Menu
what is the best way to store some variable local to each thread?
631
Thread Local Storage (TLS) is the mechanism by which each thread in a given multithreaded process allocates storage for thread-specific data. In standard multithreaded programs, data is shared among all threads of a given process, whereas thread local storage is the mechanism for allocating per-thread data.
Thread-local storage ( TLS ) is a mechanism by which variables are allocated such that there is one instance of the variable per extant thread. The runtime model GCC uses to implement this originates in the IA-64 processor-specific ABI, but has since been migrated to other processors as well.
In some ways, TLS is similar to static data. The only difference is that TLS data are unique to each thread. Most thread libraries-including Windows and Pthreads-provide some form of support for thread-local storage; Java provides support as well.
Yes, you are correct that TLS can be as fast as a pointer lookup. It can even be faster on systems with a memory management unit.
If you use .Net 4.0 or above, as far as I know, the recommended way is to use System.Threading.ThreadLocal<T> which also gives lazy initialization as a bonus.
67
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
