RedHawk Linux User's Guide version 6.3 日本語版

メッセージ・キュー・プログラム 例/* Create a child process. */child_pid = fork();if (child_pid == (pid_t)-1) {/* The fork(2) call returned an error. */perror(“fork”);/* Remove the message queue. */(void) msgctl(msqid, IPC_RMID, (struct msqid_ds *)NULL);}exit(-1);if (child_pid == 0) {/* Child process *//* Set the message type. */msg_buffer.mtype = MSGTYPE;/* Perform some work for parent. */sleep(1);/* ... *//* Copy a message into the message buffer structure. */strcpy(msg_buffer.mtext, “Results of work”);/* Send the message to the parent using the message* queue that was inherited at fork(2) time.*/retval = msgsnd(msqid, (const void *)&msg_buffer,strlen(msg_buffer.mtext) + 1, 0);if (retval) {perror(“msgsnd(child)”);/* Remove the message queue. */(void) msgctl(msqid, IPC_RMID, (struct msqid_ds *)NULL);exit(-1);}/* Send the parent a SIGRT signal. */retval = kill(parent_pid, SIGRT1);if (retval) {perror(“kill SIGRT”);}/* Remove the message queue. */(void) msgctl(msqid, IPC_RMID, (struct msqid_ds *)NULL);exit(-1);}exit(0);/* Parent *//* Setup to catch the SIGRT signal. The child process* will send a SIGRT signal to the parent after sending* the parent the message.*/sigemptyset(&set);sa.sa_mask = set;sa.sa_sigaction = sighandler;A-5