os.readlink can return errno.ESRCH

[giampaolo]

From wick...@gmail.com on May 08, 2014 04:04:21

Traceback (most recent call last):
  File "/usr/local/bin/thermos_observe/twitter/common/exceptions/__init__.py", 
line 126, in _excepting_run
  File "/usr/local/bin/thermos_observe/twitter/aurora/observer/mesos_vars.py", 
line 510, in run
  File "/usr/local/bin/thermos_observe/twitter/aurora/observer/mesos_vars.py", 
line 314, in collect
  File "/usr/local/bin/thermos_observe/twitter/aurora/observer/mesos_vars.py", 
line 324, in collect_slaves
  File 
"/root/.pex/install/3c8008ea22662d5ffd7a5f0b056c41fdc13c1c49/psutil-1.1.2-py2.6-linux-x86_64.egg/psutil/_common.py",
 line 48, in __get__
    ret = self.func(instance)
  File 
"/root/.pex/install/3c8008ea22662d5ffd7a5f0b056c41fdc13c1c49/psutil-1.1.2-py2.6-linux-x86_64.egg/psutil/__init__.py",
 line 380, in exe
    exe = self._platform_impl.get_process_exe()
  File 
"/root/.pex/install/3c8008ea22662d5ffd7a5f0b056c41fdc13c1c49/psutil-1.1.2-py2.6-linux-x86_64.egg/psutil/_pslinux.py",
 line 480, in get_process_exe
    exe = os.readlink("/proc/%s/exe" % self.pid)
OSError: [Errno 3] No such process: '/proc/563/exe' 


Happens on Python 2.6.8, Linux x86_64 2.6.50 custom kernel. Verified that this 
code is unchanged in 2.1.1.

It looks like os.readlink('/proc/pid/exe') actually raises OSError errno.ESRCH 
instead of errno.ENOENT when it races.

This is fairly rare -- the code runs on many, many machines and we've only 
experienced this issue a handful of times.

Original issue: http://code.google.com/p/psutil/issues/detail?id=503

[giampaolo]

From g.rodola on May 08, 2014 08:36:05

Thanks. Fixed in revision 1c6aac966b4f .

Status: FixedInHG
Labels: OpSys-Linux