Question

我是asyncio的新手，我正在尝试使用loop.run_in_executor在单独的线程中运行阻止代码，但是似乎没有创建新的线程来运行阻止代码，并且它仍在主线程中运行。谁能帮助我了解如何以异步方式运行阻止操作？感谢所有帮助。

我尝试做async.sleep（）以便将控件传递回主线程，但是由于已经调用了库，因此我不确定该怎么做。 loop.run_in_exeutor似乎由于某种原因无法正常工作。

async def get_xml(self, genome_key, query_string):  
    executor = concurrent.futures.ThreadPoolExecutor(max_workers=3)
    loop = asyncio.get_event_loop()
    log = logging.getLogger('run_blocking_tasks')
    log.info('starting')
    log.info('creating executor tasks')
    blocking_tasks = loop.run_in_executor(executor, self.blocking_io, genome_key, query_string)
    log.info('waiting for executor tasks')
    completed = await asyncio.wait([blocking_tasks])
    log.info('results: {!r}'.format(completed))
    log.info('exiting')

这是阻止代码：

def blocking_io(self, genome_key, query_string):
    return     NCBIWWW.qblast("blastn","nt",query_string,megablast=False,expect="1000",word_size="7",nucl_reward="1",nucl_penalty="-3",gapcosts="5 2",entrez_query=self.genome_key_dict[genome_key])

函数get_xml的调用方式如下：

async def getMatchingLocations(self,query, loop):
    r1 = self.get_max_alignment("nc_009899",query,loop)
    r2 = await asyncio.gather(r1)
    return r2

从烧瓶中调用函数getMatchingLocations像这样：

@application.route('/search',methods = ['POST'])
def getQueryResult():
    q = request.form
    myObj = Alignment_Check()
    mLocations_s =   loop.run_until_complete(myObj.getMatchingLocations(q.get("Name"), loop))

以下是示例输出：

> Thread-1 run_blocking_tasks: starting
> Thread-1 run_blocking_tasks: creating executor tasks
> Thread-1 run_blocking_tasks: waiting for executor tasks
> Thread-1 asyncio: poll took 241953.000 ms: 1 events
> Thread-1 run_blocking_tasks: results: ({> created at ***}, set())
  Thread-1 run_blocking_tasks: exiting

> As we can see that the thread too 241953.000 ms to complete and my application was doing nothing but sitting idle for that time.

> The expected behavior is that the blocking function should be executed in a separate thread and once it is done executing I should be able to update my application with the results.

loop.run_in_executor不创建单独的线程来执行代码

0 个答案: