def _check_mp_mode(km, expected=False, stream="stdout"):
execute(km=km, code="import sys")
flush_channels(km)
msg_id, content = execute(km=km,
code="print (sys.%s._check_mp_mode())" % stream)
stdout, stderr = assemble_output(km.iopub_channel)
nt.assert_equal(eval(stdout.strip()), expected)
def test_subprocess_print():
"""printing from forked mp.Process"""
with new_kernel() as km:
iopub = km.iopub_channel
_check_mp_mode(km, expected=False)
flush_channels(km)
np = 5
code = '\n'.join([
"from __future__ import print_function",
"import multiprocessing as mp",
"pool = [mp.Process(target=print, args=('hello', i,)) for i in range(%i)]" % np,
"for p in pool: p.start()",
"for p in pool: p.join()"
])
expected = '\n'.join([
"hello %s" % i for i in range(np)
]) + '\n'
msg_id, content = execute(km=km, code=code)
stdout, stderr = assemble_output(iopub)
nt.assert_equal(stdout.count("hello"), np, stdout)
for n in range(np):
nt.assert_equal(stdout.count(str(n)), 1, stdout)
nt.assert_equal(stderr, '')
_check_mp_mode(km, expected=False)
_check_mp_mode(km, expected=False, stream="stderr")
def test_subprocess_print():
"""printing from forked mp.Process"""
with new_kernel() as km:
iopub = km.iopub_channel
_check_mp_mode(km, expected=False)
flush_channels(km)
np = 5
code = '\n'.join([
"from __future__ import print_function",
"import multiprocessing as mp",
"pool = [mp.Process(target=print, args=('hello', i,)) for i in range(%i)]"
% np, "for p in pool: p.start()", "for p in pool: p.join()"
])
expected = '\n'.join(["hello %s" % i for i in range(np)]) + '\n'
msg_id, content = execute(km=km, code=code)
stdout, stderr = assemble_output(iopub)
nt.assert_equal(stdout.count("hello"), np, stdout)
for n in range(np):
nt.assert_equal(stdout.count(str(n)), 1, stdout)
nt.assert_equal(stderr, '')
_check_mp_mode(km, expected=False)
_check_mp_mode(km, expected=False, stream="stderr")
def test_simple_print():
"""simple print statement in kernel"""
with new_kernel() as km:
iopub = km.iopub_channel
msg_id, content = execute(km=km, code="print ('hi')")
stdout, stderr = assemble_output(iopub)
nt.assert_equal(stdout, 'hi\n')
nt.assert_equal(stderr, '')
_check_mp_mode(km, expected=False)
print ('hello')
def test_simple_print():
"""simple print statement in kernel"""
with new_kernel() as km:
iopub = km.iopub_channel
msg_id, content = execute(km=km, code="print ('hi')")
stdout, stderr = assemble_output(iopub)
nt.assert_equal(stdout, 'hi\n')
nt.assert_equal(stderr, '')
_check_mp_mode(km, expected=False)
print('hello')
def test_subprocess_error():
"""error in mp.Process doesn't crash"""
with new_kernel() as km:
iopub = km.iopub_channel
code = '\n'.join([
"import multiprocessing as mp",
"p = mp.Process(target=int, args=('hi',))",
"p.start()",
"p.join()",
])
msg_id, content = execute(km=km, code=code)
stdout, stderr = assemble_output(iopub)
nt.assert_equal(stdout, '')
nt.assert_true("ValueError" in stderr, stderr)
_check_mp_mode(km, expected=False)
_check_mp_mode(km, expected=False, stream="stderr")
def test_subprocess_error():
"""error in mp.Process doesn't crash"""
with new_kernel() as km:
iopub = km.iopub_channel
code = '\n'.join([
"import multiprocessing as mp",
"p = mp.Process(target=int, args=('hi',))",
"p.start()",
"p.join()",
])
msg_id, content = execute(km=km, code=code)
stdout, stderr = assemble_output(iopub)
nt.assert_equal(stdout, '')
nt.assert_true("ValueError" in stderr, stderr)
_check_mp_mode(km, expected=False)
_check_mp_mode(km, expected=False, stream="stderr")
def test_subprocess_noprint():
"""mp.Process without print doesn't trigger iostream mp_mode"""
with new_kernel() as km:
iopub = km.iopub_channel
np = 5
code = '\n'.join([
"import multiprocessing as mp",
"pool = [mp.Process(target=range, args=(i,)) for i in range(%i)]" %
np, "for p in pool: p.start()", "for p in pool: p.join()"
])
msg_id, content = execute(km=km, code=code)
stdout, stderr = assemble_output(iopub)
nt.assert_equal(stdout, '')
nt.assert_equal(stderr, '')
_check_mp_mode(km, expected=False)
_check_mp_mode(km, expected=False, stream="stderr")
def test_subprocess_noprint():
"""mp.Process without print doesn't trigger iostream mp_mode"""
with new_kernel() as km:
iopub = km.iopub_channel
np = 5
code = '\n'.join([
"import multiprocessing as mp",
"pool = [mp.Process(target=range, args=(i,)) for i in range(%i)]" % np,
"for p in pool: p.start()",
"for p in pool: p.join()"
])
msg_id, content = execute(km=km, code=code)
stdout, stderr = assemble_output(iopub)
nt.assert_equal(stdout, '')
nt.assert_equal(stderr, '')
_check_mp_mode(km, expected=False)
_check_mp_mode(km, expected=False, stream="stderr")
def _check_mp_mode(km, expected=False, stream="stdout"):
execute(km=km, code="import sys")
flush_channels(km)
msg_id, content = execute(km=km, code="print (sys.%s._check_mp_mode())" % stream)
stdout, stderr = assemble_output(km.iopub_channel)
nt.assert_equal(eval(stdout.strip()), expected)