C++11 Language-level threading

C++11 Language-level threading

Creation of Threads

Creating a thread with Std::thread is as simple as providing a thread function or function object, and you can specify parameters for the thread function at the same time.

#define_crt_secure_no_warnings#include<iostream>#include<string>#include<chrono>#include<thread>voidfunc1 () { while(true) {std::this_thread::sleep_for (Std::chrono::milliseconds ( the)); Std::cout<< __function__ <<Std::endl; }}voidFunc2 () { while(true) {std::this_thread::sleep_for (Std::chrono::milliseconds ( the)); Std::cout<< __function__ <<Std::endl; }}voidFUNC3 (intACharChConst Char*str) {std::this_thread::sleep_for (Std::chrono::milliseconds ( the)); Std::cout<<"A ="<< a <<Std::endl; Std::cout<<"ch ="<< CH <<Std::endl; Std::cout<<"str ="<< Str <<Std::endl;}voidmytest () {std::thread T1 (func1);//Sub-thread 1Std::thread T2 (FUNC2);//Sub-thread 2//threads can also receive parameters for functionsstd::thread T3 (func3,1,'a',"XYZ");//Sub-thread 3std::thread T4 (func3,2,'a',"ABC");//Sub-thread 3     while(true)//Main Thread{std::this_thread::sleep_for (Std::chrono::milliseconds ( the)); Std::cout<< __function__ <<Std::endl; }    return;}intMain () {mytest (); System ("Pause"); return 0;}

Reclaim Thread Resources

Std::thread::join waits for the thread to end ( this function blocks ) and reclaims the thread resource, and if the thread function has a return value, the return value is ignored.

#define_crt_secure_no_warnings#include<iostream>#include<string>#include<chrono>#include<thread>voidPuase_thread (intNointN)    {std::this_thread::sleep_for (Std::chrono::seconds (n)); Std::cout<<"thread-"<< No <<"Pause of"<< N <<"seconds"<<Std::endl;}voidmytest () {//std::cout << "Spawning 3 threads ..." << Std::endl;Std::thread T1 (Puase_thread,1,3); Std::thread T2 (Puase_thread,2,3); std::thread T3 (Puase_thread,3,3); Std::cout<<"Done spawning threads. Now waiting-them to join:"<<Std::endl; T1.joinable ()? T1.join (): Std::cout <<"Thread id-"<< t1.get_id () <<"can not join"<<Std::endl; T2.joinable ()? T2.join (): Std::cout <<"Thread id-"<< t2.get_id () <<"can not join"<<Std::endl; T3.joinable ()? T3.join (): Std::cout <<"Thread id-"<< t3.get_id () <<"can not join"<<Std::endl; Std::cout<<"All Threads joined!"<<Std::endl; return;}intMain () {mytest (); System ("Pause"); return 0;}

If you do not want the thread to be blocked for execution, you can call the thread's Std::thread::d etach ( This function will not block ), detach the thread from the thread object, and let the thread execute as a background thread.

It is important to note, however, that detach cannot be contacted after a thread, such as detach, after which the join is no longer available to wait for execution, and when the thread finishes executing, we cannot control it.

#define_crt_secure_no_warnings#include<iostream>#include<string>#include<chrono>#include<thread>voidPuase_thread (intNointN)    {std::this_thread::sleep_for (Std::chrono::seconds (n)); Std::cout<<"thread-"<< No <<"Pause of"<< N <<"seconds"<<Std::endl;}voidmytest () {//std::cout << "Spawning 3 threads ..." << Std::endl;Std::thread T1 (Puase_thread,1,3); Std::thread T2 (Puase_thread,2,3); std::thread T3 (Puase_thread,3,3); Std::cout<<"Done spawning threads. Now waiting-them to join:"<<Std::endl; T1.joinable ()? T1.detach (): Std::cout <<"Thread id-"<< t1.get_id () <<"can not detach"<<Std::endl; T2.joinable ()? T2.detach (): Std::cout <<"Thread id-"<< t2.get_id () <<"can not detach"<<Std::endl; T3.joinable ()? T3.detach (): Std::cout <<"Thread id-"<< t3.get_id () <<"can not detach"<<Std::endl; Std::cout<<"All Threads joined!"<<Std::endl; return;}intMain () {mytest (); System ("Pause"); return 0;}

Gets the thread ID and CPU core number

#define_crt_secure_no_warnings#include<iostream>#include<string>#include<chrono>#include<thread>voidPuase_thread (intN)    {std::this_thread::sleep_for (Std::chrono::seconds (n)); //std::this_thread::get_id () gets the thread IDStd::cout <<"thread-"<< std::this_thread::get_id () <<"Pause of"<< N <<"seconds"<<Std::endl;}voidmytest () {//std::cout << "Spawning 3 threads ..." << Std::endl;Std::thread T1 (Puase_thread,3); Std::thread T2 (Puase_thread,3); std::thread T3 (Puase_thread,3); Std::cout<<"Main ID:"<< std::this_thread::get_id () << Std::endl;//main thread IDStd::cout <<"CPU num:"<< std::thread::hardware_concurrency () << Std::endl;//gets the number of CPU cores, failed to return 0Std::cout<<"Done spawning threads. Now waiting-them to join:"<<Std::endl; //t1.get_id ()//gets T1 The ID of this threadT1.joinable ()? T1.detach (): Std::cout <<"Thread id-"<< t1.get_id () <<"can not detach"<<Std::endl; T2.joinable ()? T2.join (): Std::cout <<"Thread id-"<< t2.get_id () <<"can not join"<<Std::endl; T3.joinable ()? T3.join (): Std::cout <<"Thread id-"<< t3.get_id () <<"can not join"<<Std::endl; Std::cout<<"All Threads joined!"<<Std::endl; return;}intMain () {mytest (); System ("Pause"); return 0;}

C++11 Language-level threading