Issue 29090: PySerial crash on Windows XP and Python 3.4 (original) (raw)
Only info (Windows event viewer): Faulting application python_cc.exe, version 0.0.0.0, faulting module python34.dll, version 3.4.3150.1013, fault address 0x001059b7 Note: python_cc.exe is renamed python.exe to identify it in task manager. OS is Windows XP SP3
The following script crashes the python executable every few hours (not regular, seemingly random). The exact same script also crashes python 2.7.13. Each version has the latest pyserial module installed for the appropriate python version. When python 2.7 crashes, the reported error is always in _ctypes.dll which is used extensively in the serialwin32.py for reading the serial port, but python 3.4 fails in the main DLL.
This same script has been running without a problem for several years on the same hardware (Quad core Shuttle with CurrentCost 128 electricity monitor on COM3, using PL2303 serial/USB chipset (probably clone)). The crashes have only occured since harddisc replacement involving new XP installation and reinstallation of application software.
Occasionally, the crash results in a blue screen but usually its just the task crash notification (which I automatically dismiss using AutoIt3 watchdog script). Everything else on the machine id running normally so the serial port handling is the prime suspect.
import serial, sys, time, traceback, os import xml.etree.ElementTree as ET
correction = 1.074 # 247V when CC128 is designed for 230V path = "E:\Apache\htdocs\energy\elec_data\" log = "E:\Apache\htdocs\energy\log.txt" ser = None amps = [0,0,0,0]
def localtime(): y,m,d,h,mn,s,wd,b,c = time.localtime() return '%4d%02d%02d %02d%02d%02d' % (y,m,d,h,mn,s)
def dbg(msg): msg = msg.strip() print(msg) if len(msg) <= 2: return global log # avoid huge files if os.path.getsize(log) > 2000000: y,m,d,h,mn,s,wd,b,c = time.localtime() old = 'log_%4d%02d%02d_%02d%02d%02d.txt' % (y,m,d,h,mn,s) os.rename(log, old) f = open(log, 'a') t = localtime() f.write('%s %s\n' % (t, msg)) f.close()
try: ser = serial.Serial(port="COM3", baudrate=57600, bytesize=serial.EIGHTBITS, parity=serial.PARITY_NONE, stopbits=serial.STOPBITS_ONE, timeout=3) dbg("Connected to CurrentCost meter")
except serial.SerialException: dbg("Failed to connect to CurrentCost meter") sys.exit(1)
err_count = 0 while True: try: line = ser.readline().strip() # should be something every 6 seconds if line: watts = '' try: msg = ET.fromstring(line) watts = msg.findtext('ch1/watts') watts = float(watts) err_count = 0 except: watts = '' err_count += 1 finally: try: del exc_info except: pass
if watts:
# _ _ _ _
# _ or __ regarded as bogus
amps[0] = amps[1]; amps[1] = amps[2]; amps[2] = amps[3]
amps[3] = float(watts)*.00405 # 247 volts
bogus = False
if amps[1]>0 and amps[1] < amps[0]/2:
if amps[1] < amps[2]/2: bogus = True
if amps[1] < amps[3]/2 and amps[2] < amps[3]/2: bogus = True
#dbg('%s %s %s %s %s' % (amps[0],amps[1],amps[2],amps[3],bogus))
if not bogus and amps[2]>0 and amps[3]>0:
y,m,d,h,mn,s,a,b,c = time.localtime()
try:
line = '%f,%f' % (float(h)+float(mn)/60+float(s)/3600, amps[1])
f = open('%s\\%4d%02d%02d.csv' % (path,y,m,d), 'a')
f.write('%s\n' % line)
f.close()
except:
exc_info = sys.exc_info()
dbg('CC EXCEPTION %s ' % traceback.format_exception(*exc_info))
finally:
try:
del exc_info # force garbage collection
except:
pass
else:
if err_count > 100:
dbg("100 consecutive errors detected")
break
except serial.SerialException:
exc_info = sys.exc_info()
dbg('CC EXCEPTION %s ' % traceback.format_exception(*exc_info))
ser.close()
sys.exit(1)
except KeyboardInterrupt:
ser.close()
sys.exit(0)
except:
exc_info = sys.exc_info()
dbg('CC EXCEPTION %s ' % traceback.format_exception(*exc_info))
finally:
try:
del exc_info # force garbage collection
except:
passser.close() sys.exit(1)