diff options
Diffstat (limited to 'envmon/onewire-sysfs.py')
| -rw-r--r-- | envmon/onewire-sysfs.py | 45 |
1 files changed, 32 insertions, 13 deletions
diff --git a/envmon/onewire-sysfs.py b/envmon/onewire-sysfs.py index c10e83f..d889768 100644 --- a/envmon/onewire-sysfs.py +++ b/envmon/onewire-sysfs.py @@ -7,6 +7,7 @@ import errno import re import sys import time +import random class OnewireException(Exception): pass @@ -31,6 +32,9 @@ class SensorFacade(object): def __init__(self, addr, name): self._addr = addr self._name = name + self._cached = None + self._cachets = None + self._backoff = None def _path(self): addr = self._addr.replace('.', '-').lower() @@ -58,19 +62,34 @@ class SensorFacade(object): @property def temperature(self): - for i in range(2, 0,-1): - try: - rv = self.get_temperature() - if rv > 65 or rv < -25: - raise OutOfRange, (self._path(), rv) - return rv - except SensorNotPresent: - raise - except Exception, e: - if i == 1: - raise - sys.excepthook(*sys.exc_info()) - time.sleep(0.5) + if self._cachets > time.time() - 50: + return self._cached + if self._backoff > time.time(): + if self._cachets > time.time() - 250: + return self._cached + return None + + try: + rv = self.get_temperature() + if rv > 65 or rv < -25: + raise OutOfRange, (self._path(), rv) + self._cached = rv + self._cachets = time.time() + self._backoff = None + print '\033[32m', self._name, 'read', self._cached, '\033[m' + return self._cached + except SensorNotPresent: + self._backoff = time.time() + 2 + random.expovariate(1./3.) * 2 + print '\033[31m', self._name, 'SensorNotPresent back-off', self._backoff - time.time(), '\033[m' + if self._cachets > time.time() - 250: + return self._cached + raise + except OutOfRange: + self._backoff = time.time() + 15 + random.expovariate(1./4.) * 10 + print '\033[33m', self._name, 'OutOfRange back-off', self._backoff - time.time(), '\033[m' + if self._cachets > time.time() - 250: + return self._cached + raise def sensor(name): if name not in _sensors: |