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Full Discussion: creating a message queue using mq_open
Top Forums Programming creating a message queue using mq_open Post 302471089 by parusasi on Friday 12th of November 2010 12:38:18 AM
Old 11-12-2010
Quote:
Originally Posted by Loic Domaigne
Yeah, now I understand your problem. How do you check that the error returned by mq_open() ? On which OS do you see this problem?
Thank you for time,
I am giving below the code snippet which i use.
Code:
oflags = 0;
  oflags |= (Flags & MQ_READ)?(O_RDONLY):(0);
  oflags |= (Flags & MQ_WRITE)?(O_WRONLY):(0);
  oflags |= (Flags & MQ_READ_WRITE)?(O_RDWR):(0);
  oflags |= (Flags & MQ_NON_BLOCKING)?(O_NONBLOCK):(0);
  oflags |= (O_CREAT | O_EXCL); // try to create it first
  mqAttr.mq_maxmsg = maxMsg;
  mqAttr.mq_msgsize = msgSz + sizeof(MSG_Q_HEADER);
  
  if ((fileDesc = mq_open( "/iothreadNewTest435", oflags,(S_IRUSR | S_IWUSR),NULL)) == -1 )
  {
    rc = mqEvalErrnoOpen(pName))

}

mqEvalErrnoOpen( const char * pName )
{
 MQ_RC rc;
 int err = 0;

  switch ( errno )
  {
  case EACCES:
    rc = MQ_INVALID_ACCESS;
    break;

  case EEXIST:
    rc = MQ_ALREADY_EXISTS;
    break;

  case EFAULT:
    rc = MQ_INVALID_ADDRESS;
    break;

  case EINVAL:
    rc = MQ_INVALID_ACCESS;
    break;

  case EMFILE:
    rc = MQ_TOO_MANY_MSG_Q_DESC;
    break;

  case ENAMETOOLONG:
    rc = MQ_NAME_TOO_LONG;
    break;

  case ENFILE:
    rc = MQ_TOO_MANY_MSG_Q_DESC;
    break;

  case ENOENT:
    rc = MQ_QUEUE_NOT_PRESENT;
    break;

  case ENOMEM:
    rc = MQ_INSUFFICIENT_MEMORY;
    break;

  case ENOSPC:
    rc = MQ_INSUFFICIENT_MEMORY;
    break;

  case ENOTSUP:
    rc = MQ_NOT_SUPPORTED_CHECKPOINT_RESTART_PROC;
    break;

  default:
    rc = MQ_ERRNO;
    err = errno;
    break;
  }

Here rc is returning a value MQ_INVALID Address.
My os details are as follows Fedora Sulphur
Code:
Linux myMachine 2.6.25-14.fc9.i686 #1 SMP Thu May 1 06:28:41 EDT 2008 i686 i686 i386 GNU/Linux

Please help me with this,
Thanks again,
Paru.
Last edited by Scott; 11-15-2010 at 02:52 AM.. Reason: Code tags
 

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