Dealing with Sharing
If you don’t share, no data races can happen. Not sharing means that your thread works on local variables. This can be achieved by copying the value, by using thread-specific storage, or by transferring the result to the future via a protected data channel. The patterns in this section are quite obvious, but for completeness, I will present them with a short explanation.
Copied Value
If a thread gets its arguments by copy and not by reference, there is no need to synchronise accesses to any data. No data races and no lifetime issues are possible.
Data Races with References
The following program starts three threads. One thread gets its argument by copy, the other by reference and the last by constant reference.
1 // copiedValueDataRace.cpp
2
3 #include <functional> 4 #include <iostream> 5 #include <string> 6 #include <thread> 7
8 using namespace std::chrono_literals;
9
10 void byCopy(bool...