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 = 0;



std::thread t1( [&] () {

    int r = func();

    m.lock();

    sum += r;

    m.unlock();

});

　using RAII

std::mutex m;

int sum = 0;



std::thread t1( [&] () {

    int r = func();

    {

        lock_guard<mutex> locker(m);

        sum += r;

    }

});