Finally, the linux multi-thread compilation and multi-thread compilation errors are implemented.

Finally, the linux multi-thread compilation and multi-thread compilation errors-Linux general technology-Linux programming and kernel information are implemented. The following is a detailed description. I wrote a thrdcreat. c source file as follows:
/*
* Thrdcreat. c -- initialize strate creating a thread
*/

# Include
# Include
# Include
# Include

Void task1 (int * counter );
Void task2 (int * counter );
Void cleanup (int counter1, int counter2 );

Int g1 = 0;
Int g2 = 0;

Int main (int argc, char * argv [])
{
Pthread_t thrd1, thrd2;
Int ret;

/* Create the first thread */
Ret = pthread_create (& thrd1, NULL, (void *) task1, (void *) & g1 );
If (ret)
{
Perror ("pthread_create: task1 ");
Exit (EXIT_FAILURE );
}

/* Create the second thread */
Ret = pthread_create (& thrd2, NULL, (void *) task2, (void *) & g2 );
If (ret)
{
Perror ("pthread_create: task2 ");
Exit (EXIT_FAILURE );
}

Pthread_join (thrd2, NULL); // wait for execution in the first thread and get started. After the second thread is executed, the first thread continues to execute.
Pthread_join (thrd1, NULL );
Cleanup (g1, g2 );
Exit (EXIT_SUCCESS );
}

Void task1 (int * counter)
{
While (* counter <5)
{
Printf ("task1 count: % d \ n", * counter );
(* Counter) ++;
Sleep (1 );
}
}

Void task2 (int * counter)
{
While (* counter <5)
{
Printf ("task2 count: % d \ n", * counter );
(* Counter) ++;
// Sleep (1 );
}
}

Void cleanup (int counter1, int counter2)
{
Printf ("total iterations: % d \ n", counter1 + counter2 );
}

I thought it was a success, but it always showed up during compilation:
[Hyj @ localhost cfile] $ gcc-o thrdcreat. c
/Tmp/ccorDWTW. o: In function 'main ':
Thrdcreat. c :(. text + 0x31): undefined reference to 'pthread _ create'
Thrdcreat. c :(. text + 0x76): undefined reference to 'pthread _ create'
Thrdcreat. c :(. text + 0xaa): undefined reference to 'pthread _ join'
Thrdcreat. c :(. text + 0xbd): undefined reference to 'pthread _ join'
Collect2: ld returns 1
Pthread_create and pthread_join are not defined? Impossible. I have a header file # include Yes.
Later, I checked a lot of information and found that the thread library should be specified during compilation. Otherwise, such errors will occur.
To solve this problem, add-lpthread after gcc during compilation.
[Hyj @ localhost cfile] $ gcc-o thrdcreat. c-lpthread
[Hyj @ localhost cfile] $./thrdcreat
Task1 count: 0
Task2 count: 0
Task2 count: 1
Task2 count: 2
Task2 count: 3
Task2 count: 4
Task1 count: 1
Task1 count: 2
Task1 count: 3
Task1 count: 4
Total iterations: 10
: 0wpoi2
Success.