resource — 系统资源管理

Current Usage

# resource_getrusage.py
import resource
import time

RESOURCES = [
    ('ru_utime', 'User time'),
    ('ru_stime', 'System time'),
    ('ru_maxrss', 'Max. Resident Set Size'),
    ('ru_ixrss', 'Shared Memory Size'),
    ('ru_idrss', 'Unshared Memory Size'),
    ('ru_isrss', 'Stack Size'),
    ('ru_inblock', 'Block inputs'),
    ('ru_oublock', 'Block outputs'),
]

usage = resource.getrusage(resource.RUSAGE_SELF)

for name, desc in RESOURCES:
    print('{:<25} ({:<10}) = {}'.format(
        desc, name, getattr(usage, name)))

Resource Limits

# resource_getrlimit.py
import resource

LIMITS = [
    ('RLIMIT_CORE', 'core file size'),
    ('RLIMIT_CPU', 'CPU time'),
    ('RLIMIT_FSIZE', 'file size'),
    ('RLIMIT_DATA', 'heap size'),
    ('RLIMIT_STACK', 'stack size'),
    ('RLIMIT_RSS', 'resident set size'),
    ('RLIMIT_NPROC', 'number of processes'),
    ('RLIMIT_NOFILE', 'number of open files'),
    ('RLIMIT_MEMLOCK', 'lockable memory address'),
]

print('Resource limits (soft/hard):')
for name, desc in LIMITS:
    limit_num = getattr(resource, name)
    soft, hard = resource.getrlimit(limit_num)
    print('{:<23} {}/{}'.format(desc, soft, hard))

# resource_setrlimit_nofile.py
import resource
import os

soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
print('Soft limit starts as  :', soft)

resource.setrlimit(resource.RLIMIT_NOFILE, (4, hard))

soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
print('Soft limit changed to :', soft)

random = open('/dev/random', 'r')
print('random has fd =', random.fileno())
try:
    null = open('/dev/null', 'w')
except IOError as err:
    print(err)
else:
    print('null has fd =', null.fileno())

# resource_setrlimit_cpu.py
import resource
import sys
import signal
import time


# Set up a signal handler to notify us
# when we run out of time.
def time_expired(n, stack):
    print('EXPIRED :', time.ctime())
    raise SystemExit('(time ran out)')


signal.signal(signal.SIGXCPU, time_expired)

# Adjust the CPU time limit
soft, hard = resource.getrlimit(resource.RLIMIT_CPU)
print('Soft limit starts as  :', soft)

resource.setrlimit(resource.RLIMIT_CPU, (1, hard))

soft, hard = resource.getrlimit(resource.RLIMIT_CPU)
print('Soft limit changed to :', soft)
print()

# Consume some CPU time in a pointless exercise
print('Starting:', time.ctime())
for i in range(200000):
    for i in range(200000):
        v = i * i

# We should never make it this far
print('Exiting :', time.ctime())