操作系统实验整理

pipe

#include

#include

#include

#include

#include

#include

int main()

{

int fd[2]; //fd[1]为写端，fd[0]为读端

pid_t pid1, pid2;

char buf[256];

int result,read_count;

char *msg1 = "Child 1 is sending a message!";

char *msg2 = "Child 2 is sending a message!";

result = pipe(fd);

if(result == -1)

{

perror("Failed in calling pipe.\n");

exit(1);

}

pid1 = fork();

if(pid1 == -1)

{

perror("Failed in calling fork1.\n");

exit(1);

}else if (pid1 == 0){

close(fd[0]); //关闭读端

result = write(fd[1], msg1, strlen(msg1));

if(result == -1)

{

perror("In Child 1,Failed to write a pipe.\n");

exit(1);

}

exit(0);

}else{

read_count = read(fd[0], buf, sizeof(buf));

if(read_count == -1)

{

perror("In parent,failed to read from pipe.\n");

exit(1);

}else if(read_count == 0)

printf("In parent, 0 byte read from pipe.\n");

else{

buf[read_count] = '\0'; //设置字符串结尾为’\0’

printf("%d bytes of data received from pipe: %s\n", read_count, buf);

pid2 = fork();

if (pid2 == -1) {

perror("Failed in calling fork2.\n");

exit(1);

} else if (pid2 == 0) {

close(fd[0]);

result = write(fd[1], msg2, strlen(msg2));

if (result == -1) {

perror("In Child 2,Failed to write a pipe.\n");

exit(1);

}

exit(0);

} else {

read_count = read(fd[0], buf, sizeof (buf));

if (read_count == -1) {

perror("In parent,failed to read from pipe.\n");

exit(1);

} else if (read_count == 0)

printf("In parent, 0 byte read from pipe.\n");

else {

buf[read_count] = '\0';

printf("%d bytes of data received from pipe: %s\n", read_count, buf);

}

}

}

}

return(EXIT_SUCCESS);

}

Shell

#include

#include

#include

#include

#include

#include

#include

int main() {

int pid;

int rtn;

int exec_errorno;

char command[256];

char *p;

while (1) {

printf(">");

command[0] = '\0';

p = fgets(command, 256, stdin);

if (p == NULL) {

perror("Error in fgets()");

exit(-1);

}

command[strlen(command) - 1] = '\0'; // Delete the last char (new line) in the string returned by fgets()

// Quit if user inputs "quit"

if (!strcmp(command, "quit")) {

break;

}

// Create a child process to execute command

pid = fork();

if (pid < 0) {

perror("Failed while calling fork");

exit(-1);

}else if (pid == 0) {

char *child_program[10];

char *a = NULL;

char *b = NULL;

a = strtok_r(command, " ", &b);

int i = 0;

while (a != NULL) {

child_program[i] = a;

printf(" *a = \"%s\"; *b = \"%s\".\n", a, b);

printf("child_program[%d]: %s\n", i, child_program[i]);

a = strtok_r(NULL, " ", &b);

i++;

}

child_program[i] = NULL;

exec_errorno = execvp(child_program[0], child_program); //第一个参数是：文件名，即ls; 第二个参数是用数组表示，即-a, -l等

perror(command);

exit(exec_errorno);

}else{

wait(&rtn);

printf("\nValue returned from child process, rtn = %d\n", rtn);

printf("WEXITSTATUS(rtn) = %d\n", WEXITSTATUS(rtn));

}

}

return 0;

}

#include

#include

#include

#include

#define NUM_THREADS 2

void *PrintHello(void *threadid)

{

long tid;

tid = (long) threadid;

printf("Hello World! It's me, thread #%ld!\n", tid);

pthread_exit(NULL);

}

int main(int argc, char *argv[])

{

pthread_t threads[NUM_THREADS];

int rc;

long t;

for (t = 0; t < NUM_THREADS; t++)

{

printf("In main: creating thread %ld\n", t);

rc = pthread_create(&threads[t], NULL, PrintHello, (void *) t);

if (rc)

{

perror("Failed in calling pthread_create");

exit(-1);

}

}

pthread_exit(NULL);

}

#include

#include

#include

#include

#define NUM_THREADS 2

void *BusyWork1(void *a) {

printf("Thread 1 done. Result = %d\n", (int)a);

pthread_exit(NULL);

}

void *BusyWork2(void *b) {

printf("Thread 2 done. Result = %c\n", *((char *)b));

pthread_exit(NULL);

}

void main() {

pthread_t thread[2];

pthread_attr_t attr;

int rc;

int t;

void *status;

/* Initialize and set thread detached attribute */

pthread_attr_init(&attr);

int para;

char para2;

for (t = 0; t < NUM_THREADS; t++) {

printf("Main: creating thread %d\n", t);

switch (t) {

case 0:

para = 1;

rc = pthread_create(&(thread[t]), &attr, BusyWork1, (void*) para);

break;

case 1:

para2 = 'f';

rc = pthread_create(&(thread[t]), &attr, BusyWork2, (void*) (¶2));

break;

}

if (rc) {

printf("ERROR; return code from pthread_create() is % d\n", rc);

exit(-1);

}

}

for (t = 0; t < NUM_THREADS; t++) {

rc = pthread_join(thread[t], NULL);

if (rc) {

printf("ERROR; return code from pthread_join() is % d\n", rc);

exit(-1);

}

}

}

生产者和消费者

#include

#include

#include

#include

#include

#include

#define NUM_THREADS 2

#define BUFFER_SIZE 5

typedef int buffer_item;

buffer_item buffer[BUFFER_SIZE];

sem_t full, empty;

pthread_mutex_t mutex;

int in = 0;

int out = 0;

int insert_item(buffer_item item) {

buffer[in] = item;

if (&buffer[in] != NULL) {

in = (in + 1) % BUFFER_SIZE;

return 0;

} else {

perror("failed to insert");

return -1;

}

}

int remove_item(buffer_item *item) {

*item = buffer[out];

if (item != NULL) {

out = (out + 1) % (BUFFER_SIZE);

return 0;

} else {

perror("failed to remove ");

return -1;

}

}

void *Producer(void *p) {

int buffer_product[10];

int a;

int i = 0;

FILE *fp;

if ((int) p == 0) {

printf("This is A.\n");

fp = fopen("data1.txt", "r");

} else if ((int) p == 1) {

printf("This is B.\n");

fp = fopen("data2.txt", "r");

}

if (fp == NULL) {

perror("Can NOT open file");

exit(1);

}

for (i = 0; i < 10; i++) {

int result;

result = fscanf(fp, "%d", &buffer_product[i]); if (result != 1) {

printf("Reading failed.\n");

exit(1);

}

printf("%d ", buffer_product[i]);

}

printf("\n");

for (i = 0; i < 10; i++) {

sem_wait(&empty);

pthread_mutex_lock(&mutex);

a = insert_item(buffer_product[i]);

if (a == -1) {

sem_post(&empty);

exit(1);

}

pthread_mutex_unlock(&mutex);

sem_post(&full);

}

pthread_exit(NULL);

}

void *Consumer(void *p) {

int buffer_consumer[10];

int i = 0;

int out;

int output;

int count;

int a;

for (i = 0; i < 10; i++) {

sem_wait(&full);

pthread_mutex_lock(&mutex);

a = remove_item(&buffer_consumer[i]);

if (a == -1) {

sem_post(&full);

exit(1);

}

count = (i + 1) % 2;

if (count == 0) {

if ((int) p == 0) {

output = buffer_consumer[i - 1] + buffer_consumer[i]; printf("%d + %d = %d\n", buffer_consumer[i - 1], buffer_consumer[i], output);

} else if ((int) p == 1) {

output = buffer_consumer[i - 1] * buffer_consumer[i]; printf("%d x %d = %d\n", buffer_consumer[i - 1], buffer_consumer[i], output);

}

}

pthread_mutex_unlock(&mutex);

sem_post(&empty);

}

pthread_exit(NULL);

}

int main() {

pthread_t thread_producer[NUM_THREADS],

thread_consumer[NUM_THREADS];

pthread_attr_t attr;

int rc;

int t;

void *status;

pthread_mutex_init(&mutex, NULL);

sem_init(&full, 0, 0);

sem_init(&empty, 0, 5);

//Initialize and set thread detached attribute

pthread_attr_init(&attr);

pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);

for (t = 0; t < NUM_THREADS; t++) {

rc = pthread_create(&thread_producer[t], &attr, Producer, (void *) t);

if (rc) {

printf("ERROR; return code from pthread_create() is % d\n", rc);

exit(-1);

}

}

for (t = 0; t < NUM_THREADS; t++) {

rc = pthread_create(&thread_consumer[t], &attr, Consumer, (void *) t);

if (rc) {

printf("ERROR; return code from pthread_create() is % d\n", rc);

exit(-1);

}

}

for (t = 0; t < NUM_THREADS; t++) {

pthread_join(thread_producer[t], &status);

pthread_join(thread_consumer[t], &status);

pthread_exit(NULL);

}

}

消息队列

#include

#include

#include

#include

#include

#include

#include

#include

#define MsgKey 75

typedef struct msgbuf {

int mtype; // 消息类型，必须> 0

char mtext[1024]; // 消息文本

} msg;

msg msgBuf;

//char mtext[1024];

void server() {

int qid; //qid为系统创建的消息队列标识符

int i, receive, Delete;

if ((qid = msgget(MsgKey, IPC_CREAT | 0777)) == -1) { perror("Failed in calling msgget");

exit(1);

}

printf("In child 1, qid = %d.\n", qid);

printf("Message qid is %d\n", qid);

for (i = 10; i > 1; i--) {

printf("Server receive the %d time\n", i);

receive = msgrcv(qid, &msgBuf, 1024, 0, 0);

if (receive == -1) {

perror("receive error.\n");

exit(1);

}

printf("(Server)received\n");

}

sleep(5);

if (i == 1) {

if ((Delete = msgctl(qid, IPC_RMID, NULL)) == -1) { perror("Delete error!\n");

exit(1);

} else

printf("Delete message queue success!\n");

}

}

void client() {

int qid;

int mtype, result;

if ((qid = msgget(MsgKey, IPC_CREAT | 0777)) == -1) { perror("Failed in calling msgget");

exit(1);

}

printf("In child 2, qid = %d.\n", qid);

for (mtype = 10; mtype >= 1; mtype--) {

printf("Client send %d time\n", mtype);

msgBuf.mtype = mtype;

result = msgsnd(qid, &msgBuf, 1024, 0);

if (result == -1) {

perror("Failed to send a message");

exit(1);

}

printf("(Client)sent\n");

}

}

int main() {

int pid1, pid2;

int rtn1, rtn2;

pid1 = fork();

if (pid1 == -1) {

perror("Failed in calling fork");

exit(1);

} else if (pid1 == 0)

server();

else {

pid2 = fork();

if (pid2 == -1) {

perror("Failed in calling fork");

exit(1);

} else if (pid2 == 0)

client();

else {

wait(&rtn1);

wait(&rtn2);

}

}

}

共享内存

#include

#include

#include

#include

#include

#include

#include

#include

#define Key_t 74

int server() {

int q, rtn, qid;

int *addr;

if ((qid = shmget(Key_t, 1024, IPC_CREAT | 0777)) == -1) { perror("Failed in calling msgget");

exit(1);

}

addr = shmat(qid, NULL, 0);

while (*addr != 1)

printf("(Server)received\n");

rtn = shmdt(addr);

if (rtn == -1) {

perror("client shmdt error.\n");

exit(1);

}

q = shmctl(qid, IPC_RMID, NULL);

if (q == -1) {

perror("Failed in canceling the queue.\n");

exit(1);

} else

printf("shmctl success!\n");

exit(0);

}

int client() {

int i, rtn;

int *addr, qid;

if ((qid = shmget(Key_t, 1024, IPC_CREAT | 0777)) == -1) { perror("Failed in calling msgget");

exit(1);

}

addr = shmat(qid, NULL, 0);

if (*addr == -1) {

perror("client shmat error.\n");

exit(1);

} else {

for (i = 10; i > 1; i--) {

*addr = 0;

printf("(Client)sent %d.\n", i);

}

if (i == 1) {

printf("(Client)sent %d.\n", i);

*addr = 1;

}

}

rtn = shmdt(addr);

if (rtn == -1) {

perror("client shmdt error.\n");

exit(1);

}

exit(0);

}

int main() {

int pid1, pid2;

int rtn1, rtn2;

pid1 = fork();

if (pid1 == -1) {

perror("Failed in calling fork");

exit(1);

} else if (pid1 == 0)

server();

else {

pid2 = fork();

if (pid2 == -1) {

perror("Failed in calling fork");

exit(1);

} else if (pid2 == 0)

client();

else {

wait(&rtn1);

wait(&rtn2);

}

}}

信号

#include

#include

#include

static void sig_usr(int); /* one handler for both signals */

int pid1;

int main(void) {

pid1 = fork();

if (pid1 == -1) {

perror("Failed to calling fork");

exit(1);

} else if (pid1 == 0) {

if (signal(SIGINT, sig_usr) == SIG_ERR) {

printf("can't catch SIGINT\n");

exit(1);

}

for (;;)

pause();

} else {

if (signal(SIGINT, sig_usr) == SIG_ERR) {

printf("can't catch SIGINT\n");

exit(1);

}

for (;;)

pause();

}

}

static void sig_usr(int signo) /* argument is signal number */ { printf("%d received signal %d\n", pid1, signo);

}