80 lines
1.9 KiB
C
80 lines
1.9 KiB
C
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#include <unistd.h>
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#include <fcntl.h> /* Definition of AT_* constants */
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#include <sys/stat.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/syscall.h> /* Definition of SYS_* constants */
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#include <sys/msg.h>
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const char *main_key_file = "/tmp/IPC-SERVER-43412321";
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struct Msg_pid
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{
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long mtype;
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pid_t pid;
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} typedef msg_pid;
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struct Msg_data
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{
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long mtype;
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double data;
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} typedef msg_data;
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void handle_error(char *txt)
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{
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perror(txt);
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exit(-1);
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}
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int main()
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{
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if (access(main_key_file, F_OK) == 0)
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unlink(main_key_file);
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if (mknod(main_key_file, 0600 | S_IFREG, NULL) != 0)
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handle_error("main file creation");
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key_t main_key;
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if ((main_key = ftok(main_key_file, 0)) == -1)
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handle_error("ftok");
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int m_msg_id;
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if ((m_msg_id = msgget(main_key, 0600 | IPC_CREAT)) == -1)
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handle_error("msgget");
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msg_pid pid_msg;
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while (1)
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{
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if (msgrcv(m_msg_id, (void *)&pid_msg, sizeof(pid_t), 1, 0) == -1)
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handle_error("msgrcv");
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printf("%d\n", pid_msg.pid);
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int pid;
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if ((pid = fork()) == -1)
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handle_error("fork");
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if (pid == 0)
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{
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key_t pid_key;
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if ((pid_key = ftok(main_key_file, pid_msg.pid)) == -1)
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handle_error("ftok data");
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int d_msg_id;
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if ((d_msg_id = msgget(pid_key, 0600)) == -1)
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handle_error("msgget data");
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msg_data data_msg;
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if (msgrcv(d_msg_id, (void *)&data_msg, sizeof(double), 1, 0600) == -1)
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handle_error("msgrcv data");
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printf("Received data %f\n", data_msg.data);
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data_msg.mtype = 2;
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data_msg.data *= data_msg.data;
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if (msgsnd(d_msg_id, (void *)&data_msg, sizeof(double), 0) == -1)
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handle_error("msgsnd data");
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}
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}
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if (msgctl(m_msg_id, IPC_RMID, NULL) == -1)
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handle_error("msgctl RMID");
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return 0;
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}
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