thread-local-storage

UPDATED on 11/18/2014 - While browsing the log4net source repository, I found that the implementation of LogicalThreadContext was modified in November 2011 to that it stores its properties using CallContext.LogicalSetData (and gets them using LogicalGetData). This is important because that means that LogicalThreadContext should now work correctly. Any data stored in LogicalThreadContext should be "flowed" to any child threads or tasks. This compares to ThreadContext (and the old implementation of LogicalThreadContext) where data stored in the context would remain local to the current thread

Is there a difference between these two code segments: void f() { thread_local vector<int> V; V.clear(); ... // use V as a temporary variable } and void f() { static thread_local vector<int> V; V.clear(); ... // use V as a temporary variable } Backstory: originally I had a STATIC vector V (for holding some intermediate values, it gets cleared every time I enter the function) and a single-threaded program. I want to turn the program into a multithreading one, so somehow I have to get rid of this static modifier. My idea is to turn every static into thread_local and not worry about anything else

I am confused with the description of thread_local in C++11. My understanding is, each thread has unique copy of local variables in a function. The global/static variables can be accessed by all the threads (possibly synchronized access using locks). And the thread_local variables are visible to all the threads but can only modified by the thread for which they are defined? Is it correct? paxdiablo Thread-local storage duration is a term used to refer to data that is seemingly global or static storage duration (from the viewpoint of the functions using it) but in actual fact, there is one copy