Yes! you're right, after installation pywin32 my test works properly! Thank you!
P.S. I think that would be better to copy/paste that Attention from Overview to Session chapter and make it more *impressive* I suppose there are many people (like me) who have read an Overview once and never again. On Tuesday, August 11, 2015 at 5:25:34 PM UTC+3, Anthony wrote: > > Probably you are running web2py from source with your own Python > installation and have not installed the pywin32 > <http://sourceforge.net/projects/pywin32/> extension (which is required > for file locking). This is mentioned in the book: > http://web2py.com/books/default/chapter/29/03/overview?search=win32. > > For more details, see > https://docs.python.org/2.7/using/windows.html#pywin32 > > Anthony > > On Monday, August 10, 2015 at 8:06:12 PM UTC-4, Val K wrote: >> >> As I see, the problem is that ajax request (may be not ajax only) didn't >> wait for closing session file by another one and read/save data from/to it >> at any time! Lock did not work on my Win7 because , as I think, for Win >> it's one process. >> Request processing may be not pure parallel but fully asynchronous - I >> placed some print statement in ajax controller and got full chaos - among >> print from one request were one from another. >> Here is my littlle test. 3 ajax calls start at once but finish >> asynchronously (time.sleep()). By change time.sleep() it's possible to >> get any order (I did "start first - finish last"). At the end of all >> session contains only vars/changes of ajax which finish last. >> >> >> >> import time >> >> # it's a funny AJAX test >> #just create new app and paste it in the default controller >> # call .../default/many_ajx_form >> >> def ajx_bug(): >> if request.args(0)=='0': >> time.sleep(10) # well, now wait until fish fall asleep in the pond >> session.req_0='Only req_0 ... nothing else!!! Where are req_1, >> req_2 and other kids? It seems, that guys ignored my session lock?' >> elif request.args(0)=='1': >> time.sleep(5) >> session.req_1='I killed req_2 and created req_1 which will be >> killed by req_0 !' >> else: >> session.req_2='I created req_2' >> response.flash="click 'Print Session' !" >> if request.args(0)=='0': >> return dict(ret='Better late than never') >> else: >> return dict(ret='completed req_%s'%request.args(0)) >> >> def print_session(): >> lst=[] >> for k,v in session.items(): >> lst.append(DIV( >> DIV(k,_class='col-xs-2', >> _style="font-weight:bold; text-align:right; min-height:50px"), >> DIV(':',_class='col-xs-1'), >> DIV(v,_class='col-xs-9'), >> _class='row' >> ) >> ) >> return dict(r=DIV(*lst, _class="container", _style="max-width:800px")) >> >> >> >> #------------ CALL THIS -------------------- >> def many_ajx_form(): >> session.clear() # - for clear test >> session.dummy_data = 'dummy data' # make some action for sure init >> session >> ret={} >> for i in xrange(3): >> ret['ajx_frm_%s'%i]= \ >> DIV( >> LOAD('default','ajx_bug.load', >> args=[i], >> ajax=True, >> target='cont_%s'%i >> ), >> _id='cont_%s'%i >> ) >> >> btn_prnt=DIV(BUTTON("Print Session", _type="button",_class="btn >> btn-default", >> _onclick=myLOAD_any("default","print_session", >> target="lst")), >> DIV(_id="lst") >> ) >> >> ret['z']=btn_prnt >> >> return ret >> >> #return string, no SCRIPT tag! >> def myLOAD_any(contrl, fun, target, args=None, vars=None, ): >> >> if vars: >> vars_str='?' >> for k,v in vars.items(): >> vars_str+=('%s=%s&'%(k,v)) >> vars_str= vars_str[:-1] # remove last '&' >> else: >> vars_str='' >> if args: >> args_str='/'.join([str(it) for it in args]) >> else: >> args_str='' >> data=dict( >> rmt= "/%s/%s/%s.load/%s%s"%(request.application, contrl, fun, >> args_str, vars_str ), >> trg=target >> ) >> load_str="""$.web2py.component("%(rmt)s", "%(trg)s", 0, 1, >> $("#%(trg)s"));""" >> return load_str%data >> >> >> >> >> >> >> >> On Monday, August 10, 2015 at 4:05:57 AM UTC+3, Anthony wrote: >>> >>> All responses within the same session are supposed to have the same >>> session_id. The fact that all three Ajax requests can access the session >>> doesn't necessarily mean they are being processed in parallel (the requests >>> might still be completing one after another). >>> >>> It would be helpful if you could attach a minimal app that demonstrates >>> the problem. >>> >>> Anthony >>> >>> On Sunday, August 9, 2015 at 12:30:01 PM UTC-4, Val K wrote: >>>> >>>> I realize your advice - no effect! >>>> I analyzed *session.connect* and found strange place at the biginig >>>> of *connect *definition: >>>> ... >>>> self._unlock(response) # - *unconditional unlock *session file >>>> witch have a name == response.session_id >>>> ... >>>> >>>> Then I changed definition of ajx_bug(): form=SQLFORM.factory(Field(' >>>> any', *comment=response.session_id* ), table_name=form_name) >>>> and here is I got: >>>> >>>> Many Ajx Form >>>> ajx_frm_0: >>>> Any >>>> 127.0.0.1-dd2c6b6c-3141-4826-8887-ab1691b67350 >>>> ajx_frm_1: >>>> Any >>>> 127.0.0.1-dd2c6b6c-3141-4826-8887-ab1691b67350 >>>> ajx_frm_2: >>>> Any >>>> 127.0.0.1-dd2c6b6c-3141-4826-8887-ab1691b67350 >>>> >>>> >>>> >>>> >>>> >>>> >>>> All ajax responses have the same response_id! i.e. each ajax-process >>>> can unlock session file locked by another! >>>> In other words, requests parallel processing works properly across >>>> sessions, but not within one session, because all responses within >>>> session >>>> have the same response_id >>>> It seems, that file is not locked across parallel process (on my Win7 >>>> at least), may because it is children of one parent or something else? >>>> >>>> >>>> >>>> On Sunday, August 9, 2015 at 3:28:04 PM UTC+3, Anthony wrote: >>>>> >>>>> Does the problem occur only on the first page load of the session? If >>>>> so, does the problem go away if you add the following line at the top of >>>>> the many_ajx_form function: >>>>> >>>>> session.dummy_data = 'dummy data' >>>>> >>>>> If that's the case, then this is the same problem diagnosed in the >>>>> original thread, with something like the above as the solution. The >>>>> problem >>>>> is not that Ajax reads fail to lock the session -- the problem is that at >>>>> the very beginning of the session when the initial set of Ajax requests >>>>> are >>>>> made, there is no session file to lock at all. Adding some dummy data to >>>>> the session in the parent page will force a session file to be created, >>>>> so >>>>> the session file will then exist and therefore be locked when the Ajax >>>>> requests come in. Note, this won't work with sessions stored in the DB or >>>>> in cookies, as there is no session locking at all with those methods (you >>>>> will need some other means to avoid session race conditions in those >>>>> cases). >>>>> >>>>> Anthony >>>>> >>>>> >>>>> >>>>> >>>>> >>>>>> -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- You received this message because you are subscribed to the Google Groups "web2py-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to web2py+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
