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@magiskboy
Last active June 20, 2023 02:41
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import threading
import multiprocessing
import time
import requests
def measure(func):
def f(*args, **kwargs):
start = time.time()
ret = func(*args, **kwargs)
print(f"{func.__name__} takes {time.time()-start} seconds")
return ret
return f
def fib(n):
if n < 2:
return n
return fib(n - 1) + fib(n - 2)
@measure
def cpu_bounded_in_multiple_process():
p1 = multiprocessing.Process(target=fib, args=(40,), daemon=True)
p2 = multiprocessing.Process(target=fib, args=(40,), daemon=True)
p1.start()
p2.start()
p1.join()
p2.join()
@measure
def cpu_bounded_in_multiple_thread():
t1 = threading.Thread(target=fib, args=(40,), daemon=True)
t2 = threading.Thread(target=fib, args=(40,), daemon=True)
t1.start()
t2.start()
t1.join()
t2.join()
@measure
def cpu_bounded_in_single_thread():
fib(40)
fib(40)
@measure
def io_bounded_in_single_thread(n_iters=10):
for i in range(n_iters):
requests.get("https://api.github.com/users/magiskboy")
@measure
def io_bounded_in_multiple_threads(n_iters=10):
ts = []
for i in range(n_iters):
t = threading.Thread(
target=requests.get,
kwargs={"url": "https://api.github.com/users/magiskboy"},
daemon=True,
)
t.start()
ts.append(t)
for t in ts:
t.join()
if __name__ == "__main__":
print("Read more https://github.com/python/cpython/blob/main/Python/ceval_gil.c#L19")
cpu_bounded_in_single_thread()
cpu_bounded_in_multiple_thread()
cpu_bounded_in_multiple_process()
io_bounded_in_single_thread()
io_bounded_in_multiple_threads()
@magiskboy
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magiskboy commented May 16, 2023

On Linux
image

@magiskboy
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magiskboy commented May 16, 2023

Một trong những lý do cho việc thiết kế GIL để lock toàn bộ data mà không phải lock từng phần là giảm số lượng biến lock (atomic value), tránh rơi vào tính trạng deadlock

@magiskboy
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On MacOS
image

@magiskboy
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One of the reasons for designing GIL to lock all data instead of locking each part is to reduce the number of lock variables (atomic value), avoiding falling into deadlock.

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