我从StackOverflow的其他帖子看到,未定义的引用错误意味着定义丢失,通常要修复它,文件必须在编译中链接。但我只编译一个文件。我得到这个函数的错误pthread_detach
和pthread_create
。Undefined Reference for Single File
/tmp/ccAET7bU.o: In function `sample_thread1':
foo.c:(.text+0x2a): undefined reference to `pthread_detach'
/tmp/ccAET7bU.o: In function `main':
foo.c:(.text+0x85): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
代码:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <memory.h>
#include <signal.h>
#include <string.h>
#include <linux/unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/syscall.h>
#include <netinet/in.h>
#include <pthread.h>
pid_t gettid(void)
{
return syscall(__NR_gettid);
}
void *sample_thread1(void *x_void_ptr)
{
FILE *fp;
int counter;
pthread_detach(pthread_self());
if((fp = fopen("thread_data.txt", "w")) == NULL)
{
printf("ERROR : Thread cannot open data file.\n");
return;
}
counter = 1;
while(1);
{
fprintf(fp, "INFO : Thread1 id %d output message %10d\n",
gettid(), counter);
fflush(fp);
counter++;
sleep(1);
}
pthread_exit(NULL);
}
int main(int argc, char *argv[])
{
int counter;
pthread_t sample_thread_t1;
if(pthread_create(&sample_thread_t1, NULL, sample_thread1, NULL))
{
fprintf(stderr, "Error creating thread\n");
exit(-1);
}
system("clear");
counter = 1;
while(1)
{
printf("INFO : Main Process Counter = %d\n", counter);
counter++;
sleep(1);
}
return(0);
}
我想你需要-lpthread传递给GCC来告诉它针对并行线程库链接。未定义的参考只是意味着链接器无法找到您在代码中调用的函数 – user3109672
您正在为此运行哪个操作系统? – alk
对于Linux pease阅读这里:http://stackoverflow.com/q/1662909/694576 – alk