import gobject
# Infrastructure: tasks and jobs.
def task(function, *args):
"""Wrapps a task function (expected signature 'function(return_task, [args])'"""
return function, args
def start_job(generator):
"""Start a job (a generator that yield tasks)."""
def _next(result):
def _callback():
try:
fun, args = generator.send(result)
except StopIteration:
return
fun(_next, *args)
# isolate the advance of the coroutine to another gobject loop
gobject.idle_add(_callback)
_next(None)
# Tasks: A task is a normal function, except for the first argument, a function
# that must be called with the result of the task.
def sleep(task_return, seconds):
"""Wait 'seconds' seconds. Returns nothing."""
def _callback():
task_return(None)
gobject.timeout_add(int(seconds * 1000), _callback)
def threaded(task_return, function, *args, **kwargs):
"""Run function(*args, **kwargs) in a thread and return the value."""
from Queue import Queue
from threading import Thread
def _thread(queue):
x = function(*args, **kwargs)
queue.put(x)
def _receiver(queue):
if queue.empty():
return True
task_return(queue.get())
queue = Queue()
thread = Thread(target=_thread, args=(queue,))
thread.setDaemon(True)
thread.start()
gobject.timeout_add(100, _receiver, queue) # poll queue every 0.1 seconds
# Job example
def heavy_function(a, b):
import time
time.sleep(1.0)
return a + b
def myjob(a, b):
import random
yield task(sleep, random.uniform(1.0, 3.0))
result = yield task(threaded, heavy_function, a, b)
print result
def basso_continuo():
import sys
sys.stderr.write(".")
return True
gobject.threads_init()
start_job(myjob(1, 2))
start_job(myjob(3, 4))
start_job(myjob(5, 6))
gobject.timeout_add(100, basso_continuo)
loop = gobject.MainLoop()
loop.run()
Diff to Previous Revision
--- revision 6 2010-03-26 16:15:52
+++ revision 7 2010-03-26 16:23:30
@@ -24,26 +24,26 @@
def sleep(task_return, seconds):
"""Wait 'seconds' seconds. Returns nothing."""
- def callback():
+ def _callback():
task_return(None)
- gobject.timeout_add(int(seconds * 1000), callback)
+ gobject.timeout_add(int(seconds * 1000), _callback)
def threaded(task_return, function, *args, **kwargs):
"""Run function(*args, **kwargs) in a thread and return the value."""
from Queue import Queue
from threading import Thread
- def thread(queue):
+ def _thread(queue):
x = function(*args, **kwargs)
queue.put(x)
- def receiver(queue):
+ def _receiver(queue):
if queue.empty():
return True
task_return(queue.get())
queue = Queue()
- thread = Thread(target=thread, args=(queue,))
+ thread = Thread(target=_thread, args=(queue,))
thread.setDaemon(True)
thread.start()
- gobject.timeout_add(100, receiver, queue) # poll queue every 0.1 seconds
+ gobject.timeout_add(100, _receiver, queue) # poll queue every 0.1 seconds
# Job example
