使用C++11 STL线程库实现一个线程池。处理机制是抢占式的，即所有线程从一个队列(std::queue)中获取任务执行(计算字符串简单HASH值)，使用std::mutex和std::conditional_variable实现队列访问并发协调。

#include

#include

#include

#include

#include

#include

#include

#include

#include

using namespace std;

static std::mutex G_lockPrint;

void print_message(int value, const string& str) {

lock_guard lock(G_lockPrint);

cout<

cout<

}

#define THREAD_COUNT 10

int main()

{

thread thpool[THREAD_COUNT];

mutex quelock;

condition_variable quecv;

queue strqueue;

volatile bool stop = false;

for(int i = 0; i < THREAD_COUNT; ++i ) {

thpool[i] = thread([&quelock, &quecv, &strqueue, &stop]()

{

string str;

while ( !stop ) {

{

unique_lock lock(quelock);

if ( strqueue.empty() ) {

auto ret = quecv.wait_for(lock, chrono::seconds(1));

if ( ret == cv_status::timeout) continue;

}

if ( !strqueue.empty() ) {

str = strqueue.front();

strqueue.pop();

} else {

continue;

}

}

int hash = 0;

for(size_t i = 0; i < str.length(); ++i) {

hash = (hash << 5) - i + str[i];

}

print_message(hash, str);

} // end while

}

);

}

for(int i = 0; i < 100000; ++i) {

stringstream ss;

ss<

lock_guard lock(quelock);

strqueue.push(ss.str());

quecv.notify_one();

}

while (1) {

this_thread::sleep_for(chrono::seconds(1));

lock_guard lock(quelock);

if ( strqueue.empty()) break;

}

stop = true;

for(int i = 0; i < THREAD_COUNT; ++i ) thpool[i].join();

cout<

return 0;

}