http://www.yolinux.com/TUTORIALS/LinuxTutorialPosixThreads.html
http://www.cs.cf.ac.uk/Dave/C
Tried to find the simplest example of using pthread_create for a beginner. The man page of pthread_create, again, is rather a reference for experts who already know how to use pthread_create.
Here I have the simplest working code without all the distractions:
#include <stdio.h>
#include <pthread.h>
void* threadFunction(){//the function is the entry point of a new thread
printf("Catch = %d\n",22);
}
int main(){
pthread_t threadId;//to record the thread id of the newly created thread
//effectively pthread_t is type unsigned long int
pthread_create(&threadId, NULL, threadFunction, NULL);
//threadFunction, inputArg together is a function call equivalent to the
//more familiar form: threadFunction(inputArg);
pthread_join(threadId,NULL);
//this function call forces the main() is waiting for the thread to complete.
//(for the thread to "join" back?)
//Otherwise, the main
//may exit before the thread finishes, thus aborts the thread prematurely
printf("threadId = %lu\n",threadId);
return 0;
}
The thread function takes exactly one entrance parameter, similar to main() you can have main(char argc, char** argv). It is common practice to have the entrance parameter be a struct so that complicated data can be passed into the thread.
#include <stdio.h>
#include <pthread.h>
void* threadFunction(void* threadFunctionArg){
int* pMax = threadFunctionArg;
printf("Double the input =%d\n",*pMax * 2);
}
int main(){
int num=5;//some information to pass to the new thread
pthread_t threadId;//to record the thread id of the newly created thread
//effectively pthread_t is type unsigned long int
int threadStatus;//to record the return status of the new thread
//0 means good, otherwise an error number is recorded.
void* inputArg = #//used to pass into the thread function
threadStatus = pthread_create(&threadId, NULL, threadFunction, inputArg);
//threadFunction, inputArg together is a function call equivalent to the
//more familiar form: threadFunction(inputArg);
pthread_join(threadId,NULL);
//the main() is waiting for the thread to complete. Otherwise, the main
//may exit before the thread finishes, thus aborts the thread prematurely
printf("threadId = %lu\n",threadId);
printf("threadStatus = %d\n",threadStatus);
return 0;
}
/********************END******************/
