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 2019-8-27
 
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1 #include <unistd.h>

2 int pipe(int fd[2]); // ·µ»ØÖµ£ºÈô³É¹¦·µ»Ø0£¬Ê§°Ü·µ»Ø-1

µ±Ò»¸ö¹ÜµÀ½¨Á¢Ê±£¬Ëü»á´´½¨Á½¸öÎļþÃèÊö·û£ºfd[0]Ϊ¶Á¶ø´ò¿ª£¬fd[1]Ϊд¶ø´ò¿ª¡£ÈçÏÂͼ£º

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1 #include<stdio.h>
2 #include<unistd.h>
3
4 int main()
5 {
6 int fd[2]; // Á½¸öÎļþÃèÊö·û
7 pid_t pid;
8 char buff[20];
9
10 if(pipe(fd) < 0) // ´´½¨¹ÜµÀ
11 printf("Create Pipe Error!\n");
12
13 if((pid = fork()) < 0) // ´´½¨×Ó½ø³Ì
14 printf("Fork Error!\n");
15 else if(pid > 0) // ¸¸½ø³Ì
16 {
17 close(fd[0]); // ¹Ø±Õ¶Á¶Ë
18 write(fd[1], "hello world\n", 12);
19 }
20 else
21 {
22 close(fd[1]); // ¹Ø±Õд¶Ë
23 read(fd[0], buff, 20);
24 printf("%s", buff);
25 }
26
27 return 0;
28 }

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1 #include <sys/stat.h>
2 // ·µ»ØÖµ£º³É¹¦·µ»Ø0£¬³ö´í·µ»Ø-1
3 int mkfifo(const char *pathname, mode_t mode);

ÆäÖÐµÄ mode ²ÎÊýÓëopenº¯ÊýÖÐµÄ mode Ïàͬ¡£Ò»µ©´´½¨ÁËÒ»¸ö FIFO£¬¾Í¿ÉÒÔÓÃÒ»°ãµÄÎļþI/Oº¯Êý²Ù×÷Ëü¡£

µ± open Ò»¸öFIFOʱ£¬ÊÇ·ñÉèÖ÷Ç×èÈû±êÖ¾£¨O_NONBLOCK£©µÄÇø±ð£º

ÈôûÓÐÖ¸¶¨O_NONBLOCK£¨Ä¬ÈÏ£©£¬Ö»¶Á open Òª×èÈûµ½Ä³¸öÆäËû½ø³ÌΪд¶ø´ò¿ª´Ë FIFO¡£ÀàËÆµÄ£¬Ö»Ð´ open Òª×èÈûµ½Ä³¸öÆäËû½ø³ÌΪ¶Á¶ø´ò¿ªËü¡£

ÈôÖ¸¶¨ÁËO_NONBLOCK£¬ÔòÖ»¶Á open Á¢¼´·µ»Ø¡£¶øÖ»Ð´ open ½«³ö´í·µ»Ø -1 Èç¹ûûÓнø³ÌÒѾ­Îª¶Á¶ø´ò¿ª¸Ã FIFO£¬ÆäerrnoÖÃENXIO¡£

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write_fifo.c

1 #include<stdio.h>
2 #include<stdlib.h> // exit
3 #include<fcntl.h> // O_WRONLY
4 #include<sys/stat.h>
5 #include<time.h> // time
6
7 int main()
8 {
9 int fd;
10 int n, i;
11 char buf[1024];
12 time_t tp;
13
14 printf("I am %d process.\n", getpid()); // ˵Ã÷½ø³ÌID
15
16 if((fd = open("fifo1", O_WRONLY)) < 0) // ÒÔд´ò¿ªÒ»¸öFIFO
17 {
18 perror("Open FIFO Failed");
19 exit(1);
20 }
21
22 for(i=0; i<10; ++i)
23 {
24 time(&tp); // ȡϵͳµ±Ç°Ê±¼ä
25 n=sprintf(buf,"Process %d's time is %s",getpid(),ctime(&tp));
26 printf("Send message: %s", buf); // ´òÓ¡
27 if(write(fd, buf, n+1) < 0) // дÈëµ½FIFOÖÐ
28 {
29 perror("Write FIFO Failed");
30 close(fd);
31 exit(1);
32 }
33 sleep(1); // ÐÝÃß1Ãë
34 }
35
36 close(fd); // ¹Ø±ÕFIFOÎļþ
37 return 0;
38 }

read_fifo.c

1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<errno.h>
4 #include<fcntl.h>
5 #include<sys/stat.h>
6
7 int main()
8 {
9 int fd;
10 int len;
11 char buf[1024];
12
13 if(mkfifo("fifo1", 0666) < 0 && errno!=EEXIST) // ´´½¨FIFO¹ÜµÀ
14 perror("Create FIFO Failed");
15
16 if((fd = open("fifo1", O_RDONLY)) < 0) // ÒÔ¶Á´ò¿ªFIFO
17 {
18 perror("Open FIFO Failed");
19 exit(1);
20 }
21
22 while((len = read(fd, buf, 1024)) > 0) // ¶ÁÈ¡FIFO¹ÜµÀ
23 printf("Read message: %s", buf);
24
25 close(fd); // ¹Ø±ÕFIFOÎļþ
26 return 0;
27 }

ÔÚÁ½¸öÖÕ¶ËÀïÓà gcc ·Ö±ð±àÒëÔËÐÐÉÏÃæÁ½¸öÎļþ£¬¿ÉÒÔ¿´µ½Êä³ö½á¹ûÈçÏ£º

1 [cheesezh@localhost]$ ./write_fifo
2 I am 5954 process.
3 Send message: Process 5954's time is Mon Apr 20 12:37:28 2015
4 Send message: Process 5954's time is Mon Apr 20 12:37:29 2015
5 Send message: Process 5954's time is Mon Apr 20 12:37:30 2015
6 Send message: Process 5954's time is Mon Apr 20 12:37:31 2015
7 Send message: Process 5954's time is Mon Apr 20 12:37:32 2015
8 Send message: Process 5954's time is Mon Apr 20 12:37:33 2015
9 Send message: Process 5954's time is Mon Apr 20 12:37:34 2015
10 Send message: Process 5954's time is Mon Apr 20 12:37:35 2015
11 Send message: Process 5954's time is Mon Apr 20 12:37:36 2015
12 Send message: Process 5954's time is Mon Apr 20 12:37:37 2015

1 [cheesezh@localhost]$ ./read_fifo
2 Read message: Process 5954's time is Mon Apr 20 12:37:28 2015
3 Read message: Process 5954's time is Mon Apr 20 12:37:29 2015
4 Read message: Process 5954's time is Mon Apr 20 12:37:30 2015
5 Read message: Process 5954's time is Mon Apr 20 12:37:31 2015
6 Read message: Process 5954's time is Mon Apr 20 12:37:32 2015
7 Read message: Process 5954's time is Mon Apr 20 12:37:33 2015
8 Read message: Process 5954's time is Mon Apr 20 12:37:34 2015
9 Read message: Process 5954's time is Mon Apr 20 12:37:35 2015
10 Read message: Process 5954's time is Mon Apr 20 12:37:36 2015
11 Read message: Process 5954's time is Mon Apr 20 12:37:37 2015

 

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1 #include <sys/msg.h>
2 // ´´½¨»ò´ò¿ªÏûÏ¢¶ÓÁУº³É¹¦·µ»Ø¶ÓÁÐID£¬Ê§°Ü·µ»Ø-1
3 int msgget(key_t key, int flag);
4 // Ìí¼ÓÏûÏ¢£º³É¹¦·µ»Ø0£¬Ê§°Ü·µ»Ø-1
5 int msgsnd(int msqid, const void *ptr, size_t size, int flag);
6 // ¶ÁÈ¡ÏûÏ¢£º³É¹¦·µ»ØÏûÏ¢Êý¾ÝµÄ³¤¶È£¬Ê§°Ü·µ»Ø-1
7 int msgrcv(int msqid, void *ptr, size_t size, long type,int flag);
8 // ¿ØÖÆÏûÏ¢¶ÓÁУº³É¹¦·µ»Ø0£¬Ê§°Ü·µ»Ø-1
9 int msgctl(int msqid, int cmd, struct msqid_ds *buf);

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type == 0£¬·µ»Ø¶ÓÁÐÖеĵÚÒ»¸öÏûÏ¢£»

type > 0£¬·µ»Ø¶ÓÁÐÖÐÏûÏ¢ÀàÐÍΪ type µÄµÚÒ»¸öÏûÏ¢£»

type < 0£¬·µ»Ø¶ÓÁÐÖÐÏûÏ¢ÀàÐÍֵСÓÚ»òµÈÓÚ type ¾ø¶ÔÖµµÄÏûÏ¢£¬Èç¹ûÓжà¸ö£¬ÔòÈ¡ÀàÐÍÖµ×îСµÄÏûÏ¢¡£

¿ÉÒÔ¿´³ö£¬typeÖµ·Ç 0 ʱÓÃÓÚÒÔ·ÇÏȽøÏȳö´ÎÐò¶ÁÏûÏ¢¡£Ò²¿ÉÒÔ°Ñ type ¿´×öÓÅÏȼ¶µÄȨֵ¡££¨ÆäËûµÄ²ÎÊý½âÊÍ£¬Çë×ÔÐÐGoogleÖ®£©

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msg_server.c

1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <sys/msg.h>
4
5 // ÓÃÓÚ´´½¨Ò»¸öΨһµÄkey
6 #define MSG_FILE "/etc/passwd"
7
8 // ÏûÏ¢½á¹¹
9 struct msg_form {
10 long mtype;
11 char mtext[256];
12 };
13
14 int main()
15 {
16 int msqid;
17 key_t key;
18 struct msg_form msg;
19
20 // »ñÈ¡keyÖµ
21 if((key = ftok(MSG_FILE,'z')) < 0)
22 {
23 perror("ftok error");
24 exit(1);
25 }
26
27 // ´òÓ¡keyÖµ
28 printf("Message Queue - Server key is: %d.\n", key);
29
30 // ´´½¨ÏûÏ¢¶ÓÁÐ
31 if ((msqid = msgget(key, IPC_CREAT|0777)) == -1)
32 {
33 perror("msgget error");
34 exit(1);
35 }
36
37 // ´òÓ¡ÏûÏ¢¶ÓÁÐID¼°½ø³ÌID
38 printf("My msqid is: %d.\n", msqid);
39 printf("My pid is: %d.\n", getpid());
40
41 // Ñ­»·¶ÁÈ¡ÏûÏ¢
42 for(;;)
43 {
44 msgrcv(msqid, &msg, 256, 888, 0);// ·µ»ØÀàÐÍΪ888µÄµÚÒ»¸öÏûÏ¢
45 printf("Server: receive msg.mtext is: %s.\n", msg.mtext);
46 printf("Server: receive msg.mtype is: %d.\n", msg.mtype);
47
48 msg.mtype = 999; // ¿Í»§¶Ë½ÓÊÕµÄÏûÏ¢ÀàÐÍ
49 sprintf(msg.mtext, "hello, I'm server %d", getpid());
50 msgsnd(msqid, &msg, sizeof(msg.mtext), 0);
51 }
52 return 0;
53 }

msg_client.c

1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <sys/msg.h>
4
5 // ÓÃÓÚ´´½¨Ò»¸öΨһµÄkey
6 #define MSG_FILE "/etc/passwd"
7
8 // ÏûÏ¢½á¹¹
9 struct msg_form {
10 long mtype;
11 char mtext[256];
12 };
13
14 int main()
15 {
16 int msqid;
17 key_t key;
18 struct msg_form msg;
19
20 // »ñÈ¡keyÖµ
21 if ((key = ftok(MSG_FILE, 'z')) < 0)
22 {
23 perror("ftok error");
24 exit(1);
25 }
26
27 // ´òÓ¡keyÖµ
28 printf("Message Queue - Client key is: %d.\n", key);
29
30 // ´ò¿ªÏûÏ¢¶ÓÁÐ
31 if ((msqid = msgget(key, IPC_CREAT|0777)) == -1)
32 {
33 perror("msgget error");
34 exit(1);
35 }
36
37 // ´òÓ¡ÏûÏ¢¶ÓÁÐID¼°½ø³ÌID
38 printf("My msqid is: %d.\n", msqid);
39 printf("My pid is: %d.\n", getpid());
40
41 // Ìí¼ÓÏûÏ¢£¬ÀàÐÍΪ888
42 msg.mtype = 888;
43 sprintf(msg.mtext, "hello, I'm client %d", getpid());
44 msgsnd(msqid, &msg, sizeof(msg.mtext), 0);
45
46 // ¶ÁÈ¡ÀàÐÍΪ777µÄÏûÏ¢
47 msgrcv(msqid, &msg, 256, 999, 0);
48 printf("Client: receive msg.mtext is: %s.\n", msg.mtext);
49 printf("Client: receive msg.mtype is: %d.\n", msg.mtype);
50 return 0;
51 }

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1 #include <sys/sem.h>
2 // ´´½¨»ò»ñȡһ¸öÐźÅÁ¿×飺Èô³É¹¦·µ»ØÐźÅÁ¿¼¯ID£¬Ê§°Ü·µ»Ø-1
3 int semget(key_t key, int num_sems, int sem_flags);
4 // ¶ÔÐźÅÁ¿×é½øÐвÙ×÷£¬¸Ä±äÐźÅÁ¿µÄÖµ£º³É¹¦·µ»Ø0£¬Ê§°Ü·µ»Ø-1
5 int semop(int semid, struct sembuf semoparray[], size_t numops);
6 // ¿ØÖÆÐźÅÁ¿µÄÏà¹ØÐÅÏ¢
7 int semctl(int semid, int sem_num, int cmd, ...);

µ±semget´´½¨ÐµÄÐźÅÁ¿¼¯ºÏʱ£¬±ØÐëÖ¸¶¨¼¯ºÏÖÐÐźÅÁ¿µÄ¸öÊý£¨¼´num_sems£©£¬Í¨³£Îª1£» Èç¹ûÊÇÒýÓÃÒ»¸öÏÖÓеļ¯ºÏ£¬Ôò½«num_semsÖ¸¶¨Îª 0 ¡£

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1 struct sembuf
2 {
3 short sem_num; // ÐźÅÁ¿×éÖжÔÓ¦µÄÐòºÅ£¬0¡«sem_nums-1
4 short sem_op; // ÐźÅÁ¿ÖµÔÚÒ»´Î²Ù×÷ÖеĸıäÁ¿
5 short sem_flg; // IPC_NOWAIT, SEM_UNDO
6 }

ÆäÖÐ sem_op ÊÇÒ»´Î²Ù×÷ÖеÄÐźÅÁ¿µÄ¸Ä±äÁ¿£º

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´ËÐźÅÁ¿±»É¾³ý£¬º¯Êýsmeop³ö´í·µ»ØEIDRM£»

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sem_flgûÓÐÖ¸¶¨IPC_NOWAIT£¬Ôò½«¸ÃÐźÅÁ¿µÄsemncntÖµ¼Ó1£¬È»ºó½ø³Ì¹ÒÆðÖ±µ½ÏÂÊöÇé¿ö·¢Éú£º

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ÔÚsemctlº¯ÊýÖеÄÃüÁîÓжàÖÖ£¬ÕâÀï¾Í˵Á½¸ö³£Óõģº

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IPC_RMID£ºÉ¾³ýÒ»¸öÐźÅÁ¿¼¯ºÏ¡£Èç¹û²»É¾³ýÐźÅÁ¿£¬Ëü½«¼ÌÐøÔÚϵͳÖдæÔÚ£¬¼´Ê¹³ÌÐòÒѾ­Í˳ö£¬Ëü¿ÉÄÜÔÚÄãÏ´ÎÔËÐд˳ÌÐòʱÒý·¢ÎÊÌ⣬¶øÇÒÐźÅÁ¿ÊÇÒ»ÖÖÓÐÏÞµÄ×ÊÔ´¡£

3¡¢Àý×Ó

1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<sys/sem.h>
4
5 // ÁªºÏÌ壬ÓÃÓÚsemctl³õʼ»¯
6 union semun
7 {
8 int val; /*for SETVAL*/
9 struct semid_ds *buf;
10 unsigned short *array;
11 };
12
13 // ³õʼ»¯ÐźÅÁ¿
14 int init_sem(int sem_id, int value)
15 {
16 union semun tmp;
17 tmp.val = value;
18 if(semctl(sem_id, 0, SETVAL, tmp) == -1)
19 {
20 perror("Init Semaphore Error");
21 return -1;
22 }
23 return 0;
24 }
25
26 // P²Ù×÷:
27 // ÈôÐźÅÁ¿ÖµÎª1£¬»ñÈ¡×ÊÔ´²¢½«ÐźÅÁ¿Öµ-1
28 // ÈôÐźÅÁ¿ÖµÎª0£¬½ø³Ì¹ÒÆðµÈ´ý
29 int sem_p(int sem_id)
30 {
31 struct sembuf sbuf;
32 sbuf.sem_num = 0; /*ÐòºÅ*/
33 sbuf.sem_op = -1; /*P²Ù×÷*/
34 sbuf.sem_flg = SEM_UNDO;
35
36 if(semop(sem_id, &sbuf, 1) == -1)
37 {
38 perror("P operation Error");
39 return -1;
40 }
41 return 0;
42 }
43
44 // V²Ù×÷£º
45 // ÊÍ·Å×ÊÔ´²¢½«ÐźÅÁ¿Öµ+1
46 // Èç¹ûÓнø³ÌÕýÔÚ¹ÒÆðµÈ´ý£¬Ôò»½ÐÑËüÃÇ
47 int sem_v(int sem_id)
48 {
49 struct sembuf sbuf;
50 sbuf.sem_num = 0; /*ÐòºÅ*/
51 sbuf.sem_op = 1; /*V²Ù×÷*/
52 sbuf.sem_flg = SEM_UNDO;
53
54 if(semop(sem_id, &sbuf, 1) == -1)
55 {
56 perror("V operation Error");
57 return -1;
58 }
59 return 0;
60 }
61
62 // ɾ³ýÐźÅÁ¿¼¯
63 int del_sem(int sem_id)
64 {
65 union semun tmp;
66 if(semctl(sem_id, 0, IPC_RMID, tmp) == -1)
67 {
68 perror("Delete Semaphore Error");
69 return -1;
70 }
71 return 0;
72 }
73
74
75 int main()
76 {
77 int sem_id; // ÐźÅÁ¿¼¯ID
78 key_t key;
79 pid_t pid;
80
81 // »ñÈ¡keyÖµ
82 if((key = ftok(".", 'z')) < 0)
83 {
84 perror("ftok error");
85 exit(1);
86 }
87
88 // ´´½¨ÐźÅÁ¿¼¯£¬ÆäÖÐÖ»ÓÐÒ»¸öÐźÅÁ¿
89 if((sem_id = semget(key, 1, IPC_CREAT|0666)) == -1)
90 {
91 perror("semget error");
92 exit(1);
93 }
94
95 // ³õʼ»¯£º³õÖµÉèΪ0×ÊÔ´±»Õ¼ÓÃ
96 init_sem(sem_id, 0);
97
98 if((pid = fork()) == -1)
99 perror("Fork Error");
100 else if(pid == 0) /*×Ó½ø³Ì*/
101 {
102 sleep(2);
103 printf("Process child: pid=%d\n", getpid());
104 sem_v(sem_id); /*ÊÍ·Å×ÊÔ´*/
105 }
106 else /*¸¸½ø³Ì*/
107 {
108 sem_p(sem_id); /*µÈ´ý×ÊÔ´*/
109 printf("Process father: pid=%d\n", getpid());
110 sem_v(sem_id); /*ÊÍ·Å×ÊÔ´*/
111 del_sem(sem_id); /*ɾ³ýÐźÅÁ¿¼¯*/
112 }
113 return 0;
114 }

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Îå¡¢¹²ÏíÄÚ´æ

¹²ÏíÄڴ棨Shared Memory£©£¬Ö¸Á½¸ö»ò¶à¸ö½ø³Ì¹²ÏíÒ»¸ö¸ø¶¨µÄ´æ´¢Çø¡£

1¡¢Ìصã

¹²ÏíÄÚ´æÊÇ×î¿ìµÄÒ»ÖÖ IPC£¬ÒòΪ½ø³ÌÊÇÖ±½Ó¶ÔÄÚ´æ½øÐдæÈ¡¡£

ÒòΪ¶à¸ö½ø³Ì¿ÉÒÔͬʱ²Ù×÷£¬ËùÒÔÐèÒª½øÐÐͬ²½¡£

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2¡¢Ô­ÐÍ

1 #include <sys/shm.h>
2 // ´´½¨»ò»ñȡһ¸ö¹²ÏíÄڴ棺³É¹¦·µ»Ø¹²ÏíÄÚ´æID£¬Ê§°Ü·µ»Ø-1
3 int shmget(key_t key, size_t size, int flag);
4 // Á¬½Ó¹²ÏíÄÚ´æµ½µ±Ç°½ø³ÌµÄµØÖ·¿Õ¼ä£º³É¹¦·µ»ØÖ¸Ïò¹²ÏíÄÚ´æµÄÖ¸Õ룬ʧ°Ü·µ»Ø-1
5 void *shmat(int shm_id, const void *addr, int flag);
6 // ¶Ï¿ªÓë¹²ÏíÄÚ´æµÄÁ¬½Ó£º³É¹¦·µ»Ø0£¬Ê§°Ü·µ»Ø-1
7 int shmdt(void *addr);
8 // ¿ØÖƹ²ÏíÄÚ´æµÄÏà¹ØÐÅÏ¢£º³É¹¦·µ»Ø0£¬Ê§°Ü·µ»Ø-1
9 int shmctl(int shm_id, int cmd, struct shmid_ds *buf);

µ±ÓÃshmgetº¯Êý´´½¨Ò»¶Î¹²ÏíÄÚ´æÊ±£¬±ØÐëÖ¸¶¨Æä size£»¶øÈç¹ûÒýÓÃÒ»¸öÒÑ´æÔڵĹ²ÏíÄڴ棬Ôò½« size Ö¸¶¨Îª0 ¡£

µ±Ò»¶Î¹²ÏíÄÚ´æ±»´´½¨ÒÔºó£¬Ëü²¢²»Äܱ»Èκνø³Ì·ÃÎÊ¡£±ØÐëʹÓÃshmatº¯ÊýÁ¬½Ó¸Ã¹²ÏíÄÚ´æµ½µ±Ç°½ø³ÌµÄµØÖ·¿Õ¼ä£¬Á¬½Ó³É¹¦ºó°Ñ¹²ÏíÄÚ´æÇø¶ÔÏóÓ³Éäµ½µ÷Óýø³ÌµÄµØÖ·¿Õ¼ä£¬Ëæºó¿ÉÏñ±¾µØ¿Õ¼äÒ»Ñù·ÃÎÊ¡£

shmdtº¯ÊýÊÇÓÃÀ´¶Ï¿ªshmat½¨Á¢µÄÁ¬½ÓµÄ¡£×¢Ò⣬Õâ²¢²»ÊÇ´ÓϵͳÖÐɾ³ý¸Ã¹²ÏíÄڴ棬ֻÊǵ±Ç°½ø³Ì²»ÄÜÔÙ·ÃÎʸù²ÏíÄÚ´æ¶øÒÑ¡£

shmctlº¯Êý¿ÉÒÔ¶Ô¹²ÏíÄÚ´æÖ´ÐжàÖÖ²Ù×÷£¬¸ù¾Ý²ÎÊý cmd Ö´ÐÐÏàÓ¦µÄ²Ù×÷¡£³£ÓõÄÊÇIPC_RMID£¨´ÓϵͳÖÐɾ³ý¸Ã¹²ÏíÄڴ棩¡£

3¡¢Àý×Ó

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¹²ÏíÄÚ´æÓÃÀ´´«µÝÊý¾Ý£»

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ÏûÏ¢¶ÓÁÐÓÃÀ´ ÔÚ¿Í»§¶ËÐÞ¸ÄÁ˹²ÏíÄÚ´æºó ֪ͨ·þÎñÆ÷¶ÁÈ¡¡£

server.c

1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<sys/shm.h> // shared memory
4 #include<sys/sem.h> // semaphore
5 #include<sys/msg.h> // message queue
6 #include<string.h> // memcpy
7
8 // ÏûÏ¢¶ÓÁнṹ
9 struct msg_form {
10 long mtype;
11 char mtext;
12 };
13
14 // ÁªºÏÌ壬ÓÃÓÚsemctl³õʼ»¯
15 union semun
16 {
17 int val; /*for SETVAL*/
18 struct semid_ds *buf;
19 unsigned short *array;
20 };
21
22 // ³õʼ»¯ÐźÅÁ¿
23 int init_sem(int sem_id, int value)
24 {
25 union semun tmp;
26 tmp.val = value;
27 if(semctl(sem_id, 0, SETVAL, tmp) == -1)
28 {
29 perror("Init Semaphore Error");
30 return -1;
31 }
32 return 0;
33 }
34
35 // P²Ù×÷:
36 // ÈôÐźÅÁ¿ÖµÎª1£¬»ñÈ¡×ÊÔ´²¢½«ÐźÅÁ¿Öµ-1
37 // ÈôÐźÅÁ¿ÖµÎª0£¬½ø³Ì¹ÒÆðµÈ´ý
38 int sem_p(int sem_id)
39 {
40 struct sembuf sbuf;
41 sbuf.sem_num = 0; /*ÐòºÅ*/
42 sbuf.sem_op = -1; /*P²Ù×÷*/
43 sbuf.sem_flg = SEM_UNDO;
44
45 if(semop(sem_id, &sbuf, 1) == -1)
46 {
47 perror("P operation Error");
48 return -1;
49 }
50 return 0;
51 }
52
53 // V²Ù×÷£º
54 // ÊÍ·Å×ÊÔ´²¢½«ÐźÅÁ¿Öµ+1
55 // Èç¹ûÓнø³ÌÕýÔÚ¹ÒÆðµÈ´ý£¬Ôò»½ÐÑËüÃÇ
56 int sem_v(int sem_id)
57 {
58 struct sembuf sbuf;
59 sbuf.sem_num = 0; /*ÐòºÅ*/
60 sbuf.sem_op = 1; /*V²Ù×÷*/
61 sbuf.sem_flg = SEM_UNDO;
62
63 if(semop(sem_id, &sbuf, 1) == -1)
64 {
65 perror("V operation Error");
66 return -1;
67 }
68 return 0;
69 }
70
71 // ɾ³ýÐźÅÁ¿¼¯
72 int del_sem(int sem_id)
73 {
74 union semun tmp;
75 if(semctl(sem_id, 0, IPC_RMID, tmp) == -1)
76 {
77 perror("Delete Semaphore Error");
78 return -1;
79 }
80 return 0;
81 }
82
83 // ´´½¨Ò»¸öÐźÅÁ¿¼¯
84 int creat_sem(key_t key)
85 {
86 int sem_id;
87 if((sem_id = semget(key, 1, IPC_CREAT|0666)) == -1)
88 {
89 perror("semget error");
90 exit(-1);
91 }
92 init_sem(sem_id, 1); /*³õÖµÉèΪ1×ÊԴδռÓÃ*/
93 return sem_id;
94 }
95
96
97 int main()
98 {
99 key_t key;
100 int shmid, semid, msqid;
101 char *shm;
102 char data[] = "this is server";
103 struct shmid_ds buf1; /*ÓÃÓÚɾ³ý¹²ÏíÄÚ´æ*/
104 struct msqid_ds buf2; /*ÓÃÓÚɾ³ýÏûÏ¢¶ÓÁÐ*/
105 struct msg_form msg; /*ÏûÏ¢¶ÓÁÐÓÃÓÚ֪ͨ¶Ô·½¸üÐÂÁ˹²ÏíÄÚ´æ*/
106
107 // »ñÈ¡keyÖµ
108 if((key = ftok(".", 'z')) < 0)
109 {
110 perror("ftok error");
111 exit(1);
112 }
113
114 // ´´½¨¹²ÏíÄÚ´æ
115 if((shmid = shmget(key, 1024, IPC_CREAT|0666)) == -1)
116 {
117 perror("Create Shared Memory Error");
118 exit(1);
119 }
120
121 // Á¬½Ó¹²ÏíÄÚ´æ
122 shm = (char*)shmat(shmid, 0, 0);
123 if((int)shm == -1)
124 {
125 perror("Attach Shared Memory Error");
126 exit(1);
127 }
128
129
130 // ´´½¨ÏûÏ¢¶ÓÁÐ
131 if ((msqid = msgget(key, IPC_CREAT|0777)) == -1)
132 {
133 perror("msgget error");
134 exit(1);
135 }
136
137 // ´´½¨ÐźÅÁ¿
138 semid = creat_sem(key);
139
140 // ¶ÁÊý¾Ý
141 while(1)
142 {
143 msgrcv(msqid, &msg, 1, 888, 0); /*¶ÁÈ¡ÀàÐÍΪ888µÄÏûÏ¢*/
144 if(msg.mtext == 'q') /*quit - Ìø³öÑ­»·*/
145 break;
146 if(msg.mtext == 'r') /*read - ¶Á¹²ÏíÄÚ´æ*/
147 {
148 sem_p(semid);
149 printf("%s\n",shm);
150 sem_v(semid);
151 }
152 }
153
154 // ¶Ï¿ªÁ¬½Ó
155 shmdt(shm);
156
157 /*ɾ³ý¹²ÏíÄÚ´æ¡¢ÏûÏ¢¶ÓÁС¢ÐźÅÁ¿*/
158 shmctl(shmid, IPC_RMID, &buf1);
159 msgctl(msqid, IPC_RMID, &buf2);
160 del_sem(semid);
161 return 0;
162 }

client.c

1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<sys/shm.h> // shared memory
4 #include<sys/sem.h> // semaphore
5 #include<sys/msg.h> // message queue
6 #include<string.h> // memcpy
7
8 // ÏûÏ¢¶ÓÁнṹ
9 struct msg_form {
10 long mtype;
11 char mtext;
12 };
13
14 // ÁªºÏÌ壬ÓÃÓÚsemctl³õʼ»¯
15 union semun
16 {
17 int val; /*for SETVAL*/
18 struct semid_ds *buf;
19 unsigned short *array;
20 };
21
22 // P²Ù×÷:
23 // ÈôÐźÅÁ¿ÖµÎª1£¬»ñÈ¡×ÊÔ´²¢½«ÐźÅÁ¿Öµ-1
24 // ÈôÐźÅÁ¿ÖµÎª0£¬½ø³Ì¹ÒÆðµÈ´ý
25 int sem_p(int sem_id)
26 {
27 struct sembuf sbuf;
28 sbuf.sem_num = 0; /*ÐòºÅ*/
29 sbuf.sem_op = -1; /*P²Ù×÷*/
30 sbuf.sem_flg = SEM_UNDO;
31
32 if(semop(sem_id, &sbuf, 1) == -1)
33 {
34 perror("P operation Error");
35 return -1;
36 }
37 return 0;
38 }
39
40 // V²Ù×÷£º
41 // ÊÍ·Å×ÊÔ´²¢½«ÐźÅÁ¿Öµ+1
42 // Èç¹ûÓнø³ÌÕýÔÚ¹ÒÆðµÈ´ý£¬Ôò»½ÐÑËüÃÇ
43 int sem_v(int sem_id)
44 {
45 struct sembuf sbuf;
46 sbuf.sem_num = 0; /*ÐòºÅ*/
47 sbuf.sem_op = 1; /*V²Ù×÷*/
48 sbuf.sem_flg = SEM_UNDO;
49
50 if(semop(sem_id, &sbuf, 1) == -1)
51 {
52 perror("V operation Error");
53 return -1;
54 }
55 return 0;
56 }
57
58
59 int main()
60 {
61 key_t key;
62 int shmid, semid, msqid;
63 char *shm;
64 struct msg_form msg;
65 int flag = 1; /*whileÑ­»·Ìõ¼þ*/
66
67 // »ñÈ¡keyÖµ
68 if((key = ftok(".", 'z')) < 0)
69 {
70 perror("ftok error");
71 exit(1);
72 }
73
74 // »ñÈ¡¹²ÏíÄÚ´æ
75 if((shmid = shmget(key, 1024, 0)) == -1)
76 {
77 perror("shmget error");
78 exit(1);
79 }
80
81 // Á¬½Ó¹²ÏíÄÚ´æ
82 shm = (char*)shmat(shmid, 0, 0);
83 if((int)shm == -1)
84 {
85 perror("Attach Shared Memory Error");
86 exit(1);
87 }
88
89 // ´´½¨ÏûÏ¢¶ÓÁÐ
90 if ((msqid = msgget(key, 0)) == -1)
91 {
92 perror("msgget error");
93 exit(1);
94 }
95
96 // »ñÈ¡ÐźÅÁ¿
97 if((semid = semget(key, 0, 0)) == -1)
98 {
99 perror("semget error");
100 exit(1);
101 }
102
103 // дÊý¾Ý
104 printf("***************************************\n");
105 printf("* IPC *\n");
106 printf("* Input r to send data to server. *\n");
107 printf("* Input q to quit. *\n");
108 printf("***************************************\n");
109
110 while(flag)
111 {
112 char c;
113 printf("Please input command: ");
114 scanf("%c", &c);
115 switch(c)
116 {
117 case 'r':
118 printf("Data to send: ");
119 sem_p(semid); /*·ÃÎÊ×ÊÔ´*/
120 scanf("%s", shm);
121 sem_v(semid); /*ÊÍ·Å×ÊÔ´*/
122 /*Çå¿Õ±ê×¼ÊäÈ뻺³åÇø*/
123 while((c=getchar())!='\n' && c!=EOF);
124 msg.mtype = 888;
125 msg.mtext = 'r'; /*·¢ËÍÏûϢ֪ͨ·þÎñÆ÷¶ÁÊý¾Ý*/
126 msgsnd(msqid, &msg, sizeof(msg.mtext), 0);
127 break;
128 case 'q':
129 msg.mtype = 888;
130 msg.mtext = 'q';
131 msgsnd(msqid, &msg, sizeof(msg.mtext), 0);
132 flag = 0;
133 break;
134 default:
135 printf("Wrong input!\n");
136 /*Çå¿Õ±ê×¼ÊäÈ뻺³åÇø*/
137 while((c=getchar())!='\n' && c!=EOF);
138 }
139 }
140
141 // ¶Ï¿ªÁ¬½Ó
142 shmdt(shm);
143
144 return 0;
145 }

×¢Ò⣺µ±scanf()ÊäÈë×Ö·û»ò×Ö·û´®Ê±£¬»º³åÇøÖÐÒÅÁôÏÂÁË\n£¬ËùÒÔÿ´ÎÊäÈë²Ù×÷ºó¶¼ÐèÒªÇå¿Õ±ê×¼ÊäÈëµÄ»º³åÇø¡£µ«ÊÇÓÉÓÚ gcc ±àÒëÆ÷²»Ö§³Öfflush(stdin)£¨ËüÖ»ÊDZê×¼CµÄÀ©Õ¹£©£¬ËùÒÔÎÒÃÇʹÓÃÁËÌæ´ú·½°¸£º

1 while((c=getchar())!='\n' && c!=EOF);

Ô­ÎÄÁ´½Ó£ºhttps://www.cnblogs.com/CheeseZH/p/5264465.html

 
   
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