Linux Processes and Threads six

//inter-thread communication#include <stdio.h>#include<stdlib.h>#include<string.h>#include<errno.h>#include<unistd.h>#include<pthread.h>/*thread 1 To control thread communication method the global variable*/intg_num=Ten;void*thread_run (void*Arg) {    //thread 1 is detached, but it is best not to use the Pthread_join () function to accept, multi-threaded error memory overflowPthread_detach (Pthread_self ()); int*p= (int*) Arg; (*P) + +; G_num= A; /*thread 1 arguments to the control thread communication Method 2--pthread_exit () function*/    //Pthread_exit (P); //after executing the pthread_exit () function, the thread exits directlyprintf"thread 1 has exited! \ n"); /*Thread 1 communication method with control thread 3--in thread return*/    returnp;}intMainintArgChar*args[]) {    /** Each thread has its own stack memory, but the stack memory between each other can be accessed, * For example, in the control thread defined variables, can be accessed in thread 1 * threads 1 defined variables may not be able to control the thread access, because the variable cannot be determined because the thread is executed Freed Up **/    intindex=0;    pthread_t Thr1; if(Pthread_create (&thr1,null,thread_run,&index)! =0) {printf ("pthread_create () failed!\n"); return-1; }    //waiting for thread 1    int*p=NULL; Pthread_join (THR1, (void* *) &p); printf ("The return value of thread 1%d\n",*p); printf ("controlling the index=%d\n of a thread", index); printf ("g_num=%d\n", G_num); return 0;}

//parallel execution of Threads#include <stdio.h>#include<stdlib.h>#include<string.h>#include<errno.h>#include<unistd.h>#include<pthread.h>void*thread_run (void*Arg) {    //Pthread_detach (Pthread_self ());    if(Arg! =NULL) {        int*p = (int*) Arg; inti =0;  for(i =0; i < *p; i++) {printf ("This is the%d circle of thread%d! \ n", (int) pthread_self (), i); Sleep (1); }    }    returnNULL;}intMainintArgChar*args[]) {    inti =0; intNUM1 =Ten; intnum2 =Ten; printf ("Please enter the number of creation threads: \ n"); scanf ("%d", &NUM1); printf ("Please enter the number of laps per thread: \ n"); scanf ("%d", &num2); pthread_t thrs[ $]; /** Multithreading is run in parallel **/     for(i =0; i < NUM1; i++)    {        if(Pthread_create (&thrs[i], NULL, Thread_run, &num2)! =0) {printf ("pthread_create () failed!\n"); return-1; }    }     for(i =0; i < NUM1; i++)    {        /*If there is no Pthread_join (), then the control thread will not wait for the child thread and will exit directly */Pthread_join (thrs[i],null); }    return 0;}

Linux processes and Threads six