Msgsnd Error
Contents |
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about msgsnd example in c hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask msgsnd invalid argument Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. msgsnd linux Join them; it only takes a minute: Sign up Message queue: msgsnd failed : Invalid argument up vote 2 down vote favorite Can anyone please help me to point out as what is the error in my program? Thanks
Msgsnd Resource Temporarily Unavailable
in advance, kingsmasher1 #include
*msgp, size_t msgsz, long msgtyp, int msgflg); Description The msgsnd() and msgrcv() system calls are used, respectively, to send messages to, and receive messages from, a message queue. The calling process must have write permission on the message msgrcv system call queue in order to send a message, and read permission to receive a message.
Msgrcv In C
The msgp argument is a pointer to caller-defined structure of the following general form: struct msgbuf { long mtype; /*
Msgsnd Return Value
message type, must be > 0 */ char mtext[1]; /* message data */ }; The mtext field is an array (or other structure) whose size is specified by msgsz, a nonnegative integer value. Messages of http://stackoverflow.com/questions/5218238/message-queue-msgsnd-failed-invalid-argument zero length (i.e., no mtext field) are permitted. The mtype field must have a strictly positive integer value. This value can be used by the receiving process for message selection (see the description of msgrcv() below). msgsnd() The msgsnd() system call appends a copy of the message pointed to by msgp to the message queue whose identifier is specified by msqid. If sufficient space is available in the queue, https://linux.die.net/man/2/msgsnd msgsnd() succeeds immediately. (The queue capacity is defined by the msg_qbytes field in the associated data structure for the message queue. During queue creation this field is initialized to MSGMNB bytes, but this limit can be modified using msgctl(2).) If insufficient space is available in the queue, then the default behavior of msgsnd() is to block until space becomes available. If IPC_NOWAIT is specified in msgflg, then the call instead fails with the error EAGAIN. A blocked msgsnd() call may also fail if: * the queue is removed, in which case the system call fails with errno set to EIDRM; or * a signal is caught, in which case the system call fails with errno set to EINTR;see signal(7). (msgsnd() is never automatically restarted after being interrupted by a signal handler, regardless of the setting of the SA_RESTART flag when establishing a signal handler.) Upon successful completion the message queue data structure is updated as follows: msg_lspid is set to the process ID of the calling process. msg_qnum is incremented by 1. msg_stime is set to the current time. msgrcv() The msgrcv() system call removes a message from the queue specified by msqid and places it in the buffer pointed to by msgp. The
msgsz, int msgflg); ssize_t msgrcv(int msqid, void *msgp, size_t msgsz, long msgtyp, int msgflg); DESCRIPTION The msgsnd() and msgrcv() system calls are used, respectively, to send messages to, and receive messages from, a System V http://manpages.ubuntu.com/manpages/wily/man2/msgop.2.html message queue. The calling process must have write permission on the message queue in order to send a message, and read permission to receive a message. The msgp argument is a pointer to a caller-defined structure of the following general form: struct msgbuf { long mtype; /* message type, must be > 0 */ char mtext[1]; /* message data */ }; The in c mtext field is an array (or other structure) whose size is specified by msgsz, a nonnegative integer value. Messages of zero length (i.e., no mtext field) are permitted. The mtype field must have a strictly positive integer value. This value can be used by the receiving process for message selection (see the description of msgrcv() below). msgsnd() The msgsnd() system call appends a msgsnd example in copy of the message pointed to by msgp to the message queue whose identifier is specified by msqid. If sufficient space is available in the queue, msgsnd() succeeds immediately. The queue capacity is governed by the msg_qbytes field in the associated data structure for the message queue. During queue creation this field is initialized to MSGMNB bytes, but this limit can be modified using msgctl(2). A message queue is considered to be full if either of the following conditions is true: * Adding a new message to the queue would cause the total number of bytes in the queue to exceed the queue's maximum size (the msg_qbytes field). * Adding another message to the queue would cause the total number of messages in the queue to exceed the queue's maximum size (the msg_qbytes field). This check is necessary to prevent an unlimited number of zero-length messages being placed on the queue. Although such messages contain no data, they nevertheless consume (locked) kernel memory. If insufficient space is available in the queue, then the default behavior of msgsnd() is to block until space becomes available. If IPC_NOWAIT