Timing/syncing issue

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1

I’m experiencing an issue when communicating values from one live_loop to another:

set :cnt,0

live_loop :loop1, sync: :loop2 do
  use_real_time
  use_bpm 60
  sleep 0.1
  print "loop1", get[:cnt]
end


live_loop :loop2 do
  use_real_time
  use_bpm 60
  note, velocity = sync "/midi:midiin2_(lpminimk3_midi)_1:10/note_on"
  
  set :cnt, get[:cnt]+1
  
  print "loop2", get[:cnt]
end

I see the following log when I press a key and trigger a 2nd MIDI in event.

....
{run: 85, time: 3.248, thread: :live_loop_loop2}
 └─ "loop2" 2
 
{run: 85, time: 3.323, thread: :live_loop_loop1}
 └─ "loop1" 1
 
{run: 85, time: 3.423, thread: :live_loop_loop1}
 └─ "loop1" 1
 
{run: 85, time: 3.523, thread: :live_loop_loop1}
 └─ "loop1" 1
 
{run: 85, time: 3.623, thread: :live_loop_loop1}
 └─ "loop1" 2

How is it possible that loop1 needs 3 iterations before it sees the update of cnt?

2

It would be great if someone could run my program to confirm it is an Sonic Pi issue, and not somehow an issue in my System configuration. Thanks in advance!

3

I had a play with this this morning.
I think it works with the modification below


set :cnt,0

live_loop :loop1  do
  sync :loop2 #move the sync to here
  use_real_time
  use_bpm 60
  sleep 0.01 #makes sure set :cnt completed before you try and get it
  print "loop1", get[:cnt]
end


live_loop :loop2 do
  use_real_time
  use_bpm 60
  note, velocity = sync "/midi:usb_oxygen_8_v2:1/note_on" #adjusted for my keyboard
  
  set :cnt, get[:cnt]+1
  
  print "loop2", get[:cnt]
end

Also I think you could put the use_bmp outside the loops just once

4

Thanks for trying.

Loop1 will for example play a beat reacts on a shared variable that is set in loop2. So placing a “sync :loop2” into loop1 is problematic as it will wait for a new note.

I really don’t understand the behaviour. If loop1 has a sleep of 0.1 then it should lag at most one iteration.

5

I updated the code so that both threads start in sync

set :cnt,0

live_loop :loop1, sync: :main  do
  use_real_time
  use_bpm 60
  sleep 0.05 
  print "loop1", get[:cnt]
end


live_loop :loop2, sync: :main do
  use_real_time
  use_bpm 60
    
  note, velocity = sync "/midi:midiin2_(lpminimk3_midi)_1:1/note_on" #adjusted for my keyboard
  
  set :cnt, get[:cnt]+1
  
  print "loop2", get[:cnt]
end

sleep 1

cue :main # make sure both threads start synced

The log shows this:

At 11.8215 loop2 sets cnt to 2, but only at time 12.251 does loop1 see the change!

run: 14, time: 11.5892, thread: :live_loop_loop2}
└─ “loop2” 1

{run: 14, time: 11.651, thread: :live_loop_loop1}
└─ “loop1” 0

{run: 14, time: 11.701, thread: :live_loop_loop1}
└─ “loop1” 0

{run: 14, time: 11.751, thread: :live_loop_loop1}
└─ “loop1” 0

{run: 14, time: 11.801, thread: :live_loop_loop1}
└─ “loop1” 0

{run: 14, time: 11.8215, thread: :live_loop_loop2}
└─ “loop2” 2

{run: 14, time: 11.851, thread: :live_loop_loop1}
└─ “loop1” 0

{run: 14, time: 11.901, thread: :live_loop_loop1}
└─ “loop1” 0

{run: 14, time: 11.951, thread: :live_loop_loop1}
└─ “loop1” 1

{run: 14, time: 12.001, thread: :live_loop_loop1}
└─ “loop1” 1

{run: 14, time: 12.051, thread: :live_loop_loop1}
└─ “loop1” 1

{run: 14, time: 12.101, thread: :live_loop_loop1}
└─ “loop1” 1

{run: 14, time: 12.151, thread: :live_loop_loop1}
└─ “loop1” 1

{run: 14, time: 12.201, thread: :live_loop_loop1}
└─ “loop1” 1

{run: 14, time: 12.251, thread: :live_loop_loop1}
└─ “loop1” 2