There are two functions:
def tibidam(..., foo_dyn, index):
print("(" + str(index) + ") B:", foo_dyn)
for i in range(...):
for j ...
if j not in foo_dyn:
foo_dyn[ep] = j
print("(" + str(index) + ") A:", foo_dyn)
def tata(..., foo):
foo_dyn = Array('i', len(foo))
foo_dyn = foo
with Pool(processes=4) as pool:
pool.starmap(tibidam, [(..., foo_dyn, i)
for i in range(4)])
return foo
Output (formatted):
foo : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
(0) B: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
(1) B: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
(2) B: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
(3) B: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
(0) A: [27, 1, 2, 3, 64, 5, 6, 7, 80, 9, 10, 11]
(2) A: [0, 1, 64, 3, 4, 5, 13, 7, 8, 9, 92, 11]
(3) A: [0, 1, 2, 31, 4, 5, 6, 73, 8, 9, 10, 18]
(1) A: [0, 18, 2, 3, 4, 27, 6, 7, 8, 99, 10, 11]
...
Expected output (formatted):
foo : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
(0) B: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
(1) B: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
(2) B: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
(3) B: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
(0) A: [27, 1, 2, 3, 64, 5, 6, 7, 80, 9, 10, 11]
(2) A: [27, 1, 55, 3, 64, 5, 13, 7, 80, 9, 92, 11]
(3) A: [27, 1, 55, 31, 64, 5, 13, 73, 80, 9, 92, 18]
(1) A: [27, 87, 55, 31, 64, 88, 13, 73, 80, 99, 92, 18]
...
How I can change foo_dyn in all workers, whenever foo_dyn changes? It seems, that pool.starmap(...) creates a copy of the foo_dyn, for each process... No, I want pass foo_dyn to the pool only once. But, again, without using global variables, at all.
AFAIK, multiprocessing.Pool supports initializer and initargs arguments: I can write own initializer:
_init(foo):
global foo_dyn
foo_dyn = foo
, but it uses global variable foo_dyn (by the way, using _init function doesn't solve the problem). In passing, I saw a few questions, with almost the same trouble. However, all solutions were associated with using global variables.
I found the solution, without using the global variables:
from multiprocessing import Pool, Manager
def tibidam(..., foo_dyn, index):
for i in range(...):
for j ...
if j not in foo_dyn:
foo_dyn[ep] = j
def tata(..., foo):
foo_dyn = Manager().list(foo)
with Pool(processes=4) as pool:
pool.starmap(tibidam, [(..., foo_dyn, i)
for i in range(4)])
return foo_dyn
Thank you all! :>