C++简单学习（Part3_lecture 12）（多线程、Web编程）

Part 3高级教程

Lecture 12 多线程、Web编程

目录

Part 3高级教程

Lecture 12 多线程Web编程

目录
1多线程

2Web编程

1多线程

#include <iostream>
// 必须的头文件
#include <pthread.h>

using namespace std;

#define NUM_THREADS 5

// 线程的运行函数
void* say_hello(void* args)
{
cout << "Hello Runoob！" << endl;
return 0;
}

int main()
{
// 定义线程的 id 变量，多个变量使用数组
pthread_t tids[NUM_THREADS];
for(int i = 0; i < NUM_THREADS; ++i)
{
//参数依次是：创建的线程id，线程参数，调用的函数，传入的函数参数
int ret = pthread_create(&tids[i], NULL, say_hello, NULL);
if (ret != 0)
{
cout << "pthread_create error: error_code=" << ret << endl;
}
}
//等各个线程退出后，进程才结束，否则进程强制结束了，线程可能还没反应过来；
pthread_exit(NULL);
}

//文件名：test.cpp

#include <iostream>
#include <cstdlib>
#include <pthread.h>

using namespace std;

#define NUM_THREADS     5

void *PrintHello(void *threadid)
{
// 对传入的参数进行强制类型转换，由无类型指针变为整形数指针，然后再读取
int tid = *((int*)threadid);
cout << "Hello Runoob! 线程 ID, " << tid << endl;
pthread_exit(NULL);
}

int main ()
{
pthread_t threads[NUM_THREADS];
int indexes[NUM_THREADS];// 用数组来保存i的值
int rc;
int i;
for( i=0; i < NUM_THREADS; i++ ){
cout << "main() : 创建线程, " << i << endl;
indexes[i] = i; //先保存i的值
// 传入的时候必须强制转换为void* 类型，即无类型指针
rc = pthread_create(&threads[i], NULL,
PrintHello, (void *)&(indexes[i]));
if (rc){
cout << "Error:无法创建线程," << rc << endl;
exit(-1);
}
}
pthread_exit(NULL);
}

#include <iostream>
#include <cstdlib>
#include <pthread.h>

using namespace std;

#define NUM_THREADS     5

struct thread_data{
int  thread_id;
char *message;
};

void *PrintHello(void *threadarg)
{
struct thread_data *my_data;

my_data = (struct thread_data *) threadarg;

cout << "Thread ID : " << my_data->thread_id ;
cout << " Message : " << my_data->message << endl;

pthread_exit(NULL);
}

int main ()
{
pthread_t threads[NUM_THREADS];
struct thread_data td[NUM_THREADS];
int rc;
int i;

for( i=0; i < NUM_THREADS; i++ ){
cout <<"main() : creating thread, " << i << endl;
td[i].thread_id = i;
td[i].message = (char*)"This is message";
rc = pthread_create(&threads[i], NULL,
PrintHello, (void *)&td[i]);
if (rc){
cout << "Error:unable to create thread," << rc << endl;
exit(-1);
}
}
pthread_exit(NULL);
}

#include <iostream>
#include <cstdlib>
#include <pthread.h>
#include <unistd.h>

using namespace std;

#define NUM_THREADS     5

void *wait(void *t)
{
int i;
long tid;

tid = (long)t;

sleep(1);
cout << "Sleeping in thread " << endl;
cout << "Thread with id : " << tid << "  ...exiting " << endl;
pthread_exit(NULL);
}

int main ()
{
int rc;
int i;
pthread_t threads[NUM_THREADS];
pthread_attr_t attr;
void *status;

// 初始化并设置线程为可连接的（joinable）
pthread
4000
_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);

for( i=0; i < NUM_THREADS; i++ ){
cout << "main() : creating thread, " << i << endl;
rc = pthread_create(&threads[i], NULL, wait, (void *)&i );
if (rc){
cout << "Error:unable to create thread," << rc << endl;
exit(-1);
}
}

// 删除属性，并等待其他线程
pthread_attr_destroy(&attr);
for( i=0; i < NUM_THREADS; i++ ){
rc = pthread_join(threads[i], &status);
if (rc){
cout << "Error:unable to join," << rc << endl;
exit(-1);
}
cout << "Main: completed thread id :" << i ;
cout << "  exiting with status :" << status << endl;
}

cout << "Main: program exiting." << endl;
pthread_exit(NULL);
}

当上面的代码被编译和执行时，它会产生下列结果：

main() : creating thread, 0

main() : creating thread, 1

main() : creating thread, 2

main() : creating thread, 3

main() : creating thread, 4

Sleeping in thread

Thread with id : 4 …exiting

Sleeping in thread

Thread with id : 3 …exiting

Sleeping in thread

Thread with id : 2 …exiting

Sleeping in thread

Thread with id : 1 …exiting

Sleeping in thread

Thread with id : 0 …exiting

Main: completed thread id :0 exiting with status :0

Main: completed thread id :1 exiting with status :0

Main: completed thread id :2 exiting with status :0

Main: completed thread id :3 exiting with status :0

Main: completed thread id :4 exiting with status :0

Main: program exiting.

#include <iostream>

#include <thread>

std::thread::id main_thread_id = std::this_thread::get_id();

void hello()
{
std::cout << "Hello Concurrent World\n";
if (main_thread_id == std::this_thread::get_id())
std::cout << "This is the main thread.\n";
else
std::cout << "This is not the main thread.\n";
}

void pause_thread(int n) {
std::this_thread::sleep_for(std::chrono::seconds(n));
std::cout << "pause of " << n << " seconds ended\n";
}

int main() {
std::thread t(hello);
std::cout << t.hardware_concurrency() << std::endl;//可以并发执行多少个(不准确)
std::cout << "native_handle " << t.native_handle() << std::endl;//可以并发执行多少个(不准确)
t.join();
std::thread a(hello);
a.detach();
std::thread threads[5];                         // 默认构造线程

std::cout << "Spawning 5 threads...\n";
for (int i = 0; i < 5; ++i)
threads[i] = std::thread(pause_thread, i + 1);   // move-assign threads
std::cout << "Done spawning threads. Now waiting for them to join:\n";
for (auto &thread : threads)
thread.join();
std::cout << "All threads joined!\n";
}

之前一些编译器使用 C++11 的编译参数是 -std=c++11

g++ -std=c++11 test.cpp

2Web编程

#include <iostream>
using namespace std;

int main ()
{

cout << "Content-type:text/html\r\n\r\n";
cout << "<html>\n";
cout << "<head>\n";
cout << "<title>Hello World - 第一个 CGI 程序</title>\n";
cout << "</head>\n";
cout << "<body>\n";
cout << "<h2>Hello World! 这是我的第一个 CGI 程序</h2>\n";
cout << "</body>\n";
cout << "</html>\n";

return 0;
}

#include <iostream>
#include <stdlib.h>
#include <string>
using namespace std;

const string ENV[ 24 ] = {
"COMSPEC", "DOCUMENT_ROOT", "GATEWAY_INTERFACE",
"HTTP_ACCEPT", "HTTP_ACCEPT_ENCODING",
"HTTP_ACCEPT_LANGUAGE", "HTTP_CONNECTION",
"HTTP_HOST", "HTTP_USER_AGENT", "PATH",
"QUERY_STRING", "REMOTE_ADDR", "REMOTE_PORT",
"REQUEST_METHOD", "REQUEST_URI", "SCRIPT_FILENAME",
"SCRIPT_NAME", "SERVER_ADDR", "SERVER_ADMIN",
"SERVER_NAME","SERVER_PORT","SERVER_PROTOCOL",
"SERVER_SIGNATURE","SERVER_SOFTWARE" };

int main ()
{

cout << "Content-type:text/html\r\n\r\n";
cout << "<html>\n";
cout << "<head>\n";
cout << "<title>CGI 环境变量</title>\n";
cout << "</head>\n";
cout << "<body>\n";
cout << "<table border = \"0\" cellspacing = \"2\">";

for ( int i = 0; i < 24; i++ )
{
cout << "<tr><td>" << ENV[ i ] << "</td><td>";
// 尝试检索环境变量的值
char *value = getenv( ENV[ i ].c_str() );
if ( value != 0 ){
cout << value;
}else{
cout << "环境变量不存在。";
}
cout << "</td></tr>\n";
}
cout << "</table><\n";
cout << "</body>\n";
cout << "</html>\n";

return 0;
}

#include <iostream>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdlib.h>

#include <cgicc/CgiDefs.h>
#include <cgicc/Cgicc.h>
#include <cgicc/HTTPHTMLHeader.h>
#include <cgicc/HTMLClasses.h>

using namespace std;
using namespace cgicc;

int main ()
{
Cgicc formData;

cout << "Content-type:text/html\r\n\r\n";
cout << "<html>\n";
cout << "<head>\n";
cout << "<title>使用 GET 和 POST 方法</title>\n";
cout << "</head>\n";
cout << "<body>\n";

form_iterator fi = formData.getElement("first_name");
if( !fi->isEmpty() && fi != (*formData).end()) {
cout << "名：" << **fi << endl;
}else{
cout << "No text entered for first name" << endl;
}
cout << "<br/>\n";
fi = formData.getElement("last_name");
if( !fi->isEmpty() &&fi != (*formData).end()) {
cout << "姓：" << **fi << endl;
}else{
cout << "No text entered for last name" << endl;
}
cout << "<br/>\n";

cout << "</body>\n";
cout << "</html>\n";

return 0;
}

#include <iostream>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdlib.h>

#include <cgicc/CgiDefs.h>
#include <cgicc/Cgicc.h>
#include <cgicc/HTTPHTMLHeader.h>
#include <cgicc/HTMLClasses.h>

using namespace std;
using namespace cgicc;

int main ()
{
Cgicc formData;
bool maths_flag, physics_flag;

cout << "Content-type:text/html\r\n\r\n";
cout << "<html>\n";
cout << "<head>\n";
cout << "<title>向 CGI 程序传递复选框数据</title>\n";
cout << "</head>\n";
cout << "<body>\n";

maths_flag = formData.queryCheckbox("maths");
if( maths_flag ) {
cout << "Maths Flag: ON " << endl;
}else{
cout << "Maths Flag: OFF " << endl;
}
cout << "<br/>\n";

physics_flag = formData.queryCheckbox("physics");
if( physics_flag ) {
cout << "Physics Flag: ON " << endl;
}else{
cout << "Physics Flag: OFF " << endl;
}
cout << "<br/>\n";
cout << "</body>\n";
cout << "</html>\n";

return 0;
}

#include <iostream>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdlib.h>

#include <cgicc/CgiDefs.h>
#include <cgicc/Cgicc.h>
#include <cgicc/HTTPHTMLHeader.h>
#include <cgicc/HTMLClasses.h>

using namespace std;
using namespace cgicc;

int main ()
{
Cgicc formData;

cout << "Content-type:text/html\r\n\r\n";
cout << "<html>\n";
cout << "<head>\n";
cout << "<title>向 CGI 程序传递单选按钮数据</title>\n";
cout << "</head>\n";
cout << "<body>\n";

form_iterator fi = formData.getElement("subject");
if( !fi->isEmpty() && fi != (*formData).end()) {
cout << "Radio box selected: " << **fi << endl;
}

cout << "<br/>\n";
cout << "</body>\n";
cout << "</html>\n";

return 0;
}

#include <iostream>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdlib.h>

#include <cgicc/CgiDefs.h>
#include <cgicc/Cgicc.h>
#include <cgicc/HTTPHTMLHeader.h>
#include <cgicc/HTMLClasses.h>

using namespace std;
using namespace cgicc;

int main ()
{
Cgicc formData;

cout << "Content-type:text/html\r\n\r\n";
cout << "<html>\n";
cout << "<head>\n";
cout << "<title>向 CGI 程序传递下拉框数据</title>\n";
cout << "</head>\n";
cout << "<body>\n";

form_iterator fi = formData.getElement("dropdown");
if( !fi->isEmpty() && fi != (*formData).end()) {
cout << "Value Selected: " << **fi << endl;
}

cout << "<br/>\n";
cout << "</body>\n";
cout << "</html>\n";

return 0;
}

#include <iostream>
using namespace std;

int main ()
{

cout << "Set-Cookie:UserID=XYZ;\r\n";
cout << "Set-Cookie:Password=XYZ123;\r\n";
cout << "Set-Cookie:Domain=www.w3cschool.cc;\r\n";
cout << "Set-Cookie:Path=/perl;\n";
cout << "Content-type:text/html\r\n\r\n";

cout << "<html>\n";
cout << "<head>\n";
cout << "<title>CGI 中的 Cookies</title>\n";
cout << "</head>\n";
cout << "<body>\n";

cout << "设置 cookies" << endl;

cout << "<br/>\n";
cout << "</body>\n";
cout << "</html>\n";

return 0;
}

#include <iostream>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdlib.h>

#include <cgicc/CgiDefs.h>
#include <cgicc/Cgicc.h>
#include <cgicc/HTTPHTMLHeader.h>
#include <cgicc/HTMLClasses.h>

using namespace std;
using namespace cgicc;

int main ()
{
Cgicc cgi;
const_cookie_iterator cci;

cout << "Content-type:text/html\r\n\r\n";
cout << "<html>\n";
cout << "<head>\n";
cout << "<title>CGI 中的 Cookies</title>\n";
cout << "</head>\n";
cout << "<body>\n";
cout << "<table border = \"0\" cellspacing = \"2\">";

// 获取环境变量
const CgiEnvironment& env = cgi.getEnvironment();

for( cci = env.getCookieList().begin();
cci != env.getCookieList().end();
++cci )
{
cout << "<tr><td>" << cci->getName() << "</td><td>";
cout << cci->getValue();
cout << "</td></tr>\n";
}
cout << "</table><\n";

cout << "<br/>\n";
cout << "</body>\n";
cout << "</html>\n";

return 0;
}

#include <iostream>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdlib.h>

#include <cgicc/CgiDefs.h>
#include <cgicc/Cgicc.h>
#include <cgicc/HTTPHTMLHeader.h>
#include <cgicc/HTMLClasses.h>

using namespace std;
using namespace cgicc;

int main ()
{
Cgicc cgi;

cout << "Content-type:text/html\r\n\r\n";
cout << "<html>\n";
cout << "<head>\n";
cout << "<title>CGI 中的文件上传</title>\n";
cout << "</head>\n";
cout << "<body>\n";

// 获取要被上传的文件列表
const_file_iterator file = cgi.getFile("userfile");
if(file != cgi.getFiles().end()) {
// 在 cout 中发送数据类型
cout << HTTPContentHeader(file->getDataType());
// 在 cout 中写入内容
file->writeToStream(cout);
}
cout << "<文件上传成功>\n";
cout << "</body>\n";
cout << "</html>\n";

return 0;
}

上面的实例是在 cout 流中写入内容，但您可以打开文件流，并把上传的文件内容保存在目标位置的某个文件中。