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0d80452 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 | # Copyright 2024 The HuggingFace Inc. team. All rights reserved.
#
# 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 platform
import time
def precise_sleep(seconds: float, spin_threshold: float = 0.010, sleep_margin: float = 0.005):
"""
Wait for `seconds` with better precision than time.sleep alone at the expense of more CPU usage.
Parameters:
- seconds: duration to wait
- spin_threshold: if remaining <= spin_threshold -> spin; otherwise sleep (seconds). Default 10ms
- sleep_margin: when sleeping leave this much time before deadline to avoid oversleep. Default 5ms
Note:
The default parameters are chosen to prioritize timing accuracy over CPU usage for the common 30 FPS use case.
"""
if seconds <= 0:
return
system = platform.system()
# On macOS and Windows the scheduler / sleep granularity can make
# short sleeps inaccurate. Instead of burning CPU for the whole
# duration, sleep for most of the time and spin for the final few
# milliseconds to achieve good accuracy with much lower CPU usage.
if system in ("Darwin", "Windows"):
end_time = time.perf_counter() + seconds
while True:
remaining = end_time - time.perf_counter()
if remaining <= 0:
break
# If there's more than a couple milliseconds left, sleep most
# of the remaining time and leave a small margin for the final spin.
if remaining > spin_threshold:
# Sleep but avoid sleeping past the end by leaving a small margin.
time.sleep(max(remaining - sleep_margin, 0))
else:
# Final short spin to hit precise timing without long sleeps.
pass
else:
# On Linux time.sleep is accurate enough for most uses
time.sleep(seconds)
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