问题
Possible Duplicate:
Thread safety of std::map for read-only operations
Having std::map a can we do a.find(...)->second in multiple threads at the same time on it?
回答1:
Yes. As long as none of your threads do a write
i.e. Construct the data structure in memory
Use as many threads to find/read as you require.
If the leaf needs altering put a mutex there.
来源：https://stackoverflow.com/questions/7198332/are-find-and-read-operations-on-stdmap-threadsafe