Pleasant Goat Series "thread" Mutex + semaphore

1. Write a basic multithreaded program (the main thread creates a sub-thread inside)

/*************************************************************************> File name:1_homework.c> Author: Liang > Addr: > Created time:2015 April 22 Wednesday 15:22 34 sec. *********************************************************** /#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h># include<pthread.h> #include <semaphore.h>//sem_t declaration void *fun1 (void *arg) {Pthread_detach (pthread_self           () );        Detach from the main thread while (1) {* (int *) arg) + = 2;        printf ("Fun1 The num is:%d \ n", * ((int*) arg));    Sleep (1);      } pthread_exit (0);    Main thread End}int main () {int num=3, ret1;    pthread_t Thread1;    Ret1 = Pthread_create (&thread1, NULL, FUN1, (void *) &num);        if (Ret1! = 0) {perror ("pthread_create1");    Exit (0);    } sleep (1);    printf ("=================== main End ================\n");      Pthread_exit (0); Main thread End}

2. Change the above program to a child thread to pass the return value to the parent thread

/*************************************************************************> File name:2_homework.c> Author: Liang > Addr:> Created time:2015 April 22 Wednesday 15:39 49 seconds *********************************************************** /#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h>#    include<pthread.h> void *fun1 (void *arg) {int num=100;    printf ("---------------pthread--------------\ n");    printf ("The num is:%d \ n", num);    printf ("---------------end--------------\ n");      Pthread_exit (void *) num);    Main thread End}int main () {int ret1, num;    pthread_t Thread1;    Ret1 = pthread_create (&thread1, NULL, FUN1, NULL);        if (Ret1! = 0) {perror ("pthread_create1");    Exit (0);    } pthread_join (Thread1, (void *) &num);    printf ("---------------main--------------\ n");    printf ("Return the num is:%d \ n", (int) num);        printf ("---------------end--------------\ n"); Pthread_exit (0); Main thread End}

3. Write a program with multithreading to read and write data (can be a global variable or other data)

/*************************************************************************> File name:3_homework.c> Author: Liang > Addr: > Created time:2015 April 22 Wednesday 15:53 00 sec. *********************************************************** /#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h># include<pthread.h> #include <semaphore.h>//sem_t declaration void *fun1 (void *arg) {Pthread_detach (pthread_self           () );        Detach from the main thread while (1) {* (int *) arg) + = 2;        printf ("The num write:%d \ n", * ((int*) arg));    Sleep (1);      } pthread_exit (0);           Main thread end}void *fun2 (void *arg) {Pthread_detach (pthread_self ());        Detach from the main thread while (1) {printf ("The NUM read is:%d \ n", * ((int*) arg));    Sleep (1);      } pthread_exit (0);    Main thread End}int main () {int num=0, ret1;    pthread_t Thread1, Thread2;    Ret1 = Pthread_create (&thread1, NULL, FUN1, (void *) &num);    if (Ret1! = 0) {    Perror ("pthread_create1");    Exit (0);    } Ret1 = Pthread_create (&thread2, NULL, fun2, (void *) &num);        if (Ret1! = 0) {perror ("Pthread_create2");    Exit (0);    } sleep (1);    printf ("=================== main End ================\n");      Pthread_exit (0); Main thread End}

4. Using semaphores and mutexes respectively to realize the read-write mutex of the 3rd job

/*************************************************************************> File name:4_homework.c> Author: Liang > Addr:> Created time:2015 April 22 Wednesday 15:57 54 seconds *********************************************************** /#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h>#     Include<pthread.h> #include <semaphore.h>//sem_t's statement sem_t SEM;  Signal volume declaration pthread_mutex_t mutex;           Mutual exclusion Lock declaration void *fun1 (void *arg) {Pthread_detach (pthread_self ());        Separate while (1) {sem_wait (&AMP;SEM) from the main thread;        * ((int *) arg) + = 2;        printf ("= = semaphore = = num write:%d \ n", * ((int*) arg));        Sleep (1);    Sem_post (&sem);      } pthread_exit (0);           Main thread end}void *fun2 (void *arg) {Pthread_detach (pthread_self ());        Separate while (1) {sem_wait (&AMP;SEM) from the main thread;        printf ("= = semaphore = = num Read is:%d \ n", * ((int*) arg));        Sleep (1);    Sem_post (&sem); } pthread_exit (0);      Main thread end}void *fun3 (void *arg) {Pthread_detach (pthread_self ());        Separate while (1) {Pthread_mutex_lock (&mutex) from the main thread;        * ((int *) arg) + = 2;        printf (">> Mutex >> num write:%d \ n", * ((int*) arg));        Sleep (1);    Pthread_mutex_unlock (&mutex);      } pthread_exit (0);           Main thread end}void *fun4 (void *arg) {Pthread_detach (pthread_self ());        Separate while (1) {Pthread_mutex_lock (&mutex) from the main thread;        printf (">> mutex >> num Read is:%d \ n", * ((int*) arg));        Sleep (1);    Pthread_mutex_unlock (&mutex);      } pthread_exit (0);    Main thread End}int main () {//------------------------semaphore Mutex--------------------int num1=0, RET1;    pthread_t Thread1, Thread2;    Sem_init (&sem, 0, 1);    Ret1 = Pthread_create (&thread1, NULL, FUN1, (void *) &AMP;NUM1);        if (Ret1! = 0) {perror ("pthread_create1");    Exit (0); } Ret1 = Pthread_create (&thread2, NULL, fun2, (void *) &num1);        if (Ret1! = 0) {perror ("Pthread_create2");    Exit (0);    }//------------------------mutex mutex--------------------int num2=1000, Ret2;    pthread_t Thread_1, Thread_2;    Pthread_mutex_init (&mutex, NULL);    Ret2 = Pthread_create (&thread_1, NULL, FUN3, (void *) &num2);        if (ret2!= 0) {perror ("pthread_create1");    Exit (0);    } Ret1 = Pthread_create (&thread_2, NULL, Fun4, (void *) &num2);        if (Ret2! = 0) {perror ("Pthread_create2");    Exit (0);    } printf ("=================== main End ================\n");      Pthread_exit (0); Main thread End}

5. Use the semaphore to realize the reading and writing synchronization of the 3rd job

/*************************************************************************> File name:5_homework.c> Author: Liang > Addr: > Created time:2015 April 22 Wednesday 16:36 01 sec. *********************************************************** /#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h>#     Include<pthread.h> #include <semaphore.h>//sem_t's statement sem_t W_sem, R_sem;           Semaphore declaration void *fun1 (void *arg) {Pthread_detach (pthread_self ());        Separate while (1) {sem_wait (&AMP;W_SEM) from the main thread;        * ((int *) arg) + = 2;        printf (">>>> num write:%d \ n", * ((int*) arg));        Sleep (1);    Sem_post (&r_sem);      } pthread_exit (0);           Main thread end}void *fun2 (void *arg) {Pthread_detach (pthread_self ());        Separate while (1) {sem_wait (&AMP;R_SEM) from the main thread;        printf (">>>> num Read is:%d \ n", * ((int*) arg));        Sleep (1);    Sem_post (&w_sem); } Pthread_exiT (0);    Main thread End}int main () {//------------------------semaphore Mutex--------------------int num1=0, RET1;    pthread_t Thread1, Thread2;    Sem_init (&w_sem, 0, 1);    Sem_init (&r_sem, 0, 0);    Ret1 = Pthread_create (&thread1, NULL, FUN1, (void *) &AMP;NUM1);        if (Ret1! = 0) {perror ("pthread_create1");    Exit (0);    } Ret1 = Pthread_create (&thread2, NULL, fun2, (void *) &AMP;NUM1);        if (Ret1! = 0) {perror ("Pthread_create2");    Exit (0);    } printf ("=================== main End ================\n");      Pthread_exit (0); Main thread End}

Pleasant Goat Series "thread" Mutex + semaphore