Thread safe, means that two thing can be done with out the order mattering, and without any dependency on the other thread.
Example: Find the sum of a column 1-1000 Single Thread: 1+2+3+4....+998+999+1000 4 Threads: A= 1+2+3+4...248+249+250 B = 251+252+253+254...498+499+500 C = 501+502+503+504...748+749+750 D = 751+752+753+754...998+999+1000 Return A+B+C+D Not Thread Safe: Replace all entities with Value -1 with 0 Sum column Not Thread Safe: New A = Old A + 3 New B = New A + Old B Can be multithreaded for part of the operation: Fetch 4 URLs, Store returned data, do formula, display result. You can multithread the Fetch, and the store, but the Do formula and display result has to happen after. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Greg Sent: Tuesday, June 28, 2011 10:20 PM To: Google App Engine Subject: [google-appengine] Thread-safe Python Tips Hi - Could anyone familiar with threads explain the basic principals of python thread-safety? Cheers! Greg. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
