Concerning running parallel code in separate processes (unlike multithreading) and/or related to package `multiprocess` from PyPI.
Questions tagged [multiprocess]
462 questions
3
votes
1 answer
Socket programming: accept() delayed
I have a server written in C which is blocked at function accept() and awaits new incoming connections. When a new connection is accepted, it creates a new process by calling fork(). I don't use epoll as each client socket is handled by a…
vesontio
- 381
- 1
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3
votes
1 answer
How does process join() work?
I am trying to understand multiprocessing in Python, I wrote the following program:
from multiprocessing import Process
numOfLoops = 10
#function for each process
def func():
a = float(0.0)
for i in xrange(0, numOfLoops):
a += 0.5
…
Rakesh Adhikesavan
- 11,966
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3
votes
1 answer
Why Python Multiprocess class doesn't change the attribute?
#!/usr/bin/env python
from multiprocessing import Process
class Signprocess(Process):
"""docstring for SignThread"""
def __init__(self):
super(SignThread, self).__init__()
self.result = False
def run(self):
self.result = True
…
demonguy
- 1,977
- 5
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3
votes
1 answer
Need help understanding Perl code- Multi process / fork
I was looking for an example to limit the number of forked processes to run at the same time and I ran across this old code
#!/usr/bin/perl
#total forks, max childs, what to run
#function takes 2 scalars and a reference to code to run
sub mfork…
genx1mx6
- 425
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3
votes
1 answer
Why does my Berkeley DB concurrent data store application hang?
My application hangs when trying to open a concurrent data store (CDB) database for reading:
#0 0x0000003ad860b309 in pthread_cond_wait@@GLIBC_2.3.2 ()
from /lib64/libpthread.so.0
#1 0x00007ffff7ce67de in __db_pthread_mutex_lock (env=0x610960,…
Steve Emmerson
- 7,702
- 5
- 33
- 59
3
votes
2 answers
Multi Process Shared Preferences return wrong value in multi process environment
my shared prefs are defined like this:
sharedPreferences = context.getSharedPreferences(Consts.SHARED_PREFS_NAME, Context.MODE_MULTI_PROCESS);
my receiver is defined in a different process:
Eitan Schwartz
- 463
- 6
- 19
3
votes
3 answers
Tell consumers to stop waiting for queue elements
Here's an example. I have one producer and several consumers.
#!/usr/bin/env python2
from multiprocessing import Process, Queue
import time
def counter(low, high):
current = low
while current <= high:
yield current
current…
bbc
- 240
- 2
- 8
3
votes
1 answer
dup() followed by close() from multiple threads or processes
My program does the following in chronological order
The program is started with root permissions.
Among other tasks, A file only readable with root permissions is open()ed.
Root privileges are dropped.
Child processes are spawned with clone() and…
Will
- 2,014
- 2
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- 42
3
votes
1 answer
Django Multiprocessing oddity
In using ./manage.py shell to exercise some code, I've come across something I don't understand.
Python 2.6.6 (r266:84292, Sep 11 2012, 08:34:23)
[GCC 4.4.6 20120305 (Red Hat 4.4.6-4)] on linux2
Type "help", "copyright", "credits" or "license" for…
William Maness
- 91
- 1
- 7
3
votes
1 answer
Strange results in multiprocess signal handling program
I have this multiprocess program which consists of 9 processes. One is the main process which spawns 3 signal generating processes and 4 signal handling processes. One is the monitoring process. Now I have used two signals SIGUSR1 and SIGUSR2. Each…
user34790
- 2,020
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2
votes
3 answers
C++ how to check if file is in use - multi-threaded multi-process system
C++:
Is there a way to check if a file has been opened for writing by another process/ class/ device ?
I am trying to read files from a folder that may be accessed by other processes for writing. If I read a file that is simultaneously being written…
Thalia
- 13,637
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2
votes
2 answers
C: multi-processes stdio append mode
I wrote this code in C:
#include
#include
#include
#include
void random_seed(){
struct timeval tim;
gettimeofday(&tim, NULL);
double t1=tim.tv_sec+(tim.tv_usec/1000000.0);
srand (t1);
}
void…
Kevin Peron
- 33
- 4
2
votes
0 answers
Can I change python multiprocess entry point?
Python multiprocess entry point could be controlled?
I've injected run_entry function on entry.py.
But why new process importing main.py again?
instead of starting with run_entry func on entry.py by direct importing entry.py
I've tested it on…
Dennis Yune
- 21
- 1
2
votes
2 answers
Python: Multiprocessing.Process does not invoke target function sometimes
I have a script that runs daily and while invoking processes, out of 100+ processes sometimes randomly 2 or 3 process do not get started and my target function is not called. This started occurring recently and before some days it was running fine.…
Karan Verma
- 61
- 4
2
votes
1 answer
Building a Pandas dataframe using multiprocessing leads to errors
I am trying to build a big dataframe using a function that takes some arguments and return partial dataframes. I have a long list of documents to parse and extract relevant information that will go the big dataframe, and I am trying to do it using…
Rad
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