我正在尝试使用多个进程进行我的第一个模拟，现在每个模拟大约需要一个小时才能完成。为此我使用多处理导入。
当我在 for 循环中运行 simulation() 时，所有代码都工作正常。当程序运行时，池中的所有工作人员都开始执行相同的任务，所以我最终得到了 4 个相同的副本，但是当他们完成后，他们又一次又一次地重新开始。更重要的是，当池被创建时，整个程序从第 1 行开始同时运行四次，而不是仅仅运行模拟。
下面的代码几乎完全是多处理文档中示例的复制粘贴: http://docs.python.org/library/multiprocessing.html
我在 Windows 7 上工作，我会尽快尝试在 Linux 机器上运行它，但有人可以向我解释这里出了什么问题吗。
非常感谢
PD。 Windows 7(64 位)+ python 2.7.1
....
code where: simulation, pulse1, pulse2, sol_ref, model, algorithm and i are defined. Also
where the various imports are made. Also some print statements.
...
if __name__=='__main__':
freeze_support()
def calculate(func, args):
result = func(*args)
return '%s says that %s%s = %s' % (
multiprocessing.current_process().name,
func.__name__, args, result
)
PROCESSES = 4
print 'Creating pool with %d processes\n' % PROCESSES
pool = Pool(PROCESSES)
print 'pool = %s' % pool
print
TASKS = [(simulation, (pulse1,pulse2,sol_ref,model,algorithm,i)) for i in delta_tau]
results = [pool.apply_async(calculate, t) for t in TASKS]
for r in results:
print '\t', r.get()
print
编辑:错误日志
模拟中打印点数的行来自 if main 语句之前的代码。在此代码中，模拟在 for 循环内运行一次，以检查它是否正常工作并给出预期结果。
C:\Users\HP\Desktop\experiment>python amplifier_parallel.py
Number of z points: 169 dist: 20.0 mm dz: 118.343195266 um
Number of t points: 8192.0 window span: 69.0 ps dt: 8.4228515625 fs
delta_tau: -6.0
delta_tau: -3.85714285714
delta_tau: -1.71428571429
delta_tau: 0.428571428571
delta_tau: 2.57142857143
delta_tau: 4.71428571429
delta_tau: 6.85714285714
delta_tau: 9.0
Simulation Time: 43.1258663953 seconds
Creating pool with 4 processes
pool = <multiprocessing.pool.Pool object at 0x063E66B0>
Number of z points: 169 dist: 20.0 mm dz: 118.343195266 um
Number of t points: 8192.0 window span: 69.0 ps dt: 8.4228515625 fs
...3 more times...
delta_tau: -6.0
...3more times
delta_tau: -3.85714285714
... 3 more tiemes
delta_tau: -1.71428571429
... 3 more tiemes
delta_tau: 0.428571428571
... 3 more tiemes
delta_tau: 2.57142857143
... 3 more tiemes3
delta_tau: 4.71428571429
... 3 more tiemes
delta_tau: 6.85714285714
... 3 more tiemes
delta_tau: 9.0
... 3 more tiemes
Simulation Time: 63.3316095785 seconds
... 3 more times with slightly different times, depending on the worker who did the job
Process PoolWorker-4:
Traceback (most recent call last):
File "C:\Python27\lib\multiprocessing\process.py", line 232, in _bootstrap
self.run()
File "C:\Python27\lib\multiprocessing\process.py", line 88, in run
self._target(*self._args, **self._kwargs)
File "C:\Python27\lib\multiprocessing\pool.py", line 59, in worker
task = get()
File "C:\Python27\lib\multiprocessing\queues.py", line 352, in get
return recv()
AttributeError: 'module' object has no attribute 'calculate'
Number of z points: 169 dist: 20.0 mm dz: 118.343195266 um
Number of t points: 8192.0 window span: 69.0 ps dt: 8.4228515625 fs
Process PoolWorker-3:
Traceback (most recent call last):
File "C:\Python27\lib\multiprocessing\process.py", line 232, in _bootstrap
self.run()
File "C:\Python27\lib\multiprocessing\process.py", line 88, in run
self._target(*self._args, **self._kwargs)
File "C:\Python27\lib\multiprocessing\pool.py", line 59, in worker
task = get()
File "C:\Python27\lib\multiprocessing\queues.py", line 352, in get
return recv()
AttributeError: 'module' object has no attribute 'calculate'
delta_tau: -6.0
... this kind of stuff goes on for ever until i control-C
请您参考如下方法:
在 if __name__=="__main__" block 之外定义 calculate()。子进程看不到它 on Windows .
