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Multithreading deadlock debugger
"""Stack tracer for multi-threaded applications.
Usage:
import stacktracer
stacktracer.trace_start("trace.html",interval=5,auto=True) # Set auto flag to always update file!
....
stacktracer.trace_stop()
"""
import sys
import traceback
from pygments import highlight
from pygments.lexers import PythonLexer
from pygments.formatters import HtmlFormatter
# Taken from http://bzimmer.ziclix.com/2008/12/17/python-thread-dumps/
def stacktraces():
code = []
for threadId, stack in sys._current_frames().items():
code.append("\n# ThreadID: %s" % threadId)
for filename, lineno, name, line in traceback.extract_stack(stack):
code.append('File: "%s", line %d, in %s' % (filename, lineno, name))
if line:
code.append(" %s" % (line.strip()))
return highlight("\n".join(code), PythonLexer(), HtmlFormatter(
full=False,
# style="native",
noclasses=True,
))
# This part was made by nagylzs
import os
import time
import threading
class TraceDumper(threading.Thread):
"""Dump stack traces into a given file periodically."""
def __init__(self,fpath,interval,auto):
"""
@param fpath: File path to output HTML (stack trace file)
@param auto: Set flag (True) to update trace continuously.
Clear flag (False) to update only if file not exists.
(Then delete the file to force update.)
@param interval: In seconds: how often to update the trace file.
"""
assert(interval>0.1)
self.auto = auto
self.interval = interval
self.fpath = os.path.abspath(fpath)
self.stop_requested = threading.Event()
threading.Thread.__init__(self)
def run(self):
while not self.stop_requested.isSet():
time.sleep(self.interval)
if self.auto or not os.path.isfile(self.fpath):
self.stacktraces()
def stop(self):
self.stop_requested.set()
self.join()
try:
if os.path.isfile(self.fpath):
os.unlink(self.fpath)
except:
pass
def stacktraces(self):
fout = open(self.fpath,"w")
try:
fout.write(stacktraces())
finally:
fout.close()
_tracer = None
def trace_start(fpath,interval=5,auto=True):
"""Start tracing into the given file."""
global _tracer
if _tracer is None:
_tracer = TraceDumper(fpath,interval,auto)
_tracer.setDaemon(True)
_tracer.start()
else:
raise Exception("Already tracing to %s"%_tracer.fpath)
def trace_stop():
"""Stop tracing."""
global _tracer
if _tracer is None:
raise Exception("Not tracing, cannot stop.")
else:
_trace.stop()
_trace = None
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