Merge pull request #17 from CleoQc/master

Move I2C_mutex out of GoPiGo and GoPiGo3 and into here

Author: CleoQc

I2C_mutex.py

@@ -0,0 +1,52 @@
+import fcntl
+import time
+
+class Mutex(object):
+
+    DexterLockI2C_handle = None
+
+    def __init__(self, debug = False):
+        self.mutex_debug = debug
+
+    def acquire(self):
+        if self.mutex_debug:
+            print("I2C mutex acquire")
+
+        acquired = False
+        while not acquired:
+            try:
+                self.DexterLockI2C_handle = open('/run/lock/DexterLockI2C', 'w')
+                # lock
+                fcntl.lockf(self.DexterLockI2C_handle, fcntl.LOCK_EX | fcntl.LOCK_NB)
+                acquired = True
+            except IOError: # already locked by a different process
+                time.sleep(0.001)
+            except Exception as e:
+                print(e)
+        if self.mutex_debug:
+            print("I2C mutex acquired {}".format(time.time()))
+
+
+    def release(self):
+        if self.mutex_debug:
+            print("I2C mutex release: {}".format(time.time()))
+        if self.DexterLockI2C_handle is not None and self.DexterLockI2C_handle is not True:
+            self.DexterLockI2C_handle.close()
+            self.DexterLockI2C_handle = None
+            time.sleep(0.001)
+
+    def enableDebug(self):
+        self.mutex_debug = True
+
+    def disableDebug(self):
+        self.mutex_debug = False
+
+    def __enter__(self):
+        if self.mutex_debug:
+            print("I2C mutex enter")
+        return self
+
+    def __exit__(self, exception_type, exception_value, traceback):
+        if self.mutex_debug:
+            print("I2C mutex exit")
+        self.release()

install_script_tools.sh

@@ -49,6 +49,7 @@ fi
 
 cd $PIHOME/$DEXTER/$LIB/$DEXTER/$SCRIPT
 sudo apt-get install build-essential libi2c-dev i2c-tools python-dev libffi-dev -y
-python autodetect_setup.py install
+python setup.py install
+python3 setup.py install
 
 popd > /dev/null

autodetect_setup.py setup.pyautodetect_setup.py renamed to setup.py

@@ -23,10 +23,10 @@
 '''
 import setuptools
 setuptools.setup(
-	name="Dexter AutoDetection",
-	description="Dexter Industries Robot Autodetection",
+	name="Dexter AutoDetection and I2C Mutex",
+	description="Dexter Industries Robot Autodetection and I2C Mutex Security",
 	author="Dexter Industries",
 	url="http://www.dexterindustries.com/GoPiGo/",
-	py_modules=['auto_detect_robot', 'auto_detect_rpi'],
+	py_modules=['auto_detect_robot', 'auto_detect_rpi', 'I2C_mutex'],
 	install_requires=['smbus-cffi', 'pyserial'],
 )