# -*- coding: utf-8 -*-
# Part of the PsychoPy library
# Copyright (C) 2012-2020 iSolver Software Solutions (C) 2021 Open Science Tools Ltd.
# Distributed under the terms of the GNU General Public License (GPL).
import gc
import sys
import psutil
from ..errors import print2err
from psychopy import clock
REALTIME_PRIORITY_CLASS = -18
HIGH_PRIORITY_CLASS = -10
[docs]
class Computer():
"""Computer provides access to OS and Process level functionality:
* Read the current time in sec.msec format. The time base used is shared by
the ioHub and PsychoPy processes.
* Access the iohub and psychopy psutil.Process objects
* Get / set process priority and affinity.
* Read system memory and CPU usage
Computer contains only static methods and class attributes. Therefore
all supported functionality can be accessed directly from the Computer
class itself; an instance of the class never needs to be created.
"""
#: Access to the psutil.Process class for the current system Process.
current_process = psutil.Process()
#: The psutil Process object for the ioHub Process.
iohub_process = None
#: If Computer class is on the iohub server process, psychopy_process is
#: the psychopy process created from the pid passed to iohub on startup.
#: The iohub server checks that this process exists
#: (server.checkForPsychopyProcess()) and shuts down if it does not.
psychopy_process = None
#: The OS process ID of the ioHub Process.
iohub_process_id = None
#: True if the current process is the ioHub Server Process. False if the
#: current process is the Experiment Runtime Process.
is_iohub_process = False
#: global_clock is used as the common time base for all devices
#: and between the ioHub Server and Experiment Runtime Process. Do not
#: access this class directly, instead use the Computer.getTime()
#: and associated method name alias's to actually get the current ioHub
# time.
global_clock = clock.monotonicClock
#: The name of the current operating system Python is running on.
platform = sys.platform
#: Python Env. bits: 32 or 64. Note that when a
#: Python 32 bit runtime is used a 64 bit OS sysbits will equal 32.
pybits = 32 + int(sys.maxsize > 2 ** 32) * 32
try:
#: Attribute representing the number of *processing units* available on
#: the current computer. This includes cpu's, cpu cores, and hyperthreads.
#:
#: processing_unit_count = num_cpus * cores_per_cpu * num_hyperthreads
#:
#: where:
#: * num_cpus: Number of CPU chips on the motherboard
#: (usually 1 now).
#: * cores_per_cpu: Number of processing cores per CPU (2,4 is common)
#: * num_hyperthreads: Hyper-threaded cores = 2, otherwise 1.
processing_unit_count = psutil.cpu_count()
#: The number of cpu cores available on the computer.
#: Hyperthreads are NOT included.
core_count = psutil.cpu_count(False) #hyperthreads not included
except AttributeError:
# psutil might be too old (cpu_count added in 2.0)
import multiprocessing
processing_unit_count = multiprocessing.cpu_count()
core_count = None # but not used anyway
try:
#: Process priority when first started. If process is set to
#: high priority, this value is used when the process is set back to
#: normal priority.
_process_original_nice_value=psutil.Process().nice() # used on linux.
except TypeError:
# on older versions of psutil (in ubuntu 14.04) nice is attr not call
_process_original_nice_value=psutil.Process().nice
#: True if the current process is currently in high or real-time
#: priority mode (enabled by calling Computer.setPriority()).
in_high_priority_mode = False
def __init__(self):
print2err('WARNING: Computer is a static class, '
'no need to create an instance. just use Computer.xxxxxx')
[docs]
@staticmethod
def getPriority():
"""Returns the current processes priority as a string.
This method is not supported on OS X.
:return: 'normal', 'high', or 'realtime'
"""
proc_priority = Computer.current_process.nice()
if Computer.platform == 'win32':
if proc_priority == psutil.HIGH_PRIORITY_CLASS:
return 'high'
if proc_priority == psutil.REALTIME_PRIORITY_CLASS:
return 'realtime'
if proc_priority == psutil.NORMAL_PRIORITY_CLASS:
return 'normal'
else:
if proc_priority <= REALTIME_PRIORITY_CLASS:
return 'realtime'
if proc_priority <= HIGH_PRIORITY_CLASS:
return 'high'
if proc_priority == Computer._process_original_nice_value:
return 'normal'
return proc_priority
@staticmethod
def _setProcessPriority(process, nice_val, disable_gc):
org_nice_val = Computer._process_original_nice_value
try:
process.nice(nice_val)
Computer.in_high_priority_mode = nice_val != org_nice_val
if disable_gc:
gc.disable()
else:
gc.enable()
return True
except psutil.AccessDenied:
print2err('WARNING: Could not set process {} priority '
'to {}'.format(process.pid, nice_val))
return False
[docs]
@staticmethod
def setPriority(level='normal', disable_gc=False):
"""
Attempts to change the current processes priority based on level.
Supported levels are:
* 'normal': sets the current process priority to
NORMAL_PRIORITY_CLASS on Windows, or to the processes original
nice value on Linux.
* 'high': sets the current process priority to HIGH_PRIORITY_CLASS
on Windows, or to a nice value of -10 value on Linux.
* 'realtime': sets the current process priority to
REALTIME_PRIORITY_CLASS on Windows, or to a nice value of -18
value on Linux.
If level is 'normal', Python GC is also enabled.
If level is 'high' or 'realtime', and disable_gc is True, then the
Python garbage collection (GC) thread is suspended.
This method is not supported on OS X.
:return: Priority level of process when method returns.
"""
level = level.lower()
current_process = Computer.current_process
nice_val = Computer._process_original_nice_value
if level == 'normal':
disable_gc = False
elif level == 'high':
nice_val = HIGH_PRIORITY_CLASS
if Computer.platform == 'win32':
nice_val = psutil.HIGH_PRIORITY_CLASS
elif level.lower() == 'realtime':
nice_val = REALTIME_PRIORITY_CLASS
if Computer.platform == 'win32':
nice_val = psutil.REALTIME_PRIORITY_CLASS
Computer._setProcessPriority(current_process, nice_val, disable_gc)
return Computer.getPriority()
[docs]
@staticmethod
def getProcessingUnitCount():
"""
Return the number of *processing units* available on the current
computer.
Processing Units include: cpu's, cpu cores, and hyper threads.
Notes:
* processing_unit_count = num_cpus*num_cores_per_cpu*num_hyperthreads.
* For single core CPU's, num_cores_per_cpu = 1.
* For CPU's that do not support hyperthreading, num_hyperthreads =
1, otherwise num_hyperthreads = 2.
Args:
None
Returns:
int: the number of processing units on the computer.
"""
return Computer.processing_unit_count
[docs]
@staticmethod
def getProcessAffinities():
"""Retrieve the current PsychoPy Process affinity list and ioHub
Process affinity list.
For example, on a 2 core CPU with hyper-threading, the possible
'processor'
list would be [0,1,2,3], and by default both the PsychoPy and ioHub
Processes can run on any of these 'processors', so::
psychoCPUs,ioHubCPUS=Computer.getProcessAffinities()
print psychoCPUs,ioHubCPUS
>> [0,1,2,3], [0,1,2,3]
If Computer.setProcessAffinities was used to set the PsychoPy
Process to core 1
(index 0 and 1) and the ioHub Process to core 2 (index 2 and 3),
with each using both hyper threads of the given core, the set call
would look like::
Computer.setProcessAffinities([0,1],[2,3])
psychoCPUs,ioHubCPUS=Computer.getProcessAffinities()
print psychoCPUs,ioHubCPUS
>> [0,1], [2,3]
If the ioHub is not being used (i.e self.hub is None), then only the
PsychoPy
Process affinity list will be returned and None will be returned for
the
ioHub Process affinity::
psychoCPUs,ioHubCPUS=Computer.getProcessAffinities()
print psychoCPUs,ioHubCPUS
>> [0,1,2,3], None
**But in this case, why are you using the ioHub package at all? ;)**
This method is not supported on OS X.
Args:
None
Returns:
(list,list) Tuple of two lists: PsychoPy Process affinity ID
list and ioHub Process affinity ID list.
"""
curproc_affinity = Computer.current_process.cpu_affinity()
iohproc_affinity = Computer.iohub_process.cpu_affinity()
return curproc_affinity, iohproc_affinity
[docs]
@staticmethod
def setProcessAffinities(experimentProcessorList, ioHubProcessorList):
"""Sets the processor affinity for the PsychoPy Process and the ioHub
Process.
For example, on a 2 core CPU with hyper-threading, the possible
'processor'
list would be [0,1,2,3], and by default both the experiment and ioHub
server processes can run on any of these 'processors',
so to have both processes have all processors available
(which is the default), you would call::
Computer.setProcessAffinities([0,1,2,3], [0,1,2,3])
# check the process affinities
psychoCPUs,ioHubCPUS=Computer.getProcessAffinities()
print psychoCPUs,ioHubCPUS
>> [0,1,2,3], [0,1,2,3]
based on the above CPU example.
If setProcessAffinities was used to set the experiment process to
core 1
(index 0,1) and the ioHub server process to core 2 (index 2,3), with
each using both hyper threads of the given core, the set call would
look
like::
Computer.setProcessAffinities([0,1],[2,3])
# check the process affinities
psychoCPUs,ioHubCPUS=Computer.getProcessAffinities()
print psychoCPUs,ioHubCPUS
>> [0,1], [2,3]
Args:
experimentProcessorList (list): list of int processor ID's to set
the PsychoPy Process affinity to. An empty list means all
processors.
ioHubProcessorList (list): list of int processor ID's to set the
ioHub Process affinity to. An empty list means all processors.
Returns:
None
"""
Computer.current_process.cpu_affinity(experimentProcessorList)
Computer.iohub_process.cpu_affinity(ioHubProcessorList)
[docs]
@staticmethod
def autoAssignAffinities():
"""Auto sets the PsychoPy Process and ioHub Process affinities based on
some very simple logic.
It is not known at this time if the implementation of this method makes
any sense in terms of actually improving performance. Field tests and
feedback will need to occur, based on which the algorithm can be
improved.
Currently:
* If the system is detected to have 1 processing unit, or greater
than 8 processing units, nothing is done by the method.
* For a system that has two processing units, the PsychoPy Process
is assigned to index 0, ioHub Process assigned to 1.
* For a system that has four processing units, the PsychoPy Process
is assigned to index's 0,1 and the ioHub Process assigned to 2,3.
* For a system that has eight processing units, the PsychoPy Process
is assigned to index 2,3, ioHub Process assigned to 4,5. All other
processes running on the OS are attempted to be assigned to indexes
0,1,6,7.
Args:
None
Returns:
None
"""
cpu_count = Computer.processing_unit_count
if cpu_count == 2:
# print 'Assigning experiment process to CPU 0, ioHubServer process
# to CPU 1'
Computer.setProcessAffinities([0, ], [1, ])
elif cpu_count == 4:
# print 'Assigning experiment process to CPU 0,1, ioHubServer
# process to CPU 2,3'
Computer.setProcessAffinities([0, 1], [2, 3])
elif cpu_count == 8:
# print 'Assigning experiment process to CPU 2,3, ioHubServer
# process to CPU 4,5, attempting to assign all others to 0,1,6,7'
Computer.setProcessAffinities([2, 3], [4, 5])
Computer.setAllOtherProcessesAffinity(
[0, 1, 6, 7],
[Computer.currentProcessID, Computer.iohub_process_id])
else:
print('autoAssignAffinities does not support %d processors.' % (
cpu_count,))
[docs]
@staticmethod
def getCurrentProcessAffinity():
"""
Returns a list of 'processor' ID's (from 0 to
Computer.processing_unit_count-1)
that the current (calling) process is able to run on.
Args:
None
Returns:
None
"""
return Computer.current_process.cpu_affinity()
[docs]
@staticmethod
def setCurrentProcessAffinity(processorList):
"""
Sets the list of 'processor' ID's (from 0 to
Computer.processing_unit_count-1)
that the current (calling) process should only be allowed to run on.
Args:
processorList (list): list of int processor ID's to set the
current Process affinity to. An empty list means all processors.
Returns:
None
"""
return Computer.current_process.cpu_affinity(processorList)
[docs]
@staticmethod
def setProcessAffinityByID(process_id, processor_list):
"""
Sets the list of 'processor' ID's (from 0 to
Computer.processing_unit_count-1)
that the process with the provided OS Process ID is able to run on.
Args:
processID (int): The system process ID that the affinity should
be set for.
processorList (list): list of int processor ID's to set process
with the given processID too. An empty list means all processors.
Returns:
None
"""
p = psutil.Process(process_id)
return p.cpu_affinity(processor_list)
[docs]
@staticmethod
def getProcessAffinityByID(process_id):
"""
Returns a list of 'processor' ID's (from 0 to
Computer.processing_unit_count-1)
that the process with the provided processID is able to run on.
Args:
processID (int): The system process ID that the affinity should
be set for.
Returns:
processorList (list): list of int processor ID's to set process
with the given processID too. An empty list means all processors.
"""
p = psutil.Process(process_id)
return p.cpu_affinity()
[docs]
@staticmethod
def setAllOtherProcessesAffinity(
processor_list,
exclude_process_id_list=[]):
"""
Sets the affinity for all OS Processes other than those specified in
the
exclude_process_id_list, to the processing unit indexes specified in
processor_list.
Valid values in the processor_list are between 0 to
Computer.processing_unit_count-1.
exclude_process_id_list should be a list of OS Process ID integers,
or an empty list (indicating to set the affiinty to all processing
units).
Note that the OS may not allow the calling process to set the affinity
of every other process running on the system. For example, some system
level processing can not have their affinity set by a user level
application.
However, in general, many processes can have their affinity set by
another user process.
Args:
processor_list (list): list of int processor ID's to set all OS
Processes to. An empty list means all processors.
exclude_process_id_list (list): A list of process ID's that
should not have their process affinity settings changed.
Returns:
None
"""
for p in psutil.pids():
if p not in exclude_process_id_list:
try:
psutil.Process(p).cpu_affinity(processor_list)
except Exception:
pass
@staticmethod
def getProcessFromName(pnames, id_only=False):
procs = []
if isinstance(pnames, str):
pnames = [pnames, ]
for p in psutil.process_iter():
if p.name() in pnames:
if id_only:
procs.append(p.pid)
else:
procs.append(p)
return procs
[docs]
@staticmethod
def getTime():
"""
Returns the current sec.msec-msec time of the system.
The underlying timer that is used is based on OS and Python version.
Three requirements exist for the ioHub time base implementation:
* The Python interpreter does not apply an offset to the times
returned based on when the timer module being used was loaded or
when the timer function first called was first called.
* The timer implementation used must be monotonic and report elapsed
time between calls, 'not' CPU usage time.
* The timer implementation must provide a resolution of 50 usec or
better.
Given the above requirements, ioHub selects a timer implementation
as follows:
* On Windows, the Windows Query Performance Counter API is used
using ctypes access.
* On other OS's, if the Python version being used is 2.6 or lower,
time.time is used. For Python 2.7 and above,
the timeit.default_timer function is used.
Args:
None
Returns:
None
"""
return Computer.global_clock.getTime()
[docs]
@staticmethod
def syncClock(params):
"""
Sync parameters between Computer.global_clock and a given dict.
Parameters
----------
params : dict
Dict of attributes and values to apply to the computer's global clock. See
`psychopy.clock.MonotonicClock` for what attributes to include.
"""
for key, value in params.items():
setattr(Computer.global_clock, key, value)
[docs]
@staticmethod
def getPhysicalSystemMemoryInfo():
"""Return a class containing information about current memory usage.
Args:
None
Returns:
vmem: (total=long, available=long, percent=float, used=long,
free=long)
Where:
* vmem.total: the total amount of memory in bytes.
* vmem.available: the available amount of memory in bytes.
* vmem.percent: the percent of memory in use by the system.
* vmem.used: the used amount of memory in bytes.
* vmem.free: the amount of memory that is free in bytes.On Windows,
this is the same as vmem.available.
"""
m = psutil.virtual_memory()
return m
[docs]
@staticmethod
def getCPUTimeInfo(percpu=False):
"""Return a float representing the current CPU utilization as a
percentage.
Args:
percpu (bool): If True, a list of cputimes objects is returned,
one for each processing unit for the computer.
If False, only a single cputimes object is returned.
Returns:
object: (user=float, system=float, idle=float)
"""
return psutil.cpu_times_percent(percpu=percpu)
[docs]
@staticmethod
def getCurrentProcess():
"""Get the current / Local process.
On Windows and Linux, this is a psutil.Process class instance.
Args:
None
Returns:
object: Process object for the current system process.
"""
return Computer.current_process
[docs]
@staticmethod
def getIoHubProcess():
"""Get the ioHub Process.
On Windows and Linux, this is a psutil.Process class instance.
Args:
None
Returns:
object: Process object for the ioHub Process.
"""
return Computer.iohub_process
