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![Christian Heimes](/assets/img/avatar_default.png)
svn+ssh://pythondev@svn.python.org/python/trunk ........ r59987 | raymond.hettinger | 2008-01-15 21:52:42 +0100 (Tue, 15 Jan 2008) | 1 line Refactor if/elif chain for clarity and speed. Remove dependency on subclasses having to implement _empty and _full. ........ r59988 | raymond.hettinger | 2008-01-15 22:22:47 +0100 (Tue, 15 Jan 2008) | 1 line Fix-up half-written paragraph in the docs ........ r59989 | amaury.forgeotdarc | 2008-01-15 22:25:11 +0100 (Tue, 15 Jan 2008) | 3 lines test_doctest fails since r59984. Not sure if these are the correct values, but save_stdout has to be set before its usage... ........ r59992 | andrew.kuchling | 2008-01-16 01:32:03 +0100 (Wed, 16 Jan 2008) | 1 line Docstring typos ........ r59993 | andrew.kuchling | 2008-01-16 04:17:25 +0100 (Wed, 16 Jan 2008) | 1 line Add PEP 3141 section ........ r59998 | andrew.kuchling | 2008-01-16 14:01:51 +0100 (Wed, 16 Jan 2008) | 1 line Markup fix ........ r59999 | georg.brandl | 2008-01-16 17:56:29 +0100 (Wed, 16 Jan 2008) | 2 lines Fix MSDN library URL. (#1854) ........ r60006 | georg.brandl | 2008-01-16 21:27:56 +0100 (Wed, 16 Jan 2008) | 3 lines Add Python-specific content to Doc dir. Update configuration file to work with the newest Sphinx. ........ r60007 | georg.brandl | 2008-01-16 21:29:00 +0100 (Wed, 16 Jan 2008) | 2 lines Doc build should work with 2.4 now. ........ r60009 | raymond.hettinger | 2008-01-17 00:38:16 +0100 (Thu, 17 Jan 2008) | 1 line Minor wordsmithing. ........ r60010 | raymond.hettinger | 2008-01-17 00:40:45 +0100 (Thu, 17 Jan 2008) | 1 line Add queues will alternative fetch orders (priority based and stack based). ........ r60011 | raymond.hettinger | 2008-01-17 00:49:35 +0100 (Thu, 17 Jan 2008) | 1 line Add news entry. ........ r60013 | raymond.hettinger | 2008-01-17 04:02:14 +0100 (Thu, 17 Jan 2008) | 1 line Make starmap() match its pure python definition and accept any itertable input (not just tuples). ........ r60015 | gregory.p.smith | 2008-01-17 08:43:20 +0100 (Thu, 17 Jan 2008) | 3 lines Comply with RFC 3207. Fixes issue 829951 - http://bugs.python.org/issue829951 ........ r60018 | gregory.p.smith | 2008-01-17 09:03:17 +0100 (Thu, 17 Jan 2008) | 2 lines entry for r60015 ........ r60019 | raymond.hettinger | 2008-01-17 09:07:05 +0100 (Thu, 17 Jan 2008) | 1 line Note versionadded. ........ r60020 | gregory.p.smith | 2008-01-17 09:35:49 +0100 (Thu, 17 Jan 2008) | 8 lines Fixes (accepts patch) issue1339 - http://bugs.python.org/issue1339 - Factor out the duplication of EHLO/HELO in login() and sendmail() to a new function, ehlo_or_helo_if_needed(). - Use ehlo_or_helo_if_needed() in starttls() - Check for the starttls exception in starttls() in the same way as login() checks for the auth extension. Contributed by Bill Fenner. ........ r60021 | andrew.kuchling | 2008-01-17 13:00:15 +0100 (Thu, 17 Jan 2008) | 1 line Revise 3141 section a bit; add some Windows items ........ r60022 | brett.cannon | 2008-01-17 19:45:10 +0100 (Thu, 17 Jan 2008) | 2 lines Fix a function pointer declaration to silence the compiler. ........ r60024 | raymond.hettinger | 2008-01-17 20:31:38 +0100 (Thu, 17 Jan 2008) | 1 line Issue #1861: Add read-only attribute listing upcoming events in the order they will be run. ........ r60025 | andrew.kuchling | 2008-01-17 20:49:24 +0100 (Thu, 17 Jan 2008) | 1 line Correction from Jordan Lewis: halfdelay() uses tenths of a second, not milliseconds ........ r60026 | raymond.hettinger | 2008-01-17 23:27:49 +0100 (Thu, 17 Jan 2008) | 1 line Add advice on choosing between scheduler and threading.Timer(). ........ r60028 | christian.heimes | 2008-01-18 00:01:44 +0100 (Fri, 18 Jan 2008) | 2 lines Updated new property syntax. An elaborate example for subclassing and the getter was missing. Added comment about VS 2008 and PGO builds. ........ r60029 | raymond.hettinger | 2008-01-18 00:32:01 +0100 (Fri, 18 Jan 2008) | 1 line Fix-up Timer() example. ........ r60030 | raymond.hettinger | 2008-01-18 00:56:56 +0100 (Fri, 18 Jan 2008) | 1 line Fix markup ........ r60031 | raymond.hettinger | 2008-01-18 01:10:42 +0100 (Fri, 18 Jan 2008) | 1 line clearcache() needs to remove the dict as well as clear it. ........ r60033 | andrew.kuchling | 2008-01-18 03:26:16 +0100 (Fri, 18 Jan 2008) | 1 line Bump verson ........ r60034 | andrew.kuchling | 2008-01-18 03:42:52 +0100 (Fri, 18 Jan 2008) | 1 line Typo fix ........ r60035 | christian.heimes | 2008-01-18 08:30:20 +0100 (Fri, 18 Jan 2008) | 3 lines Coverity issue CID #197 var_decl: Declared variable "stm" without initializer ninit_use_in_call: Using uninitialized value "stm" (field "stm".tm_zone uninitialized) in call to function "mktime" ........ r60036 | christian.heimes | 2008-01-18 08:45:30 +0100 (Fri, 18 Jan 2008) | 11 lines Coverity issue CID #167 Event alloc_fn: Called allocation function "metacompile" [model] Event var_assign: Assigned variable "gr" to storage returned from "metacompile" gr = metacompile(n); Event pass_arg: Variable "gr" not freed or pointed-to in function "maketables" [model] g = maketables(gr); translatelabels(g); addfirstsets(g); Event leaked_storage: Returned without freeing storage "gr" return g; ........ r60038 | christian.heimes | 2008-01-18 09:04:57 +0100 (Fri, 18 Jan 2008) | 3 lines Coverity issue CID #182 size_error: Allocating 1 bytes to pointer "children", which needs at least 4 bytes ........ r60041 | christian.heimes | 2008-01-18 09:47:59 +0100 (Fri, 18 Jan 2008) | 4 lines Coverity issue CID #169 local_ptr_assign_local: Assigning address of stack variable "namebuf" to pointer "filename" out_of_scope: Variable "namebuf" goes out of scope use_invalid: Used "filename" pointing to out-of-scope variable "namebuf" ........ r60042 | christian.heimes | 2008-01-18 09:53:45 +0100 (Fri, 18 Jan 2008) | 2 lines Coverity CID #168 leaked_storage: Returned without freeing storage "fp" ........
135 lines
5 KiB
Python
135 lines
5 KiB
Python
"""A generally useful event scheduler class.
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Each instance of this class manages its own queue.
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No multi-threading is implied; you are supposed to hack that
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yourself, or use a single instance per application.
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Each instance is parametrized with two functions, one that is
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supposed to return the current time, one that is supposed to
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implement a delay. You can implement real-time scheduling by
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substituting time and sleep from built-in module time, or you can
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implement simulated time by writing your own functions. This can
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also be used to integrate scheduling with STDWIN events; the delay
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function is allowed to modify the queue. Time can be expressed as
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integers or floating point numbers, as long as it is consistent.
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Events are specified by tuples (time, priority, action, argument).
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As in UNIX, lower priority numbers mean higher priority; in this
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way the queue can be maintained as a priority queue. Execution of the
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event means calling the action function, passing it the argument
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sequence in "argument" (remember that in Python, multiple function
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arguments are be packed in a sequence).
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The action function may be an instance method so it
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has another way to reference private data (besides global variables).
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"""
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# XXX The timefunc and delayfunc should have been defined as methods
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# XXX so you can define new kinds of schedulers using subclassing
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# XXX instead of having to define a module or class just to hold
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# XXX the global state of your particular time and delay functions.
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import heapq
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from collections import namedtuple
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__all__ = ["scheduler"]
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Event = namedtuple('Event', 'time, priority, action, argument')
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class scheduler:
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def __init__(self, timefunc, delayfunc):
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"""Initialize a new instance, passing the time and delay
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functions"""
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self._queue = []
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self.timefunc = timefunc
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self.delayfunc = delayfunc
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def enterabs(self, time, priority, action, argument):
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"""Enter a new event in the queue at an absolute time.
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Returns an ID for the event which can be used to remove it,
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if necessary.
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"""
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event = Event(time, priority, action, argument)
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heapq.heappush(self._queue, event)
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return event # The ID
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def enter(self, delay, priority, action, argument):
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"""A variant that specifies the time as a relative time.
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This is actually the more commonly used interface.
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"""
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time = self.timefunc() + delay
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return self.enterabs(time, priority, action, argument)
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def cancel(self, event):
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"""Remove an event from the queue.
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This must be presented the ID as returned by enter().
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If the event is not in the queue, this raises RuntimeError.
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"""
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self._queue.remove(event)
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heapq.heapify(self._queue)
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def empty(self):
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"""Check whether the queue is empty."""
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return not self._queue
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def run(self):
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"""Execute events until the queue is empty.
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When there is a positive delay until the first event, the
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delay function is called and the event is left in the queue;
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otherwise, the event is removed from the queue and executed
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(its action function is called, passing it the argument). If
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the delay function returns prematurely, it is simply
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restarted.
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It is legal for both the delay function and the action
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function to to modify the queue or to raise an exception;
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exceptions are not caught but the scheduler's state remains
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well-defined so run() may be called again.
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A questionable hack is added to allow other threads to run:
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just after an event is executed, a delay of 0 is executed, to
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avoid monopolizing the CPU when other threads are also
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runnable.
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"""
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# localize variable access to minimize overhead
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# and to improve thread safety
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q = self._queue
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delayfunc = self.delayfunc
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timefunc = self.timefunc
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pop = heapq.heappop
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while q:
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time, priority, action, argument = checked_event = q[0]
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now = timefunc()
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if now < time:
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delayfunc(time - now)
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else:
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event = pop(q)
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# Verify that the event was not removed or altered
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# by another thread after we last looked at q[0].
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if event is checked_event:
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action(*argument)
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delayfunc(0) # Let other threads run
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else:
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heapq.heappush(event)
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@property
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def queue(self):
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"""An ordered list of upcoming events.
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Events are named tuples with fields for:
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time, priority, action, arguments
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"""
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# Use heapq to sort the queue rather than using 'sorted(self._queue)'.
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# With heapq, two events scheduled at the same time will show in
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# the actual order they would be retrieved.
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events = self._queue[:]
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return map(heapq.heappop, [events]*len(events))
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