Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Possible Duplicate:
Is volatile expensive?
I heard that using volatile variable in multithreaded application brings some performance issues.
Does anybody explain why?
Declaring a variable as
volatilecauses the JIT compiler to use instructions that read from / write to memory each time the variable is used. In the latter case, the cache-line has to be flushed to main memory do that other processors see the changes immediately. The read / write memory cycles to execution time.By contrast, if you don’t declare the variable as volatile, the JIT compiler may emit instructions to read / write the state of the variable from a register or from 1st or 2nd level memory cache. On average, this will save a few clock cycles for each read or write.
For a more detailed treatment read the answers to Is volatile expensive?.