3
\ P @ sb d Z dZddlZddlZddlmZ ddlZddlmZ ddlZddlm Z ddl
m Z ddl Z ddl
Z
ddlmZ ddlZddlZe
j Zd ad
d Zd ZG d
d deZG dd dZdd ZG dd deZ G dd deZ G dd deZ dd Z dd Z d d Z!d d Z"d!d" Z#d a$da%d#d$ Z&d%d& Z'G d'd( d(e(Z)G d)d* d*ej*Z+ej,e dS )+a* Implements ProcessPoolExecutor.
The follow diagram and text describe the data-flow through the system:
|======================= In-process =====================|== Out-of-process ==|
+----------+ +----------+ +--------+ +-----------+ +---------+
| | => | Work Ids | => | | => | Call Q | => | |
| | +----------+ | | +-----------+ | |
| | | ... | | | | ... | | |
| | | 6 | | | | 5, call() | | |
| | | 7 | | | | ... | | |
| Process | | ... | | Local | +-----------+ | Process |
| Pool | +----------+ | Worker | | #1..n |
| Executor | | Thread | | |
| | +----------- + | | +-----------+ | |
| | <=> | Work Items | <=> | | <= | Result Q | <= | |
| | +------------+ | | +-----------+ | |
| | | 6: call() | | | | ... | | |
| | | future | | | | 4, result | | |
| | | ... | | | | 3, except | | |
+----------+ +------------+ +--------+ +-----------+ +---------+
Executor.submit() called:
- creates a uniquely numbered _WorkItem and adds it to the "Work Items" dict
- adds the id of the _WorkItem to the "Work Ids" queue
Local worker thread:
- reads work ids from the "Work Ids" queue and looks up the corresponding
WorkItem from the "Work Items" dict: if the work item has been cancelled then
it is simply removed from the dict, otherwise it is repackaged as a
_CallItem and put in the "Call Q". New _CallItems are put in the "Call Q"
until "Call Q" is full. NOTE: the size of the "Call Q" is kept small because
calls placed in the "Call Q" can no longer be cancelled with Future.cancel().
- reads _ResultItems from "Result Q", updates the future stored in the
"Work Items" dict and deletes the dict entry
Process #1..n:
- reads _CallItems from "Call Q", executes the calls, and puts the resulting
_ResultItems in "Result Q"
z"Brian Quinlan (brian@sweetapp.com) N)_base)Full) SimpleQueue)wait)partialFc C sJ da ttj } x| D ]\}}|jd qW x| D ]\}}|j q2W d S )NT) _shutdownlist_threads_queuesitemsputjoin)r
tq r /usr/lib64/python3.6/process.py _python_exitO s r c @ s e Zd Zdd Zdd ZdS )_RemoteTracebackc C s
|| _ d S )N)tb)selfr r r r __init__a s z_RemoteTraceback.__init__c C s | j S )N)r )r r r r __str__c s z_RemoteTraceback.__str__N)__name__
__module__ __qualname__r r r r r r r ` s r c @ s e Zd Zdd Zdd ZdS )_ExceptionWithTracebackc C s0 t jt|||}dj|}|| _d| | _d S )N z
"""
%s""") tracebackformat_exceptiontyper excr )r r r r r r r g s
z _ExceptionWithTraceback.__init__c C s t | j| jffS )N) _rebuild_excr r )r r r r
__reduce__l s z"_ExceptionWithTraceback.__reduce__N)r r r r r" r r r r r f s r c C s t || _| S )N)r __cause__)r r r r r r! o s
r! c @ s e Zd Zdd ZdS ) _WorkItemc C s || _ || _|| _|| _d S )N)futurefnargskwargs)r r% r& r' r( r r r r t s z_WorkItem.__init__N)r r r r r r r r r$ s s r$ c @ s e Zd ZdddZdS ) _ResultItemNc C s || _ || _|| _d S )N)work_id exceptionresult)r r* r+ r, r r r r { s z_ResultItem.__init__)NN)r r r r r r r r r) z s r) c @ s e Zd Zdd ZdS ) _CallItemc C s || _ || _|| _|| _d S )N)r* r& r' r( )r r* r& r' r( r r r r s z_CallItem.__init__N)r r r r r r r r r- s r- c g s0 t | }x"ttj|| }|s"dS |V q
W dS )z, Iterates over zip()ed iterables in chunks. N)ziptuple itertoolsislice) chunksize iterablesitchunkr r r _get_chunks s r6 c s fdd|D S )z Processes a chunk of an iterable passed to map.
Runs the function passed to map() on a chunk of the
iterable passed to map.
This function is run in a separate process.
c s g | ] } | qS r r ).0r' )r& r r
<listcomp> s z"_process_chunk.<locals>.<listcomp>r )r& r5 r )r& r _process_chunk s r9 c C s x| j dd}|dkr(|jtj dS y|j|j|j}W nB tk
r~ } z&t||j }|jt
|j |d W Y dd}~X qX |jt
|j |d qW dS )a Evaluates calls from call_queue and places the results in result_queue.
This worker is run in a separate process.
Args:
call_queue: A multiprocessing.Queue of _CallItems that will be read and
evaluated by the worker.
result_queue: A multiprocessing.Queue of _ResultItems that will written
to by the worker.
shutdown: A multiprocessing.Event that will be set as a signal to the
worker that it should exit when call_queue is empty.
T)blockN)r+ )r, ) getr osgetpidr& r' r(
BaseExceptionr
__traceback__r) r* )
call_queue result_queueZ call_itemrer r r r _process_worker s
&
rD c C sx xr|j rdS y|jdd}W n tjk
r4 dS X | | }|jj rh|jt||j|j |j
dd q| |= qqW dS )aM Fills call_queue with _WorkItems from pending_work_items.
This function never blocks.
Args:
pending_work_items: A dict mapping work ids to _WorkItems e.g.
{5: <_WorkItem...>, 6: <_WorkItem...>, ...}
work_ids: A queue.Queue of work ids e.g. Queue([5, 6, ...]). Work ids
are consumed and the corresponding _WorkItems from
pending_work_items are transformed into _CallItems and put in
call_queue.
call_queue: A multiprocessing.Queue that will be filled with _CallItems
derived from _WorkItems.
NF)r: T) Zfullr; queueZEmptyr% Z set_running_or_notify_cancelr r- r& r' r( )pending_work_itemsZwork_idsr@ r* work_itemr r r _add_call_item_to_queue s
rH c s dfdd} fdd}|j }xlt|| dd j D } t|g| }
||
krf|j } nr| dk rd_d_dx&|j D ]\} }
|
jj t
d ~
qW |j xj D ] }|j qW | dS t
| trj| }|j sR| dS nJ| dk rR|j| jd}
|
dk rR| jrB|
jj | j n|
jj| j ~
| | ry|sr| dS W n tk
r Y nX dq(W dS )
a Manages the communication between this process and the worker processes.
This function is run in a local thread.
Args:
executor_reference: A weakref.ref to the ProcessPoolExecutor that owns
this thread. Used to determine if the ProcessPoolExecutor has been
garbage collected and that this function can exit.
process: A list of the multiprocessing.Process instances used as
workers.
pending_work_items: A dict mapping work ids to _WorkItems e.g.
{5: <_WorkItem...>, 6: <_WorkItem...>, ...}
work_ids_queue: A queue.Queue of work ids e.g. Queue([5, 6, ...]).
call_queue: A multiprocessing.Queue that will be filled with _CallItems
derived from _WorkItems for processing by the process workers.
result_queue: A multiprocessing.Queue of _ResultItems generated by the
process workers.
Nc s t p d kp jS )N)r _shutdown_threadr )executorr r
shutting_down s z/_queue_management_worker.<locals>.shutting_downc sZ t dd j D } x td| D ]} jd q"W j xj D ] }|j qFW d S )Nc s s | ]}|j V qd S )N)Zis_alive)r7 pr r r <genexpr> s zD_queue_management_worker.<locals>.shutdown_worker.<locals>.<genexpr>r )sumvaluesrangeZ
put_nowaitcloser )Znb_children_aliveirL )r@ processesr r shutdown_worker s z1_queue_management_worker.<locals>.shutdown_workerc S s g | ]
}|j qS r )sentinel)r7 rL r r r r8 s z,_queue_management_worker.<locals>.<listcomp>Tz^A process in the process pool was terminated abruptly while the future was running or pending.)Z_readerrH rO r Zrecv_brokenrI r
r% Z
set_exceptionBrokenProcessPoolclearZ terminate
isinstanceintpopr r* r+ Z
set_resultr, r )Zexecutor_referencerS rF Zwork_ids_queuer@ rA rK rT readerZ sentinelsZreadyZ result_itemr* rG rL r )r@ rJ rS r _queue_management_worker sb
r] c C sh t rtrttda ytjd} W n ttfk
r: d S X | dkrHd S | dkrTd S d| attd S )NTSC_SEM_NSEMS_MAXr z@system provides too few semaphores (%d available, 256 necessary))_system_limits_checked_system_limitedNotImplementedErrorr< sysconfAttributeError
ValueError)Z nsems_maxr r r _check_system_limitsQ s rg c c s. x(| D ] }|j x|r$|j V qW qW dS )z
Specialized implementation of itertools.chain.from_iterable.
Each item in *iterable* should be a list. This function is
careful not to keep references to yielded objects.
N)reverser[ )iterableelementr r r _chain_from_iterable_of_listsh s
rk c @ s e Zd ZdZdS )rW zy
Raised when a process in a ProcessPoolExecutor terminated abruptly
while a future was in the running state.
N)r r r __doc__r r r r rW t s rW c sh e Zd ZdddZdd Zdd Zdd Zejjj e_ dd
d fd d
Z
dddZ ejj j e _ Z S )ProcessPoolExecutorNc C s t |dkr tj pd| _n|dkr.td|| _tj| jt | _d| j_ t
| _ t j | _
d| _i | _d| _tj | _d| _d| _i | _dS )a/ Initializes a new ProcessPoolExecutor instance.
Args:
max_workers: The maximum number of processes that can be used to
execute the given calls. If None or not given then as many
worker processes will be created as the machine has processors.
Nr r z"max_workers must be greater than 0TF)rg r< cpu_count _max_workersrf multiprocessingZQueueEXTRA_QUEUED_CALLS _call_queueZ
_ignore_epiper
_result_queuerE _work_ids_queue_management_thread
_processesrI threadingZLock_shutdown_lockrV _queue_count_pending_work_items)r max_workersr r r r | s$
z ProcessPoolExecutor.__init__c C sp | j fdd}| jd krl| j tjttj| || j| j | j
| j | j fd| _d| j_ | jj
| j t| j< d S )Nc S s |j d d S )N)r )_r r r r
weakref_cb s zFProcessPoolExecutor._start_queue_management_thread.<locals>.weakref_cb)targetr' T)rs ru _adjust_process_countrw ZThreadr] weakrefrefrv rz rt rr Zdaemonstartr )r r} r r r _start_queue_management_thread s
z2ProcessPoolExecutor._start_queue_management_threadc C sJ xDt t| j| jD ].}tjt| j| jfd}|j || j|j
< qW d S )N)r~ r' ) rP lenrv ro rp ZProcessrD rr rs r pid)r r| rL r r r r s z)ProcessPoolExecutor._adjust_process_countc O s | j t | jrtd| jr$tdtj }t||||}|| j| j < | j
j | j | j d7 _ | j j d | j
|S Q R X d S )NzKA child process terminated abruptly, the process pool is not usable anymorez*cannot schedule new futures after shutdownr )rx rV rW rI RuntimeErrorr ZFuturer$ rz ry rt r rs r )r r& r' r( fwr r r submit s zProcessPoolExecutor.submitr )timeoutr2 c s: |dk rt dt jtt|t|d|i|d}t|S )aj Returns an iterator equivalent to map(fn, iter).
Args:
fn: A callable that will take as many arguments as there are
passed iterables.
timeout: The maximum number of seconds to wait. If None, then there
is no limit on the wait time.
chunksize: If greater than one, the iterables will be chopped into
chunks of size chunksize and submitted to the process pool.
If set to one, the items in the list will be sent one at a time.
Returns:
An iterator equivalent to: map(func, *iterables) but the calls may
be evaluated out-of-order.
Raises:
TimeoutError: If the entire result iterator could not be generated
before the given timeout.
Exception: If fn(*args) raises for any values.
r zchunksize must be >= 1.r2 )r )rf supermapr r9 r6 rk )r r& r r2 r3 results) __class__r r r s zProcessPoolExecutor.mapTc C sT | j d| _W d Q R X | jr8| jjd |r8| jj d | _d | _d | _d | _d S )NT)rx rI ru rs r r rr rv )r r r r r shutdown s
z ProcessPoolExecutor.shutdown)N)T)
r r r r r r r r Executorrl r r
__classcell__r r )r r rm { s
(
rm )-rl
__author__atexitr< concurrent.futuresr rE r rp r Zmultiprocessing.connectionr rw r functoolsr r0 r WeakKeyDictionaryr r r rq Exceptionr r r! objectr$ r) r- r6 r9 rD rH r] ra rb rg rk r rW r rm registerr r r r <module>, sJ
%s