我正在阅读有关C ++中线程的教程,并测试了以下代码:
#include <iostream>
#include <pthread.h>
#include <cstdlib>
using namespace std;
#define NUM_THREADS 5
void *PrintHello(void *threadid)
{
long tid;
tid = (long)threadid;
cout << "Hello World! Thread ID, " << tid << endl;
pthread_exit(NULL);
}
int main ()
{
pthread_t threads[NUM_THREADS];
int rc;
int i;
for( i=0; i < NUM_THREADS; i++ ){
cout << "main() : creating thread, " << i << endl;
rc = pthread_create(&threads[i], NULL,
PrintHello, &threads[i]);
if (rc){
cout << "Error:unable to create thread," << rc << endl;
exit(-1);
}
}
pthread_exit(NULL);
}
我尝试使用gcc和g ++编译此代码,但我总是遇到编译错误。
使用gcc -pthread thread_test.c:
你能帮忙吗?我是否必须做一些事情,以便此代码在Linux和Windows上运行?/tmp/ccmpQLyp.o:在函数
PrintHello(void*)': thread_test.cpp:(.text+0x1a): undefined reference to
std :: cout'中 thread_test.cpp :(。text + 0x1f):对std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)' thread_test.cpp:(.text+0x2e): undefined reference to
std :: ostream :: operator&lt;&lt;(long)'的未定义引用 thread_test.cpp :(。text + 0x33):未定义引用std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)' thread_test.cpp:(.text+0x3b): undefined reference to
std :: ostream :: operator&lt;&lt;(std :: ostream&amp;(*)(std :: ostream&amp;))' /tmp/ccmpQLyp.o:在函数main': thread_test.cpp:(.text+0x63): undefined reference to
std :: cout'中 thread_test.cpp :(。text + 0x68):未定义引用std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)' thread_test.cpp:(.text+0x75): undefined reference to
std :: ostream :: operator&lt;&lt;(int)' thread_test.cpp :(。text + 0x7a):未定义引用std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)' thread_test.cpp:(.text+0x82): undefined reference to
std :: ostream :: operator&lt;&lt;(std :: ostream&amp;(*)(std :: ostream&amp;))' thread_test.cpp :(。text + 0xcc):未定义引用std::cout' thread_test.cpp:(.text+0xd1): undefined reference to
std :: basic_ostream&gt;&amp;的std ::运营商LT;&LT; &gt;(std :: basic_ostream&gt;&amp;,char const *)' thread_test.cpp :(。text + 0xde):未定义引用std::ostream::operator<<(int)' thread_test.cpp:(.text+0xe3): undefined reference to
std :: basic_ostream&gt;&amp; std :: endl&gt;(std :: basic_ostream&gt;&amp;)' thread_test.cpp :(。text + 0xeb):对std::ostream::operator<<(std::ostream& (*)(std::ostream&))' /tmp/ccmpQLyp.o: In function
__ static_initialization_and_destruction_0(int,int)'的未定义引用: thread_test.cpp :(。text + 0x141):未定义引用std::ios_base::Init::Init()' thread_test.cpp:(.text+0x150): undefined reference to
std :: ios_base :: Init :: ~Init()' /tmp/ccmpQLyp.o:(.eh_frame+0x47):对__gxx_personality_v0'的未定义引用 collect2:错误:ld返回1退出状态
答案 0 :(得分:3)
使用g++
代替gcc
,或手动链接-lstdc++
。
答案 1 :(得分:0)
对于任何在2020年阅读此书的人:
在GCC中,当针对pthread进行链接时,请勿使用“ -lpthread”,而仅使用“ -pthread” CLI选项。