# Data Parallel Control (dpctl)
#
# Copyright 2020-2022 Intel Corporation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import timeit
from . import SyclQueue
__doc__ = "This module implements :class:`dpctl.SyclTimer`."
[docs]class SyclTimer:
"""
SyclTimer(host_timer=timeit.default_timer, time_scale=1)
Python class to measure device time of execution of commands submitted to
:class:`dpctl.SyclQueue` as well as the wall-time.
:Example:
.. code-block:: python
import dpctl
# Create a default SyclQueue
q = dpctl.SyclQueue(property='enable_profiling')
# create the timer
milliseconds_sc = 1e-3
timer = dpctl.SyclTimer(time_scale = milliseconds_sc)
# use the timer
with timer(queue=q):
code_block
# retrieve elapsed times in milliseconds
sycl_dt, wall_dt = timer.dt
Remark:
The timer submits barriers to the queue at the entrance and the
exit of the context and uses profiling information from events
associated with these submissions to perform the timing. Thus
:class:`dpctl.SyclTimer` requires the queue with "enable_profiling"
property. In order to be able to collect the profiling information
the property `dt` ensures that both submitted barriers complete
their execution and thus effectively synchronizing the queue.
Args:
host_timer (callable): A callable such that host_timer() returns current
host time in seconds.
time_scale (int, float): Ratio of the unit of time of interest and
one second.
"""
def __init__(self, host_timer=timeit.default_timer, time_scale=1):
self.timer = host_timer
self.time_scale = time_scale
self.queue = None
self.host_start = None
self.host_finish = None
self.event_start = None
self.event_finish = None
def __call__(self, queue=None):
if isinstance(queue, SyclQueue):
if queue.has_enable_profiling:
self.queue = queue
else:
raise ValueError(
"The given queue was not created with the "
"enable_profiling property"
)
else:
raise TypeError(
"The passed queue must have type dpctl.SyclQueue, "
f"got {type(queue)}"
)
return self
def __enter__(self):
self.event_start = self.queue.submit_barrier()
self.host_start = self.timer()
return self
def __exit__(self, *args):
self.event_finish = self.queue.submit_barrier()
self.host_finish = self.timer()
@property
def dt(self):
"""Returns a tuple of elapsed times where first
element is the duration as measured by the host timer,
while the second element is the duration as measured by
the device timer and encoded in profiling events"""
self.event_start.wait()
self.event_finish.wait()
return (
(self.host_finish - self.host_start) * self.time_scale,
(
self.event_finish.profiling_info_start
- self.event_start.profiling_info_end
)
* (1e-9 * self.time_scale),
)