Vince Harron 85d1965abd dotest.py - debug feature that helps find dosep races
SUMMARY
dosep.py starts lots and lots of dotest instances.

This option helps you find if two (or more) dotest instances are using
the same directory at the same time.

Enable it to cause test failures and stderr messages if dotest
instances try to run in the same directory simultaneously.

It is disabled by default because it litters the test directories with
".dirlock" files

TEST PLAN
Set lldbtest.debug_confirm_directory_exclusivity = True
run ./dosep.py

Differential Revision: http://reviews.llvm.org/D9868

llvm-svn: 237935
2015-05-21 19:09:29 +00:00

28 lines
617 B
Python

"""
Interprocess mutex based on file locks
"""
import fcntl
import os
class Lock:
def __init__(self, filename):
self.filename = filename
# This will create it if it does not exist already
unbuffered = 0
self.handle = open(filename, 'a+', unbuffered)
def acquire(self):
fcntl.flock(self.handle, fcntl.LOCK_EX)
# will throw IOError if unavailable
def try_acquire(self):
fcntl.flock(self.handle, fcntl.LOCK_NB | fcntl.LOCK_EX)
def release(self):
fcntl.flock(self.handle, fcntl.LOCK_UN)
def __del__(self):
self.handle.close()