#103 wait_for_edge() raises "Error waiting for edge" in multi-threaded app

[Alexander Simakov]

Hello Ben,

In my application I have several threads and each one is calling
wait_for_edge() on it's own pin. It turns out that I cannot call
wait_for_edge() if another thread is also calling this method:

#!/usr/bin/python

import RPi.GPIO as GPIO
from threading import Thread

GPIO.setmode(GPIO.BCM)

GPIO.setup(14, GPIO.IN)
GPIO.setup(16, GPIO.IN)

def callback():
    GPIO.wait_for_edge(14, GPIO.RISING)

t = Thread(target=callback)
t.daemon = True
t.start()

GPIO.wait_for_edge(16, GPIO.RISING)

Error:

Traceback (most recent call last):
  File "./wait_for_edge.py", line 18, in <module>
    GPIO.wait_for_edge(16, GPIO.RISING)
RuntimeError: Error waiting for edge

Is this a bug or by design?

RPi.GPIO version 0.5.11
Raspberry Pi B+
Raspbian Linux (/etc/debian_version=7.6)

[Ben Croston]

This might be fixed in release 0.6.3. I need to add a test for this case.

[Ray Cox]

I am seeing this behavior still in 0.6.3. Is there any kind of workaround?

[Jeff Chua]

Any update?

[ssph]

I use 0.7.0 and have the same problem.