Error trying to use pthread on Ubuntu
I'm reading a tutorial about threads in C++ and tested the following code:
#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);
}
I've tried to compile this code using both gcc and g++, but I always get compilation errors.
Using gcc -pthread thread_test.c:
/tmp/ccmpQLyp.o: In function PrintHello(void*)': thread_test.cpp:(.text+0x1a): undefined reference to std::cout' thread_test.cpp:(.text+0x1f): undefined reference to 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<<(long)' thread_test.cpp:(.text+0x33): undefined reference to 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<<(std::ostream& (*)(std::ostream&))' /tmp/ccmpQLyp.o: In function main': thread_test.cpp:(.text+0x63): undefined reference to std::cout' thread_test.cpp:(.text+0x68): undefined reference to 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::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<<(int)' thread_test.cpp:(.text+0x7a): undefined reference to 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<<(std::ostream& (*)(std::ostream&))' thread_test.cpp:(.text+0xcc): undefined reference to std::cout' thread_test.cpp:(.text+0xd1): undefined reference to std::basic_ostream >& std::operator<< >(std::basic_ostream >&, char const*)' thread_test.cpp:(.text+0xde): undefined reference to std::ostream::operator<<(int)' thread_test.cpp:(.text+0xe3): undefined reference to std::basic_ostream >& std::endl >(std::basic_ostream >&)' thread_test.cpp:(.text+0xeb): undefined reference to std::ostream::operator<<(std::ostream& (*)(std::ostream&))' /tmp/ccmpQLyp.o: In function __static_initialization_and_destruction_0 (int, int)': thread_test.cpp:(.text+0x141): undefined reference to std::ios_base::Init::Init()' thread_test.cpp:(.text+0x150): undefined reference to std::ios_base::Init::~Init()' /tmp/ccmpQLyp.o:(.eh_frame+0x47): undefined reference to `__gxx_personality_v0' collect2: error: ld returned 1 exit status
Can you help? Do I have to do something so this code runs on Linux and Windows?
使用g++而不是gcc ，或手动链接-lstdc++ 。
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