AtlRunQueryMemUtil.py

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# Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
 
import os
 
_proc_status = '/proc/%d/status' % os.getpid()
 
_scale = {'kB': 1024.0, 'mB': 1024.0*1024.0,
          'KB': 1024.0, 'MB': 1024.0*1024.0}
 
def _VmB(VmKey):
    '''Private.
    '''
    global _proc_status, _scale
     # get pseudo file  /proc/<pid>/status
    try:
        t = open(_proc_status)
        v = t.read()
        t.close()
    except (OSError,ValueError):
        return 0.0  # non-Linux?
     # get VmKey line e.g. 'VmRSS:  9999  kB\n ...'
    i = v.index(VmKey)
    v = v[i:].split(None, 3)  # whitespace
    if len(v) < 3:
        return 0.0  # invalid format?
     # convert Vm value to bytes
    return float(v[1]) * _scale[v[2]]
 
 
def memory(since=0.0):
    '''Return memory usage in bytes.
    '''
    return _VmB('VmSize:') - since
 
 
def resident(since=0.0):
    '''Return resident memory usage in bytes.
    '''
    return _VmB('VmRSS:') - since
 
 
def stacksize(since=0.0):
    '''Return stack size in bytes.
    '''
    return _VmB('VmStk:') - since