::now();
+       if(t<next)
+               return false;
 
-                               if(control.debug>=2)
-                               {
-                                       string reply_hex;
-                                       for(unsigned i=0; i<rlength; ++i)
-                                               reply_hex += format(" %02X", static_cast<unsigned char>(reply[i]));
-                                       IO::print("> %02X%s\n", rlength^0xFF, reply_hex);
-                               }
+       cmd.command[0] = MFX_ANNOUNCE;
+       cmd.command[1] = control.mfx_announce_serial>>8;
+       cmd.command[2] = control.mfx_announce_serial;
+       cmd.length = 3;
+       next = t+400*Time::msec;
 
-                               unsigned char type = reply[0];
-                               if((type&0xE0)==0x80)
-                               {
-                                       got_reply = true;
-                                       if(type!=COMMAND_OK)
-                                               IO::print("Error %02X\n", type);
-                                       else if(tag && !repeat_count)
-                                               control.push_completed_tag(tag);
-                               }
-                               else if(type==POWER_STATE && rlength==2)
-                               {
-                                       control.power.set(reply[1]);
+       return true;
+}
 
-                                       Tag ptag;
-                                       ptag.type = Tag::GENERAL;
-                                       ptag.command = POWER;
-                                       ptag.serial = control.power.serial;
-                                       control.push_completed_tag(ptag);
-                               }
-                               else if(type==MFX_FEEDBACK && rlength==2)
-                               {
-                                       if(command[0]==MFX_SEARCH)
-                                       {
-                                               bool finished = true;
-                                               if(reply[1])
-                                               {
-                                                       if(mfx_search_size==32)
-                                                       {
-                                                               if(control.debug>=1)
-                                                                       IO::print("Assigning MFX address %d to decoder %08X\n", control.next_mfx_address, mfx_search_bits);
-
-                                                               QueuedCommand qcmd;
-                                                               qcmd.command[0] = MFX_ASSIGN_ADDRESS;
-                                                               qcmd.command[1] = control.next_mfx_address>>8;
-                                                               qcmd.command[2] = control.next_mfx_address;
-                                                               for(unsigned i=0; i<4; ++i)
-                                                                       qcmd.command[3+i] = mfx_search_bits>>(24-i*8);
-                                                               qcmd.length = 7;
-                                                               control.push_command(qcmd);
-                                                               ++control.next_mfx_address;
-                                                       }
-                                                       else
-                                                       {
-                                                               ++mfx_search_size;
-                                                               finished = false;
-                                                       }
-                                               }
-                                               else if(mfx_search_size>0)
-                                               {
-                                                       unsigned mask = 1<<(32-mfx_search_size);
-                                                       if(!(mfx_search_bits&mask))
-                                                       {
-                                                               mfx_search_bits |= mask;
-                                                               finished = false;
-                                                       }
-                                               }
-
-                                               if(finished)
-                                               {
-                                                       next_mfx_search = t+2*Time::sec;
-                                                       mfx_search_bits = 0;
-                                                       mfx_search_size = 0;
-                                               }
-                                       }
-                               }
-                               else if(type==S88_DATA && rlength>2)
-                               {
-                                       unsigned offset = static_cast<unsigned char>(reply[1]);
-                                       unsigned count = rlength-2;
 
-                                       SensorMap::iterator begin = control.sensors.lower_bound(offset*8+1);
-                                       SensorMap::iterator end = control.sensors.upper_bound((offset+count)*8);
-                                       for(SensorMap::iterator i=begin; i!=end; ++i)
-                                       {
-                                               unsigned bit_index = i->first-1-offset*8;
-                                               bool state = (reply[2+bit_index/8]>>(7-bit_index%8))&1;
-                                               i->second.state.set(state);
-
-                                               Tag stag;
-                                               stag.type = Tag::SENSOR;
-                                               stag.command = Sensor::STATE;
-                                               stag.serial = i->second.state.serial;
-                                               stag.id = i->first;
-                                               control.push_completed_tag(stag);
-                                       }
+ArduControl::MfxSearchTask::MfxSearchTask(ArduControl &c):
+       control(c),
+       size(0),
+       bits(0),
+       pending(false)
+{ }
 
-                                       if(count>s88_octets_remaining)
-                                               s88_octets_remaining = 0;
-                                       else
-                                               s88_octets_remaining -= count;
-                               }
+bool ArduControl::MfxSearchTask::get_work(PendingCommand &cmd)
+{
+       if(size==32)
+       {
+               if(control.debug>=1)
+                       IO::print("Assigning MFX address %d to decoder %08X\n", control.next_mfx_address, bits);
+
+               cmd.command[0] = MFX_ASSIGN_ADDRESS;
+               cmd.command[1] = control.next_mfx_address>>8;
+               cmd.command[2] = control.next_mfx_address;
+               for(unsigned i=0; i<4; ++i)
+                       cmd.command[3+i] = bits>>(24-i*8);
+               cmd.length = 7;
+
+               size = 0;
+               bits = 0;
+               ++control.next_mfx_address;
+
+               return true;
+       }
+
+       Time::TimeStamp t = Time::now();
+       if(t<next)
+               return false;
+
+       cmd.command[0] = MFX_SEARCH;
+       for(unsigned i=0; i<4; ++i)
+               cmd.command[1+i] = bits>>(24-i*8);
+       cmd.command[5] = size;
+       cmd.length = 6;
+
+       next = t+200*Time::msec;
+       pending = true;
+
+       if(control.debug>=1)
+               IO::print("Search %08X/%d\n", bits, size);
+
+       return true;
+}
+
+void ArduControl::MfxSearchTask::process_reply(const char *reply, unsigned length)
+{
+       unsigned char type = reply[0];
+       if(type==MFX_FEEDBACK && length==2 && pending)
+       {
+               pending = false;
+               bool finished = true;
+               if(reply[1])
+               {
+                       if(size<32)
+                               ++size;
+                       finished = false;
+               }
+               else if(size>0)
+               {
+                       unsigned mask = 1<<(32-size);
+                       if(!(bits&mask))
+                       {
+                               bits |= mask;
+                               finished = false;
                        }
                }
+
+               if(finished)
+               {
+                       next = Time::now()+2*Time::sec;
+                       bits = 0;
+                       size = 0;
+               }
        }
 }
 
 
-ArduControl::QueuedCommand::QueuedCommand():
-       length(0)
-{ }
+ArduControl::ControlThread::ControlThread(ArduControl &c):
+       control(c),
+       done(false)
+{
+       tasks.push_back(new MfxAnnounceTask(control));
+       tasks.push_back(new MfxSearchTask(control));
+       tasks.push_back(new S88Task(control));
+       tasks.push_back(new RefreshTask(control));
 
-ArduControl::QueuedCommand::QueuedCommand(GeneralCommand cmd):
-       length(0)
+       launch();
+}
+
+void ArduControl::ControlThread::exit()
 {
-       tag.type = Tag::GENERAL;
-       tag.command = cmd;
+       done = true;
+       join();
 }
 
-ArduControl::QueuedCommand::QueuedCommand(Locomotive &loco, Locomotive::Command cmd, unsigned index)
+void ArduControl::ControlThread::main()
 {
-       tag.type = Tag::LOCOMOTIVE;
-       tag.command = cmd;
-       tag.id = loco.id;
-       if(cmd==Locomotive::SPEED)
+       while(!done)
        {
-               tag.serial = loco.speed.serial;
-               length = loco.create_speed_dir_command(command);
+               PendingCommand cmd;
+               if(get_work(cmd))
+               {
+                       bool success = true;
+                       for(unsigned i=0; (success && i<cmd.repeat_count); ++i)
+                               success = (do_command(cmd)==COMMAND_OK);
+                       if(success && cmd.tag)
+                               control.push_completed_tag(cmd.tag);
+               }
+               else
+                       Time::sleep(10*Time::msec);
        }
-       else if(cmd==Locomotive::REVERSE)
+}
+
+bool ArduControl::ControlThread::get_work(PendingCommand &cmd)
+{
+       if(control.pop_command(cmd))
+               return true;
+
+       for(vector<Task *>::iterator i=tasks.begin(); i!=tasks.end(); ++i)
+               if((*i)->get_work(cmd))
+                       return true;
+
+       // As fallback, send an idle packet for the MM protocol
+       cmd.command[0] = MOTOROLA_SPEED;
+       cmd.command[1] = 80;
+       cmd.command[2] = 0;
+       cmd.command[3] = 0;
+       cmd.length = 4;
+
+       return true;
+}
+
+unsigned ArduControl::ControlThread::do_command(const PendingCommand &cmd)
+{
+       if(control.debug>=2)
        {
-               tag.serial = loco.reverse.serial;
-               length = loco.create_speed_dir_command(command);
+               string cmd_hex;
+               for(unsigned i=0; i<cmd.length; ++i)
+                       cmd_hex += format(" %02X", static_cast<unsigned char>(cmd.command[i]));
+               IO::print("< %02X%s\n", cmd.length^0xFF, cmd_hex);
        }
-       else if(cmd==Locomotive::FUNCTIONS)
+
+       control.serial.put(cmd.length^0xFF);
+       control.serial.write(cmd.command, cmd.length);
+
+       unsigned result = 0;
+       while(1)
        {
-               tag.serial = loco.funcs.serial;
-               length = loco.create_speed_func_command(index, command);
+               bool got_data;
+               if(result)
+                       got_data = IO::poll(control.serial, IO::P_INPUT, Time::zero);
+               else
+                       got_data = IO::poll(control.serial, IO::P_INPUT);
+
+               if(!got_data)
+                       break;
+
+               unsigned rlength = control.serial.get()^0xFF;
+               if(rlength>15)
+               {
+                       IO::print("Invalid length %02X\n", rlength);
+                       continue;
+               }
+
+               char reply[15];
+               unsigned pos = 0;
+               while(pos<rlength)
+                       pos += control.serial.read(reply+pos, rlength-pos);
+
+               if(control.debug>=2)
+               {
+                       string reply_hex;
+                       for(unsigned i=0; i<rlength; ++i)
+                               reply_hex += format(" %02X", static_cast<unsigned char>(reply[i]));
+                       IO::print("> %02X%s\n", rlength^0xFF, reply_hex);
+               }
+
+               unsigned r = process_reply(reply, rlength);
+               if(r && !result)
+                       result = r;
        }
-       else
-               throw invalid_argument("QueuedCommand");
+
+       return result;
 }
 
-ArduControl::QueuedCommand::QueuedCommand(Accessory &acc, Accessory::Command cmd, unsigned index)
+unsigned ArduControl::ControlThread::process_reply(const char *reply, unsigned rlength)
 {
-       tag.type = Tag::ACCESSORY;
-       tag.command = cmd;
-       tag.id = acc.address;
-       if(cmd==Accessory::ACTIVATE || cmd==Accessory::DEACTIVATE)
+       unsigned char type = reply[0];
+       if((type&0xE0)==0x80)
        {
-               tag.serial = acc.state.serial;
-               length = acc.create_state_command(index, (cmd==Accessory::ACTIVATE), command);
+               if(type!=COMMAND_OK)
+                       IO::print("Error %02X\n", type);
+               return type;
+       }
+       else if(type==POWER_STATE && rlength==2)
+       {
+               control.power.set(reply[1]);
+
+               Tag tag;
+               tag.type = Tag::GENERAL;
+               tag.command = POWER;
+               tag.serial = control.power.serial;
+               control.push_completed_tag(tag);
        }
        else
-               throw invalid_argument("QueuedCommand");
+       {
+               for(vector<Task *>::iterator i=tasks.begin(); i!=tasks.end(); ++i)
+                       (*i)->process_reply(reply, rlength);
+       }
+
+       return 0;
 }
 
 } // namespace R2C2
index 3a86ceeacc09790bbfc1c7afa04ac6dab29093ff..d794d00cd83150e4a6bcbb9c455d5faaaf049c1a 100644 (file)
@@ -166,11 +166,90 @@ private:
                Sensor(unsigned);
        };
 
+       struct PendingCommand
+       {
+               Tag tag;
+               char command[15];
+               unsigned char length;
+               unsigned repeat_count;
+
+               PendingCommand();
+               PendingCommand(GeneralCommand);
+               PendingCommand(Locomotive &, Locomotive::Command, unsigned = 0);
+               PendingCommand(Accessory &, Accessory::Command, unsigned = 0);
+       };
+
+       class Task
+       {
+       protected:
+               Task() { }
+       public:
+               virtual ~Task() { }
+
+               virtual bool get_work(PendingCommand &) = 0;
+               virtual void process_reply(const char *, unsigned) { }
+       };
+
+       class RefreshTask: public Task
+       {
+       private:
+               ArduControl &control;
+               Locomotive *loco;
+               unsigned phase;
+
+       public:
+               RefreshTask(ArduControl &);
+
+               virtual bool get_work(PendingCommand &);
+       };
+
+       class S88Task: public Task
+       {
+       private:
+               ArduControl &control;
+               unsigned octets_remaining;
+
+       public:
+               S88Task(ArduControl &);
+
+               virtual bool get_work(PendingCommand &);
+               virtual void process_reply(const char *, unsigned);
+       };
+
+       class MfxAnnounceTask: public Task
+       {
+       private:
+               ArduControl &control;
+               Msp::Time::TimeStamp next;
+
+       public:
+               MfxAnnounceTask(ArduControl &);
+
+               virtual bool get_work(PendingCommand &);
+       };
+
+       class MfxSearchTask: public Task
+       {
+       private:
+               ArduControl &control;
+               Msp::Time::TimeStamp next;
+               unsigned size;
+               unsigned bits;
+               bool pending;
+
+       public:
+               MfxSearchTask(ArduControl &);
+
+               virtual bool get_work(PendingCommand &);
+               virtual void process_reply(const char *, unsigned);
+       };
+
        class ControlThread: public Msp::Thread
        {
        private:
                ArduControl &control;
                bool done;
+               std::vector<Task *> tasks;
 
        public:
                ControlThread(ArduControl &);
@@ -178,18 +257,9 @@ private:
                void exit();
        private:
                virtual void main();
-       };
-
-       struct QueuedCommand
-       {
-               Tag tag;
-               char command[15];
-               unsigned char length;
-
-               QueuedCommand();
-               QueuedCommand(GeneralCommand);
-               QueuedCommand(Locomotive &, Locomotive::Command, unsigned = 0);
-               QueuedCommand(Accessory &, Accessory::Command, unsigned = 0);
+               bool get_work(PendingCommand &);
+               unsigned do_command(const PendingCommand &);
+               unsigned process_reply(const char *, unsigned);
        };
 
        typedef std::map<unsigned, Locomotive> LocomotiveMap;
@@ -211,7 +281,7 @@ private:
        AccessoryPtrList accessory_queue;
        Accessory *active_accessory;
        Msp::Time::TimeStamp off_timeout;
-       std::list<QueuedCommand> command_queue;
+       std::list<PendingCommand> command_queue;
        std::list<Tag> completed_commands;
 
        SensorMap sensors;
@@ -278,8 +348,8 @@ public:
        virtual void flush();
 
 private:
-       void push_command(const QueuedCommand &);
-       bool pop_command(QueuedCommand &);
+       void push_command(const PendingCommand &);
+       bool pop_command(PendingCommand &);
        void push_completed_tag(const Tag &);
        Tag pop_completed_tag();
 };