Problema de multiprocessamento Python / incompreensão
Estou tendo um problema com o multiprocessamento; Estou usando python2.7 no linux 2.6.36. Eu sei que isso seria muito mais fácil com um módulo ou uma biblioteca de nível superior, mas estou tentando usar as funções de nível inferior (os.fork () e os.exec *) para garantir que eu realmente entenda. Este é um tipo de exercício de aprendizado .
Abaixo é o meu código, é um utilitário 'ping' de multiprocessamento. O problema é que, embora pareça estar em execução, lança um OSError de vez em quando na linha os.wait (). "Nenhum processo filho"
Isso não faz sentido para mim, pois os.wait () só deve ser chamado quando o programa receber um sinal de que um processo filho saiu e precisa ser colhid
A seguir, o código é uma amostra de saíd
O que estou fazendo errado
#!/usr/bin/python2.7
import os
import time
import sys
import signal
kids = []
def chldClean(SIG, FRM):
global kids
pid, status = os.wait()
kids.pop(kids.index(pid))
signal.signal(signal.SIGCHLD, chldClean)
hosts = ( '10.98.232.66',
'10.86.144.241',
'10.86.144.242',
'10.98.193.130',
'10.98.198.130',
'10.86.116.161',
'10.86.120.161',
'10.99.21.254',
'10.97.98.102',
'10.97.111.180' )
while True:
for HOST in hosts:
while len(kids) > 7:
time.sleep(0.1)
pid = os.fork()
if pid == 0:
os.closerange(0, 4)
os.execl('/bin/ping', 'PING', '-c', '1', '-w', '2', HOST)
else:
kids.append(pid)
print kids
Saída de amostra com erros abaixo ----------------------------------------
[18188]
[18188, 18189]
[18188, 18189, 18190]
[18188, 18189, 18190, 18191]
[18188, 18189, 18190, 18191, 18192]
[18188, 18189, 18190, 18191, 18192, 18193]
[18188, 18189, 18190, 18191, 18192, 18193, 18194]
[18188, 18189, 18190, 18191, 18192, 18193, 18194, 18195]
[18188, 18189, 18191, 18192, 18193, 18194, 18195, 18196]
[18188, 18191, 18192, 18193, 18194, 18195, 18196, 18197]
[18188, 18191, 18192, 18194, 18195, 18196, 18197, 18198]
[18191, 18192, 18194, 18195, 18196, 18197, 18198, 18201]
[18191, 18194, 18195, 18196, 18197, 18198, 18201, 18202]
[18191, 18195, 18196, 18197, 18198, 18201, 18202, 18203]
[18195, 18196, 18197, 18198, 18201, 18202, 18203, 18204]
[18196, 18197, 18198, 18202, 18203, 18204, 18205]
[18196, 18197, 18198, 18202, 18203, 18204, 18205, 18206]
[18197, 18198, 18202, 18203, 18204, 18205, 18206, 18207]
[18198, 18203, 18204, 18205, 18206, 18207, 18210]
[18198, 18203, 18204, 18205, 18206, 18207, 18210, 18211]
Traceback (most recent call last):
File "./sunmon-mp", line 33, in <module>
pid = os.fork()
File "./sunmon-mp", line 12, in chldClean
pid, status = os.wait()
OSError: [Errno 10] No child processes
[18203, 18204, 18205, 18206, 18207, 18210, 18211, 18212]
[18203, 18204, 18206, 18207, 18210, 18211, 18212, 18213]
[18203, 18204, 18206, 18207, 18211, 18212, 18213, 18214]
[18203, 18204, 18206, 18207, 18211, 18212, 18214, 18215]
[18203, 18204, 18206, 18207, 18212, 18214, 18215, 18217]
[18203, 18204, 18206, 18207, 18214, 18215, 18217, 18218]
[18203, 18204, 18206, 18207, 18215, 18217, 18218, 18219]
[18204, 18206, 18207, 18215, 18217, 18218, 18219, 18220]
[18204, 18206, 18207, 18217, 18218, 18219, 18220, 18221]
[18206, 18207, 18217, 18218, 18219, 18220, 18221, 18223]
[18207, 18217, 18218, 18219, 18220, 18221, 18223, 18224]
[18217, 18218, 18219, 18220, 18221, 18223, 18224, 18225]
[18217, 18219, 18220, 18221, 18223, 18224, 18225, 18226]
[18217, 18219, 18220, 18221, 18223, 18225, 18226, 18227]
[18217, 18219, 18220, 18221, 18223, 18226, 18227, 18228]
[18217, 18220, 18221, 18223, 18226, 18227, 18228, 18229]
[18217, 18220, 18221, 18223, 18227, 18228, 18229, 18230]
[18217, 18220, 18221, 18223, 18227, 18228, 18230, 18231]
[18220, 18221, 18223, 18227, 18228, 18230, 18231, 18233]
[18221, 18223, 18227, 18228, 18230, 18231, 18233, 18234]
[18223, 18227, 18228, 18230, 18231, 18233, 18234, 18235]
[18223, 18227, 18228, 18231, 18233, 18234, 18235, 18236]
[18223, 18227, 18228, 18231, 18233, 18234, 18236, 18237]
[18223, 18227, 18228, 18231, 18233, 18234, 18237, 18239]
[18227, 18228, 18231, 18233, 18234, 18237, 18239, 18240]
[18228, 18231, 18233, 18234, 18237, 18239, 18240, 18241]
[18228, 18231, 18233, 18237, 18239, 18240, 18241, 18242]
[18231, 18233, 18237, 18239, 18240, 18241, 18242, 18243]
[18231, 18233, 18239, 18240, 18241, 18242, 18243, 18244]
[18231, 18233, 18239, 18240, 18242, 18243, 18244, 18245]
[18231, 18233, 18239, 18242, 18243, 18244, 18245, 18246]
[18231, 18233, 18242, 18243, 18244, 18245, 18246, 18247]
[18233, 18242, 18243, 18244, 18245, 18246, 18247, 18248]
[18242, 18243, 18244, 18245, 18246, 18247, 18248, 18249]
[18243, 18244, 18245, 18246, 18247, 18248, 18249, 18250]
[18243, 18245, 18246, 18247, 18248, 18249, 18250, 18251]
[18243, 18245, 18247, 18248, 18249, 18250, 18251, 18252]
[18243, 18245, 18248, 18249, 18250, 18251, 18252, 18253]
[18243, 18245, 18249, 18250, 18251, 18252, 18253, 18254]
[18243, 18245, 18249, 18250, 18252, 18253, 18254, 18255]
[18245, 18249, 18250, 18252, 18253, 18254, 18255, 18258]
[18249, 18250, 18252, 18253, 18254, 18255, 18258, 18259]
[18249, 18250, 18253, 18254, 18255, 18258, 18259, 18260]
[18249, 18250, 18253, 18254, 18255, 18258, 18260, 18261]
[18249, 18250, 18253, 18254, 18255, 18260, 18261, 18262]
[18250, 18253, 18254, 18255, 18260, 18261, 18262, 18263]
[18253, 18254, 18255, 18260, 18261, 18262, 18263, 18264]
[18253, 18254, 18255, 18261, 18262, 18263, 18264, 18265]
[18253, 18254, 18255, 18261, 18262, 18264, 18265, 18266]
[18254, 18255, 18261, 18262, 18264, 18265, 18266, 18267]
[18255, 18261, 18262, 18264, 18265, 18266, 18267, 18268]
[18261, 18262, 18264, 18265, 18266, 18267, 18268, 18269]
[18261, 18262, 18265, 18266, 18267, 18268, 18269, 18270]
[18261, 18262, 18265, 18266, 18267, 18268, 18270, 18271]
[18261, 18262, 18265, 18266, 18267, 18270, 18271, 18273]
[18261, 18262, 18265, 18266, 18270, 18271, 18273, 18274]
[18261, 18262, 18265, 18266, 18271, 18273, 18274, 18275]
[18261, 18262, 18265, 18266, 18271, 18273, 18275, 18276]
[18262, 18265, 18266, 18271, 18273, 18275, 18276, 18277]
[18262, 18265, 18266, 18273, 18275, 18276, 18277, 18278]
[18265, 18266, 18273, 18276, 18277, 18278, 18280]
[18265, 18266, 18273, 18276, 18277, 18278, 18280, 18281]
Traceback (most recent call last):
File "./sunmon-mp", line 33, in <module>
pid = os.fork()
File "./sunmon-mp", line 12, in chldClean
pid, status = os.wait()
OSError: [Errno 10] No child processes
[18265, 18273, 18276, 18277, 18278, 18280, 18282]
[18265, 18276, 18277, 18278, 18280, 18281, 18282, 18283]
[18265, 18276, 18278, 18281, 18282, 18283, 18284]
[18265, 18276, 18278, 18281, 18282, 18283, 18284, 18285]
[18265, 18276, 18278, 18282, 18283, 18284, 18285, 18286]
[18265, 18276, 18278, 18283, 18284, 18286, 18289]
[18265, 18276, 18278, 18283, 18284, 18286, 18289, 18290]
Traceback (most recent call last):
File "./sunmon-mp", line 33, in <module>
pid = os.fork()
File "./sunmon-mp", line 12, in chldClean
pid, status = os.wait()
OSError: [Errno 10] No child processes
[18265, 18276, 18278, 18283, 18284, 18289, 18290, 18291]
[18276, 18278, 18283, 18284, 18289, 18290, 18291, 18292]
[18276, 18278, 18283, 18284, 18290, 18291, 18292, 18293]
[18276, 18278, 18283, 18284, 18290, 18291, 18293, 18294]
[18276, 18278, 18283, 18284, 18290, 18291, 18294, 18295]
[18278, 18283, 18284, 18290, 18291, 18294, 18295, 18297]
[18283, 18284, 18290, 18291, 18294, 18295, 18297, 18298]
[18283, 18284, 18290, 18291, 18295, 18297, 18298, 18299]