C++11 Concurrency Features

Concept	Header	Summary
Threads	<thread>	Standard, low-level, type-safe;
Futures	<future>	Via async function, hides threading;
Locks	<mutex>	Standard, low-level locking primitives
Condition Vars	<condition_variable>	Low-level synchronization primitives
Atomics	<atomic>	Predictable, concurrent access without data race

• How to avoid data races

1. redesign to eliminate sharing data
2. use thread-safe entities(e.g. parallel collections)
3. use synchronization(e.g. lock atom...)

• Using RAII( Resource Acquisition Is Initialization ) to avoid data races

old style

#include <mutex>
#include <thread>

std::mutex m;
int sum = ;

std::thread t1( [&] () {
    int r = func();
    m.lock();
    sum += r;
    m.unlock();
});

　using RAII

std::mutex m;
int sum = ;

std::thread t1( [&] () {
    int r = func();
    {
        lock_guard<mutex> locker(m);
        sum += r;
    }
});